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The importance of renewable and environmentally acceptable materials in the construction industry is increasing. Wood is one of the most important construction materials and its use in building applications has further expanded in recent decades, mainly due to the development of modern composites, firstly glue lam, OSB (Oriented Strand Board), LVL (Laminated Veneer Lumber) and a considerable breakthrough was later achieved with the development of cross-laminated timber. In order to enable even more extensive and reliable use of wood in outdoor applications, factors affecting a wood’s service life need to be understood. It is well known that fungal degradation of wood is predominantly affected by temperature and wood moisture content. In order to elucidate the influence of these two factors, long-term monitoring of temperature, relative humidity and moisture content at the newly-built Annex of the Department of Wood Science and Technology was carried out. The Annex is designed from CLT composites and glue-lam beams and was finished in December 2015. The results clearly show that microclimatic conditions in the monitored building in the first years of use are far below the limit required for fungal decay or mould growth.

Aims The aim of this study was to investigate the effectiveness of bread as substrate for γ-aminobutyric acid (GABA) biosynthesis, establishing a valorization strategy for surplus bread, repurposing it within the food chain. Methods and Results Surplus bread was fermented by lactic acid bacteria (LAB) to produce GABA. Pediococcus pentosaceus F01, Levilactobacillus brevis MRS4, Lactiplantibacillus plantarum H64 and C48 were selected among 33 LAB strains for the ability to synthesize GABA. Four fermentation experiments were set up using surplus bread as such, added of amylolytic and proteolytic enzymes, modifying the pH or mixed with wheat bran. Enzyme-treated slurries led to the release of glucose (up to 20 mg g−1) and free amino acid, whereas the addition of wheat bran (30% of bread weight) yielded the highest GABA content (circa 800 mg kg−1 of dry weight) and was the most suitable substrate for LAB growth. The selected slurry was ultimately used as an ingredient in bread making causing an increase in free amino acids. Conclusions Besides the high GABA concentration (148 mg kg−1 dough), the experimental bread developed in this study was characterized by good nutritional properties, highlighting the efficacy of tailored bioprocessing technologies as means to mitigate food wastage. Significance and Impact of Study Our results represent a proof of concept of effective strategies to repurpose food industry side streams.

International audience; The cyanobacterium Arthrospira platensis, spirulina, is a source of pigments such as phycobiliprotein, phycocyanin. Phycocyanin is used in the food, cosmetic, and pharmaceutical industries because of its antioxidant, anti-inflammatory, and anticancer properties. The different steps involved in extraction and purification of this protein can alter the final properties. In this review, the stability of phycocyanin (pH, temperature, and light) is discussed, considering the physicochemical parameters of kinetic modeling. The optimal working pH range for phycocyanin is between 5.5 and 6.0 and it remains stable up to 45 °C; however, exposure to relatively high temperatures or acidic pH decreases its half-life and increases the degradation kinetic constant. Phycobiliproteins are sensitive to light and preservatives such as mono- and di-saccharides, citric acid, or sodium chloride appear to be effective stabilizing agents. Encapsulation within nano- or micro-structured materials such as nanofibers, microparticles, or nanoparticles, can also preserve or enhance its stability.

Graphical Abstract

In August 2016, tomato plants grown during a hot, wet summer with heavy soil flooding, displaying symptoms of wilting, dead plant, root rot with crown and stem rot, at Beni Suef and Fayoum governorates were examined. A number of 16 fungal isolates were isolated from tomato plants displaying the above symptoms. These isolates were classified as belonging to six species, namely: Alternaria solani, Chaetomium globosum, Fusarium solani, Fusarium oxysporum, Pythium spp. and Rhizoctonia solani. Isolates of Pythium spp. were prevalent and were found to be more pathogenic than the other fungal isolates. This species causes damping-off, root rot, sudden death, stem rot and fruit rot. The pathogen was identified as Pythium aphanidermatum based on morphological, cultural, and molecular characteristics. Biogenic silver nanoparticles (AgNPs) were produced using the F. oxysporum strain and characterized by transmission electron microscopy (TEM). The size of these spherical particles ranged from 10 to 30 nm. In vitro, biogenic AgNPs showed antifungal activity against P. aphanidermatum. In greenhouse and field experiments, AgNPs treatment significantly reduced the incidence of dead tomato plants due to root rot caused by P. aphanidermatum compared to the control. All of the investigated treatments were effective and the treatment of root dipping plus soil drenching was the most effective. To the best of our knowledge, this study describes P. aphanidermatum on tomato in Egypt for the first time. Also, biogenic AgNPs could be used for controlling root rot disease caused by this pathogen.

In this work, a novel mathematical model for the description of the osmotic behavior during the cryopreservation of human Mesenchymal Stem Cells (hMSCs) from Umbilical Cord Blood (UCB) is proposed. In cryopreservation, the two-parameter formalism of perfect osmometer behavior is typically adopted and preferred due to its simplicity: cell volume osmotic excursions are described as due only to the passive trans-membrane transport of water and permeant solutes such as cryoprotectant agents (CPAs); intracellular solutes, responsible of the isotonic osmolality, are assumed to be impermeant. The application of the two-parameter model fails to capture the osmotic response of hMSCs whenever a swelling phase is involved, as demonstrated by the authors. To overcome this limitation, the imperfect osmometer behavior of hMSCs is successfully modelled herein by improving the two-parameter formalism through the coupling of osmosis with cell mechanics and cell membrane Surface Area Regulation (SAR): now the transmembrane permeation of solutes (ions/salt) during the swelling phase through the temporary opening of mechanosensitive channels is allowed. This way cells can reach an equilibrium volume different from the initial isotonic one, when isotonic conditions are re-established after contact with impermeant or permeant solutes, such as sucrose or dimethyl-sulfoxide (DMSO), respectively. The sequential best-fit procedure adopted to adjust model parameters is reported herein along with model validation through full predictions.

Alternative food sources are garnering increasing interest owing to overpopulation and environmental stresses. Edible insects are a promising alternative protein source. In this study, we evaluated the effect of pH and NaCl concentration on the quality and technical properties of extracted Protaetia brevitarsis protein. Nine different solutions were used to extract edible insect protein (pH 1, 4, 7, 10, and 14 and 0, 0.1, 0.5, and 1 M NaCl). The pH of the extracted protein increased with increasing pH (1.12±0.02 to 12.81±0.03) and decreasing NaCl concentration (6.52±0.02 to 6.89±0.01). Colour difference increased when deviating from neutral pH and 0 M NaCl. Further, surface hydrophobicity (μg) and solubility (mg/ml) of the protein decreased at pH 1 (12.25±1.39 μg and 0.74±0.08 mg/ml) and 14 (20.62±1.48 μg and 0.18±0.02 mg/ml) compared with pH 7 (71.81±1.76 μg and 1.26±0.22 mg/ml). Higher pH and NaCl concentrations yielded higher thermal stability. Foaming capacity was the highest at 0.5 (110.5±0.71%) and 1 M (100.5±10.61%) NaCl, and pH 14 (122.5±3.54%), followed by that at pH 1 (72.50±3.54%), although with low stability. Furthermore, emulsifying capacity and stability of the protein increased when deviating from pH 4. Therefore, the protein of P. brevitarsis had high functionality when extracted at highly alkaline conditions using NaCl.

Кровотеча смертельно небезпечна. Проведення екстреного, ефективного гемостазу є основним завданням при наданні допомоги як у мирному житті, так і в період військових конфліктів. Тому догоспітальна гемостатична допомога повинна надаватися в найкоротший термін. Ефективний гемостатичний матеріал повинен бути доступним в екстреній ситуації, легко наноситися і надійно контролювати кровотечу з великих судин. Таким рішенням може стати вітчизняний гемостатичний бинт на нетканій основі з хітозаном Revul®, який відповідає всім вимогам, що висуваються до даних матеріалів. Гемостатика на основі хітозану при зупинці масивних кровотеч відноситься до першої медичної допомоги за класифікацією НАТО. Тому гемостатичний бинт на хімічній основі (хітозан та ін.), згідно з інструкціями з догляду за пораненими на тактичному рівні (ТССС — Tactical Combat Casualty Саrе, 2009 р.), керівництвом з інтенсивної терапії при травмі на догоспітальному етапі в районі бойових дій (BATLS — Battlefild Advanced Trauma Life Support), включений у сучасну аптечку стандарту НАТО як обов’язковий компонент.

Ergothioneine is a naturally occurring antioxidant that has shown potential in ameliorating neurodegenerative and cardiovascular diseases. In this study, we investigated the potential of the Crabtree-negative, oleaginous yeast Yarrowia lipolytica as an alternative host for ergothioneine production. We expressed the biosynthetic enzymes EGT1 from Neurospora crassa and EGT2 from Claviceps purpurea to obtain 158 mg/L of ergothioneine in small-scale cultivation, with an additional copy of each gene improving the titer to 205 mg/L. The effect of phosphate limitation on ergothioneine production was studied, and finally, a phosphate-limited fed-batch fermentation in 1 L bioreactors yielded 1.63 ± 0.04 g/L ergothioneine in 220 hours, corresponding to an overall volumetric productivity of 7.41 mg L-1 h-1 , showing that Yarrowia lipolytica is a promising host for ergothioneine production.

This study aimed to evaluate the physicochemical characteristics and mineral contents of dried extract of Averrhoa bilimbi and its antioxidant and antibacterial properties. Dried extracts leaves powder of A. bilimbi were analysed for its physicochemical properties and mineral compositions. The antioxidant and antibacterial capacities of extracts were determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the disc diffusion method respectively. The functional groups from active compounds were identified by Fourier Transforms Infrared Spectrophotometer (FTIR). Physicochemical characteristics of A. bilimbi dried extracts, including pH and total acids dissolved in water and ethanol solvents, showed negligible differences. The dried leaves powder of A. bilimbi was rich in carbohydrate, protein, and ash contents. It also exhibited essential minerals in which potassium was the highest content. Compared to water, ethanol extract showed more scavenging property against DPPH (82.82 mg GAE/ g DW) and gave a more inhibitory effect on the growth of Salmonella sp., Escherichia coli, and Staphylococcus aureus. The FTIR spectra showed phenolic compounds might be associated with the antioxidant and antibacterial activities of this extract. A. Bilimbi leaves are promising a source for the development of functional food to prevent diseases related to stress oxidative and bacterial infections.

Renewable biofuel has a great potential in replacing the conventional transportation fuels as well as aiding the current issue of climate change and global warming. In the present scenario, tremendous initiatives have been implemented to encourage large-scale biofuel production and reduce greenhouse gas emissions. However, the information on the current biofuel status specifically in Canada and where it lacks in biofuel production, tax rebate and policies in comparison with other countries is limited. In this sense, the current work focuses on the liquid biofuel status, recent advancements and evaluation of programs aimed at reducing greenhouse gas emissions in coming years. Additionally, the role of private and government programs in scaling up the projects is elaborated using several examples of successful as well as failed attempts to commercialize biofuels. Moreover, the Canadian government regulations and policies for greenhouse gas mitigation, and biofuel blending policies are also briefly described. In summary, future aspects and suggestions to further increase biofuel production are portrayed in this review.

This study was conducted to compare the correlations between free radical antioxidant activity and anti-wrinkling activity. Areca nut was extracted using various concentrations of ethanol (0, 40, 80, and 100%) and methanol (0, 40, 80, and 100%) at 100 °C for 90 min. The ethanolic and methanolic extracts of Areca nut were evaluated for total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, including total antioxidant capacity (TAC), FRAP, DPPH, ABTS, and superoxide anion radical scavenging activity (SRSA), and anti-wrinkling activity (collagenase inhibition and elastase inhibition). In addition, the antioxidant activities were correlated with collagenase inhibition. The antioxidant activities of the extracts exhibited little correlation (R=0.008-0.0760) with TPC, TFC, and TAC; however, significant correlation (R=0.825-0.891) was shown with collagenase inhibition. The 40% and 80% EtOH extracts showed the highest levels of antioxidant activities, and also had the highest phenolic and flavonoid contents. The antioxidant activities of the 80% EtOH extracts was greater than that of other extracts. These results indicate that the collagenase inhibition effects of Areca nut extracts may be due to free radical antioxidant activities, and the optimal extraction condition was 80% EtOH.

Strain engineering and bioprocessing strategies were applied for biobased production of porphobilinogen (PBG) using Escherichia coli as the cell factory. The non-native Shemin/C4 pathway was first implemented by heterologous expression of hemA from Rhodopseudomonas spheroids to supply carbon flux from the natural tricarboxylic acid (TCA) pathways for PBG biosynthesis via succinyl-CoA. Metabolic strategies were then applied for carbon flux direction from the TCA pathways to the C4 pathway. To promote PBG stability and accumulation, Clustered Regularly Interspersed Short Palindromic Repeats interference (CRISPRi) was applied to repress hemC expression and, therefore, reduce carbon flowthrough toward porphyrin biosynthesis with minimal impact to cell physiology. To further enhance PBG biosynthesis and accumulation under the hemC-repressed genetic background, we further heterologously expressed native E. coli hemB. Using these engineered E. coli strains for bioreactor cultivation based on ~ 30 g L−1 glycerol, we achieved high PBG titers up to 209 mg L−1, representing 1.73% of the theoretical PBG yield, with improved PBG stability and accumulation. Potential biochemical, genetic, and metabolic factors limiting PBG production were systematically identified for characterization. Graphical Abstract

Vine shoots (Vitis vinifera L.) constitute an abundant lignocellulosic source which is frequently underutilised. Alkaline and acidic pretreatments (with and without washing steps) were compared and optimised to release fermentable sugars from vine shoots. An acidic pretreatment using 1.72% H2SO4 at 134 °C for 17 min (with 10% w/w solid biomass), followed by an enzymatic hydrolysis, offered the most cost-effective results, releasing 40.21 g/L sugars. Three thermotolerant strains, namely, Bacillus coagulans DSM 2314, Geobacillus stearothermophilus DSM 2313, and G. stearothermophilus DSM 494, were assessed to produce lactic acid from vine-shoot hydrolysates under aerobic and non-sterile conditions, without the need of detoxification steps. In addition, wine lees were satisfactorily employed as nitrogen sources for the fermentation, providing similar results to yeast extract and being the only nutrient added to vine-shoot hydrolysates. Under optimal conditions, B. coagulans DSM 2314 produced 29.21 ± 0.23 g/L lactic acid in 24 h, with a sugar consumption of 98.74 ± 0.07% and a yield of 96.38 ± 0.76%, when supplemented with red wine lees. The purity of the isomer L( +) reached 97.59 ± 1.35% of the total lactic acid produced. Although G. stearothermophilus was able to transform the hexoses from vine-shoot hydrolysates into lactic acid, it proved to be inefficient for metabolising pentoses, thus obtaining lower lactic acid values (16–18 g/L).

Microalgae can produce industrially relevantmetabolites using atmospheric CO2 and sunlight as carbon and energy sources, respectively. Developing molecular tools for high-throughputgenome engineering could accelerate the generation oftailored strains with improved traits. To this end, we developed a genome editing strategy based on Cas12a ribonucleoprotein (RNPs) and homology-directed repair (HDR) to generate scarlessand markerless mutants of the microalga Nannochloropsis oceanica. We also developed an episomal plasmid-based Cas12a system forefficiently introducing indels at the target site. Additionally, weexploited the ability of Cas12a to process an associated CRISPRarray to perform multiplexed genome engineering. We efficientlytargeted three sites in the host genome in a singletransformation,thereby making a major step toward high-throughput genome engineering in microalgae. Furthermore, a CRISPR interference(CRISPRi) tool based on Cas9 and Cas12a was developed for effective downregulation of target genes. We observed up to 85%reduction in the transcript levels upon performing CRISPRi with dCas9 in N. oceanica. Overall, these developments substantiallyaccelerate genome engineering efforts in N. oceanica and potentially provide a general toolbox for improving othermicroalgal strains.

Introduction. The article provides a review of technologies for membrane fractionation of various hydrolyzed food substrates in membrane bioreactors (MBR). In food industry, MBRs are popular in functional food production, especially in the processing of whey, which is a very promising raw material due to its physicochemical composition. Study objects and methods. The research was based on a direct validated analysis of scientific publications and featured domestic and foreign experience in MBR hydrolysis of protein raw material. Results and discussion. The MBR hydrolysis of proteins combines various biocatalytic and membrane processes. This technology makes it possible to intensify the biocatalysis, optimize the use of the enzyme preparation, and regulate the molecular composition of hydrolysis products. The paper reviews MBRs based on batch or continuous stirring, gradient dilution, ceramic capillary, immobilized enzyme, etc. Immobilized enzymes reduce losses that occur during the production of fractionated peptides. Continuous MBRs are the most economically profitable type, as they are based on the difference in molecular weight between the enzyme and the hydrolysis products. Conclusion. Continuous stirred tank membrane reactors have obvious advantages over other whey processing reactors. They provide prompt separation of hydrolysates with the required biological activity and make it possible to reuse enzymes.

Introduction. Grape pomace is the most important by-product of winemaking that can be used as an additional raw material. There is a need for an optimal storage technology so that pomace can be further processed to obtain new types of products. We aimed to study the effect of grape pomace treatment on its microflora. Study objects and methods. We identified and quantified microflora on the fresh and one-month-stored pomace samples from white and red grape varieties. The samples were exposed to conventional drying at 60–65°C, infrared drying at 60–65°C, as well as sulfitation with sulfur dioxide and sodium metabisulfite. Results and discussion. The pomace microflora can be considered a microbial community. Almost all the samples stored for one month in an open area contained Saccharomyces cerevisiae yeasts, higher concentrations of filmy yeasts of the Candida, Pichia, Hansenula, Hanseniaspora/Kloeckera, and Torulaspora genera, as well as conidia of Mucor, Aspergillus niger, and Penicillium molds. Prevalent bacteria included acetic acid (mainly Acetobacter aceti) and lactic acid (Lactobacillus plantarum, Pediococcus, Leuconostoc) bacteria. These microorganisms significantly changed concentrations of volatile and non-volatile components, decreasing total polysaccharides, phenolic compounds, and anthocyanins 1.7–1.9, 3.7–4.0, and 4.0–4.5 times, respectively. The contents of micromycetes and bacteria in the one-month-stored samples were significantly higher than in the fresh pomace. Predrying and sulfitation decreased bacterial contamination, but to a lesser extent compared to micromycetes. Conclusion. Long-term storage spoiled pomace, leading to significant changes in its chemical composition. Sulfitation reduced microorganism growth during storage, but did not provide long-term preservation (over a month), while pre-drying at 60–65°C promoted longer storage.

While nepetalactone, the active ingredient in catnip, is a potent insect repellent, its low in planta accumulation limits its commercial viability as an alternative repellent. Here we describe a platform for de novo nepetalactone production in Saccharomyces cerevisiae, enabling sustainable and scalable production. Nepetalactone production required introduction of eight exogenous genes including the cytochrome P450 geraniol-8-hydroxylase, which represented the bottleneck of the heterologous pathway. Combinatorial assessment of geraniol-8-hydroxylase and cytochrome P450 reductase variants, as well as copy-number variations were used to overcome this bottleneck. We found that several reductases improved hydroxylation activity, with a higher geraniol-8-hydroxylase ratio further increasing 8-hydroxygeraniol titers. Another roadblock was the accumulation of an unwanted metabolite that implied inefficient channeling of carbon through the pathway. With the native yeast old yellow enzymes previously shown to use monoterpene intermediates as substrates, both homologs were deleted. These deletions increased 8-hydroxygeraniol yield, resulting in a final de novo accumulation of 3.10 mg/L/OD600 of nepetalactone from simple sugar in microtiter plates. Our pathway optimization will aid in the development of high yielding monoterpene S. cerevisiae strains.

In recent years, attention to m icrobial dehalogenase has continually increased due to its potential application, both in bioremediation and in the biosynthesis of fine chemicals. Many microbial recombinant strains carrying dehalogenase gene have been developed, particularly to increase the dehalogenase production and its quality. In this study, we aimed to find the optimum condition for the production of active haloacid dehalogenase by E. coli BL21 (DE3) harboring recombinant plasmid pET- bcfd1 that carried haloacid dehalogenase gene from Bacillus cereus IndB1 local strain. This would be examined by assessing the ability of whole cell life culture to degrade monochloroacetic acid (MCA) and quantifying the chloride ion released into the medium. Several variables were evaluated to find this optimal condition. We found that the best condition for MCA biodegradation using this recombinant clone was at 0.2 mM MCA, 10 μM of isopropyl β -D-1-thiogalactopyranoside (IPTG), 6 hours of pre-induction incubation at 37 o C with shaking, 2 hours IPTG induction at 30 o C with shaking, at pH 7 in Luria Bertani (LB) liquid medium without NaCl, which produced about 0.056 mM chloride ions. Inducer concentration, pre-induction incubation time and temperature, as well as induction time and temperature were apparent to be associated with the expression of the protein, while the MCA concentration and the pH of the medium influenced the ability of the recombinant E. coli BL21 (DE3)/pET- bcfd1 to grow in toxic environment. Our findings laid the foundation for exploration of dehalogenases from local Bacillus strains through genetic engineering for MCA biodegradation

Introduction. A disadvantage of the ancestral method (la méthode ancestrale), which is widely used in the production of sparkling wine, is that it is difficult to control fermentation. We aimed to identify the optimal yeast race for obtaining high-quality young sparkling wines with varietal aroma without yeast tones. Study objects and methods. Our study objects were base and young sparkling wines from Cabernet-Sauvignon prepared on various yeast races. Organic acids, sugars, and ethanol contents were determined by high performance liquid chromatography. Phenolic and coloring substances were measured by colorimetric method. Foaming properties were determined by air barbotage of a wine sample in a measuring cylinder; sparkling properties, by measuring the CO2 desorption rate; CO2 content, by volumetric method; viscosity, with a viscometer. Sensory evaluation was carried out according to standard methods. Results and discussion. The wines produced on the Odesskiy Chernyi-SD13 yeast race received the highest tasting scores of 7.82 and 9.05 points for base wine and young sparkling wines, respectively. They contained larger amounts of phenolic substances (1103 mg/dm3) and coloring agents (275 mg/dm3) and had higher color intensity (1.614). The panelists rated them highly on their complex varietal aroma and harmonious, velvety flavor, as well as their foaming and sparkling properties. This yeast race ensured intensive fermentation of sugars and a great amount of bound CO2 (up to 24.93%). Conclusion. The Odesskiy Chernyi-SD13 yeast race is optimal for making base and young sparkling wines by the bottle method. This technology can be used to produce high-quality sparkling wines in the crop year by large and small enterprises.

Introduction. The present research featured the effect of carbonyls, phenols, furans, fatty alcohols, ethers, and other chemical compounds on the sensory properties of cognac distillates of different ages. The research objective was to identify additional criteria of sensory evaluation by measuring the effect of various compounds on perception intensity. Study objects and methods. The study featured cognac samples of different ages. The experiment involved standard methods, including high-performance liquid and gas chromatography and a mathematical analysis based on Microsoft software. Results and discussion. The content of fatty alcohols, ethers, and carbonyl compounds that formed as a result of fermentation demonstrated little change during the aging period in oak casks. A longer extraction increased the content of phenolic and furan compounds and sugars. The content of terpene compounds decreased due to their high lability. The study revealed the effect of organic compounds on taste descriptors. The article introduces multivariate equations that calculate the dependences of the descriptor intensity on the content of organic compounds. A correlation and regression analysis revealed that phenolic compounds had a significant effect on the taste formation of cognac samples, depending on the aging time. Conclusion. Organic compounds proved to affect the taste profiles of cognac samples of different ages, as well as sensory evaluation descriptors.

A sound or a noise that accompanies wood machining processes is introduced by the tool rotation itself, by the friction of moving machine parts, or by wood-tool interaction. The sounds generated during machining with a circular saw could be analysed in order to monitor and possibly control the cutting process. Applying altered cutting parameters while cutting beech wood (Fagus sylvatica L.), which is the most common wood species in the Republic of Serbia, caused acoustic emissions that could be analysed throughout corresponding spectra. As shown in previous studies, altering the cutting parameters, e.g., the feed speed and tool override, resulted in variations in power consumption, surface roughness, and acoustic emission (or acoustic pressure). The aim of this paper was to provide a possible correlation between the applied cutting parameters and the acoustic emission spectra with respect to consumed power and the state of the machined surface. Along with acoustic emissions, the power consumption and surface roughness data were also acquired in order to make a possible relationship. By associating the idle circular saw acoustic spectra with background noise and comparing them with those obtained during machining, it was possible to indicate spectrum areas of particular interest for further analysis.

Made available in DSpace on 2022-04-28T19:46:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Academy of Finland We investigated whether highly available organic residues in Brazil can be used as substrates for the production of the oyster mushroom Pleurotus ostreatus, instead of the conventional cultivation using the eucalyptus sawdust substrate. We assessed the mushroom yield on 13 substrates, of which 12 were formulated with different concentrations of organic residues and one with pure eucalyptus sawdust, and verified whether the raw material used in the substrate formula and the concentration of such alternative residues influenced their biological efficiencies. Substrates containing eucalyptus bark resulted in higher mushroom yield than those containing eucalyptus sawdust, which generally resulted in similar mushroom yield to the remaining formulas. Moreover, the raw material and the concentration of each residue affected the biological efficiency of the substrates. We show that the conventional substrate for P. ostreatus can be replaced by substrates easily accessible to producers without loss in productivity. Furthermore, that the concentration of these mixtures affects the mushroom productivity and should be considered when formulating the growth medium. Graduate Program in Agriculture – Energy in Agriculture School of Agricultural Sciences São Paulo State University (UNESP) Department of Microbiology University of Helsinki Graduate Program in Biological Sciences (Botany) Institute of Biosciences São Paulo State University (UNESP) Department of Biodiversity Laboratory of Phenology Institute of Biosciences São Paulo State University (UNESP) Graduate Program in Agriculture – Energy in Agriculture School of Agricultural Sciences São Paulo State University (UNESP) Graduate Program in Biological Sciences (Botany) Institute of Biosciences São Paulo State University (UNESP) Department of Biodiversity Laboratory of Phenology Institute of Biosciences São Paulo State University (UNESP) CAPES: 001 Academy of Finland: 308284

The replacement of conventional protein supply has been studied in the context of continuous population growth and the consequent environmental problems. Among protein substitutes, edible insects have gained relevance due to their high breeding efficiency. This study was conducted to estimate the effect of the partial replacement of porcine myofibril protein (pork protein; PP) with protein extracted from Protaetia brevitarsis (insect protein; IP) in protein-containing solutions and gels. The protein concentration was regulated at 30 and 1 mg/ml for gels and solutions, respectively, and the replacement percentages were increased by 20%. Gels containing IP showed a lower viscosity and thermal stability; the texture and surface of the gels were negatively impacted as the replacement percentage increased. Therefore, heating is not an appropriate method to induce the gelation of IP containing solutions. However, the replacement of PP with IP increased the foam capacity and emulsion capacity in solutions. In conclusion, we show that the partial replacement of PP with IP positively impacts on protein solutions but impairs their gelation.

Identifying the factors and mechanisms that regulate metabolism under normal and diseased states requires methods to quantify metabolic fluxes of live tissues within their physiological milieu. A number of recent developments have expanded the reach and depth of isotope-based in vivo flux analysis, which have in turn challenged existing dogmas in metabolism research. First, minimally invasive techniques of intravenous isotope infusion and sampling have advanced in vivo metabolic tracer studies in animal models and human subjects. Second, recent breakthroughs in analytical instrumentation have expanded the scope of isotope labeling measurements and reduced sample volume requirements. Third, innovative modeling approaches and publicly available software tools have facilitated rigorous analysis of sophisticated experimental designs involving multiple tracers and expansive metabolomics datasets. These developments have enabled comprehensive in vivo quantification of metabolic fluxes in specific tissues and have set the stage for integrated multi-tissue flux assays.

The importance of bioimaging and biosensing has been clear with the onset of the COVID-19 pandemic. In addition to viral detection, detection of tumors, glucose levels, and microbes is necessary for improved disease treatment and prevention. Bionanoparticles, such as extracellular vesicles and protein nanoparticles, are ideal platforms for biosensing and bioimaging applications because of their propensity for high density surface functionalization and large loading capacity. Scaffolding large numbers of sensing modules and detection modules onto bionanoparticles allows for enhanced analyte affinity and specificity as well as signal amplification for highly sensitive detection even at low analyte concentrations. Here we demonstrate the potential of bionanoparticles for bioimaging and biosensing by highlighting recent examples in literature that utilize protein nanoparticles and extracellular vesicles to generate highly sensitive detection devices with impressive signal amplification.

Fish skin is a raw material used for gelatin production. It can satisfy consumers with specific socio-cultural and religious needs. Different technologies have been studied for drying gelatin. Therefore, it is relevant to understand the influence of drying conditions on the final product. This study aims to optimize drying methods such as convection hot air alone and combined with infrared radiation to obtain gelatin from acoupa weakfish skin by using composite central rotational designs 22 and 23 and response surface methodology. The gelatin obtained from the optimized conditions were characterized based on their physical, chemical, technological, and functional properties. The desirability function results show the convection hot air as the most effective method when conducted at 59.14 \textdegreeC for 12.35 h. Infrared radiation at 70 \textdegreeC for 2.0 h and convective drying at 70 \textdegreeC for 3.5 h were the best condition of the combined process. The gelatins obtained had gel strength of 298.00 and 507.33 g and emulsion activity index of 82.46 and 62.77 m2/g in the combined and convective methods, respectively, and protein content above 90\\%. These results indicate that the processes studied can be used to produce gelatin with suitable technological and functional properties for several applications., The authors are thankful for the Coordination for the Improvement of Higher Education Personnel (CAPES), the Provost’s Office of Research and Graduate Studies (PROPESP) of UFPA and at National Council for Scientific and Technological Development (CNPq), case 469101/2014-8. Enrique Pino-Hernández acknowledges the European Social Fund (call NORTE-69-2015-15) by the financial support provided through fellowship NORTE-08-5369-FSE-000036., info:eu-repo/semantics/publishedVersion

Metabolic modeling strives to develop modeling approaches that are robust and highly predictive. To achieve this, various modeling designs, including hybrid models, and parameter estimation methods that define the type and number of parameters used in the model, are adapted. Accurate input data play an important role so that the selection of experimental methods that provide input data of the required precision with low measurement errors is crucial. For the biopharmaceutically relevant protein glycosylation, the most prominent available models are kinetic models which are able to capture the dynamic nature of protein N-glycosylation. In this review we focus on how to choose the most suitable model for a specific research question, as well as on parameters and considerations to take into account before planning relevant experiments., 15 pages, 2 figures, 63 references

International audience; Background: Seafood processing activity causes production of considerable amount of waste/by-products and discards, resulting in negative economic and environmental impacts. Management of sustainable utilisation of seafood resources is essential to avoid environmental problems and provide resource sustainability. Scope and approach: Fishery discards and seafood by-products are rich in bioactive compounds, including omega3 long-chain polyunsaturated fatty acids, amino acids, peptides, enzymes, gelatine, collagen, chitin, vitamins, polyphenolic constituents, carotenoids etc. Fish discards are also regarded as a good and cheap material for biodiesel production. These high value added compounds have potential applications in many industrial sectors including food, nutraceuticals, pharmacology, medical, agriculture, depending on their functional and structural characteristics. This review will provide a comprehensive information on recent approaches for valorisation of bioactive compounds derived from discards and seafood by products. Key findings and conclusions: Many studies on the bioactive compounds derived from fishery discards and processing by-products were carried out in terms of nutritional and functional properties. Further studies on bioavailability of nutrients, yield, physicochemical properties, interaction with other ingredients, together with innovative approaches for extraction methods and legislation and safety issues should be considered

Due to their versatility and the high biomass yield produced, cultivation of phototrophic organisms is an increasingly important field. In general, open ponds are chosen to do it because of economic reasons; however, this strategy has several drawbacks such as poor control of culture conditions and a considerable risk of contamination. On the other hand, photobioreactors are an attractive choice to perform cultivation of phototrophic organisms, many times in a large scale and an efficient way. Furthermore, photobioreactors are being increasingly used in bioprocesses to obtain valuable chemical products. In this review, we briefly describe different photobioreactor set-ups, including some of the recent designs, and their characteristics. Additionally, we discuss the current challenges and advantages that each different type of photobioreactor presents, their applicability in biocatalysis and some modern modeling tools that can be applied to further enhance a certain process.

Polyunsaturated fatty acids (PUFAs), primarily docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have received worldwide attention in recent years due to an increasing awareness of their uniqueness in improving diet and human health and their apparently inevitable shortage in global availability. Microbial cell factories are a major solution to supplying these precious molecules in sufficient amounts and providing PUFA-rich aquafeed, superfoods, and medical formulations. This review assesses the PUFA world markets and highlights recent advances in upgrading and streamlining microalgae, yeasts, fungi, and bacteria for high-level PUFA production and broadening of the PUFA spectrum.

Technological advances and changes in consumer preferences for safer food with better shelf life have led to packaging innovations like smart packaging. Smart packaging systems involve the blend of active and intelligent packaging properties. Most of the smart packaging systems in food sector are mainly focused on fish, sea, food, meat, poultry, fruits and vegetables. With cheese being the major dairy product and its market expanding exponentially, smart packaging systems for cheese are exhaustively addressed in this book chapter. Some of the smart packaging systems pertaining to cheese like antioxidant releasers, antimicrobial packaging, ripening indicator and self-cleaning rinds can hasten commercial acceptance and reliability of cheese products. This book chapter also tabulates the recent data related to production, and consumption of cheese, permitted additives, types of active and intelligent packaging systems explored for cheese and commercial suppliers of smart packaging systems. Along with, future research directions for smart packaging of cheese are also presented.

Lignin is an abundant natural feedstock that offers great potential as a renewable substitute for fossil‐based resources. Its polyaromatic structure and unique properties have attracted significant research efforts. The advantages of an enzymatic over chemical or thermal approach to construct or deconstruct lignins are that it operates in mild conditions, requires less energy, and usually uses non‐toxic chemicals. Laccase is a widely investigated oxidative enzyme that can catalyze the polymerization and depolymerization of lignin. Its dual nature causes a challenge in controlling the overall direction of lignin‐laccase catalysis. In this Review, the factors that affect laccase‐catalyzed lignin polymerization were summarized, evaluated, and compared to identify key features that favor lignin polymerization. In addition, a critical assessment of the conditions that enable production of novel lignin hybrids via laccase‐catalyzed grafting was presented. To assess the industrial relevance of laccase‐assisted lignin valorization, patented applications were surveyed and industrial challenges and opportunities were analyzed. Finally, our perspective in realizing the full potential of laccase in building lignin‐based materials for advanced applications was deduced from analysis of the limitations governing laccase‐assisted lignin polymerization and grafting., Laccases as builders: Similar to their role in the formation of lignin in nature, laccases are capable of building advanced lignin‐based materials, given the optimum laboratory conditions. This Review evaluates the factors that affect laccase‐catalyzed lignin polymerization and grafting reactions. Patented applications of lignin‐based materials produced via laccase catalysis are highlighted and potential routes towards unlocking the full capacity of laccase in lignin valorization are proposed.

Background: Epithelial-Mesenchymal Transition (EMT) is a molecular reprogramming that leads to an increased ability to migrate, which can promote invasion and metastasis. EMT can be initiated in response to the activity of signaling pathways such as Wnt as well as miRNAs. Objective: The aim of the study was to determine the expression profile of EMT-related genes involved in signal transduction via the Wnt pathway and cadherins and to assess which miRNAs can participate in the regulation of their expression. Methods: The study material consisted of 50 endometrial samples: 40 with diagnosed endometrial cancer and 10 without neoplastic changes. The expression profile of EMT-related genes was assessed with microarrays and validated by RT-qPCR. MicroRNA expression profiling was performed using microarrays. It was also determined which miRNAs may participate in the expression regulation of EMT-related genes. Results: CDH1 overexpression was observed in all three endometrial cancer grades using both mRNA microarrays and RT-qPCR. The microarray experiment showed a decrease in CDH2 level regardless of the endometrial cancer grade, however, it was only partially validated with RT-qPCR. Low levels of WNT2, WNT4, WNT5A have also been observed. Decreased expression of WNT2 and WNT5A may be caused by miR-331-3p and miR-200b-5p, respectively. Conclusions: The Wnt signaling is disrupted in endometrial cancer, which may be due to miR-331-3p and miR-200b-5p activity. In addition, a change in WNT5A level in endometrial cancer compared to control may indicate that it acts as a suppressor gene and that its low expression is associated with tumor progression.

Six different bread wheat genotypes; two Egyptian commercial varieties (control); Giza-168 and Gemmeiza-11, and four promising lines; L84 and L148, resulted via hybridization and M10 and M34 via radiation mutation program) were rheologically evaluated using extensograph and for protein, analysis using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The radiation mutant M10 and M34 had the highest maximum resistance which is a very good indicator of strong gluten. The amount of gluten content was higher in M10, L148, and M34 compared to the control samples Gz168 and Gm11. Sulfide amino acids (CYS and MET) are slightly higher in M10. The electrophoretic results and amino acid analyzers show that the best technological quality was exhibited by M10. Radiation mutants wheat genotypes have a protein with good characteristics, mainly gluten which is significantly higher compared to control samples. The rheological properties measured as extensograph and gel electrophoresis were much better in irradiated lines M10 and M34. Resumo Seis diferentes genótipos de trigo de pão, duas variedades comerciais egípcias (controle) – Giza-168 e Gemmeiza-11 – e quatro linhas promissoras – L84 e L148, obtidas via hibridação, e M10 e M34, via programa de mutação por radiação – foram avaliados reologicamente por meio de extensógrafo, enquanto, para proteínas, foram feitas análises utilizando eletroforese em gel de poliacrilamida com dodecilsulfato de sódio (SDS-PAGE). Os mutantes de radiação M10 e M34 apresentaram a maior resistência máxima, o que é um indicador muito bom de glúten forte. A quantidade de glúten foi maior em M10, L148 e M34 em comparação com as amostras de controle Gz168 e Gm11. Os aminoácidos sulfurados (CYS e MET) são um pouco mais altos no M10. Os resultados eletroforéticos e analisadores de aminoácidos mostram que a melhor qualidade tecnológica foi exibida pelo M10. Os genótipos de trigo mutantes da radiação possuem uma proteína com boas características, principalmente o glúten, que é significativamente maior em comparação às amostras do grupo controle. As propriedades reológicas medidas, como extensógrafo e eletroforese em gel, foram muito melhores nas linhas irradiadas M10 e M34.

Nanobodies are the smallest antibody fragments which bind to antigens with high affinity and specificity. Due to their outstanding physicochemical stability, simplicity and cost-effective production, nanobodies have become powerful agents in therapeutic and diagnostic applications. In this work, the advantages of nanobodies were exploited to develop generic and standardized anti-human IgM reagents for serology and IgM+ B-cell analysis. Selection of anti-IgM nanobodies was carried out by evaluating their yields, stability, binding kinetics and cross-reactivity with other Ig isotypes. High affinity nanobodies were selected with dissociation constants (KDs) in the nM range and high sensitivities for detection of total IgM by ELISA. The nanobodies also proved to be useful for capturing IgM in the serodiagnosis of an acute infection as demonstrated by detection of specific IgM in sera of dengue virus patients. Finally, due to the lack of an Fc region, the selected nanobodies do not require Fc receptor blocking steps, facilitating the immunophenotyping of IgM+ cells by flow cytometry, an important means of diagnosis of immunodeficiencies and B-cell lymphoproliferative disorders. This work describes versatile anti-IgM nanobodies that, due to their recombinant nature and ease of reproduction at low cost, may represent an advantageous alternative to conventional anti-IgM antibodies in research and diagnosis.

Background: A previous genome-wide association study (GWAS) identified the kinesin family member 16B (KIF16B) as a candidate gene related to sheep wool production. In this work, DNA pool sequencing and SNPscanTM high-throughput genotyping methods were used to detect single-nucleotide polymorphisms (SNPs) in the sheep KIF16B gene. The correlations between the SNPs and wool length and greasy wool yield were systematically assessed. Results: Forty-five SNPs were identified and 37 of them were genotyped, including 10 exon mutations, 26 intron mutations, and 1 promoter region mutation. Most of the SNPs were of medium genetic diversity and at Hardy-Weinberg equilibrium (HWE). Among them, 10 SNPs were associated with greasy wool yield and 28 SNPs impact the wool length. Five specific SNPs were found to exert significant effects on the wool length in all body parts analyzed in this study. Furthermore, linkage disequilibrium (LD) analysis was conducted among SNP loci and they were found to be significantly associated with economically important traits. Two strongly linked SNP blocks were identified within these SNPs and they might exert significant impacts on the greasy wool yield and wool length. Conclusions: The identified SNPs exert significant effects on wool production and could be considered as potential DNA markers for selecting the individuals with superior phenotypes. How to cite: Zhao H, Hu R, Li F, et al. Two strongly linked blocks within the KIF16B gene significantly influence wool length and greasy yield in fine wool sheep (Ovis aries). Electron J Biotechnol 2021:52. https://doi.org/10.1016/j.ejbt.2021.05.003

Many commonly used bacterial promoters employed for recombinant protein production (RPP) in Escherichia coli are capable of high-level protein expression. However, such promoter systems are often too strong, being ill suited for expressing proteins that are difficult to fold, targeted to the membrane or secreted out of the cytoplasm. To circumvent this problem, a suite of bacterial promoters has been constructed with a range of different promoter strengths, assigning them specific "promoter activity ratings" (PARs). Selecting three of these PAR promoters, with low, intermediate and high strengths, it is demonstrated that the expression of target proteins, such as green fluorescent protein (GFP), human growth hormone (hGH) and single chain variable region antibody fragments (scFvs), can be set to three levels when expressed in E. coli. It is shown that the PAR promoter system is extremely flexible, operating in a variety of E. coli strains and under various different culture regimes. Furthermore, due to its tight regulation, it is shown that this system can also express a toxic outer membrane protein, at levels which do not affect bacterial growth. Thus, the PAR promoter system can be used to tailor the expression levels of target proteins in E. coli and maximize RPP.

This study aimed to evaluate the effects of by-product molasses and waste orange peels (WOP) as the nutrient medium on lipase production with Rhizopus arrhizus NRRL 2286 and investigate the inductive effect of waste cooking oil (WCO) on activity. The results showed that the highest specific growth rate and the maximum biomass concentration were obtained 0.424 h−1 and 3.83 g dry weight/L for 70 g/L WOP, respectively. Additionally, the highest intracellular and extracellular lipase activities were attained in 50 g/L WOP as 400 U/g and 13.2 U/mL, correspondingly. Next, the inductive effects of WCO and olive oil were tested in lipase production. Intracellular lipase activity enhanced and reached a maximum of 520 U/g in the presence of 10 g/L WCO with an increase of 30% compared to the one without WCO. However, both inducers caused a diminish in extracellular lipase hydrolysis activity. Overall, this study reveals that the lipase production of R. arrhizus can be accomplished using WOP and WCO with the optimum conditions.

Two strains, Afipia sp. 624S and Diaphorobacter sp. 624L, were isolated from an enrichment culture with 4-aminobenzenesulfonate (4-ABS) as the only carbon source. Strain 624S utilized 4-ABS as the only source of carbon and energy and degraded 3.8 mM 4-ABS in 2 weeks, releasing a small amount of sulfate ions. On the other hand, strain 624L did not utilize 4-ABS. Additionally, a co-culture of strains 624S and 624L resulted in the enhanced degradation of 4-ABS, and no sulfite was accumulated in the degradation of 4-ABS. When incubated in 50 mM Tris-HCl buffer (pH 8.0) containing 2.2 mM sodium sulfite, strain 624S exhibited no sulfite oxidation; however, strain 624L completely oxidized the sulfite after 2 days. Furthermore, when manganase, which has the ability to oxidize sulfite, was added to the medium, the degradation rate of 4-ABS was increased in comparison with the non-addition control. These results indicate that the sulfite oxidation might stimulate the degradation of 4-ABS by strain 624S, suggesting syntrophic interaction between strains 624S and 624L based on sulfite oxidation.

Syngas, which contains large amount of CO2 as well as H2 and CO, can be convert to acetic acid chemically or biologically. Nowadays, acetic acid become a cost-effective nonfood-based carbon source for value-added biochemical production. In this study, acetic acid and CO2 were used as substrates for the biosynthesis of 3-hydroxypropionic acid (3-HP) in metabolically engineered Escherichia coli carrying heterogeneous acetyl-CoA carboxylase (Acc) from Corynebacterium glutamicum and codon-optimized malonyl-CoA reductase (MCR) from Chloroflexus aurantiacus. Strategies of metabolic engineering included promoting glyoxylate shunt pathway, inhibiting fatty acid synthesis, dynamic regulating of TCA cycle, and enhancing the assimilation of acetic acid. The engineered strain LNY07(M*DA) accumulated 15.8 g/L of 3-HP with the yield of 0.71 g/g in 48 h by whole-cell biocatalysis. Then, syngas-derived acetic acid was used as substrate instead of pure acetic acid. The concentration of 3-HP reached 11.2 g/L with the yield of 0.55 g/g in LNY07(M*DA). The results could potentially contribute to the future development of an industrial bioprocess of 3-HP production from syngas-derived acetic acid.

There is increasing interest in new protein sources for the food and feed industry and for the agricultural sector, and microalgae are considered a good alternative, having a high protein content and a well-balanced amino acid profile. However, protein production from microalgae presents several unsolved issues, as the biomass composition changes markedly as a function of cultivation operating conditions. Continuous systems, however, may be properly set to boost the accumulation of protein in the biomass, ensuring stable production. Here, two microalgae and two cyanobacterial species were cultivated in continuous operating photobioreactors (PBR) under nonlimiting nutrient conditions, to study the effects of light intensity and residence time on both biomass and protein productivity at steady state. Although light strongly affected biomass growth inside the PBR, the overall protein pool did not vary in response to irradiance. On the other hand, shorter residence times resulted in protein accumulation of up to 68 % in cyanobacteria, in contrast with green algae, where a minor influence of residence time on biomass composition was observed. Energy balance showed that light conversion to protein decreased with light intensity. Protein content was also related to energy costs for cell maintenance. In conclusion, it is shown that residence time is the key variable to increase protein content and yield of protein production, but its effect depends on the specific species.

Stoichiometric genome-scale metabolic network models (GEMs) have been widely used to predict metabolic phenotypes. In addition to stoichiometric ratios, other constraints such as enzyme availability and thermodynamic feasibility can also limit the phenotype solution space. Extended GEM models considering either enzymatic or thermodynamic constraints have been shown to improve prediction accuracy. In this paper, we propose a novel method that integrates both enzymatic and thermodynamic constraints in a single Pyomo modeling framework (ETGEMs). We applied this method to construct the EcoETM (E. coli metabolic model with enzymatic and thermodynamic constraints). Using this model, we calculated the optimal pathways for cellular growth and the production of 22 metabolites. When comparing the results with those of iML1515 and models with one of the two constraints, we observed that many thermodynamically unfavorable and/or high enzyme cost pathways were excluded from EcoETM. For example, the synthesis pathway of carbamoyl-phosphate (Cbp) from iML1515 is both thermodynamically unfavorable and enzymatically costly. After introducing the new constraints, the production pathways and yields of several Cbp-derived products (e.g. L-arginine, orotate) calculated using EcoETM were more realistic. The results of this study demonstrate the great application potential of metabolic models with multiple constraints for pathway analysis and phenotype prediction.

Ethyl carbamate (EC), widely found in alcoholic beverages, has been revealed to be a probable carcinogen in humans. Urethanase (EC 3.5.1.75) is an effective enzyme for the degradation of EC; however, the previously identified urethanases exhibited insufficient acid and alcohol resistance. In this study, an enantioselective amidase (AmdA) screened from Agrobacterium tumefaciens d3 exhibited urethanase activity with excellent alcohol resistance. AmdA was first overexpressed in Escherichia coli; however, the recombinant protein was primarily located in inclusion bodies, and thus, co-expression of molecular chaperones was used. The activity of AmdA increased 3.1 fold to 307 U/L, and the specific activity of urethanase with C-terminal His-tags reached 0.62 U/mg after purification through a Ni–NTA column. Subsequently, the enzymatic properties and kinetic constants of AmdA were investigated. The optimum temperature for AmdA was 55 °C, it showed the highest activity at pH 7.5, and the Km was 0.964 mM. Moreover, after 1 h of heat treatment at 37 °C in a 5–20% (v/v) ethanol solution, the residual urethanase activity was higher than 91%, considerably more than that reported thus far.

Quinolinic acid (QA) is a key intermediate of nicotinic acid (Niacin) which is an essential human nutrient and widely used in food and pharmaceutical industries. In this study, a quinolinic acid producer was constructed by employing comprehensive engineering strategies. Firstly, the quinolinic acid production was improved by deactivation of NadC (to block the consumption pathway), NadR (to eliminate the repression of L-aspartate oxidase and quinolinate synthase), and PtsG (to slow the glucose utilization rate and achieve a more balanced metabolism, and also to increase the availability of the precursor phosphoenolpyruvate). Further modifications to enhance quinolinic acid production were investigated by increasing the oxaloacetate pool through overproduction of phosphoenolpyruvate carboxylase and deactivation of acetate-producing pathway enzymes. Moreover, quinolinic acid production was accelerated by assembling NadB and NadA as an enzyme complex with the help of peptide-peptide interaction peptides RIAD and RIDD, which resulted in up to 3.7 g/L quinolinic acid being produced from 40 g/L glucose in shake-flask cultures. A quinolinic acid producer was constructed in this study, and these results lay a foundation for further engineering of microbial cell factories to efficiently produce quinolinic acid and subsequently convert this product to nicotinic acid for industrial applications.

Background: Biosurfactants are surface active molecules produced by microorganisms which have the ability to disrupt the plasma membrane. Biosurfactant properties are important in the food, pharmaceutical and oil industries. Lactic acid bacteria can produce cell-bound and excreted biosurfactants. Results: The biosurfactant-producing ability of three Lactobacillus strains was analyzed, and the effects of carbon and nitrogen sources and aeration conditions were studied. The three species of lactobacillus evaluated were able to produce biosurfactants in anaerobic conditions, which was measured as the capacity of one extract to reduce the surface tension compared to a control. The decreasing order of biosurfactant production was L. plantarum>Lactobacillus sp.>L. acidophilus. Lactose was a better carbon source than glucose, achieving a 23.8% reduction in surface tension versus 12.9% for glucose. Two complex nitrogen sources are required for growth and biosurfactant production. The maximum production was reached at 48 h under stationary conditions. However, the highest level of production occurred in the exponential phase. Biosurfactant exhibits a critical micelle concentration of 0.359 ± 0.001 g/L and a low toxicity against E. coli. Fourier transform infrared spectroscopy indicated a glycoprotein structure. Additionally, the kinetics of fermentation were modeled using a logistic model for the biomass and the product, achieving a good fit (R2 > 0.9). Conclusions: L. plantarum derived biosurfactant production was enhanced using adequate carbon and nitrogen sources, the biosurfactant is complex in structure and because of its low toxicity could be applied to enhance cell permeability in E. coli.How to cite: Montoya Vallejo C, Florez Restrepo MA, Guzmán Duque FL, et al. Production, characterization and kinetic model of biosurfactant produced by lactic acid bacteria. Electron J Biotechnol 2021;52. https://doi.org/10.1016/j.ejbt.2021.06.001

The etiological agent of melioidosis, Burkholderia pseudomallei, utilises a type III secretion system cluster 3 (T3SS3) to deliver proteins termed type III effectors (T3SEs) into the host cytoplasm in order to establish an intracellular lifecycle in phagocytic and non-phagocytic cells, thus playing an important role in pathogenesis. To gain insight into possible functional roles for BapA, a putative T3SE with unknown function, in the intracellular lifecycle of B.pseudomallei, bapA gene knockout mutant was constructed. The effect of the knockout on virulence to the otherwise isogenic parental strain, K96243, was studied by cellular infection assays and Caenorhabditis elegans killing assay. The attachment and subsequent entry into A549 cells was significantly (P < 0.05) attenuated in the Delta bapA compared to K96243. However, intracellular replication was not affected. Furthermore, the cell-to-cell spreading capacity of Delta bapA was impaired although the mutant exhibited no evident defect in its actin tail formation. Additionally, phagocytosis and intracellular replication rates of Delta bapA in U937 macrophage cells were significantly reduced relative to K96243 without phagosomal escape being affected. Based on these observations, we conclude that the BapA T3SE could play an important role in B.pseudomallei intracellular lifecycle, especially, in the early stages of attachment and entry into the host cell.

Indigo is a fabric dye that requires reduction by microbial activity or chemical reagents to render it soluble in water. Sources of indigo for fermentation are primarily divided into composted indigo-containing plants and indigo extracted from plants. To elucidate the factors responsible for bacterial diversity, and for sustaining reduced state of indigo in different preparations, this study assessed fermentation-derived fluids using composted plant leaves, sukumo, and extracted indigo (Ryukyu-ai paste, and Indian indigo cake) prepared using different procedures. Regardless of the indigo source, obligate anaerobic bacteria, including the families Proteinivoraceae and Tissierellaceae, predominate (16.9-46.1%), suggesting their high affinity for this fermentation ecosystem (hyperalkaline and low redox potential). Moreover, bacterial communities in sukumo fermentations are more diverse than those from indigo extracts with the diversity tending to increase based on the fermentation period. Our results further suggest that the microbiota composition in sukumo fermentation is associated with the various bacterial nutrients derived from sukumo, including seed microorganisms. In addition, the debris derived from sukumo can reduce the pH stress experienced by the microorganisms. Further, regardless of 5.4 years difference in the fermentation age, the bacterial flora in two Ryukyu-ai batches exhibit similar features with low microbial diversities. The uniformity of the nutrient, along with the simple, yet strong, bacterial network in Ryukyu-ai fluids may be responsible for the stable bacterial flora composition. Taken together, these results indicate that the microbiota in indigo fermentation is highly influenced by the seed culture, the nutrient derived from raw materials, and the fermentation conditions.

Background: Arsenic contamination in the ground water of rural India is a recurrent problem and decontamination is mostly based on the chemical or physical treatments until now. Microbial bioremediation is eco-friendly, cheap, time-efficient and does not produce any toxic by-products. Result: In the present study, a high arsenic tolerant bacteria Brevundimonas aurantiaca PFAB1 was isolated from Panifala hot spring located in West Bengal, India. Previously Panifala was also reported to be an arsenic-rich hot spring. B. aurantiaca PFAB1 exhibited both positive arsenic reductase and arsenite oxidase activity. It was tolerant to arsenite up to 90 mM and arsenate up to 310 mM. Electron microscopy has proved significant changes in cellular micromorphology and stalk appearance under the presence of arsenic in growth medium. Bioaccumulation of arsenic in As (III) treated cells were 0.01% of the total cell weight, while 0.43% in case of As (V) treatment. Conclusions: All experimental lines of evidence prove the uptake/accumulation of arsenic within the bacterial cell. All these features will help in the exploitation of B. aurantiaca PFAB1 as a potent biological weapon to fight arsenic toxicity in the near future.How to cite: Banerjee A, Sarkar S, Gorai S, et al. High arsenic tolerance in Brevundimonas aurantiaca PFAB1 from an arsenic-rich Indian hot spring. Electron J Biotechnol 2021:52. https://doi.org/10.1016/j.ejbt.2021.05.006