Search

[Display omitted] • Marine filamentous cyanobacterium Leptolyngbya valderiana was investigated. • Nitrate stress enhanced carbohydrate content by ∼47 % of dry cell weight. • Strategizing two-stage cultivation raised carbohydrate yield by ∼80 %. • The rise in fermentable sugars accumulation resulted ≥80 % higher bioethanol yield. • Standardized physiochemical condition augmented C-phycocyanin production ∼77 %. The investigation aimed to augment carbohydrate accumulation in the marine cyanobacterium Leptolyngbya valderiana BDU 41001 to facilitate bioethanol production. Under the standardised physiochemical condition (SPC), i.e. 90 µmol photon m−2 s−1 light intensity, initial culture pH 8.5, 35 °C temperature and mixing at 150 rpm increased the carbohydrate productivity ∼70 % than the control, while a 47 % rise in content was obtained under the nitrate (N)-starved condition. Therefore, a two-stage cultivation strategy was implemented, combining SPC at the 1st stage and N starvation at the 2nd stage, resulting in 80 % augmentation of carbohydrate yield, which enhanced the bioethanol yield by ∼86 % as compared to the control employing immobilised yeast fermentation. Moreover, biomass utilisation was maximised by extracting C-phycocyanin, where a ∼77 % rise in productivity was recorded under the SPC. This study highlights the potential of L. valderiana for pilot-scale biorefinery applications, advancing the understanding of sustainable biofuel production. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study firstly reported the role of DpME and nitrogen limitation in D. parva. • DpME overexpression and N stress caused increase of 27.41% in lipid content. • DpME overexpression and N stress caused increase of 26.43% in carotenoid content. • This study enhanced the application value of D. parva (an oil-producing microalga). Overexpression of Dunaliella parva (D. parva) malic enzyme (ME) gene (DpME) significantly increased DpME expression and ME enzyme activity in transgenic D. parva. Nitrogen limitation had an inhibitory effect on protein content, and DpME overexpression could improve protein content. Nitrogen limitation increased carbohydrate content, and Dunaliella parva overexpressing malic enzyme gene under nitrogen limitation (DpME-N−) group showed the lowest starch content among all groups. Dunaliella parva overexpressing malic enzyme gene under nitrogen sufficient condition (DpME) and DpME-N− groups showed considerably high mRNA levels of DpME. ME activity was significantly enhanced by DpME overexpression, and nitrogen limitation caused a smaller increase. DpME overexpression and nitrogen limitation obviously enhanced lipid accumulation, and DpME overexpression had more obvious effect. Compared with control (wild type), lipid content (68.97%) obviously increased in DpME-N− group. This study indicated that the combination of DpME overexpression and nitrogen limitation was favorable to the production of microalgae biodiesel. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dilute acid pretreatment of corn bran with low temperature (90 °C for 60 min). • High sugar yields (95% for starch, 77% for both cellulose and xylan). • Highly efficient fermentation (100 % glucose and 91 % xylose conversion within 24 h). • The process was scaled up to 150-L. Fractionated corn bran was processed to maximize ethanol production from starch, cellulose, and xylan. After various bench-scale experiments, an optimized process with dilute acid pretreatment (1.5 % w/w H 2 SO 4) at 90 °C for 60 min was utilized followed by enzymatic hydrolysis using cellulase and hemicellulase for 48 hr. After simultaneous saccharification (regarding starch) and fermentation at 150 L using an engineered yeast, which consumes both glucose and xylose to make ethanol, the 86 % total sugar conversion yield was achieved, including conversions of 95 % for starch, 77 % for cellulose and 77 % for xylan. Also, an accurate mass balance was formulated for ethanol-producing carbohydrates including starch, cellulose, and xylan from feedstock to final ethanol. A highly efficient process of converting corn fiber to ethanol was successfully scaled up to 150 L. [ABSTRACT FROM AUTHOR]

[Display omitted] • Algae are the source of unique hetero- & homo-polysaccharides rich in bioactivity. • Exploitation of saccharides as value-added product can enhance process feasibility. • Nucleotide-sugars are the key precursor metabolite for saccharide biosynthesis. • Large-scale cultivation systems and downstream process are still the bottlenecks. • High-producer strains & sustainable process design is critical for commercialization. Algae play a significant role in the global carbon cycle by utilizing photosynthesis to efficiently convert solar energy and atmospheric carbon dioxide into various chemical compounds, notably carbohydrates, pigments, lipids, and released oxygen, making them a unique sustainable cellular factory. Algae mostly consist of carbohydrates, which include a broad variety of structures that contribute to their distinct physical and chemical properties such as degree of polymerization, side chain, branching, degree of sulfation, hydrogen bond etc., these features play a crucial role in regulating many biological activity, nutritional and pharmaceutical properties. Algal carbohydrates have not received enough attention in spite of their distinctive structural traits linked to certain biological and physicochemical properties. Nevertheless, it is anticipated that there will be a significant increase in the near future due to increasing demand, sustainable source, biofuel generation and their bioactivity. This is facilitated by the abundance of easily accessible information on the structural data and distinctive characteristics of these biopolymers. This review delves into the different types of saccharides such as agar, alginate, fucoidan, carrageenan, ulvan, EPS and glucans synthesized by various macroalgal and microalgal systems, which include intracellular, extracellular and cell wall saccharides. Their structure, biosynthetic pathway, sources, production strategies and their applications in various field such as nutraceuticals, pharmaceuticals, biomedicine, food and feed, cosmetics, and bioenergy are also elaborately discussed. Algal polysaccharide has huge a scope for exploitation in future due to their application in food and pharmaceutical industry and it can become a huge source of capital and income. [ABSTRACT FROM AUTHOR]

[Display omitted] • FW components exert significant impact on FW methane yield. • HPLFW feeds showed significantly higher CH 4 yield than HCFW feeds. • FW CH 4 production can be described by a modified two-component kinetic model. • Element formula of organic content of FW were determined. This study assessed the methane production from food waste (FW) with dominant components of Meat (MFW), Fruit &Veg (VFW), Grain (GFW), Dairy (DFW), and the mixed feed of these components (MixFW). The high protein and lipid content FW (HPLFW) of MFW, DFW, and MixFW showed the methane yields of 337.0 ± 3.0, 307.4 ± 0.8, and 297.1 ± 1.2 ml-CH 4 /gCOD, respectively, while those for the high carbohydrate content FW (HCFW) of VFW and GFW were 238.3 ± 1.2 and 171.2 ± 0.3 ml-CH 4 /gCOD, respectively. A modified two-component kinetic (MTK) model was demonstrated to be the best to describe the methane production kinetics of both HPLFW and HCFW types of feeds. The element balance analysis revealed the element formula of the FW feeds and the methane-conversion organic content. The results obtained from this study showed that the high lipid and animal protein content increased the methane yield and biogas methane composition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Utilization of pretreated biomass and detoxified hydrolysate was integrated. • Exopolysaccharide adsorbs more furan and phenolics than commercial galactomannan. • Exopolysaccharide hydrogel was stable in recycling experiment on detoxification. • C. flavigena and K. aerogenes synergically converts polysaccharides to hydrogen. • Methanogenic digestion of spent liquor utilized the VFAs and reduced the COD. In this study, the exopolysaccharide from cyanobacteria was used for detoxification of acid hydrolysate of water hyacinth biomass. Exopolysaccharide-hydrogel showed phenolics and furans removal of 86 % and 97 %, respectively, with sugar recovery of 98.3 %. The fermentation of detoxified acid hydrolysate was integrated with that of pretreated biomass subjected to enzymatic saccharification derived from commercial cellulose (ESF) or from microbe (MSF). The maximum hydrogen production of 69.2 mL/g-VS was obtained in MSF, which is 1.2- and 1.6-fold higher than ESF and undetoxified acid hydrolysate, respectively. Additionally, the methane production of 12.6 mL/g-VS by mixed methanogenic consortia was obtained using the spent liquor containing volatile fatty acids. This enhanced hydrogen and methane production in subsequent microbial processes is mainly attributed to the selective removal of inhibitors in combination with an integrated carbohydrate utilization. [ABSTRACT FROM AUTHOR]

Aqueous galactose solutions containing eggshell was heated at 120 °C to produce calcium supplements containing rare sugars. Galactose was isomerized to rare sugars with improving rare sugar yields compared to those without eggshell. Organic acids were also formed as byproducts during the reaction. These acids were neutralized by dissolving eggshells with increasing the calcium ion concentration in the solution. When eggshell components (calcium carbonate, magnesium carbonate, or calcium phosphate) were used for the treatment, rare sugars were also formed. Especially, addition of magnesium carbonate improved rare sugar yield, but byproduct formation became more pronounced. Eggshells used in the treatment were used for repeated treatments. When eggshells were used three times, rare sugar yield changed only slightly but the selectivity of rare sugars improved significantly. By these processes, we obtained an aqueous solution of rare sugars containing calcium ion at 295 mg/L, which has potential as ingredients for dietary supplements., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: T. Kobayashi reports financial support was provided by Kieikai and JSPS. Other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The potential of hydrolytic enzyme cocktail obtained from designed bacterial consortium WSh-1 comprising Bacillus subtilis CRN 16, Paenibacillus dendritiformis CRN 18, Niallia circulans CRN 24, Serratia marscens CRN 29, and Streptomyces sp. CRN 30, was investigated for maximum saccharification. Activity was further enhanced to 1.01 U/ml from 0.82 U/ml by supplementing growth medium with biotin and cellobiose as a cofactor and inducer. Through kinetic analysis, the enzyme cocktail showed a high wheat straw affinity with Michaelis-Menten constant (Km) of 0.68 µmol/L and a deconstruction rate (Vmax) of 4.5 U/ml/min. The statistical optimization of critical parameters increased saccharification to 89 %. The optimized process in a 5-L lab-scale bioreactor yielded 501 mg/g of reducing sugar from NaOH-pretreated wheat straw. Lastly, genomic insights revealed unique abundant oligosaccharide deconstruction enzymes with the most diverse CAZyme profile. The consortium-mediated enzyme cocktails offer broader versatility with efficiency for the economical and sustainable valorization of lignocellulosic waste., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A large quantity of orange peel waste (OPW) is generated per year, yet effective biorefinery methods are lacking. In this study, Trichosporonoides oedocephalis ATCC 16958 was employed for hydrolyzing OPW to produce soluble sugars. Glycosyl hydrolases from Paenibacillussp.LLZ1 which can hydrolyze cellulose and hemicellulose were mined and characterized, with the highest β-mannanase activity of 39.1 U/mg at pH 6.0 and 50 ℃. The enzyme was overexpressed in T. oedocephalis and the sugar production was enhanced by 16 %. The accumulated sugar contains 57 % value-added mannooligosaccharides by the hydrolysis of mannans. The process was intensified by a pretreatment combining H 2 O 2 submergence and steam explosion to remove potential inhibitors. The mannooligosaccharides yield of 6.5 g/L was achieved in flask conversion and increased to 9.7 g/L in a 5-L fermenter. This study improved the effectiveness of orange peel waste processing, and provided a hydrolysis-based methodology for the utilization of fruit wastes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

• Nutrient enrichment enhanced the biomass and lipid productivity in C. gracilis. • Protein, carbohydrate and lipid content was highest in 2 f setup of T. weissflogii. • Nutrient limitation enhanced phenol and flavonoid content in T. weissflogii. Marine diatoms have high adaptability and are known to accumulate lipids under nutrient stress conditions. The present study involves determining the effect of varying macro and micronutrients on growth kinetics and metabolite production of oleaginous marine diatoms, Thalassiosira weissflogii and Chaetoceros gracilis. The results highlighted that C. gracilis and T. weissflogii showed maximum biomass yield of 0.86 ± 0.06 g/L and 0.76 ± 0.01 g/L in the 2 f and f supplemented medium respectively. A 2.5-fold increase in cellular lipid content was recorded in the 2 f culture setup of both strains ranging from 20 % to 26.7 % (w/w). The study also reveals that high eutrophic nutrient media (f , 2 f and 4 f) triggered biomass productivity as well as total protein and carbohydrate content in both strains. Thus, providing a reproducible insight of trophic flexibility of diatoms, concomitant with the increment in multiple commercially valuable products. [ABSTRACT FROM AUTHOR]

• Stirred bead milling extracts over 95% of proteins and 60% carbohydrates. • Optimal conditions were found for mid-range values of bead size and rotation speed. • The higher the microalgae concentration, the more efficient is the process. • Although extraction yields are similar, the pendular mode consumes the least energy. Stirred bead milling proved to be an efficient cell destruction technique in a biorefinery unit for the extraction of over 95 % of proteins and 60 % of carbohydrates from the green marine microalga Tetraselmis suecica. Optimum conditions, expressed in terms of metabolite yield and energy consumption, were found for average values of bead size and agitator rotation speed. The higher the microalgae concentration, up to 100 g.L−1, which is adequate for biofilm algae growth in an industrial unit, the more efficient the cell destruction process. Cell destruction rates and metabolite extraction yields are similar in pendular and recycling modes, but the pendular configuration reduces the residence time of the suspension in the grinding chamber, which is less costly. With regard to the cell destruction mechanism, it was concluded that bead shocks first damage cells by permeabilizing them, and that after a longer period, all cells are shredded and destroyed, forming elongated debris. [ABSTRACT FROM AUTHOR]

Microalgae's exceptional photosynthetic prowess, CO 2 adaptation, and high-value bioproduct accumulation make them prime candidates for microorganism-based biorefineries. However, most microalgae research emphasizes downstream processes and applications rather than fundamental biomass and biochemical balances and kinetic under the influence of greenhouse gases such as CO 2 . Therefore, three distinctly different microalgae species were cultivated under 0% to 20% CO 2 treatments to examine their biochemical responses, biomass production and metabolite accumulations. Using a machine learning approach, it was found that Chlorella sorokiniana showed a positive relationship between biomass and chl a, chl b, carotenoids, and carbohydrates under increasing CO 2 treatments, while Chlamydomonas angulosa too displayed positive relationships between biomass and all studied biochemical contents, with minimal trade-offs. Meanwhile, Nostoc sp. exhibited a negative correlation between biomass and lipid contents under increasing CO 2 treatment. The study showed the potential of Chlorella, Chlamydomonas and Nostoc for commercialization in biorefineries and carbon capture systems where their trade-offs were identified for different CO 2 treatments and could be prioritized based on commercial objectives. This study highlighted the importance of understanding trade-offs between biomass production and biochemical yields for informed decision-making in microalgae cultivation, in the direction of mass carbon capture for climate change mitigation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Valorization of herbal extraction residues (HERs) into value-added products is pivotal for the sustainability of Chinese medicine industry. Here, seven different enzymatic hydrolysates of dilute acid pretreated HERs were evaluated for lipid production by Cutaneotrichosporon oleaginosum. Among them, the highest sugar yield via hydrolysis and the maximum lipid production were obtained from Radix paeoniae alba residue (RPAR). More interestingly, high proportion of sugar polymers was disintegrated into fermentable sugars during the pretreatment step, allowing a cheap non-enzymatic route for producing sugars from RPAR. A repeated dilute acid pretreatment gained a high sugar concentration of 241.6 g/L through reusing the pretreatment liquor (PL) for four times. Biomass, lipid concentration, and lipid content achieved 49.5 g/L, 35.7 g/L and 72.2 %, respectively, using fed-batch culture of PL. The biodiesel parameters indicated lipids produced from HERs were suitable for biodiesel production. This study offers a cost-effective way to upgrade the HERs waste into micro-biodiesel., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Food waste biorefinery is a sustainable approach to producing green chemicals, however the essential substrate-related factors hindering the efficacy of enzymatic hydrolysis have never been clarified. This study explored the key rate-limiting parameters and mechanisms of carbohydrate-rich food after different cooking and storing methods, i.e., impacts of compositions, structural diversities, and hornification. Shake-flask enzymatic kinetics determined the optimal dosages (0.5 wt% glucoamylase, 3 wt% cellulase) for food waste hydrolysis. First order kinetics and simulation results determined that reaction coefficient (K) of cooked starchy food was ∼ 3.63 h -1 (92 % amylum digestibility) within 2 h, while those for cooked cellulosic vegetables were 0.25-0.5 h -1 after 12 h of hydrolysis. Drying and frying reduced ∼ 71-89 % hydrolysis rates for rice, while hydrothermal pretreatment increased the hydrolysis rate by 82 % on vegetable wastes. This study provided insights into advanced control strategy and reduced the operational costs by optimized enzyme doses for food waste valorization., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Chinese distillers' grains (CDGs) have low fermentation efficiency due to the presence of lignocellulosic components, such as rice husk. In this study, a microbial consortium synthesized was used based on the "functional complementarity" principle to produce lignocellulolytic crude enzyme. The crude enzyme was used to hydrolyze CDGs. After enzymatic hydrolysis, lignocellulose was damaged to varying degrees and the crystallinity decreased. Subsequently, the feed protein was produced using yeast through two pathways. The results showed that the crude enzyme produced by the microbial consortium (comprising Trichoderma reesei, Aspergillus niger, and Penicillium) exhibited excellent enzymatic efficiency, yielding 27.88%, 19.64%, and 10.88% of reducing sugar, cellulose, and hemicellulose. The true protein content of CDGs increased by 53.49% and 48.35% through the first and second pathways, respectively. Notably, the second pathway demonstrated higher economic benefits to produce feed protein. This study provides a pathway for high-quality utilization of CDGs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Highlights • Lp A1 could enhance the ensilage process and enzymatic saccharification. • Pretreatment with Lp A1 could reduce the fiber content of corn stalk silage. • Cellulose + Lp A1 had better performance in reducing lignocellulose. • Lp A1 had better performance in reducing lignocellulose at 25 °C rather than 40 °C. Abstract The effects of Acremonium cellulase and L. plantarum A1 with ferulic acid esterase activity on corn stalk silage fermentation characteristics, carbohydrate composition and enzymatic saccharification were studied at 25 and 40 °C, respectively. Corn stalk was ensiled without additive (C), Acremonium cellulase (AC), L. plantarum A1 (Lp) and AC + Lp for 60 days. Pretreatment with Lp or AC + Lp promoted the better silage fermentation and the degradation of lignocellulose as indicated by high lactic acid and low pH and lignocellulose content compared to control silages at 25 °C. AC + Lp performed better in reducing lignocellulose and DM loss. In addition, Lp alone enhanced enzymatic saccharification of corn stalk silage. However, the influence of L. plantarum A1 on corn stalk silage was not obvious at 40 °C. Corn stalk ensiled with combined additive is a suitable pretreatment method for subsequent biofuel production at 25 °C, but addition of Acremonium cellulase alone at 40 °C may be a promising method. [ABSTRACT FROM AUTHOR]

Highlights • Flavobacteria, Firmicutes and Chloroflexi caused slow membrane fouling of the S-MBR. • The enrichment of β-proteobacterium brought about the rise-associated in TMP of the C-MBR. • SMP c in conjunction with EPS c and SMP p accelerated the membrane fouling. • A quick rise in SMP c triggered an abrupt increase in TMP. • The EPS c and SMP p caused the sustained increase in TMP. Abstract The biofouling characteristics of an MBR (S-MBR) combined with the worm reactor and a conventional MBR (C-MBR) were analyzed, respectively, over the three-stage (fast-slow-fast) process. Whether it was in the C-MBR or the S-MBR, the species of the active sludge (AS) were similar to that of the cake sludge (CS) in stage 1 (before day 1), the bacterial adsorption and the metabolites attachment contributed to this transmembrane pressure (TMP) rise. In the stage 2, the TMP increasing rate of the C-MBR was eight times more than that of the S-MBR. During this period, a characteristic community colonized the AS and CS of the S-MBR with the microbes, ie Flavobacteria, Firmicutes and Chloroflexi which were responsible for the degradation of extracellular polymeric substances (EPS) and soluble microbial products (SMP). These dominant species caused the slower accumulation of biofouling metabolites in the CS, resulting in the slow rise-related in TMP. Meanwhile, the enrichment of β-proteobacterium and the absence of Mycobacterium and Propionibacterium in AS and CS of the C-MBR were deemed as the main biological factors bringing about the rise-associated in TMP. In the stage 3, the biofilm was matured, and the cake layer was more compacted, which resulted in an abrupt rise in TMP and severe membrane fouling. Additionally, the statistical analysis revealed that a highly correlation between the TMP increasing rate and the content of carbonhydrates in SMP (SMP c). When the SMP c content increased slowly, there was a relatively slow biofouling. But, when the SMP c increasing rate was greater, it led to a more serious membrane fouling with the sudden TMP jump. Additionally, there was also a highly significant correlation coefficient for the TMP rise and the content of carbonhydrates in EPS (EPS c) and the protein in SMP (SMP p), rather than the protein in EPS (EPS p). The cluster analysis showed that the microbes contributing to membrane fouling were more abundant in the C-MBR, while the microbes related to organic compounds degradation were more abundant in the S-MBR. There was significant correlation between the microbes and their metabolites. The SMP c in conjunction with EPS c and SMP p were the main factors accelerating the membrane fouling. It was concluded that a quick rise in SMP c triggered an abrupt increase in TMP, while the EPS c and SMP p caused the sustained increase in TMP. [ABSTRACT FROM AUTHOR]

Highlights • Chlorella fusca cultivated with 120 ppm of fly ashes exhibited 47.6% of protein. • The protein content was not impaired in the cultivations with 0.75 g L−1 of NaNO 3. • Chlorella fusca reached up to 35.2% of carbohydrates using 0.75 g L−1 of NaNO 3. • The carbohydrates increased up to 25% with a reduction in the nitrogen supply. • CO 2 and fly ashes are a strategy to reduce costs of nutrients in algae growth. Abstract Fly ashes present several minerals that along with carbon dioxide (CO 2) represent a promising nutrient source and an alternative to reduce environmental problems. Thus, the objective of this study was to investigate if CO 2 , thermoelectric fly ashes and reduction in nitrogen supply alters the production of macromolecules in Chlorella fusca LEB 111. For this purpose, 1.5 or 0.75 g L−1 of NaNO 3 , injection of 10% (v v−1) of CO 2 as well as 0, 40 and 120 ppm of fly ashes were studied. The protein content was not impaired in cultivations with 0.75 g L−1 of NaNO 3 since nitrogen was not fully consumed. Nevertheless, this cultivation strategy increased carbohydrate content by up to 25%, which could be fermented to produce bioethanol. Therefore, Chlorella fusca presented not only potential for CO 2 biofixation and assimilation of nutrients from fly ashes but also for enhancement of carbohydrates accumulation when the nitrogen supply was reduced. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Co-production of functional XOS and fermentable sugars from SCB. • AO pretreatment conditions for the XOS production were optimized. • A novel and feasible strategy for the biorefinery of SCB was proposed. • XOS products mainly composed of xylobiose were analyzed by HPLC-UV and MALDI-TOF-MS. Abstract High chemical input is required for enzymatic production of xylo-oligosaccharides (XOS) using xylan extracted from lignocellulosic biomass. In this study, enzymatic hydrolysis of alkaline oxidation (AO) treated sugarcane bagasse (SCB) directly for the production of XOS was conducted. The effect of AO pretreatment on the chemical compositions and hydrolytic properties of SCB was investigated. The AO pretreatment conditions with low chemical input for the production of XOS were optimized by orthogonal design. Stepwise enzymatic hydrolysis of AO pretreated SCB with xylanase and cellulase produced XOS (1.78 g/L), meanwhile, the cellulose conversion increased from 84.97% to 91.51% compared with directly enzymatic hydrolysis using cellulase. HPLC-UV and MALDI-TOF-MS analysis indicated that the obtained XOS products were mainly composed of xylobiose and xylose with a small amount of arabinose/4- O -methylglucuronic acid substituted xylotriose and xylotetraose. The proposed strategy for the co-production of functional XOS and fermentable sugars from SCB showed potential of industrial application. [ABSTRACT FROM AUTHOR]

Highlights • Mixotrophic microalga showed better growth and stronger tolerance to high ammonium. • The synthesis of microalgal carbohydrates was inhibited by higher ammonium. • Ammonium increased microalgal lipids in mixotrophic cultivation. • Inhibition to the photosynthetic activity was intensified by elevated ammonium. Abstract To enhance microalgal growth and optimize ammonium utilization, the effect of ammonium on microalgal growth, biochemical composition and photosynthetic performance were investigated by mixotrophic cultivation of microalga Spirulina platensis comparing with autotrophic cultivation. The results indicated that elevated ammonium significantly affected the microalgal growth, but the microalga in mixotrophic cultivation showed better growth and stronger tolerance to higher ammonium. The microalgal proteins were increased by increasing nitrogen concentration. The synthesis of microalgal carbohydrates was inhibited by higher ammonium, especially in mixotrophic cultivation. The addition of ammonium decreased the microalgal lipids in autotrophic cultivation but increased microalgal lipids in mixotrophic cultivation. Ammonium negatively affected the microalgal photosynthetic performance. The inhibition was intensified by elevated ammonium, inducing stronger photosystem protection mechanism, particularly in mixotrophic cultivation. The rate of ammonium inhibition to the microalgal photosystem was quick in the early stage by decreasing electron transport rate of PS II. [ABSTRACT FROM AUTHOR]

Highlights • Phosphate maintains the glycogen biosynthetic machinery in Synechocystis sp. PCC 6714. • A feeding strategy was developed to maximize glycogen storage in Synechocystis 6714. • Media optimization was done for an easy one-step process for PHB production. • During one-step cultivation PHB content of 1.16 g L−1 was obtained for MT_a24. • Maximum of 2.6 g L−1 glycogen was obtained for the MT_a24 using phosphate feeding. Abstract Recently, several mutants of Synechocystis sp. PCC 6714 were obtained showing superior PHB content and productivities. Here, the most promising mutant named MT_a24 is compared in detail with the wild-type in controlled photobioreactors. In order to provide an easily scalable and alternative approach to the normally done two-step process -comprising of growth phase and limitation phase- a one-step cultivation was optimized. The multivariate experimental design approach was used for the optimization of the one-step, self-limiting media. During one-step cultivation of MT_a24 with optimized media 30 ± 4% (DCW) corresponding to 1.16 g L−1 PHB was obtained. Using pulse experiments it was demonstrated that phosphate is the key driver of glycogen synthesis in Synechocystis sp. PCC 6714 and it can be used to boost glycogen productivity. The maximum glycogen content acquired was 2.6 g L−1 (76.2% DCW) for mutant MT_a24 using phosphate feeding and carbon dioxide as carbon source. [ABSTRACT FROM AUTHOR]

Highlights • Current FW treatment capacity is 19.50% in China. • FW treatment capacity in China is concentrated in regions with high GDP. • Carbohydrates and ether extracts exhibited large variations. • Anaerobic digestion is the most prevalent of the current FW pilot projects (76.1%). • Strategies to improve FW treatment capacity and efficiency are suggested. Abstract The current status of FW generation, including its characteristics, management, and current challenges in China, were analyzed, and further suggestions were made with regards to improvement. About 19.50% of the FW generated could be treated under the current designs for treatment capacity in China. FW characteristics show great variability in different economic regions in China, where both treatment efficiency and FW management are poor. Combined pretreatment and three-phase separation is the most used pretreatment method, and of the current FW pilot projects, anaerobic digestion is the most prevalent, accounting for 76.1% of all projects. Significant regional characteristics have been identified regarding FW generation and the treatment capacity for FW processing. Possible factors influencing FW management in China were also discussed. Finally, detailed suggestions are given for further development of FW treatment capacity, particularly regarding potential technical routes and management measures. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The moisture content of feedstock showed no effect on hydrochar performances. • Carbohydrates were the main contributors to the formation of hydrochar. • Proteins were able to enhance nitrogenous heterocyclic functional groups. • Lipids did not participate in the carbonization reaction. • The main hydrolyzates of lipids were adsorbed to the surface of hydrochar. Abstract This study aims to figure out the influence of moisture content and chemical constitution, i.e. carbohydrates, proteins and lipids, of waste lettuce on the physicochemical structure of hydrochar produced via hydrothermal carbonization. The experimental results showed that homogenized carbon material can be obtained by hydrothermal treatment, regardless of the moisture content of feedstock. During the hydrothermal carbonization process of waste lettuce, carbohydrates were the most active reactants contributing to hydrochar formation. Meanwhile, Maillard reaction between proteins and carbohydrates occurred, which promoted the aromatization of the organic intermediates and increased the relative content of nitrogenous heterocyclic functional groups on the surface of hydrochar from 10.7 to 18.7%. Different from these two constitution, lipids did not participate in the carbonization reaction, the main hydrolyzates of lipids were adsorbed to the surface of hydrochar, leading to an increase in the mass of solid products. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • "Specific" bacteria in chicken manure transformed protein and carbohydrate. • "Universal" bacteria in bovine manure transformed both of protein and carbohydrate. • More than 79% of the variance of protein and carbohydrate were transformed by bacteria. Abstract The aim of this study was to assess the roles of bacteria in degrading protein and carbohydrate during chicken and bovine manures composting. The results showed that protein and carbohydrate degraded greatly, especially during the thermophilic phase of composting. This was mainly caused by the abundant bacteria communities that related with protein and carbohydrate transformation in the thermophilic phase, which identified by the network analysis. Besides, the microbial degradation of nutrient substances performed specificity and universality. "Specificity" and "Universality" meant protein and carbohydrate degraded by certain bacteria and diverse groups of bacteria, respectively. "Specific" bacteria transformed protein and carbohydrate during chicken manure composting, whereas the transformation characteristic of bacteria to protein and carbohydrate in bovine manure was "universality". Structural equation models also verified these results, and they showed that more than 79% of protein and carbohydrate changes were transformed by bacteria. [ABSTRACT FROM AUTHOR]

Highlights • Spirulina reached 59.1% (w w−1) of carbohydrate content with 8.4 g L−1 of NaHCO 3. • 0.3 vvm of CO 2 injected for 5 min resulted in 49.3% (w w−1) of carbohydrates. • Biomass concentration increased with addition of larger amounts of CO 2. • If fermented this biomass could result in high amount of bioethanol. Abstract This study focused on verifying if production of Spirulina biomass with high carbohydrate content is stimulated by reduced supply of nitrogen associated to addition of NaHCO 3 or CO 2 at different flow rates and times of injection. For this purpose, addition of 0.25 g L−1 of NaNO 3 allowed Spirulina to accumulate up to 49.3% (w w−1) of carbohydrates with the highest amount of CO 2 (0.3 vvm injected for 5 min). This value reached 59.1% (w w−1) when NaHCO 3 was the carbon source. Meanwhile, biomass concentration achieved 0.81 and 0.97 g L−1, respectively. In contrast, protein content was inversely proportional to carbohydrate accumulation in the experiments. Thus, this study represents an important step to define cultivation conditions to enhance carbohydrate content in Spirulina. The carbohydrate-rich biomass could be further fermented to produce bioethanol. [ABSTRACT FROM AUTHOR]

• Three novel SDES were prepared for corn stalks pretreament. • The yield of carbohydrates in pyrolysis oil increased from 0.63% to 49.37%. • Multi-purpose fluorescent lignin was prepared from regenerated lignin. • Weak interaction and frontier orbital between molecules were calculated by DFT. In this study, β -CD was used as a receptor to prepare three novel SDES, which were used to pretreat corn stalks for obtaining fluorescent lignin and promoting biomass pyrolytic saccharification. It was found that GA-residue had a high cellulose retention ratio (94.63%) and the highest lignin removal ratio (61.78%). Besides, the yield of carbohydrates in bio-oil was increased from 0.63% to 49.37%, and fluorescent lignin was prepared for explosion detection, fluorescent film, and information encryption. It was confirmed that the weak interaction between β -CD and HBDs or dimer was mainly performed by hydrogen bond and van der Waals force. The minimum frontier orbital energy difference ΔE U (0.1976 a.u.) and high binding energy (-5456.71 kJ/mol) between molecules were calculated by DFT. Moreover, the mechanism of biomass pretreatment was explored. The green and efficient SDES developed in this study were of great significance for biomass pretreatment and efficient utilization of components. [ABSTRACT FROM AUTHOR]

[Display omitted] • An easy-recycled ethylenediamine pretreatment (EREP) was developed. • EREP significantly improved the enzymatic hydrolysis of carbohydrates. • EREP introduced Schiff base and amide structures in the lignin molecules. • EDA-lignin showed a pH-responsive behavior and excellent flocculation capacity. • The molecular mechanism was proposed for the lignin modification by EREP. Lignocellulosic biomass (LCB) is the promising feedstock for value-added products, which would contribute to the bioeconomy and sustainable development. The efficient pretreatment is still required in the biorefinery of LCB. To make a simultaneous utilization of carbohydrates and lignin, a novel easy-recycled ethylenediamine (EDA) pretreatment was designed and evaluated in the present study. The results highlighted that this pretreatment yielded 96% glucose and 70% xylose in enzymatic hydrolysis. It simultaneously promoted the depolymerization of lignin into small molecules and functionalized the yielded lignin with Schiff base and amide structures. These animated-lignins showed a pH-responsive behavior and the excellent flocculation capacity by reducing more than 90% turbidity of kaolin suspensions. Therefore, easy-recycled EDA pretreatment hold the promise to simultaneously enhance the enzymatic hydrolysis of carbohydrates and endowed the new functionality of lignin toward downstream valorization, which improved the process feasibility and potentially enable the sustainability of LCB utilization. [ABSTRACT FROM AUTHOR]

• The whole fractionation processes of different pretreatment strategies were assessed. • Above 85% lignin removal and 85% carbohydrates retention was obtained. • Maximum ethanol (85.74 g/L) output was firstly achieved from poplar wood. • The fate of lignin after pretreatment was particularly emphasized. Appropriate fractionation of lignocellulosic biomass into useable forms is a key challenge to achieving an economic bioethanol production. In the present study, four different fractionation strategies of hydrothermal-, NaOH-, ethanol-, and NaOH catalyzed ethanol pretreatment were investigated to compare their abilities of cellulose conversion. Results showed that NaOH catalyzed ethanol pretreatment showed a rather high extent of delignification of 85.92%, which also enhanced the retention of cellulose (92.56%) and hemicellulose (76.57%); while other pretreatments tended to produce cellulose fraction which was insufficient to achieve the whole component utilization. After simultaneous saccharification and fermentation at high solids loading, synergistic maximization of xylose (42.47 g/L) and ethanol (85.74 g/L) output was achieved via alkaline ethanol pretreatment. Lignin characterization information showed that alkaline ethanol pretreatment facilitates the cleavage of β- O-4 linkage and further converts into arylglycerol. Moreover, less condensed substructure units with high processing activity were also generated in S- and G- lignin. [ABSTRACT FROM AUTHOR]

[Display omitted] • SCP and lipid were coproduced from wheat straw and (NH 4) 2 SO 4 by oleaginous yeast. • Engineered Trichosporon cutaneum MP11 with excellent adaptability was employed. • The cellulosic SCP and lipid titer reached 24.4 ± 1.5 g/L and 11.8 ± 1.2 g/L at 48 h. • Residual (NH 4) 2 SO 4 in wastewater was recycled with stable fermentation performance. Co-production of single cell protein (SCP) and lipid from lignocellulose-derived carbohydrates and inorganic ammonia offers a promising alternative for poultry or aquaculture feeds. An engineered oleaginous yeast Trichosporon cutaneum MP11 showed great potential for producing SCP and lipid from wheat straw and ammonia sulfate with minimum nutrient input. Trichosporon cutaneum MP11 showed stronger SCP and lipid fermentability using dry acid pretreated and biodetoxified wheat straw than using pure sugars. The residual ammonium sulfate in fermentation broth was recycled up to five times, resulting in ∼70% of nitrogen fixation into SCP. The overall yield of SCP and lipid from lignocellulose-derived sugars was 0.15 g/g and 0.11 g/g, respectively. This translates to the production of one ton of SCP (0.56 ton) and lipid (0.44 ton) from 6.6 tons of wheat straw, or one ton of SCP and lipid containing yeast cells (dry) from 4.8 tons of wheat straw. [ABSTRACT FROM AUTHOR]

The present investigation is targeted towards the facile fabrication of a carbon-based nanocatalyst (CNCs) using Kans grass biomass (KGB) and its sustainable application in microbial cellulase enhancement for the alleviation of enzymatic hydrolysis for sugar production. Different pretreatments, including physical, KGB extract-mediated treatment, followed by KOH pretreatment, have been applied to produce CNCs using KGB. The presence of CNCs influences the pretreatment of KGB substrate, fungal cellulase production, stability, and sugar recovery in the enzymatic hydrolysis of KGB. Using 1.0% CNCs pretreated KGB-based solid-state fermentation, 33 U/gds FPA and 126 U/gds BGL were obtained at 72 h, followed by 107 U/gds EG at 48 h in the presence of 0.5% CNCs. Further, 42 °C has been identified as the optimum temperature for cellulase production, while the enzyme showed thermal stability at 50 °C up to 20 h and produced 38.4 g/L sugar in 24 h through enzymatic hydrolysis of KGB., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The conventional production of polyhydroxyalkanoate (PHA) from waste biomass requires a pretreatment step (acid or alkali) for reducing sugar extraction, followed by bacterial fermentation. This study aims to find a greener approach for PHA production from brown seaweed. Saccharophagus degradans can be a promising bacterium for simultaneous reducing sugar and PHA production, bypassing the need for a pretreatment step. Cell retention cultures of S. degradans in membrane bioreactor resulted in approximately 4- and 3-fold higher PHA concentrations than batch cultures using glucose and seaweed as carbon sources, respectively. X-ray diffraction, Fourier transform infrared spectroscopy, and nuclear magnetic resonance results revealed identical peaks for the resulting PHA and standard poly(3-hydroxybutyrate). The developed one step process using cell retention culture of S. degradans could be a beneficial process for scalable and sustainable PHA production., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Low-value agricultural by-products can be converted into high-value biological products by fermentation with probiotic strains or by enzymatic hydrolysis. However, the high costs of enzyme preparations significantly limit their applications in fermentation. In this study, the solid-state fermentation of millet bran was performed using a cellulase preparation and compound probiotics producing cellulase (CPPC), respectively. The results showed that both factors effectively destroyed the fiber structure, reduced the crude fiber content by 23.78% and 28.32%, respectively, and significantly increased the contents of beneficial metabolites and microorganisms. Moreover, CPPC could more effectively reduce the anti-nutrient factors and increase the content of anti-inflammatory metabolites. The correlation analysis revealed that Lactiplantibacillus and Issatchenkia had synergistic growth during fermentation. Overall, these results suggested that CPPC could replace cellulase preparation and improve antioxidant properties while reducing anti-nutrient factors of millet bran, thus providing a theoretical reference for the efficient utilization of agricultural by-products., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This study aimed to produce enhanced fermentable sugars from a novel stover system through the bioprocessing of its soluble sugars and insoluble carbohydrates. The pretreatment conditions were optimized for this high sugar-containing stover (HSS) to control inhibitor formation and obtain enhanced fermentable sugar concentrations. The optimum temperature, acid loading, and reaction time for the pretreatment were 155 °C, 0.5%, and 30 min, respectively, providing up to 97.15% sugar yield and 76.51 g/L total sugars at 10% solid-load. Sugar concentration further increased to 126.9 g/L at 20% solid-load, generating 3.89 g/L acetate, 0.92 g/L 5-hydroxymethyl furfural, 0.82 g/L furfural, and 3.75 g/L total phenolics as inhibitors. To determine the effects of soluble sugars in HSS on fermentable sugar yield and inhibitor formation, sugar-removed HSS was further studied under the optimum conditions. Although prior removal of sugars exhibited a reduction in inhibitor generation, it also decreased total fermentable sugar production to 115.45 g/L., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Presently, the use of lignocellulosic biomass is mainly focused on creating pulp/paper, energy, sugars and bioethanol from the holocellulose component, leaving behind lignin to be discarded or burned as waste despite of its highest aromatic carbon and energy content (22-29 KJ/g). During the pulping process, lignin undergoes significant structural changes to yield technical lignin. For a circular bioeconomy, there is an urgent need to enhance the use of native lignin for generating more valuable products. Over the last few years, a new method called 'lignin-first', or 'reductive catalytic fractionation' (RCF), has been devised to achieve selective phenolic monomers under mild reaction conditions. This involves deconstructing lignin before capitalizing on carbohydrates. The objective of this study is to record the recent developments of the 'lignin-first' process. This review also underlines the contribution of RCF biorefinery towards achieving sustainable development goals (SDGs) and concludes with an overview of challenges and upcoming opportunities., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Biological inoculants were tested on Pennisetum sinese for their effects on fermentation characteristics, structural carbohydrates degradation, and enzymatic conversion yields. Pennisetum sinese was ensiled without additive, Lactobacillus plantarum (Lp), Trichoderma reesei (Tr), fibrolytic enzymes (E), and Enterococcus faecium (Y83) for 90 days. Y83 silages had higher LA and lower AA, ammonia-N and DM loss as compared to E and Tr silages. Tr and E had superior effects for degrading lignocellulose while Y83 had intermediate effects. The first-order exponential decay models (R 2  = 0.928–0.998) predicted nonstructural carbohydrates kinetics and demonstrated high water soluble carbohydrate (g/kg DM) preservation potential in Y83 (21.40), followed by Tr (18.94) and E (16.74). Addition of Y83 improved the conversion efficiency of P. sinese silage than Tr and E, indicated by higher glucose and total reducing sugars yield (22.49 and 36.89 w/w % DM, respectively). In conclusion, Y83 can be exploited for the ensiling lignocellulosic biomass before grass processing. [ABSTRACT FROM AUTHOR]

In this work, a simplified and cost-effective chlorite pretreatment method to improve the hydrolysabiliy of biomass was developed. Compared to common used sodium chlorite-acetic acid (SCA) pretreatment (18.1%), sodium chlorite (SC) pretreatment resulted in less xylan loss (7.8%), thus led more carbohydrates retention. Moreover, the Chinese silvergrass pretreated by SC for 2 h achieved higher glucose yield (70.5%) than the substrate pretreated by SCA under the same pretreatment conditions did (58.7%), after 48 h enzymatic hydrolysis by cellulase. By synergistic action of cellulase and xylanase, the glucose yield of SC pretreated (12 h) samples reached to 93.5% with 808.7 mg/g DM total reducing sugars yields. In addition, without the usage of acetic acid could decrease the process cost and result in less inhibitor generation in pretreatment process. [ABSTRACT FROM AUTHOR]

This work explores molecular, morphological as well as biotechnological features of the highly promising polyhydroxyalkanoates (PHA) producer Halomonas halophila . Unlike many other halophiles, this bacterium does not require expensive complex media components and it is capable to accumulate high intracellular poly(3-hydroxybutyrate) (PHB) fractions up to 82% of cell dry mass. Most remarkably, regulating the concentration of NaCl apart from PHB yields influences also the polymer’s molecular mass and polydispersity. The bacterium metabolizes various carbohydrates including sugars predominant in lignocelluloses and other inexpensive substrates. Therefore, the bacterium was employed for PHB production on hydrolysates of cheese whey, spent coffee grounds, sawdust and corn stover, which were hydrolyzed by HCl; required salinity of cultivation media was set up during neutralization by NaOH. The bacterium was capable to use all the tested hydrolysates as well as sugar beet molasses for PHB biosynthesis, indicating its potential for industrial PHB production. [ABSTRACT FROM AUTHOR]

This study firstly evaluated the microbial role when choosing the acclimated anaerobic granular sludge (AGS) and waste activated sludge (WAS) as microbial and nutritional regulators to improve the biomethanation of fruit and vegetable wastes (FVW). Results showed that the enriched hydrogenotrophic methanogens, and Firmicutes and Spirochaeta in the AGS were responsible for the enhanced methane yield. A synthetic waste representing the mixture of WAS and FVW was then used to investigate the influences of different substrate composition on methane generations. The optimal mass ratio of carbohydrate/protein/cellulose was observed to be 50:45:5, and the corresponding methane yield was 411 mL/g-VS added . Methane kinetic studies suggested that the modified Gompertz model fitted better with those substrates of carbohydrate- than protein-predominated. Parameter results indicated that the maximum methane yield and production rate were enhanced firstly and then reduced with the decreasing carbohydrate and increasing protein percentages; the lag phase time however increased continuously. [ABSTRACT FROM AUTHOR]

This study investigated the effect of combination of pretreatment methods such as ultra-sonication and electrolysis for the minimum energy input to recover the maximal carbohydrate and solubilization (in terms of sCOD) from mixed microalgae biomass. The composition of the soluble chemical oxygen demand (COD), protein, carbohydrate revealed that the hydrolysis method had showed positive impact on the increasing quantity and thus enhanced methane yields. As a result, the combination of these 2 pretreatments showed the greatest yield of soluble protein and carbohydrate as 279 and 309 mg/L, which is the recovery of nearly 85 and 90% in terms of total content of them. BMP tests showed peak methane production yield of 257 mL/g VS added , for the hydrolysate of combined pretreatment as compared to the control experiment of 138 mL/g VS added. [ABSTRACT FROM AUTHOR]

• Alkaline, thermal, thermal-PMS and APG pretreatment methods were compared. • All pretreatments improved sludge hydrolysis and inhibited methanogenesis. • Alkaline addition showed best performance towards VFAs yield and sludge reduction. • Refractory substances released in thermal-PMS and APG pretreatments. • Firmicutes are significantly enriched and play an essential role for VFAs production. This study compared the effects of alkaline, thermal, thermal-peroxymonosulfate (PMS), and alkyl polyglucose (APG) pretreatments on volatile fatty acids (VFAs) production from refinery waste activated sludge (RWAS), including VFAs yield, composition, organics components, microbial communities, and the potential improvement of mechanisms. All pretreatments effectively enhanced the bioconversion of RWAS and consequently promoted the hydrolysis process, which inhibited the methanogenesis process. However, the release of lignin/carboxyl-rich alicyclic molecules (CRAM)-like compounds and tannin substances in Thermal-PMS and APG groups significantly influenced the acidogenesis and acetogenesis processes. Among all pretreatments, alkaline pretreatment showed the highest VFAs yield of 95.06 mg/g volatile solids (VS) and VS removal of 17%. This result could be associated with the enrichment of functional hydrolytic-acidification bacteria, such as Planococcus and Soehngenia , and increased metabolism of amino acids, carbohydrates, and nucleotides. By considering an economical and efficient perspective, this study recommended the alkaline pretreatment for the anaerobic fermentation of RWAS. [ABSTRACT FROM AUTHOR]

[Display omitted] • The conversion of carbohydrates to monosaccharides is 87.0%. • Adding water to DES promotes the conversion of carbohydrate to monosaccharides. • Xylose yield from hydrated DES hydrolyzate is higher than that of DES. • Glucose yield from enzymatic hydrolysis increases by 10.3 times. In this work, a rapid one-pot hydrated deep eutectic solvent (DES) pretreatment was proposed to facilitate the conversion of carbohydrates from lignocellulosic biomass to monosaccharides. Specifically, the pure and hydrated DES based on benzyl triethylammonium chloride (BTEAC), formic acid (FA) and water was used to pretreat bamboo shoot shells (BSS) by microwave heating. The pretreated solid residues were enzymatically saccharified to produce fermentable sugars, and the hydrolyzed carbohydrates and lignin remained in the hydrolyzate. The results showed that the yield of monosaccharides from the hydrated DES hydrolyzate (193.7–228.4 g/kg) was significantly higher than that (45.9–66.1 g/kg) of pure DES. The 30% hydrated DES pretreatment achieved the best glucose yield (89.03%) and a total monosaccharides yield of 555.4 g/kg, which corresponded to a conversion ratio of carbohydrates to monosaccharides of 87.0%. The proposed process is a robust method for the efficiently convert carbohydrates from BSS into monosaccharides. [ABSTRACT FROM AUTHOR]

[Display omitted] • Candy-waste had 23.66-fold higher sugar content than seaweed. • L. plantarum was more productive in candy-waste than the other tested bacteria. • Digestate optimization increased relative lactic acid production by 4.53-fold. • Co-fermentation of candy-waste and digestate produced 65.65 g/L lactic acid. To substitute petroleum-based materials with bio-based alternatives, microbial fermentation combined with inexpensive biomass is suggested. In this study Saccharina latissima hydrolysate , candy-factory waste, and digestate from full-scale biogas plant were explored as substrates for lactic acid production. The lactic acid bacteria Enterococcus faecium , Lactobacillus plantarum , and Pediococcus pentosaceus were tested as starter cultures. Sugars released from seaweed hydrolysate and candy-waste were successfully utilized by the studied bacterial strains. Additionally, seaweed hydrolysate and digestate served as nutrient supplements supporting microbial fermentation. According to the highest achieved relative lactic acid production, a scaled-up co-fermentation of candy-waste and digestate was performed. Lactic acid reached a concentration of 65.65 g/L, with 61.69% relative lactic acid production, and 1.37 g/L/hour productivity. The findings indicate that lactic acid can be successfully produced from low-cost industrial residues. [ABSTRACT FROM AUTHOR]

[Display omitted] • Laccase and cellulase can synergistically inhibit the enrichment of ARGs. • Soluble carbohydrates and humic acids are key factors to inhibit ARGs enrichment. • The addition of ≥ 30 % CS to RHS effectively reduced the abundance of ARGs in EFS. Effectively reduce antibiotic resistance genes (ARGs) in ectopic fermentation system (EFS) is essential for practical production. In this study, three experiments were performed to explore how to remove ARGs in EFS effectively. Results demonstrated that ARGs were easily enriched in rice-husk-sawdust padding; simultaneous addition of laccase and cellulase suppressed the ARGs, mainly by increasing soluble carbohydrate concentration and promoting humic acid concentration; addition of corn stalks into rice-husk-sawdust decreased the abundance of ARGs by improving the carbon source structure and enhancing cellulase activity. In conclusion, the present study provides a guidance to reduce the threat of ARGs in EFS, which paved a potential pathway to safely utilize manure resources. [ABSTRACT FROM AUTHOR]