Search

D-allulose, a naturally occurring monosaccharide, is present in small quantities in nature. It is considered a valuable low-calorie sweetener due to its low absorption in the digestive tract and zero energy for growth. Most of the recent efforts to produce D-allulose have focused on in vitro enzyme catalysis. However, microbial fermentation is emerging as a promising alternative that offers the advantage of combining enzyme manufacturing and product synthesis within a single bioreactor. Here, a novel approach was proposed for the efficient biosynthesis of D-allulose from glycerol using metabolically engineered Escherichia coli. FbaA, Fbp, AlsE, and A6PP were used to construct the D-allulose synthesis pathway. Subsequently, PfkA, PfkB, and Pgi were disrupted to block the entry of the intermediate fructose-6-phosphate (F6P) into the Embden−Meyerhof−Parnas (EMP) and pentose phosphate (PP) pathways. Additionally, GalE and FryA were inactivated to reduce D-allulose consumption by the cells. Finally, a fed-batch fermentation process was implemented to optimize the performance of the cell factory. As a result, the titer of D-allulose reached 7.02 g/L with a maximum yield of 0.287 g/g. • Design of a synthesis pathway capable of producing only D-allulose from glycerol. • Enhancing cell factory performance by gene knockout and fermentation optimization. • Substrate conversion was dramatically increased compared to Izumoring epimerization. • Using glycerol rather than hexoses theoretically facilitates product purification. • Development of a green route that is widely applicable to synthesizing rare sugars. [ABSTRACT FROM AUTHOR]

A homo-aromatic polyester was produced from glucose for the first time. Aromatic polyhydroxyalkanoate (PHA) was produced to the highest titer yet achieved. 3D model-based rational engineering of PHA synthase was used to enhance aromatic PHA production. Polymer production was enhanced by utilizing heterologous phasins. Pilot-scale fermentative production of aromatic PHAs was successful. We report the development of a metabolically engineered bacterium for the fermentative production of polyesters containing aromatic side chains, serving as sustainable alternatives to petroleum-based plastics. A metabolic pathway was constructed in an Escherichia coli strain to produce poly[ d -phenyllactate(PhLA)], followed by three strategies to enhance polymer production. First, polyhydroxyalkanoate (PHA) granule-associated proteins (phasins) were introduced to increase the polymer accumulation. Next, metabolic engineering was performed to redirect the metabolic flux toward PhLA. Furthermore, PHA synthase was engineered based on in silico simulation results to enhance the polymerization of PhLA. The final strain was capable of producing 12.3 g/l of poly(PhLA), marking it the first bio-based process for producing an aromatic homopolyester. Additional heterologous gene introductions led to the high level production of poly(3-hydroxybutyrate- co -11.7 mol% PhLA) copolymer (61.4 g/l). The strategies described here will be useful for the bio-based production of aromatic polyesters from renewable resources. Graphical abstract [Display omitted] The production of polyhydroxyalkanoates (PHAs) containing aromatic repeating units has been studied for decades, but has yet to be demonstrated in large-scale fermentation. This study reports the successful production of aromatic polyesters from glucose in high titers that was performed both in lab-scale (5 l) and pilot-scale (30 l) fermenters. Therefore, the current Technology Readiness Level (TRL) of this technology lies between 4 and 5. To advance this technology for industrialization, demonstration in industry-scale fermenters and the development of large-scale downstream processes will be necessary. Nevertheless, given the ongoing development of various fermentation technologies and purification processes for other PHAs, we anticipate that the industrialization of aromatic PHAs is feasible, potentially replacing petroleum-based aromatic polymers for use as commodity, engineering, and biomedical plastics. Lee et al. report the fermentative production of aromatic polyesters, which can serve as sustainable alternatives to petroleum-based plastics. This represents the first instance of homo-aromatic polyester production using glucose. Further pathway engineering facilitated the production of poly(3-hydroxybutyrate- co - d -phenyllactate), achieving the highest titer of aromatic polyester reported using microorganisms thus far. [ABSTRACT FROM AUTHOR]

Microbial fermentations are widely used for the production of chemicals used as pharmaceuticals, food ingredients, materials, solvents, and biofuels. Technoeconomic analysis of a given fermentation process is important to perform before scaling the process to levels that enable commercial production. Titer, rate, and yield (TRY) of the fermentation process are key metrics that are used for technoeconomic analysis. TRY metrics have different impacts on the technoeconomic analysis, and it is important to be aware of these differences. Microbial fermentations offer the opportunity to produce a wide range of chemicals in a sustainable fashion, but it is important to carefully evaluate the production costs. This can be done on the basis of evaluation of the titer, rate, and yield (TRY) of the fermentation process. Here we describe how the three TRY metrics impact the technoeconomics of a microbial fermentation process, and we illustrate the use of these for evaluation of different processes in the production of two commodity chemicals, 1,3-propanediol (PDO) and ethanol, as well as for the fine chemical penicillin. On the basis of our discussions, we provide some recommendations on how the TRY metrics should be reported when new processes are described. [ABSTRACT FROM AUTHOR]

Lactobacillus delbrueckii ssp. bulgaricus M-58 (M58) and Streptococcus thermophilus S10 (S10) are both dairy starter strains known for their favorable fermentation characteristics. Therefore, this research aimed to study the effects of 1-d low-temperature ripening on the physicochemical properties and metabolomics of fermented milk. Initially, the performance of single (M58 or S10) and dual (M58+S10) strain fermentation was assessed, revealing that the M58+S10 combination resulted in a shortened fermentation time, a stable gel structure, and desirable viscosity, suggesting positive strain interactions. Subsequently, nontargeted metabolomics analyses using liquid chromatography-MS and GC-MS were performed to comparatively analyze M58+S10 fermented milk samples collected at the end of fermentation and after 1 d of low-temperature ripening. The results showed a significant increase in almost all small peptides and dodecanedioic acid in the samples after 1 d of ripening, although there was a substantial decrease in indole and amino acid metabolites. Moreover, notable increases were observed in high-quality flavor compounds, such as geraniol, delta-nonalactone, 1-hexanol,2-ethyl-, methyl jasmonate, and undecanal. This study provides valuable insights into the fermentation characteristics of the dual bacterial starter consisting of M58 and S10 strains and highlights the specific contribution of the low-temperature ripening step to the overall quality of fermented milk. The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. [ABSTRACT FROM AUTHOR]

This research explores the remarkable impact of fermented cereals such as sorghum, maize, and wheat with Pediococcus acidilactici WS07, a strain isolated from Ethiopia's traditional borde beverage. The fermented cereal extracts were thoroughly evaluated for antioxidant activity, inhibition of pancreatic lipase and α-glucosidase, metabolite identification through UHPLC-Q-TOF-MS/MS, and in vivo efficacy using the C. elegans model. The results revealed significant enhancements in the bioactive compounds of fermented cereals, demonstrating promising directions for obesity prevention strategies. Notably, the fermented sorghum extracts improved lipase (88.23 %) and α-glucosidase (85.62 %) inhibitory activities compared to its unfermented counterparts. The antioxidant properties of all fermented samples were confirmed through improved DPPH (67.77–71.86 %) and ABTS (59.91–65.49 %) scavenging activities. Fermentation also led to a notable increase in polyphenols and flavonoids, with detailed metabolite analysis revealing a dynamic shift in the composition of these bioactive compounds. Additionally, C. elegans indicates that fermented extracts extend lifespan, reduce lipid accumulation, and lower triglycerides, highlighting their potential as functional foods for health enhancement and obesity management. This study not only underscores the efficacy of P. acidilactici WS07 fermentation in transforming cereals into nutrient-rich functional foods but also provides insight into how microbial fermentation can unlock the health-promoting potential of traditional diets. [Display omitted] • Fermented sorghum extracts inhibited lipase (88.23 %) and α-glucosidase (85.62 %). • Fermented extracts showed superior antioxidant properties vs. unfermented. • Fermented sorghum and sorghum-maize extended lifespan, reduced lipids in C. elegans. • P. acidilactici WS07-fermented sorghum can be used to develop anti-obesity foods. [ABSTRACT FROM AUTHOR]

The microbial production of lactic acid, a crucial platform chemical for the development of biobased products, aims to replace fossil-based materials, although current production costs remain relatively high. Fermentation requires the addition of yeast extract (YE) to exclude nutritional lag, which increases the cost of production; therefore, optimizing its amount is essential. This study explores batch fermentation with varying concentrations of YE (5 %, 10 %, 15 % and 20 %) in a medium using the strain Bacillus coagulans A166 to produce lactic acid from glucose. The results reveal that the level of YE significantly influences the product yield, substrate consumption rate, and process productivity. The kinetic model applied to experimental data indicates that higher YE concentrations lead to increased glucose uptake and microbial growth rates, while concentrations exceeding 10 % result in reduced performance. It was determined that a concentration of 10 % YE in the medium delivered the highest maximum specific rates for glucose consumption and microbial growth, leading to a 0.99 g/g yield of glucose lactic acid. Furthermore, a real-time monitoring strategy for glucose consumption and lactic acid formation was established using a mathematical model based on the rate of alkaline consumption throughout fermentation. The cross-validation results demonstrate the reliability of this approach, with mean absolute errors (expressed as a percentage of the concentration range) for the prediction of glucose ranging from 2.8 % to 5.0 % and for the prediction of lactic acid ranging from 3.4 % to 5.4 %. [Display omitted] • Yeast extract increase in LA production let to reduced fermentation completion time. • Key kinetic parameters correspond to the optimized production processes dynamics. • The optimal yield of LA from glucose with 10 % YE in the medium. • Absolute errors for glucose and LA predictions are less or equal to 5.05 % and 5.43 % respectively. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Botanical extracts (BE; Apex, Adisseo) have demonstrated enhanced DMI and improved gut health, whereas direct-fed microbials (DFM), such as Lactobacillus acidophilus fermentation product (Excell [EX], Pacer Technology Inc.), have demonstrated improved gut health and growth performance of growing Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance and intestinal health. Eighty 2- to 5-d-old Holstein bull calves were blocked by BW and randomly assigned to 1 of 8 treatments arranged in a 2 × 4 factorial using a randomized complete block design. The main factors were milk replacer (MR) without (control) and with EX added at 5 g/d fed and calf starter (CS). The CS containing no additives (control); CS containing BE at 496 mg/kg; CS containing EX at 2.50 g/kg; and CS containing BE and EX at the same inclusion rates. The MR were fed 2×/d at 0630 and 1800 h along with free choice CS (amounts and orts weighed daily) and water. Weaning occurred after d 42 for the 56-d experiment. No MR by CS main effects interactions were detected for BW, ADG, CS intake, total DMI, feed efficiency, or body frame gain parameters. The BW gain (38.0 and 39.3 kg for control and EX, respectively) for MR main effect was similar for calves fed both MR treatments, whereas CS main effects (38.7, 39.7, 39.2, and 37.2 kg for control, BE, EX, and BE+EX, respectively) was similar among all CS. Gains in body length (10.6 and 10.8 cm), hip width (4.5 and 4.5 cm), withers height, (10.5 and 10.6 cm), heart girth (18.6 and 19.9 cm), and body length (9.1 and 7.9 cm) were similar for calves fed both MR, while CS main effects for hip height (10.5, 10.2, 10.3, and 10.9 cm), hip width (4.7, 4.6, 4.4, and 4.3 cm), withers height (10.7, 10.9, 10.3 and 10.6 cm), heart girth (19.9, 18.9, 18.9, and 19.4 cm), and body length (11.7, 9.1, 8.3, and 8.4 cm) were similar. Total days of a fecal score = 0 was greater for calves fed control MR and BE CS compared with calves fed control MR and the combination of BE+EX, with calves fed the remaining treatments being intermediated and similar. This study demonstrated little calf growth performance and health benefits when feeding a BE or EX alone or in combination compared with calves fed control treatments. [ABSTRACT FROM AUTHOR]

5-Hydroxytryptophan (5-HTP), a precursor of the neurotransmitter serotonin in mammals, has demonstrated efficacy in treating various diseases such as depression, fibromyalgia and obesity. However, conventional biosynthesis methods of 5-HTP are limited by low yield and high reagent and process costs. In this study, the strain C1T7-S337A/F318Y with optimized promoter distribution was obtained, and the 5-HTP yield was 60.30 % higher than that of the initial strain. An efficient fermentation process for 5-HTP synthesis was developed using strain C1T7-S337A/F318Y with whey powder as a substrate for cell growth and inducer production. Shake flask fermentation experiments yielded 1.302 g/L 5-HTP from 2.0 g/L L-tryptophan (L-Trp), surpassing the whole-cell biocatalysis by 42.86 %. Scale-up to a 5 L fermenter further increased the yield to 1.649 g/L. This fermentation strategy substantially slashed reagent cost by 95.39 %, providing a more economically viable and environmentally sustainable route for industrial biosynthesis of 5-HTP. Moreover, it contributes to the broader utilization of whey powder in various industries. [Display omitted] • An efficient 5-HTP fermentation process was realized by condition optimization. • Whey powder was used as a substrate for cell growth and inducer production. • The strain C1T7 increased the 5-HTP yield by 60.30 % through promoter adjustment. • The 5-HTP yield of the new fermentation process was increased by 42.86 %. • The total reagent cost of the new fermentation process was reduced by 95.39 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wheet feed hydrolysate can serve as both hydrophilic carbon and nitrogen source. • At TN concentrations <1.5 g/L production and growth presented a linear relationship. • 0.31 g/L TN from wheat feed hydrolysate led to 60 g/L diacetylated lactonic C18:1. • Sophorolipid gravimetrical quantification should be complemented with HPLC analysis. • Biomass hydrolysates composition influences sophorolipid congeners profile. To explore a sustainable sophorolipid production, several hydrolysates from agricultural byproducts, such as wheat feed, rapeseed meal, coconut waste and palm waste were used as nitrogen sources. The four hydrolysates overperformed the controls after 168 h of fermentation using Starmerella bombicola ATCC 22214. Wheat feed and coconut waste hydrolysates were the most promising feedstocks presenting a linear relationship between yeast growth and diacetylated lactonic C18:1 production at total nitrogen concentrations below 1.5 g/L (R2 = 0.90 and 0.83, respectively). At 0.31 g/L total nitrogen, wheat feed hydrolysate achieved the highest production, yielding 72.20 ± 1.53 g/L of sophorolipid crude extract and 60.05 ± 0.56 g/L of diacetylated lactonic C18:1 at shake flask scale with productivities of 0.43 and 0.36 g/L/h, respectively. Results were confirmed in a 2-L bioreactor increasing 15 % diacetylated lactonic C18:1 production. Moreover, wheat feed hydrolysate supplemented only with a hydrophobic carbon source was able to produce mainly diacetylated lactonic C18:1 congener (88.5 % wt.), suggesting that the composition of the hydrolysate significantly influences the congeners profile. Overall, this study provides valuable insights into agricultural byproduct hydrolysates as potential nitrogen feedstocks for sophorolipid production and their further application on industrial biotechnology. [ABSTRACT FROM AUTHOR]

• Acidification and fermentation preserved a high BSFL-rearing performance. • Acidification and fermentation contribute to the all-year provision of feedstock. • Acidification led to a higher bioconversion rate compared to fermentation. • The nutrient-rich feedstock did not benefit from inoculating lactic acid bacteria. Maintaining a consistent supply of feedstock for efficient bioconversion of black soldier fly larvae (BSFL) presents challenges due to the fluctuating availability of biowastes and agri-food products. To address the challenge of consistent feedstock supply for BSFL, this study investigated the influence of three preservation methods: wild fermentation, inoculated fermentation, and acidification on agri-food by-products applied over three storage durations (1, 7, and 14 days), evaluating their impact on BSFL bioconversion, and feedstock nutrient and microbiota composition. The preserved feedstocks were characterized for gross nutrient, sugar, fermentation metabolite, and bacterial community analyses. All feedstock preservation methods and storage durations had a high bioconversion rate (21–25 % dry mass) and wet larval mass (170–196 mg). Notably, 7-and-14-day acidified feedstock had a significantly higher bioconversion rate compared to fermented feedstock. Acidification preserved feedstock nutrients best with only a 10 % difference compared to initial nutrient values. Fermentation produced typical lactic acid fermentation metabolites with reducing sugar contents; however, adding a lactic acid bacterial inoculum (7 log 10 CFU kg feedstock−1) had no benefit, presumably due to the high nutrient content and existing richness in lactic acid bacteria. Preservations had little influence on Enterobacteriaceae (6.2–7.5 log 10 CFU g−1) in freshly harvested larvae. Future research should assess the acidification and fermentation of different BSFL feedstocks and investigate the roles of feedstock pH, organic acids, and fermentation metabolites in more detail. Therefore, this study advances toward reliable and efficient insect-based nutrient recovery from agri-food by-products within the food system. [ABSTRACT FROM AUTHOR]

Therapeutic oligonucleotides (ONs) are typically manufactured via solid-phase synthesis, characterized by limited scalability and huge environmental footprint, limiting their availability. Biomanufactured ONs have the potential to reduce the immunogenic side-effects, and to improve the sustainability of their chemical counterparts. Rhodovulum sulfidophilum was demonstrated a valuable host for the extracellular production of recombinant ONs. However, low viable cell densities and product titer were reported so far. In this work, perfusion cell cultures were established for the intensification of ON biomanufacturing. First, the perfusion conditions were simulated in 50 mL spin tubes, selected as a scale-down model of the process, with the aim of optimizing the medium composition and process parameters. This optimization stage led to an increase in the cell density by 44 % compared to the reference medium formulation. In addition, tests at increasing perfusion rates were conducted until achieving the maximum viable cell density (VCD max), allowing the determination of the minimum cell-specific perfusion rate (CSPR min) required to sustain the cell culture. Intriguingly, we discovered in this system also a maximum CSPR, above which growth inhibition starts. By leveraging this process optimization, we show for the first time the conduction of perfusion cultures of R. sulfidophilum in bench-scale bioreactors. This process development pipeline allowed stable cultures for more than 20 days and the continuous biomanufacturing of ONs, testifying the great potential of perfusion processes. • Medium composition and design space defined for perfusion cultures of Rhodovulum sulfidophilum. • Process scaled up to a 2 L bioreactor with ATF and effect of perfusion rate investigated. • Stable perfusion cultures for >20 days, with cell densities lager than in fed-batch. • Oligonucleotides continuously harvested, with titers 2 orders of magnitudes larger than literature. • First report on continuous biomanufacturing of oligonucleotides. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The aim of this study was to determine the components and cytokine and immunoglobulin levels of koumiss during different fermentation periods, and to reveal the interrelation between these parameters. For achieving this objective, 10 samples of koumiss were prepared and randomly divided into 2 groups: the first group was sampled at 0, 1, 5, 12, and 24 h of incubation at room temperature for analysis. The second group was stored at +4°C, and samples were taken on d 5, 10, 15, and 20. The counts of Enterobacteriaceae spp., Staphylococcus , and Micrococcus spp. progressively decreased with the period of fermentation until becoming undetectable in the final samples of both groups. We fond positive or negative correlations between cytokine and immunoglobulin levels and the physicochemical and microbiological parameters in the koumiss samples in both groups. However, the levels of IFN-γ, IL-2, TNF-α, and IgG did not change significantly over time in both groups. Overall, it is clear that traditionally prepared koumiss under different fermentation times and temperatures does not show any differences in cytokine and immunoglobulin concentrations. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The continued efficient use of whey as a fermentable substrate to produce alcoholic beverages will benefit from improving the measurement of key components relevant to the fermentability of whey. One component of fermentation that is not well studied in whey is the concentration of fermentable nitrogen, either as free amino nitrogen (FAN) or yeast-assimilable nitrogen (YAN). Fermentable nitrogen in media is essential for yeast cells to replicate. Insufficient concentrations of FAN or YAN to support the growing yeast population can result in sluggish or "stuck" fermentations. We evaluated 3 common methods of fermentable nitrogen determination and compared them for use in whey fermentation systems, based on ninhydrin, nitrogen by o- phthalaldehyde (NOPA), and formaldehyde pH (Sørensen titration) values. Each measurement method was evaluated independently using standard addition curves and compared for overall accuracy using paired t -tests (α = 0.05). Although the formaldehyde pH method showed high precision, it did not measure nitrogen accurately, as it overestimated YAN in whey by up to 6 times relative to other tests. The ninhydrin and NOPA methods both showed accuracy for fermentable nitrogen determination in whey based on analysis of standardized nitrogen sources. We concluded that either the ninhydrin FAN or NOPA YAN method may be used to determine the fermentable nitrogen content in whey. This is expected to improve the ability of producers to use whey as a fermentation medium. [ABSTRACT FROM AUTHOR]

This study unravels some of the complex microbial interactions established in the fermentation of sugarcane vinasse. The microbial communities of four thermophilic (55 °C) fixed-bed vinasse-fed reactors were analyzed by 16S rRNA gene amplicon sequencing and the marker gene data were aligned with reference genomes to predict metabolic functions of the microorganisms. The production (by Lactobacillus) and utilization (mainly by Thermoanaerobacterium and Caproiciproducens) of lactate explain the primary pathways associated with substrate fermentation towards biohydrogen, whilst only a single genus (Desulfotomaculum) and very low abundances of the enzymes involved in sulfate reduction were found. Although the abundant microbes in the inocula failed to grow during the continuous operation in all reactors, these fermentative consortia behave like microbial pantries containing bacteria that will grow according to the operating conditions, shaping lactate-accumulating (pH < 5.0) or lactate-consuming (pH > 5.0) and eventually sulfate-reducing (pH > 6.0) microbial communities in vinasse thermophilic fermentation. [Display omitted] • Metabolic functions of bacteria involved in vinasse fermentation were predicted. • Microbial composition depends on operating conditions, and not on inoculum source. • Lactobacillus is omnipresent in vinasse conversion as the main fermenting genus. • The ferredoxin hydrogenase gene was virtually absent in all four reactors. • Thermoanaerobacterium drives most of bioH 2 production utilizing lactate. [ABSTRACT FROM AUTHOR]

Fermentation is an important link in the process of cigar production, which directly determines the quality of tobacco leaves. "Humi" fermentation is a traditional method of manually adding materials, which can highlight the aroma characteristics and improve industrial availability of tobacco leaves. However, the mechanism of "Humi" fermentation is still unclear. This study was aimed to explore the effect of the "Humi" characteristic fermentation on the quality of cigar leaves, and the potential mechanisms. Cigar variety Dexue 1 was used. Three degrees of "Humi" water were prepared and water was used as control. 16 S rDNA sequencing and metabolomics analyses were carried out to determine the changes in microbes and metabolites during fermentation. "Humi" fermentation significantly improved the evaluation quality of cigar tobacco. The microbial richness and community diversity in "Humi" fermentation group were higher than that in natural fermentation group. Total 214 genera were detected, with Staphylococcus , Corynebacterium_1 , and Oceanobacillus as the dominant genera in the "Humi" fermentation group. With the extension of fermentation time, the relative abundance of Corynebacterium_1 increased, and of Oceanobacillus and Staphylococcus first increased and then decreased. Moreover, Corynebacterium_1 were significantly negatively correlated with total nitrogen, protein and alkaloid content, and significantly positively correlated with amino acids, starch, reducing sugars and total sugars. Metabolome analysis revealed 2759 known metabolites in 36 samples and "Humi" fermentation increased the nitrogenous heterocyclic compounds, sugars, alkaloids and organic acids in tobacco leaves. These metabolites were closely related to the bacterial community. Our study provides a theoretical basis for inheriting and optimizing the "Humi" characteristic fermentation technology. [Display omitted] • "Humi" fermentation significantly improved cigar tobacco evaluation quality. • "Humi" fermentation increased the nitrogenous heterocyclic compounds. • The microbial richess and community diversity in "Humi" fermentation were higher than that in natural fermentation. [ABSTRACT FROM AUTHOR]

PDO (1,3-propanediol) is a platform chemical that is obtained by petrochemical routes and by fermentation. The latter needs relatively complex downstream processing after fermentation, due to the modest concentration of the high-boiling product, and the presence of microorganisms and many impurities in the fermentation medium. This novel research proposes an original large-scale (production capacity of 23 – 32 ktonne/y) process for the final purification of PDO and dominant by-products, from the fermentation of glucose or glycerol. Following the initial microfiltration, diafiltration, ultrafiltration and ion exchange steps, heat pump-assisted vacuum distillation was implemented to remove most of the water from the broth. Afterwards, an advanced highly-integrated dividing-wall column was designed to allow the final purification of PDO (product purity > 99.9 wt%) from light and heavy by-products. Fermentation by-products that are present in significant amounts can also be recovered and valorized. Overall, the developed final purification processes demonstrate cost-effectiveness (0.150 – 0.274 $/kg) and energy-efficiency (1.258 – 3.175 kW th h/kg) which contributes to the competitiveness of the overall downstream processing (0.256 – 0.384 $/kg and 1.487 – 3.496 kW th h/kg). [Display omitted] • Eco-efficient and fermentation-adjustable downstream processing of 1,3-propanediol • PDO and by-products can all be recovered at high purity and valorized accordingly • Low energy intensity (1.25–3.17 kW th h/kg) and cost-effective process (0.15–0.27 $/kg) • Competitive overall downstream processing (0.25–0.38 $/kg; 1.48–3.49 kW th h/kg) [ABSTRACT FROM AUTHOR]

Leveraging renewable carbon-based resources for energy and chemical production is a promising approach to decrease reliance on fossil fuels. This entails a thermo/biotechnological procedure wherein bacteria, notably Clostridia , ferment syngas, converting CO or CO 2 + H 2 into Hexanol, Butanol and Ethanol (H-B-E fermentation). This work reports of Clostridium carboxidivorans performance in a stirred tank reactor continuously operated with respect to the gas and the cell/liquid phases. The primary objective was to assess acid and solvent production at pH 5.6 by feeding pure CO or synthetic syngas under gas flow differential conditions. Fermentation tests were conducted at four different dilution rates (D L) of the fresh medium in the range 0.034–0.25 h−1. The fermentation pathways of C. carboxidivorans were found to be nearly identical for both CO and syngas, with consistent growth and metabolite production at pH 5.6 within a range of dilution rates. Wash-out conditions were observed at a D L of 0.25 h−1 regardless of the carbon source. Ethanol was the predominant solvent produced, but a shift towards butanol production was observed with CO as the substrate and towards hexanol production with synthetic syngas. In particular, the maximum cell concentration (0.5 g DM /L) was obtained with pure CO at D L 0.05 h−1; the highest solvent productivity (60 mg/L*h of total solvent) was obtained at D L 0.17 h−1 by using synthetic syngas as C-source. The findings highlight the importance of substrate composition and operating conditions in syngas fermentation processes. These insights contribute to the optimization of syngas fermentation processes for biofuel and chemical production. [Display omitted] • C. carboxidivorans was grown in a CSTR at pH= 5.6. • The effect of substrate gas and dilution rate was evaluated. • max cell concentration (0.5 g DM /L) was obtained with pure CO at D L 0.05 h−1. • max solvent productivity was 60 mg/L*h, at D L 0.17 h−1 using synthetic syngas. [ABSTRACT FROM AUTHOR]

• Variability of food processor waste and derived hydrolysate quantified. • Addressing this variability is key for single-organism high-value bioproduct synthesis. • Hydrolysate assessed via bioproduct synthesis in yeast, bacteria, and archaea. • Importance of carbon and nitrogen levels, and specific substrates demonstrated. • Industrial-scale valorization strategies for variable food waste discussed in-depth. Unavoidable food wastes could be an important feedstock for industrial biotechnology, while their valorization could provide added value for the food processor. However, despite their abundance and low costs, the heterogeneous/mixed nature of these food wastes produced by food processors and consumers leads to a high degree of variability in carbon and nitrogen content, as well as specific substrates, in food waste hydrolysate. This has limited their use for bioproduct synthesis. These wastes are often instead used in anaerobic digestion and mixed microbial culture, creating a significant knowledge gap in their use for higher value biochemical production via pure and single microbial culture. To directly investigate this knowledge gap, various waste streams produced by a single food processor were enzymatically hydrolyzed and characterized, and the degree of variability with regard to substrates, carbon, and nitrogen was quantified. The impact of hydrolysate variability on the viability and performance of polyhydroxyalkanoates biopolymers production using bacteria (Cupriavidus necator) and archaea (Haloferax mediterranei) as well as sophorolipids biosurfactants production with the yeast (Starmerella bombicola) was then elucidated at laboratory-scale. After which, strategies implemented during this experimental proof-of-concept study, and beyond, for improved industrial-scale valorization which addresses the high variability of food waste hydrolysate were discussed in-depth, including media standardization and high non-selective microbial organisms growth-associated product synthesis. The insights provided would be beneficial for future endeavors aiming to utilize food wastes as feedstocks for industrial biotechnology. [ABSTRACT FROM AUTHOR]

Nutrient signaling pathways play a pivotal role in regulating the balance among metabolism, growth and stress response depending on the available food supply. They are key factors for the biotechnological success of the yeast Saccharomyces cerevisiae during food-producing fermentations. One such pathway is Retrograde Response, which controls the alpha-ketoglutarate supply required for the synthesis of amino acids like glutamate and lysine. Repressor MKS1 is linked with the TORC1 complex and negatively regulates this pathway. Deleting MKS1 from a variety of industrial strains causes glycerol to increase during winemaking, brewing and baking. This increase is accompanied by a reduction in ethanol production during grape juice fermentation in four commercial wine strains. Interestingly, this does not lead volatile acidity to increase because acetic acid levels actually lower. Aeration during winemaking usually increases acetic acid levels, but this effect reduces in the MKS1 mutant. Despite the improvement in the metabolites of oenological interest, it comes at a cost given that the mutant shows slower fermentation kinetics when grown in grape juice, malt and laboratory media and using glucose, sucrose and maltose as carbon sources. The deletion of RTG2 , an activator of Retrograde Response that acts as an antagonist of MKS1 , also results in a defect in wine fermentation speed. These findings suggest that the deregulation of this pathway causes a fitness defect. Therefore, manipulating repressor MKS1 is a promising approach to modulate yeast metabolism and to produce low-ethanol drinks. • MKS1 gene deletion increases glycerol and reduces ethanol during winemaking. • This increase in glycerol does not imply an overproduction of acetic acid. • Glycerol also increases in brewing and baking yeasts. [ABSTRACT FROM AUTHOR]

The current study investigated the impact of Saccharomyces cerevisiae fermentation on apricot kernel oil extraction and the resulting quality characteristics of the oil. The seed kernels underwent physicochemical and antioxidant studies after being separated, gelatinized, and fermented. The results revealed 43.6 % of oil yield by fermentation. The extracted oil had a lower acid value (3.74 mg KOH/g), and peroxide value (4.25 meq/kg). The investigation of additional oil properties was included, like iodine value (100.26 mg KOH/g), saponification value (190.5 mg KOH/g), specific gravity (0.919), viscosity (4.62), moisture content (0.592 %), and refractive index (1.4836), which signifies optimum physicochemical parameters of oil. As per the FTIR data, some distinct functional groups like C-H stretch and C O, C C, CH3, OH, and R-O-R esters were found in the extracted oil. The oil's fatty acid composition, with 50.47 % saturated, 22.23 % mono-unsaturated, and 35.13 % polyunsaturated fatty acids, enhances stability, oxidative resistance, and nutritional value, justifying its favorable physicochemical properties. The DPPH radical scavenging activity of the oil showed to have good antioxidant activity. Metabolic modeling of S. cerevisiae provided information about compounds received after fermentation. Hence, it can be concluded that fermentation is a suitable approach to extract apricot seed kernel oil with beneficial properties. [Display omitted] • Apricot seed kernel is a good source of oil, we can use it for multiple purposes. • Saccharomyces cerevisiae -based fermentation, we can get 43.6 % of oil. • Different beneficial fatty acids were obtained from this oil: Caprylic, Lauric, Margaric, Paullinic, Phthalic acid, etc. [ABSTRACT FROM AUTHOR]

Probiotics-based beverages are cherished as convenient and functional food due to their excellent nutritional profile, sensory quality, and shelf life. The need for fruit juice-based probiotic beverages has been sparked as certain consumers are allergic to dairy products or vegan. The purpose of this study is to comprehensively review various fruit-based probiotic beverages developed by fortification or fermentation using various probiotics, methods used to prepare these beverages, health benefits of resultant beverages and the mechanism involved. In addition, advanced methods such as encapsulation/immobilization and spray drying to enhance the shelf life and stability of these beverages have also been discussed in detail. Overall, this review emphasizes the development and exceptional advantages of fruit-based probiotics. This study will be helpful for food scientists and food processors to develop novel probiotic beverages with enhanced health benefits and assist industries in determining the most economical raw materials and production processes for producing fruit juice-based beverages. [Display omitted] • Consumer's demand for fruit juice-based probiotic beverages (FJPB) is high. • Different fruits-based fermented/non-fermented probiotic beverages are discussed. • Technological interventions to enhance overall quality of FJPB are reviewed. • In vivo and in vitro health benefits of FJPB are also discussed in detail. • Instant, safe and quality FJPB have to be developed from regional low-cost fruits. [ABSTRACT FROM AUTHOR]

This research analyzed the contribution of different electron transfer pathways for H 2 production in a bioelectrochemicallly assisted dark fermentation system (BEDF), and compared to an electric field-driven dark fermentation (EFDF) reactor. The results showed that intrinsic extracellular electron transfer (iEET) via dark fermentation accounted for 76.3% of the H 2 production in the BEDF reactor. In comparison, the extracellular electron transfer (bEET) pathway via the bioelectrode enhanced by the bioelectrochemical system and the electric field-driven extracellular electron transfer (eEET) in the bulk solution accounted for 5% and 18.7%, respectively. This suggests that the main electron transfer pathway for H 2 production comes from the bulk solution rather than that on the bioelectrodes. Under the condition of electric field, extracellular polymeric substances (EPS) were secreted in large quantities in the bulk solution, and electroactive microorganisms such as Proteobacteria were significantly enriched, which further promote the H 2 production through the eEET pathway. [Display omitted] • H 2 production was increased by electric field rather than that on bioelectrode. • BEET and eEET pathways account for 5% and 18.7% of total hydrogen production. • Electric fields activate more hydrogen-producing microbial metabolic pathways. • Electric field enriches bacteria that affect EPS secretion in bulk solution. [ABSTRACT FROM AUTHOR]

Hydrogen has received attention as a next-generation renewable energy source; accordingly, sustainable production and safe transportation are crucial for its effective utilization. In this study, we focused on dihydrolevoglucosenone (Cyrene TM ), which was a biodegradable ketone derived from cellulose, as a renewable organic hydride. Furthermore, hydrogenation using alcoholic fermentation with baker's yeast was proposed for a novel hydrogen storage, wherein water and nicotinamide adenine dinucleotide serve as hydrogen sources. Cyrene TM was hydrogenated with baker's yeast to produce 1,6-anhydro-3,4-dideoxy- β -D- threo -hexopyranose (Cyrene-OH). Cyrene-OH stored hydrogen via chemical bonding, and was dehydrogenated by warming in the presence of an iridium complex catalyst to produce hydrogen gas and reproduce Cyrene TM . Therefore, this study demonstrated a new sustainable and renewable hydrogen gas production and storage cycle. This cycle, which uses readily available Cyrene TM and baker's yeast, enables hydrogen energy production and storage in isolated areas and should contribute to Sustainable Development Goal 7 (Affordable and Clean Energy). • Cyrene TM derived from cellulose was used as a renewable organic hydride. • Hydrogenation and hydrogen storage using alcoholic fermentation was demonstrated. • A new sustainable hydrogen gas production and storage cycle was established. [ABSTRACT FROM AUTHOR]

Anaerobic fermentation has attracted wide attention to effectively reduce carbon footprint and alleviate potential energy shortages, which is being regarded as a sustainable and promising technology to obtain high biohydrogen production from widespread organic wastes. However, biohydrogen commercial uptake is now dominantly inhibited by the low hydrogen yield and process instability. In this work, Al 2 O 3 /BaFe 2 O 4 nanoparticles (NPs) are successfully applied to anaerobic fermentation for investigating their effects on hydrogen yield, activity of bacteria and microbial community structure. The benefits of Al 2 O 3 /BaFe 2 O 4 NPs with respect to microbial metabolism, reactivity of enzymes and process optimization are systematically researched through batch experiments. In addition, various characterizations are used to verify the physical and chemical properties of Al 2 O 3 /BaFe 2 O 4 NPs. The results show that the activity of hydrogenases and microbe metabolism can be significantly inhibited by excess addition of Al 2 O 3 /BaFe 2 O 4 NPs (150 mg/L and 200 mg/L) while the optimum addition 100 mg/L of Al 2 O 3 /BaFe 2 O 4 NPs can boost the biohydrogen yield by 49% via facilitating microorganism growth and enhancing key enzymatic activities, which indicate that the Al 2 O 3 /BaFe 2 O 4 NPs display a beneficial influence on electron transfer efficiency and process stability. The existence of Fe3+, Al3+and Ba2+ derived from the corrosion of Al 2 O 3 /BaFe 2 O 4 NPs by organic acids synergistically improve the microbial transmembrane transportation and substrate utilization, which contribute to higher conversion rate of glucose into acetate, butyrate and H 2. Meanwhile, the complementary functions of Fe3+ and Al3+ can powerfully shorten the lag phase and promote the glycolysis, which finally accelerate the dark fermentation process. Compared with the control group, Clostridium _ sensu _ stricto _1 is selectively enriched by the addition of Al 2 O 3 /BaFe 2 O 4 NPs, which keep heavily involved in the synthesis of H 2. On balance, this study provides an effective strategy to enhance hydrogen productivity and maintain process stability, which offer the valuable information for the sustainable utilization of sewage sludge. [Display omitted] • Al 2 O 3 /BaFe 2 O 4 NPs are synthesized to enhance H 2 production. • Al 2 O 3 /BaFe 2 O 4 NPs show positive effects on activity of H 2 -producing bacteria. • The addition of Al 2 O 3 /BaFe 2 O 4 NPs can facilitate H 2 -producing bacteria growth. • Humic acids are reduced by addition of Al 2 O 3 /BaFe 2 O 4 NPs. • Firmicutes and Clostridium_sensu_stricto_ 1 are selectively enriched by Al 2 O 3 /BaFe 2 O 4 NPs. [ABSTRACT FROM AUTHOR]

• Cardiometabolic health benefits of dairy foods vary by fat content and product fermentation • Dairy fat intakes are associated with neutral to beneficial cardiometabolic activities • Full-fat dairy intakes have no demonstrated adverse impact on cardiovascular risk • Fermented dairy intakes positively influence lipid profiles • Milk polar lipids contribute to improved blood lipid profiles • Dietary recommendations concerning dairy likely require greater precision Bovine dairy milk is a nutrient-rich matrix, but consumption of full-fat dairy food varieties has been claimed historically to be associated with poorer cardiometabolic health, a notion often attributed to the saturated fat content. However, continued investigation that includes observational studies and randomized controlled trials (RCTs) provide evidence that favorably supports full-fat dairy foods and their bioactive components on cardiometabolic health. This review addresses this controversy by examining the evidence surrounding full-fat dairy foods and their implications for human health. Dairy foods are heterogeneous, not just in their fat content but also in other compositional aspects within and between fermented (e.g., yogurt, cheese) and nonfermented products (e.g., milk) that could differentially influence cardiometabolic health. Drawing from complementary lines of evidence from epidemiological studies and RCTs, this review describes the health effects of dairy foods regarding their fat content, as well as their polar lipids that are concentrated in the milk fat globule fraction. Observational studies have limitedly supported the consumption of full-fat dairy to protect against cardiometabolic disorders. However, this framework has been disputed by RCTs indicating that dairy foods, regardless of their fat content or fermentation, are not detrimental to cardiometabolic health and may instead alleviate certain cardiometabolic risk factors. As dietary recommendations evolve, which currently indicate to avoid full-fat dairy foods, it is essential to consider the totality of evidence, especially from RCTs, while also recognizing that investigation is needed to evaluate the complexity of dairy foods within diverse dietary patterns and their impacts on cardiometabolic health. This review examines the cardiometabolic effects of dairy, comparing full-fat and low-fat types. It starts with observational study findings on total dairy intake and its fat content, then explores the health benefits of specific dairy types, considering fat content and whether they are fermented. Next, it presents evidence from controlled trials to establish efficacy of the correlative outcomes suggested by observational studies. This approach offers insights for future dietary recommendations. [Display omitted] [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the effects of a genetically modified corn hybrid with α-amylase expressed in the kernel (AMY) on fermentation profile, aerobic stability, nutrient composition, and starch disappearance of whole-plant corn silage (WPCS) and earlage. Both hybrids, AMY and an isogenic corn hybrid (ISO), were grown in 10 replicated plots (5 for WPCS and 5 for earlage). Samples of each plot were collected at harvest, homogenized, and divided into 5 subsamples which were randomly assigned to 5 storage lengths (0, 30, 60, 90, and 120 d). Both datasets (WPCS and earlage), were analyzed separately as a completely randomized block design in a factorial arrangement of treatments, with a model including the fixed effects of hybrid, storage length, and their interaction, and the random effect of block. Minor differences on fermentation profile were observed between AMY and ISO for WPCS and earlage. An interaction between hybrid and storage length was observed for DM losses in WPCS, where losses were similar at 30, 60 and 90 d, but lower for AMY compared with ISO at 120 d. No effect of hybrid was observed on yeast and mold counts for WPCS or earlage. The aerobic stability of WPCS was greater for AMY than ISO. For earlage, AMY had greater DM losses and aerobic stability than ISO. An interaction between hybrid and storage length was observed for ammonia-N in both WPCS and earlage, where ammonia-N was similar at 0 d but greater for AMY than ISO throughout later storage lengths. A similar interaction was observed for water-soluble carbohydrates (WSC) concentrations in WPCS, where ISO had greater WSC than AMY at 0 d but was similar throughout later storage lengths. However, AMY earlage had a greater WSC concentration throughout storage length, but a lesser magnitude after ensiling. Starch concentration was greater for AMY than ISO in WPCS and earlage. Greater starch disappearances at 0 h and 6 h were observed for ISO in WPCS and earlage. Minor effects on fermentation profile, microbial counts, aerobic stability and nutrient composition suggests that AMY can be ensiled for prolonged periods with no concerns for undesirable fermentation or nutrient losses. However, in situ starch disappearance was lower for AMY compared with ISO. [ABSTRACT FROM AUTHOR]

Ice cream manufacture commonly results in the accumulation of wasted product that contains valuable food-grade quality components, including fat, carbohydrates, and protein. Methods have been developed for recovering the fat from this waste stream, but this results in the generation of a co-product rich in fermentable carbohydrates. This study aimed to investigate the potential for using this co-product as a fermentation substrate for production of antimicrobial peptides, called bacteriocins, by dairy starter cultures. Results showed that Streptococcus thermophilus B59671 and Lactococcus lactis 11454 produced the broad-spectrum bacteriocins thermophilin 110 and nisin, respectively, when the fermentation substrate was melted ice cream, or a co-product generated by a modified butter churning technique. Bacteriocin production varied depending on the brand and variety of vanilla ice cream used in this study. When an alternate enzyme-assisted fat extraction technique was used, S. thermophilus metabolism was impaired within the resulting co-product, and thermophilin 110 production was not observed. Lactococcus lactis was still able to grow in this co-product, but antimicrobial activity was not observed. Results from this study suggest the co-product generated when using the churning technique is a better choice to use as a base medium for future studies to optimize bacteriocin production. [ABSTRACT FROM AUTHOR]

Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus are symbiotic starters widely used in yogurt fermentation. They exchange metabolites to meet their nutritional demands during fermentation, promoting mutual growth. Although S. thermophilus produces fumaric acid, and the addition of fumaric acid has been shown to promote the growth of L. bulgaricus monoculture, whether fumaric acid produced by S. thermophilus is used by L. bulgaricus during coculture remains unclear. Furthermore, the importance of fumaric acid metabolism in the growth of L. bulgaricus is yet to be elucidated. Therefore, in this study, we investigated the importance of fumaric acid metabolism in L. bulgaricus monocultures and coculture with S. thermophilus. We deleted the fumarate reductase gene (frd), which is responsible for the metabolism of fumaric acid to succinic acid, in L. bulgaricus strains 2038 and NCIMB 701373. Both Δ frd strains exhibited longer fermentation times than their parent strains, and fumaric acid was metabolized to malic acid rather than succinic acid. Coculture of Δ frd strains with S. thermophilus 1131 also resulted in a longer fermentation time, and the accumulation of malic acid was observed. These results indicated that fumaric acid produced by S. thermophilus is used by L. bulgaricus as a symbiotic substance during yogurt fermentation and that the metabolism of fumaric acid to succinic acid by fumarate reductase is a key factor determining the fermentation ability of L. bulgaricus. [ABSTRACT FROM AUTHOR]

Escherichia coli FocA and FocB formate channels export formate or import it for further disproportionation by the formate hydrogenlyase (FHL) complex to H 2 and CO 2. Here, we show that under pH and osmotic stress FocA and FocB play important roles in regulating proton and potassium fluxes and couple this with H 2 production in stationary-phase cells. Using whole-cell assays with glucose as electron donor, a focB mutant showed a 50 % decrease in V H2 , while N'N' -dicyclohexylcarbodiimide (DCCD) treatment of osmotically stressed cells underlined the role of F O F 1 ATPase in H 2 production. At pH 7.5 and under osmotic stress FocB contributed to the proton flux but not to the potassium flux. At pH 5.5 both formate channels contributed to the proton and potassium fluxes. Particulalry, a focA mutant had 40 % lower potassium flux whereas the proton flux increased approximately two-fold. Moreover, at pH 5.5H 2 production was totally inhibited by DCCD in the focA mutant. Taken together, our results suggest that depending on external pH, the formate channels play an important role in osmoregulation by helping to balance proton/potassium fluxes and H 2 production, and thus assist the proton F O F 1 -ATPase in maintenance of ion gradients in fermenting stationary-phase cells. [Display omitted] • At pH 7.5 and under osmotic stress FocB contributed to the proton flux but not to the potassium flux. • At pH 5.5 both formate channels contributed to the proton and potassium fluxes. • At low pH H 2 production was totally inhibited by DCCD in the focA mutant. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the physiology of 13 yeast strains by assessing their kinetic parameters under anaerobic conditions. They included Saccharomyces cerevisiae CAT-1 and 12 isolated yeasts from different regions in Brazil. The study aimed to enhance understanding of the metabolism of these strains for more effective applications. Measurements included quantification of sugars, ethanol, glycerol, and organic acids. Various kinetic parameters were analyzed, such as specific substrate utilization rate (q S), maximum specific growth rate (μ max), doubling time, biomass yield, product yield, maximum cell concentration, ethanol productivity (P Eth), biomass productivity, and CO 2 concentration. S. cerevisiae CAT-1 exhibited the highest values in glucose for μ max (0.35 h−1), q S (3.06 h−1), and P Eth (0.69 gEth L−1 h−1). Candida parapsilosis Recol 37 did not fully consume the substrate. In fructose, S. cerevisiae CAT-1 stood out with higher values for μ max (0.25 h−1), q S (2.24 h−1), and P Eth (0.60 gEth L−1 h−1). Meyerozyma guilliermondii Recol 09 and C. parapsilosis Recol 37 had prolonged fermentation times and residual substrate. In sucrose, only S. cerevisiae CAT-1, S. cerevisiae BB9, and Pichia kudriavzevii Recol 39 consumed all the substrate, displaying higher P Eth (0.72, 0.51, and 0.44 gEth L−1 h−1, respectively) compared to other carbon sources. [Display omitted] • The physiology of 13 yeasts was investigated under anaerobic conditions using glucose, fructose, or sucrose. • Saccharomyces cerevisiae CAT-1 showed the higher fermentation capacity and rapid substrate consumption. • Candida glabrata Recol 43 also exhibited favourable metabolic traits and high ethanol productivity. • Only S. cerevisiae CAT-1, S. cerevisiae BB9, and Pichia kudriavzevii Recol 39 consumed all the sucrose. • All yeast strains exhibited higher ethanol yields when using fructose as a substrate. [ABSTRACT FROM AUTHOR]

Fermentation of food waste to lactic acid (LA) is a strategy for resource recovery. However, the poor yield and optical activity (OA) of L-lactic acid (L-LA) are major bottlenecks for such efforts. This study focuses on enhancing L-LA yield and optical purity from the food waste without sterilization and inoculation at pilot-scale. First, the effects of temperature on LA production were explored. A higher LA yield but lower purity was obtained under mesophilic conditions, whereas the opposite results were represented at high temperature. On the basis of these findings, a novel two-stage temperature regulation strategy was developed that combined the benefits of both temperature conditions. This strategy not only ensured a L-LA yield of 0.371 g/g volatile solid, but also achieved a high optical purity of 98.0%. The underlying mechanism is that high temperature could enrich L-lactic acid bacteria (LAB) and inhibit LAB producing both L- and D-LA. Overall, this innovative strategy may be well-suited for generating optically pure L-LA from food waste fermentation. [Display omitted] • The effect of temperature on lactic acid (LA) production at pilot-scale was explored. • A novel two-stage temperature regulation strategy was developed for LA production. • A high LA concentration of 22.5 g/L and an optical purity of 98.0% were obtained. • The underlying mechanism is that high temperature could enrich L-LA bacteria. • A thermophilic bacteria that produces only L-LA was isolated and characterized. [ABSTRACT FROM AUTHOR]

Probiotic lactic acid bacteria (LAB) have garnered substantial attention for their potential health benefits, particularly in supporting the balance of gut microbiota. This study sought to assess LAB isolates from honeybees stomach as potential probiotics by evaluating their tolerance to acid and bile, autoaggregation, hydrophobicity, co-aggregation with pathogens, antioxidant activity, haemolysis, exopolysaccharide (EPS) production, in vitro cell adherence, and their performance in milk-based fermented products. The LAB isolates exhibited impressive resilience to gastric acid, surviving exposure to simulated gastric juice at pH 2 after 2 h of incubation. Autoaggregation and hydrophobicity, crucial for probiotic adhesion to intestinal epithelial cells, were observed in several LAB isolates. Notably, Ehb3, Ehb5, and Ehb8 displayed the highest values, indicating their potential for effective intestinal adhesion. The antioxidant activities of intracellular and cell-free lactic acid bacteria strain extracts were evaluated using DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging tests. Ehb3 and Ehb5 demonstrated outstanding antioxidant capabilities, suggesting their potential for enhancing the shelf life and health benefits of probiotic products. These lactic acid bacteria strains were also proficient in fermenting milk, maintaining viability above the technological requirements for probiotic products during storage. Finally, lactic acid bacteria isolate from honey bee stomach exhibit promising characteristics that make them suitable candidates for potential probiotics with health benefits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermo-acid pretreatments increased sugar solubilization. • Thermo-acid pretreatments did not improve dark fermentation performances. • Pretreatments were responsible for metabolic and bacterial community changes. • Inactivation of indigenous bacteria led to no metabolic changes. • Thermo-acid pretreatments were detrimental to the process reproducibility. Complex organic matter represents a suitable substrate to produce hydrogen through dark fermentation (DF) process. To increase H 2 yields, pretreatment technology is often required. The main objective of the present work was to investigate thermo-acid pretreatment impact on sugar solubilization and biotic parameters of DF of sorghum or organic fraction of municipal solid waste (OFMSW). Biochemical hydrogen potential tests were carried out without inoculum using raw or thermo-acid pretreated substrates. Results showed an improvement in sugar solubilization after thermo-acid pretreatments. Pretreatments led to similar DF performances (H 2 and total metabolite production) compared to raw biomasses. Nevertheless, they were responsible for bacterial shifts from Enterobacteriales towards Clostridiales and Bacillales as well as metabolic changes from acetate towards butyrate or ethanol. The metabolic changes were attributed to the biomass pretreatment impact on indigenous bacteria as no change in the metabolic profile was observed after performing thermo-acid pretreatments on irradiated OFMSW (inactivated indigenous bacteria and inoculum addition). Consequently, acid pretreatments were inefficient to improve DF performances but led to metabolic and bacterial community changes due to their impact on indigenous bacteria. [ABSTRACT FROM AUTHOR]

Dark fermentation is a promising technology for biohydrogen (bioH 2) production. Augmenting the dark fermentation process with conductive materials has drawn significant research interests improving the bioH 2 yield. This study evaluated the feasibility of using carbon fiber brush (CB) as an additive to increase the efficiency of mesophilic dark fermentation using glucose as substrate and heat-shock pretreated anaerobic sludge as inoculum. Effect of electrode packing density on bioH 2 yield, soluble metabolite product formation, and substrate degradation was investigated. Maximal bioH 2 yield of 334.6 mL/g-glucose was obtained using medium-sized CB with 72.5% higher than the control (194 mL/g-glucose) and butyrate-type fermentation was the dominant metabolic pathway. Further, enhanced concentrations of proteins and polysaccharides on CB biofilm suggested the critical role of extracellular polymeric substances in microbial electron transfer. This was supported via electron transport activity in CB biofilm. Finally, microbial community analysis revealed a selective enrichment of the potentially electroactive Clostridium_sensu_stricto_1 on the CB (56.6%) compared to 40.9% abundance in control. Insights gained from this study demonstrated that CB aided dark fermentation can be an economical and environmentally benign strategy for improving bioH 2 yield. [Display omitted] • Carbon brush (CB) feasibility in dark fermentation was investigated. • Electrode packing density influenced bioH 2 yield and soluble metabolite products. • Highest bioH 2 yield of 334.6 mL/g-glucose was obtained with CB-medium. • CB enhanced extracellular polymeric secretion and electron transport activity. • Clostridium_sensu_stricto_1 was enriched on the CB surface. [ABSTRACT FROM AUTHOR]

Optimization of additives was achieved for hydrogen and butyric acid production modelled through a three-level Box-Behnken Design of the response surface methodology. Seventeen runs were designed with variables of sodium chloride (0.1–5 g/L), sodium thiosulphate (0–200 mg/L) and minerals (Zinc, iron, cupper and nickel (0–0.8 mM). The model fit to a cubic model with a high R2 of 96% and P value of 0.03. Some of the interactive variables have significant effect on butyrate production. The butyrate concentrations were close to the predicted ones. The model showed that higher butyric acid concentrations were observed with low sodium chloride and high sodium thiosulphate and minerals concentrations. Butyrate/Acetate ratios (BA/A), hydrogen production yield and rates increased with mean values of the independent variables. A cumulative hydrogen formation of 155 mL, yield of 2.6 mmol H 2 /mmol lactose, and rate of 3.6 mL/g/h was observed with the highest BA/AA ratio obtained from experiments. [Display omitted] • Box-Behnken design was applied to enhance butyric acid production. • A modified third-order polynomial regression models were developed with high accuracy. • The interactive variables have significant effect on butyric acid production. • The biohydrogen amount produced was the highest among the literature compared. • The highest BA/AA ratio maximizing butyric acid gave a high hydrogen production potential. [ABSTRACT FROM AUTHOR]

A hazelnut-based fermented creamy structure was developed from whole hazelnut kernels in the scope of plant-based food production. Firstly, heat-induced and acid-induced gelation of aqueous slurries of raw or roasted hazelnut kernels were investigated. The final structure was formed by heat treatment and fermentation by yoghurt culture along with supplementary sucrose. A stabilizer mixture of locust bean gum and xanthan gum was needed to prevent phase separation. Roasting treatment of hazelnuts reduced the temperature and increased the pH at which gelation started; however, a weak gel was obtained. On the other hand, fermentation of raw hazelnuts resulted in a gel structure with higher strength, yield stress, flow point and spreadability. Phase separation was not observed in the structures during storage. Viable lactic acid bacteria count was above 6 log cfu/g in the samples and a slight decrease was observed after storage at 4°C. Soluble protein content in the samples was reduced by roasting and fermentation but increased after storage. Roasting enhanced allergenicity of the water-soluble fraction while fermentation decreased it by about 70%. Raw hazelnuts are recommended for preparation of stable fermented gel structures with reduced allergenicity towards plant-based food production. [ABSTRACT FROM AUTHOR]

This study investigated the preventive effects of whey protein fermented with Lactobacillus gasseri IM13 (F-WP) against dexamethasone (DEX)-induced muscle atrophy. C2C12 muscle cells were treated with F-WP followed by DEX treatment. Dexamethasone treatment inhibited myotube formation and the expression of myogenic regulatory factors; however, pretreatment with F-WP attenuated DEX-induced damage. The F-WP significantly activated the phosphorylation of the IGF-1/PI3K/AKT pathway and improved muscle homeostasis suppressed by DEX. Moreover, F-WP alleviated the phosphorylation of mTOR, S6K1, and 4E-BP1 and enhanced muscle protein synthesis. Muscle-specific ubiquitin ligases and autophagy lysosomes, which were activated by the dephosphorylation of FOXO3a by DEX treatment, were significantly attenuated by F-WP pretreatment of myotubes. For peptidomic analysis, F-WP was fractionated using preparative HPLC (prep-HPLC), and the AA sequences of 11 peptides were identified using MALDI-TOF/MS/MS. In conclusion, fermentation of whey protein by the specific probiotic strain IM13 produced bioactive peptides with high antioxidant and anti-sarcopenic-sarcopenic effects, which markedly enhanced myogenesis and muscle protein synthesis while diminishing muscle protein degradation compared with intact whey protein. [Display omitted] [ABSTRACT FROM AUTHOR]

Ethyl lactate is the most abundant ester in semi-solid rice baijiu fermentation, affecting the flavor of baijiu to a great extent. The present study aimed to investigate the spatial distribution and formation contributor of ethyl lactate by removing the microorganisms and extracellular enzymes from the upper, middle, and lower fermentation broth during the later fermentation stage. The removal of suspended substances by centrifugation did not affect the ethyl lactate content in the top and middle fermentation broth containing free cells, enzymes, and starch particles. After day 5 of fermentation, only the lower fermentation broth containing granular cells attached to the starch could continue to accumulate lactic acid, thereby increasing the ethyl lactate content. The results showed that the chemical reactions were the main contributor to the increased ethyl lactate content at the anaphase of fermentation rather than enzymatic catalysis or microbial metabolism. Sequencing of granular cells revealed the main lactic acid producers at different fermentation stages. Lactobacillus helveticus showed the highest abundance of 94.45–95.40% on day 5, which decreased to 29.58–30.20% on day 15, while Lactobacillus acetotolerans showed the highest abundance of 47.93–49.72% at day 15. Additionally, the granular cells were recovered and used for supplementary inoculation in the next batch, which significantly increased the ethyl lactate content. This study provided a novel strategy for improving the ethyl lactate content in semi-solid baijiu fermentation. [Display omitted] • Esterification of cells and enzymes was studied in baijiu fermentation anaphase. • Ethyl lactate was mainly formed by chemical rather than biological reaction. • Lactic acid was mainly produced by granular cells attached to starch on the bottom. • Lactobacillus helveticus and L. acetotolerans were the major lactic acid producers. • Adding recovered granular cells in anaphase could much increase ethyl lactate. [ABSTRACT FROM AUTHOR]

A high-yielding microbial polysaccharide-producing strain, named RM1603, was isolated from rhizosphere soil and identified by morphological and phylogenetic analysis. The extracellular polysaccharides (EPS) were identified by thin-layer chromatography and infrared spectroscopy. The fermentation conditions were optimized by single factor experiments in shake flasks and a 5-L fermentor. The results of morphological and phylogenetic tree analysis showed that RM1603 was a strain of Aureobasidium pullulans. Its microbial polysaccharide was identified as pullulan, and the EPS production capacity reached 33.07 ± 1.03 g L−1 in shake flasks. The fermentation conditions were optimized in a 5-L fermentor, and were found to encompass an initial pH of 6.5, aeration rate of 2 vvm, rotor speed of 600 rpm, and inoculum size of 2 %. Under these conditions, the pullulan yield of RM1603 reached 62.52 ± 0.24 g L−1. Thus, this study contributes RM1603 as a new isolation with high-yielding pullulan and potential application value in biotechnology. [ABSTRACT FROM AUTHOR]

Optimization of fermentation parameters can effectively increase microbial metabolites. The fermentation conditions of biosynthesis lipopeptides by Bacillus altitudinis Q7 (B. altitudinis Q7) in 5 L reactor were optimized and the fermentation kinetics were monitored throughout the fermentation process. By design-response surface methodology, the results showed that under optimal conditions (72 h, pH 6.6, 31 °C, 3% inoculum, 200 rpm, 1.5 L/min aeration), the lipopeptide yield reached 1.689 mg/mL, 24.5% higher than under single-factor conditions, with maximum biomass dry weight of 1.650 g/L. According to the logistic and Luedeking-Piret approximate models, kinetic equation models of growth, product (lipopeptide) synthesis, and substrate (glucose) utilization during the fermentation process were simulated. This was done to fit variables and devise optimal control strategies. The research has improved the yield of target products in fermentation processes, reduced production costs and provided a theoretical basis for the simulation, optimisation and regulation of fermentation in modern industry. [Display omitted] • Optimize Bacillus. altitudinis Q7 fermenter parameters and composition for increased synthetic lipopeptide. • After optimization, lipopeptide synthesis increased by 1.5 times to 1.69 mg/mL. • Dissolved oxygen level is the main limiting factor for lipopeptide synthesis. • The Bacillus. altitudinis Q7 fermentation kinetics equation has been established. [ABSTRACT FROM AUTHOR]

Fault diagnosis plays a pivotal role in identifying the root causes of a fault. Current fault diagnosis methods encounter the shortcomings being unable to assess the fault amplitude or having low efficiency for batch fermentation process. In order to solve the above problems, this paper proposes a fault detection model named convolutional neural network based on variational autoencoder (CNN-VAE) and a fault diagnosis based on counterfactual inference (FDCI). To begin with, quality-related process variables are selected using mutual information (MI). Next, a two-dimensional moving window is used to obtain input sequences from the process data. Then, two statistics from the latent and residual domains of the CNN-VAE model are constructed for fault detection. Additionally, once a fault occurs, FDCI is used to locate the root cause of a fault. Finally, a simulation process and a real-world L. plantarum batch fermentation process are provided to demonstrate the effectiveness of the proposed approache. • A novel model named CNN-VAE is proposed for batch fermentation processes monitoring. • An innovative fault diagnosis strategy named FDCI is proposed. • A simulation and an experiment verify the efficiency of the CNN-VAE and FDCI strategy. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the lipid-lowering activity of LFBEP-C1 in high glucose-fed Caenorhabditis elegans (C. elegans). In this study, the fermented barley protein LFBEP-C1 was prepared and tested for its potential anti-obesity effects on C. elegans. The worms were fed Escherichia coli OP50 (E. coli OP50), glucose, and different concentrations of LFBEP-C1. Body size, lifespan, movement, triglyceride content, and gene expression were analyzed. The results were analyzed using ANOVA and Tukey's multiple comparison test. Compared with the model group, the head-swing frequency of C. elegans in the group of LFBEP-C1 at 20 μg/mL increased by 33.88%, and the body-bending frequency increased by 27.09%. This indicated that LFBEP-C1 improved the locomotive ability of C. elegans. The average lifespan of C. elegans reached 13.55 days, and the body length and width of the C. elegans decreased after LFBEP-C1 intake. Additionally, LFBEP-C1 reduced the content of lipid accumulation and triglyceride levels. The expression levels of sbp-1 , daf-2 , and mdt-15 significantly decreased, while those of daf-16 , tph-1 , mod-1 , and ser-4 significantly increased after LFBEP-C1 intake. Changes in these genes explain the signaling pathways that regulate lipid metabolism. LFBEP-C1 significantly reduced lipid deposition in C. elegans fed a high-glucose diet and alleviated the adverse effects of a high-glucose diet on the development, lifespan, and exercise behavior of C. elegans. In addition, LFBEP-C1 regulated lipid metabolism mainly by mediating the expression of genes in the sterol regulatory element-binding protein, insulin, and 5-hydroxytryptamine signaling pathways. [ABSTRACT FROM AUTHOR]

In the present study, an innovative method of fermentation osmotic activation was employed to produce activated carbon derived from rice husk. The fermentation procedure dismantles the robust lignin present on the rice husk surface, thereby liberating amorphous SiO 2 , enhances osmotic activation, and promotes pore development. Following the high-temperature osmosis treatment utilizing a KOH solution, a significant portion of the amorphous SiO 2 on the husk's surface is successfully dissolved and removed, leading to the formation of numerous carbon skeletons. This procedure culminates in the production of activated carbon characterized by a high specific surface area and substantial pore volume, attributed to the role of K ions during carbonization. The sample DFRO1-AC exhibited the most effective hydrogen gravimetric storage capacity of 1.21 wt% at room temperature (25 °C) and 80 bar pressure, featuring a BET specific surface area of 2270 m2/g. Compared to other activated carbons used for hydrogen storage, our materials demonstrate superior hydrogen storage capacity and employ renewable agricultural waste, indicating high feasibility and broad application prospects. • An innovative method of fermentation osmotic activation. • The fermentation can promote pore development. • Osmotic activation eliminates SiO 2 and etches the carbon skeleton. • Excellent hydrogen storage capacity at room temperature. [ABSTRACT FROM AUTHOR]

• Food Waste extract was used for homolactic fermentation and MCFAs production. • Selected pH (6) prevented lactate and excessive ethanol oxydation. • Ethanol elongation was slower than fermentation, resulting in ethanol accumulation. • Lactate self elongation to butyrate was the dominant pathway. This study explored the potential of Food Waste (FW) extract as a suitable substrate for Medium Chain Fatty Acids (MCFAs) production, in a single-phase reactor, where both fermentation and Chain Elongation (CE) processes occurred simultaneously. A continuous experiment was conducted with an Organic Loading Rate (OLR) = 20 gCOD L-1 d-1 and was fed in batch mode twice a week with pH = 6. In addition, four batch tests were performed, to assess the effects on the MCFAs production of caproate inhibition, hydrogen partial pressure (P H2) and different lactate/acetate ratios. Thermodynamics and electron flux were calculated to gain insights into the process pathways. Due to the presence of aminoacids, fermentation was mostly homolactic and both lactate and ethanol were produced as Electron Donors (EDs); the average MCFAs production efficiency was ∼ 12 %, although after 4 weeks the elongation process was halted, resulting in EDs accumulation. This occurred regardless of inoculum selection and the presence of caproate as a possible inhibitor, suggesting that EDs accumulation was due to the elongation process kinetics being slower than those of the fermentation step, thus calling for a longer Hydraulic Retention Time (HRT). It's worth noting that lactate was prevalently self-elongated to butyrate, whereas ethanol elongation only took place after lactate depletion, but was more efficient since it required other Electron Acceptors (EAs) such as butyrate, propionate or valerate. Moreover, the selected pH limited the acrylate pathway to a reasonable extent, whereas the high P H2 prevented both ethanol and lactate oxydation to acetate. [ABSTRACT FROM AUTHOR]

Previously, we used secondary electrospray ionization-mass spectrometry (SESI-MS) to investigate the diurnal patterns and signal intensities of exhaled (EX) volatile fatty acids (VFA) of dairy cows. The current study aimed to validate the potential of an exhalomics approach for evaluating rumen fermentation. The experiment was conducted in a switchback design, with 3 periods of 9 d each, including 7 d for adaptation and 2 d for sampling. Four rumen-cannulated original Swiss Brown (Braunvieh) cows were randomly assigned to 1 of 2 diet sequences (ABA or BAB): (A) low starch (LS; 6.31% starch on a dry matter basis) and (B) high starch (HS; 16.2% starch on a dry matter basis). Feeding was once per day at 0830 h. Exhalome (with the GreenFeed System), and rumen samples were collected 8 times to represent every 3 h of a day, and EX-VFA and ruminal (RM)-VFA were analyzed using SESI-MS and HPLC, respectively. Furthermore, the VFA concentration in the gas phase (HR-VFA) was predicted based on RM-VFA and Henry's Law (HR) constants. No interactions were identified between the types of diets (HS vs. LS) and the measurement methods on daily average VFA profiles (RM vs. EX or HR vs. EX), suggesting a consistent performance among the methods. Additionally, when the 3-h interval VFA data from HS and LS diets were analyzed separately, no interactions were observed between methods and time of day, indicating that the relative daily pattern of VFA molar proportions was similar regardless of the VFA measurement method used. The results revealed that the levels of acetate sharply increased immediately after feeding, trailed by an increase in the acetate:propionate ratio and a steady increase for propionate (2 h after feeding the HS diet, 4 h for LS), and butyrate. This change was more pronounced for the HS diet than the LS diet. However, there was no overall diet effect on the VFA molar proportions, although the measurement methods affected the molar proportions. Furthermore, we observed a strong positive correlation between the levels of RM and EX acetate for both diets (HS: r = 0.84; LS: r = 0.85), RM and EX propionate (r = 0.74), and RM and EX acetate:propionate ratio (r = 0.80). Both EX-VFA and RM-VFA exhibited similar responses to feeding and dietary treatments, suggesting that EX-VFA could serve as a useful proxy for characterizing RM-VFA molar proportions to evaluate rumen fermentation. Similar relationships were observed between RM-VFA and HR-VFA. In conclusion, this study underscores the potential of exhalomics as a reliable approach for assessing rumen fermentation. Moving forward, research should further explore the depth of exhalomics in ruminant studies to provide a comprehensive insight into rumen fermentation metabolites, especially across diverse dietary conditions. [ABSTRACT FROM AUTHOR]

Xylitol is an increasingly popular functional food additive, and the newly isolated yeast Wickerhamomyces anomalus WA has shown extensive substrate utilization capability, with the ability to grow on hexose (d -galactose, d -glucose, d -mannose, l -fructose, and d -sorbose) and pentose (d -xylose and l -arabinose) substrates, as well as high tolerance to xylose at concentrations of up to 300 g/L. Optimal xylitol fermentation conditions were achieved at 32 °C, 140 rpm, pH 5.0, and initial cell concentration OD 600 of 2.0, with YP (yeast extract 10 g/L, peptone 20 g/L) as the optimal nitrogen source. Xylitol yield increased from 0.61 g/g to 0.91 g/g with an increase in initial substrate concentration from 20 g/L to 180 g/L. Additionally, 20 g/L glycerol was found to be the optimal co-substrate for xylitol fermentation, resulting in an increase in xylitol yield from 0.82 g/g to 0.94 g/g at 140 rpm, enabling complete conversion of xylose to xylitol. [ABSTRACT FROM AUTHOR]

One of the key modes of microbial metabolism occurring in the gut microbiome is fermentation. This energy-yielding process transforms common macromolecules like polysaccharides and amino acids into a wide variety of chemicals, many of which are relevant to microbe-microbe and microbe-host interactions. Analogous transformations occur during the production of fermented foods, resulting in an abundance of bioactive metabolites. In foods, the products of fermentation can influence food safety and preservation, nutrient availability, and palatability and, once consumed, may impact immune and metabolic status, disease expression, and severity. Human signaling pathways perceive and respond to many of the currently known fermented food metabolites, though expansive chemical novelty remains to be defined. Here we discuss several aspects of fermented food-associated microbes and metabolites, including a condensed history, current understanding of their interactions with hosts and host-resident microbes, connections with commercial probiotics, and opportunities for future research on human health and disease and food sustainability. Caffrey et al. provide a perspective of fermented foods' effects on health by synthesizing relevant basic and clinical science using as a framework the gut microbiome and its established mechanistic connections to human health while highlighting research gaps. [ABSTRACT FROM AUTHOR]

Sotol bagasse (SB) is a byproduct generated during the fermentation of the sotol plant (Dasylirium sp.) for the production of a traditional alcoholic beverage in Mexico. In this study, a novel ethanol purification distillation sequence is proposed, utilizing ethanol produced from SB treatment as described by González-Chavez et al. (2022). Prior to purification, the ethanol-water mixtures exhibited ratios of 0.054 and 0.935. The proposed distillation sequence comprises three columns: i) depletion, ii) extraction (employing ethylene glycol as the solvent agent), and iii) solvent recovery. To assess energy consumption and controllability, three solvent:feed ratios (1.5:1, 2:1, 2.5:1) were examined, taking into account the feed to the second column. The lowest energy consumption was observed at 31 × 103 kW, corresponding to the 1.5:1 ratio. Optimal controllability was achieved at a solvent:feed ratio of 2.5:1, as evidenced by the lowest Integral Absolute Error (IAE) value of 3.3 × 10–3 and the highest proportional gain (Kc) value of 250. In summary, we leveraged previously reported experimental data to design a new distillation sequence with potential applications in the ethanol purification derived from SB fermentation. The outcomes of this investigation underscore the importance of promoting circular economy practices, particularly in the northern region of Mexico, where significant quantities of agrowastes are generated. [Display omitted] • The dynamic control properties of an ethanol-water azeotropic mixture obtained from BS were determined. • The controllability increases with the increase in solvent. • The energy expenditure decreases as the solvent decreases. [ABSTRACT FROM AUTHOR]