Fermentable Sugars Research Articles

Comparative Analysis of Acidic and Alkaline Pretreatment Techniques for Bioethanol Production from Perennial Grasses

This review paper examines acid and alkaline pretreatments on perennial grasses for second-generation (2G) bioethanol production, a relatively unexplored area in this field. It compares the efficiency of these pretreatments in producing fermentable sugar and bioethanol yield. This study finds that alkaline pretreatment is more effective than acidic pretreatment in removing lignin and increasing sugar yield, leading to higher ethanol yields. However, it is costlier and requires longer reaction times than acidic pretreatment, while acidic pretreatment often leads to the formation of inhibitory compounds at higher temperatures, which is undesirable. The economic and environmental impacts of lignocellulosic biomass (LCB) are also assessed. It is revealed that LCB has a lower carbon but higher water footprint and significant costs due to pretreatment compared to first-generation biofuels. This review further explores artificial intelligence (AI) and advanced technologies in optimizing bioethanol production and identified the gap in literature regarding their application to pretreatment of perennial grasses. This review concludes that although perennial grasses hold promise for 2G bioethanol, the high costs and environmental challenges associated with LCB necessitate further research. This research should focus on integrating AI to optimize the pretreatment of LCB, thereby improving efficiency and sustainability in 2G biofuel production.

Sweet Sorghum for Biofuel Production in Sub-Tropical India

Sweet sorghum (Sorghum bicolor L. Moench), a sugar crop with wider adaptation and high potential for bioenergy and ethanol production is expected to meet food, feed, fodder, fuel and fibre demands. It produces high biomass (50-80 t/ha) and alcohol (1500-2800 l/ha) and multiple income opportunities exist with this crop. Some sweet sorghum lines attain juice yields of about 78% of total plant biomass, containing from 15 to 23% soluble fermentable sugars which are composed mainly of sucrose (70–80%), fructose and glucose. Due to its short growing period (3-4 months), it could be cultivated and supplied during the lean period of sugarcane crushing thus extending the crushing period before and after sugarcane crushing and stretch the sugar mill operation. The major advantage with this crop is that no CAPEX is required when used in a sugar mill system as same machinery can be used for crushing and fermentation. It will help farmers to fetch additional income and provide an opportunity for better utilization of industrial facilities during sugarcane off-season. Promising sweet sorghum genotypes developed by ICAR-IIMR, Hyderabad are being tested for their suitability to sub-tropical conditions in February and June-July plantings at the NSI, Kanpur to establish a sustainable cropping system. Five sweet sorghum genotypes were tested during kharif 2021 for sweet sorghum productivity traits. The fresh stalk yield ranged from 45-60 t/ha and based on TRS, maximum alcohol percentage in wash was observed in three varieties, i.e., Phule Vasundhara, CSH 22SS and SSV 74 which was 8.4%, 8.38% and 7.8% respectively. Maximum ethanol yield of 53.05 L/T was recorded in CSH 22 SS followed by SSV 74 (50.93 L/T). Phule Vasundhara, with a highest stalk yield of 60 t/ha recorded highest ethanol content of 2837 L/ha followed by CSH 22SS (2780 L/ha) and SSV 74 (2411 L/ha).

Optimization of xylitol production through Candida tropicalis in xylose hydrolysate from rice husk

AbstractOwing to the extensive cultivation and production of rice, which consequently generates a high amount of rice husk, rice husk is an easily available lignocellulosic waste; however, the applications it currently has do not entirely exploit its potential. This study aims the production of xylitol as an opportunity to value this residue through fermentation of rice husk hydrolysate. For it, the best particle size of rice husk among 0.25–0.6 mm, 0.6–1.2 mm, and unmilled rice husk (URH) for dilute acid hydrolysis was determined by using a randomized complete block design (RCBD) to select the particle size that produced the highest amount of xylose release; subsequently, adaptation of Candida tropicalis was carried out as an alternative to common detoxification methods, by increasing the concentration of hydrolysate in the medium in 20% every 2 days, and then, xylitol fermentation from the best particle size hydrolysate with C. tropicalis was optimized performing a central composite design (CCD) 22. The best particle size for dilute acid hydrolysis was URH and produced a xylose concentration of 12.85 g/L, and the optimal conditions for xylitol fermentation were 4.41 g/L of inoculum and 68.28 g/L of xylose and accomplished a concentration of 36.74 g/L of xylitol, a yield of 0.58 g/g xylose, and a volumetric productivity of 0.34 g/L/h, providing evidence that rice husk has the potential to be valorized as a source of fermentable sugars for the production of xylitol as a high-value metabolite and proving adaptation method as a viable alternative for the strain’s growth as well as xylitol production.

Utilization of Inulin from Mangrove Apple and Pineapple Juice as Prebiotic Drink to Recovery Covid-19 Patients

Amidst the COVID-19 pandemic, some individuals have turned to functional foods in an effort to bolster their immune systems. One such functional option is prebiotic drinks. These beverages are crafted from fermented sugars, which serve as a carbon source for lactic acid bacteria. To enhance their functional properties, prebiotic drinks often incorporate inulin—a type of prebiotic. Traditionally, these drinks are milk-based, but for those who cannot tolerate dairy, alternatives have emerged. For instance, pineapple-based prebiotic drinks enriched with inulin from mangrove apples have gained popularity. The process involves extracting inulin from mangrove apples and combining it with pineapple to create a probiotic drink. The resulting beverage derives its sweetness from the natural sugars found in pineapples and mangrove apples. Pineapple contains approximately 2.32% glucose, 1.42% fructose, and 7.89% sucrose, while mangrove apples boast 5.08% inulin, 9.67% soluble dietary fiber, and 0.66% FOS. These sugars serve as nourishment for lactic acid bacteria, ultimately stimulating the production of IgG and IgM antibodies. In summary, the combination of inulin-rich mangrove apples and pineapple’s total soluble solids can contribute to fortifying the body’s immune system during the COVID-19 pandemic.

Insights into the transcriptomic mechanism and characterization of endoglucanases from Aspergillus terreus in cellulose degradation

Filamentous fungi are the main industrial source of cellulases which are important in the process of converting cellulose to fermentable sugars. In this study, transcriptome analysis was conducted on Aspergillus terreus NEAU-7 cultivated using corn stover and glucose as carbon sources. Four putative endoglucanases (EG5A, EG7A, EG12A, and EG12C) from A. terreus NEAU-7 were efficiently expressed in Pichia pastoris. Among them, EG7A exhibited the highest enzyme activity (75.17 U/mg) with an optimal temperature of 40 °C and pH 5.0. EG5A and EG12A displayed specific activities of 19.92 U/mg and 14.62 U/mg, respectively, at 50 °C. EG12C showed acidophilic characteristics with an optimal pH of 3.0 and a specific activity of 12.21 U/mg at 40 °C. With CMC-Na as the substrate, the Km value of EG5A, EG7A, EG12A or, EG12C was, 11.08 ± 0.87 mg/mL, 6.82 ± 0.74 mg/mL, 7.26 ± 0.64 mg/mL, and 9.88 ± 0.86 mg/mL, with Vmax values of 1258.23 ± 51.62 μmol∙min−1∙mg−1, 842.65 ± 41.53 μmol∙min−1∙mg−1, 499.38 ± 20.42 μmol∙min−1∙mg−1, and 681.41 ± 30.08 μmol∙min−1∙mg−1, respectively. The co-treatment of EG7A with the commercial cellulase increased the yield of reducing sugar by 155.77 % (filter paper) and 130.49 % (corn stover). Molecular docking assay showed the interaction energy of EG7A with cellotetraose at −10.50 kcal/mol, surpassing EG12A (−10.43 kcal/mol), EG12C (−10.28 kcal/mol), and EG5A (−9.00 kcal/mol). Root Mean Square Deviation (RMSD) and Solvent Accessible Surface Area (SASA) values revealed that the presence of cellotetraose stabilized the molecular dynamics simulation of the cellotetraose-protein complex over a 100 ns time scale. This study provides valuable insights for developing recombinant enzymes and biomass degradation technologies.

Effects of Ca2+ signal on the activities of key enzymes and expression of related genes in yeast ethanol metabolism and mitochondrial function during high sugar fermentation.

During high sugar fermentation, yeast is mainly affected by high sugar stress in the early stage. It becomes jointly affected by high sugar and ethanol stress as ethanol accumulates during fermentation. Ca2+, as the second messenger of the cell, mediates various metabolic processes. In this study, the effects of the Ca2+ signal on the activities of key enzymes, expression of related genes of ethanol metabolism, and mitochondrial function were investigated. The results showed a significant increase in the activities of enzymes related to ethanol metabolism in yeast cells under a high sugar environment. Ca2+ significantly promoted the activities of enzymes related to mitochondrial respiratory metabolism and regulated the carbon flow between ethanol metabolism and the tricarboxylic acid cycle. The high sugar environment affected the expression of genes related to carbon metabolism, while the addition of Ca2+ stabilized the expression of related genes. Ca2+ signal participated in ethanol and mitochondrial metabolism and regulated the key enzymes and related gene expression to enhance the resistance of yeast to stress during high sugar fermentation. © 2024 Society of Chemical Industry.

Unlocking peach juice byproduct potential in food waste biorefineries: Phenolic compounds profile, antioxidant capacity and fermentable sugars

This work assesses an integrated pathway for the revalorization of peach byproduct (PB) within a biorefinery. PB was subjected to an oven-drying (OD) treatment for its evaluation as a storage treatment. It was compared to freeze-drying and untreated material in terms of antioxidant capacity (AOC), phenolic compounds (PC) profile and fermentable sugar production. OD reduced the water content to less than 15 % while preserving the bound hydrolysable polyphenols, which were the more abundant PC (≈64 %) with the highest AOC. Drying treatments hampered polysaccharide accessibility, but some enzyme preparations released 60–70 g/L of fermentable sugars at relatively high solids loading (10 %). This study proposes a novel enzyme-based strategy for the valorisation of fermentable sugars and antioxidant compounds from PB. The sugars can be fermented into several building blocks while the solid residue enriched in recalcitrant phenolic compounds and proteins could be used to develop novel functional products for food/feed sectors.

Dilute nitric acid pretreatment of Ulva biomass for production of fermentable sugars and its validation using Design of Experiments (DoE)

Dilute nitric acid pretreatment of Ulva biomass for production of fermentable sugars and its validation using Design of Experiments (DoE)

Processing of Agricultural Residues with a High Concentration of Structural Carbohydrates into Biogas Using Selective Biological Products

Biomass, particularly agricultural residues and biomass rich in structural carbohydrates, offers significant potential for sustainable biogas production. Biological pretreatment using microorganisms, particularly Trichoderma species, is discussed as a cost-effective and environmentally sustainable approach to improving the decomposition of structural carbohydrates into fermentable sugars. This study aimed to assess the impact of employing a selective biological product (BP) on the biogas production process and biomethane potential using winter wheat straw (WWS) as a representative feedstock. The biological product, consisting of microorganisms of the Trichoderma spp. genus, was introduced to enhance microbial activity. The biogas potential results showed that WWS treated with the BP exhibited a remarkable improvement in biogas production. Specifically, biogas yield increased from 364.1 L/kg of mass in untreated straw to 439.9 L/kg in BP-treated straw, representing a substantial 20.8% increase. Furthermore, in continuous loading tests, the steady-state biogas yield from BP-treated straw ranged from 553.6 to 582.0 L/kg VS, which was notably higher compared to untreated straw with a yield of 490.0 L/kg VS. Overall, the results of this study demonstrated that the application of selective biological products significantly enhanced biogas production and biomethane potential from structural carbohydrates containing biomass sources.

Characterization of Lactic Acid Bacteria (LAB) Isolated from Homemade Fermented Kimchi in Bangladesh

The purpose of this present study was to explore lactic acid bacteria (LAB) from homemade kimchi. Traditionally, kimchi was made in this study at home using fresh vegetables such as cabbage, carrots, radish, green onion leaf, red pepper, garlic, ginger, salt and rice flour, and fermented for seven days. LAB were isolated using selective media and identified by macroscopic and microscopic morphological analysis and short biochemical tests such as catalase, oxidase and Kliger's iron agar (KIA) test. Probiotic potential of LAB was investigated by acid, salt, temperature tolerance and sugar including glucose, fructose, sucrose, xylose and lactose fermentation test. Four distinct single colonies were isolated from four different kimchi preparations. All isolated bacteria were identified as lactic acid bacteria and found gram positive, non-spore forming, survive in both aerobic and anaerobic condition, catalase and oxidase negative. Isolated LAB survive in both highly acidic (pH 2) and alkaline (pH 8) medium, up to 4% NaCl concentrations and at temperatures ranging from 4°C to 55°C. The isolated LAB have also ability to ferment sugars. These findings reveal that isolated LAB found suitable to survive in the environment of human gastrointestinal tract and have probiotic potential. Bangladesh Pharmaceutical Journal 27(1): 103-109, 2024 (January)

Calcium signaling positively regulates cellulase translation and secretion in a Clr-2-overexpressing, catabolically derepressed strain of Penicillium funiculosum

BackgroundLow-cost cellulase production is vital to sustainable second-generation biorefineries. The catabolically derepressed strain of Penicillium funiculosum NCIM1228 (PfMig188 or ∆Mig1) secretes a superior set of cellulolytic enzymes, that are most suitable for 2G biorefineries. At a 3% (w/w) load, the ∆Mig1 secretome can release > 80% of fermentable sugars from lignocellulose at a 15% (w/v) biomass load, irrespective of the type of biomass and pretreatment. The robustness of the secretome can be further increased by improving the cellulase production capacity of the fungal strain.ResultsWe began by identifying the transcription factor responsible for cellulase production in NCIM1228. An advanced RNA-seq screen identified three genes, clr-2, ctf1a and ctf1b; the genes were cloned under their native promoters and transformed into NCIM1228. Of the three, clr-2 overexpression led to twofold higher cellulase production than the parent strain and was thus identified as the transcriptional activator of cellulase in NCIM1228. Next, we overexpressed clr-2 in ∆Mig1 and expected an exponential increase in cellulolytic attributes accredited to the reinforced activation mechanisms, conjoint with diminished negative regulation. Although clr-2 overexpression increased the transcript levels of cellulase genes in ∆Mig1, there was no increase in cellulase yield. Even a further increase in the transcript levels of clr-2 via a stronger promoter was ineffective. However, when the CaCO3 concentration was increased to 5 g/l in the growth medium, we achieved a 1.5-fold higher activity of 6.4 FPU/ml in the ∆Mig1 strain with clr-2 overexpression. Enthused by the calcium effect, a transcriptomic screen for genes encoding Ca2+-activated kinase identified ssp1, whose overexpression could further increase cellulase yield to ~ 7.5 FPU/ml. Investigation of the mechanism revealed that calcium signaling exclusively enhances the translation and secretion of cellulase in Penicillium funiculosum.ConclusionsOur study identifies for the first time that cellulose activates two discrete signaling events to govern cellulase transcription and posttranscriptional processes (translation, processing and secretion) in P. funiculosum NCIM1228. Whereas Clr-2, the transcriptional activator of cellulase, governs transcription, calcium signaling specifically activates cellulase translation and secretion.

Enhancing Beverage Fermentation through Synergy of Saccharomycopsis fibuligera and Saccharomyces cerevisiae: A Mini-Review

Microbial fermentation; a natural process dating back over 7000 years BC, plays a pivotal role in beverage production. While Saccharomyces cerevisiae dominates the industry, recent research emphasizes the importance of co-culture with non-Saccharomyces yeasts for enhanced flavor and aroma. This review explores the cooperative interaction between Saccharomycopsis fibuligera and S. cerevisiae in alcoholic fermentation, shedding light on their enzymatic capabilities. S. fibuligera, an ascomycete with potent amylolytic activity, demonstrates the ability to efficiently convert starch into alcohol, contributing to improved fermentation stability. Co-culturing with S. cerevisiae unleashes a biochemical diversity that enhances the sensory attributes of beverages. Beyond flavor complexity, the co-culture strategy influences key compounds, including phenolic compounds and esters, elevating overall quality. The review delves into the biochemical intricacies of starch-based fermentation, emphasizing the potential of S. fibuligera in hydrolyzing starch into fermentable sugars. S. cerevisiae, a versatile and genetically diverse yeast, adapts to different environmental conditions crucial for successful fermentation. The co-culture approach not only accelerates fermentation but also combats contamination and reduces overall processing time.

Assessing Ionizing Radiation and Chlorine Dioxide (ClO2) as Potential Aseptization Treatments for Yeast Recycling on Mixed Wort of Corn and Sugarcane in Brazil

Yeast recycling, which is a common practice in sugarcane ethanol plants, could be expanded if it could be successfully implemented in corn-based ethanol production. However, the process of recycling the yeast remaining after fermentation is hampered by contaminating microorganisms that reduce the fermentation efficiency and compete with the yeast for the fermentable sugars. Currently, antibiotics are used to control microbial contamination. This study proposes chlorine dioxide and electron beam irradiation as alternative control methods for completely inactivating contaminants and minimizing their effect on recycled yeast. For that, wort sterilization using electron radiation (20 kGy) and treatment with a chemical biocide, namely chlorine dioxide (125 mg kg−1), were compared with non-treated wort. Five fermentation cycles were performed using fed-batch systems with 300 g L−1 of fermentable sugars. The results obtained in this study showed the inactivation of contaminants under the effect of electron beam irradiation, which led to an increase in the productivity, yield, and efficiency of fermentation by 0.21 g L−1h−1, 2.6%, and 4.7%, respectively. However, ClO2 did not show promising results in reducing contamination or improving fermentative parameters. Thus, electron beam irradiation of contaminated wort may be a suitable alternative to chemical biocides and would allow the use of recycled yeast in corn-based ethanol plants.

Application of Trametes pubescens for dye removal and biological pretreatment of sugarcane bagasse

AbstractSugarcane bagasse (SB) is an abundantly available agrowaste that is used extensively as a substrate for the production of different industrial enzymes. It is a renewable resource, rich in fermentable sugars. However, the presence of lignin makes it difficult for microbes to degrade it and so it is difficult to utilize it. Keeping in mind the role of white rot fungi in lignin degradation, Trametes pubescens MB89 was used in this study for the delignification of SB with the simultaneous production of laccase. The fungus was also used for the degradation of malachite green dye. A Box–Behnken design (BBD) was used to optimize variables affecting solid state fermentation of SB for laccase production. The leftover SB after fermentation was used for cellulase production by the thermophilic bacterium Neobacillus sedimentimangrovi UE25. The BBD depicted optimized conditions as 60% moisture, particle size 100 μ, 10 days’ incubation period, 450 μM CuSO4, and a temperature of 30 °C. The laccase titers of 1271 IU mL−1 were obtained under optimized conditions. Neobacillus sedimentimangrovi UE25 produced 4.574 IU mL−1 of endoglucanase and 1.812 IU mL−1 of β‐glucosidase by utilizing fungal pretreated SB. Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed the impact of fungal cultivation on SB. Pores were observed after microbial pretreatment and there were changes in the morphological characteristics such as the pith and fiber of SB. To test the ability of laccase to break down aromatic dyes, we grew the fungus T. pubescens MB89 in a nutrient‐rich medium supplemented with malachite green dye. The fungus was able to remove 73.68% of the malachite green dye from the medium in 24 h. This shows that T. pubescens MB89 has a range of potential applications for environmental and industrial purposes.

Exploring the use of supercritical carbon dioxide in enzymatic hydrolysis of cellulosic substrate

Enzymes are critical components for production of fermentable sugars in lignocellulosic biorefineries. Their activity could be influenced by various reaction parameters. Herein, a formulated cellulolytic enzyme cocktail was immobilized into mesoporous aerogel material and used under high pressure environment of supercritical CO2 (scCO2). The cocktail was immobilized at different enzyme loads (36.0 to 144.0 mg enzyme/g aerogel) using sol-gel entrapment method and scCO2 drying. The immobilized cocktail at 144.0 mg/g aerogel enzyme load retained a residual yield of >50.0 % after fourth cycle of reuse compared to first cycle under atmospheric pressure. Sugar yield by the cocktail aerogel was below 10 wt% in second cycle under scCO2 due to enzyme leaching. Additionally, surface area and porous volume of reused aerogels was decreased over the reuse cycles. The study suggests that scCO2 could be employed for aerogel preparation after optimizing the immobilization process for pure enzymes rather than crude enzymes.

Applications of diastatic Saccharomyces cerevisiae in brewing, distilling and biofuel production

Why was the work done: Diastatic variants of Saccharomyces cerevisiae are unusual in producing an extracellular glucoamylase which enables the breakdown of starch to fermentable sugars. Diastatic S. cerevisiae has long been viewed negatively as a contaminant of especially beer packaged in cans or bottles. However, this view is being reconsidered due to the opportunities that diastatic strains present for niche fermented products and distillation applications. What are the main findings: This review highlights the utilisation of diastatic S. cerevisiae for its flavour potential, and processing applications in the brewing, distilling, and biofuel industries. Further, genetic differences are compared with non-diastatic strains of S. cerevisiae, together with commonly employed and emerging methods of detection. Why is the work important: Diastatic yeast strains can be used to create flavour profiles that resemble traditional beverages and can be used to achieve fermentation with higher attenuation. This offers greater fermentation efficiency in, for example, the development of low-calorie beers. Additionally, the ability of diastatic strains of S. cerevisiae to convert non-fermentable oligosaccharides to fermentable sugars enables applications that range from novel beverages using unusual raw materials to more efficient distillation and biofuel production. The negative attributes that are associated with diastatic S. cerevisiae yeasts can be managed through co-inoculation or hybridisation with standard strains.

Comparative study of chemical and enzymatic pre-treatments of Kitchen waste (KW) to generate fermentable sugars for the production of polyhydroxyalkanoates (PHA)

Kitchen waste (KW) production is anticipated to rise because of accelerated urban and economic growth, particularly in Asian nations. Therefore, applications/recycling of KW should be explored for its effective utilization to generate a sustainable source of energy that will ultimately avoid massive economic and energy losses. The main goal of this study was to investigate the combinational effect of thermochemical and enzymatic pre-treatment on synthetic KW to enhance the release of fermentable sugars for the synthesis of value-added products such as polyhydroxyalkanoates (PHAs). The thermochemical pre-treatment of KW samples was performed using 4 N HCl, 4 N H2SO4, and 4 N NaOH at a concentration of 0–30% (v/v), 30–100 °C for 0–120 min. Furthermore, to enhance the total fermentable sugars, variable enzyme dosages were added after acidic or alkaline pre-treatments (0–1% v/v α-amylase and 0–1% v/v amyloglucosidase-AMG) while maintaining a constant pH 5, temperature 50 °C, and time 30 min. Pre-treatment of KW with acid (15% v/v 4 N HCl in water) at temperature 100 °C, followed by enzymatic hydrolysis, i.e., 0.6% (v/v) α-amylase and 0.4% (v/v) amyloglucosidase (at pH 5, 50 0C and 60 min) resulted in the maximum concentration of fermentable reducing sugars (46.13 g/L) in the hydrolysate.

Potential of Ecoenzymes and N2 Nanobubbles on the Growth of Phalaenopsis sp. Orchid at the Acclimatization Stage

Growth is a quantitative change during one plant’s life cycle and is irreversible.withaddition An in crease the volume or dry weight of plants or other organs is due to the adding, of new structural elements. Phalaenopsis (moth orchid) is a genus of orchids appeal. The diversity of colors, shapes, and textures, as well as its aroma, make Phalaenopsis orchids one of the charming flowers of Indonesia. Ecoenzyme is a solution of complex organic substances produced from the fermentation of organic residues, sugar, and water. Nanobubbles (NBs) are an example of nanotechnology. NBs have a diameter of 1-100 nm and are nanoscopic gas bubbles in a solution or water that can change the characteristics of water and are stable. This study aims to determine the potential of giving Ecoenzyme and NBs N2 on the growth of Phalaenopsis orchids during the acclimatization stage. This research was conducted from October to December 2022 at the Orchidology and Nursery Laboratory, Islamic University of Malang. This study used an experimental method with a completely randomized design (CRD) with 10 treatments, namely 0 mL/L (control), 1 mL/L Ecoenzyme, 2 mL/L Ecoenzyme, 3 mL/L Ecoenzyme, 4 mL/L Ecoenzyme, 4 combination NBs N2 and Ecoenzymes, and 5 mL NBs N2 with 3 replications, making a total of 30 treatment units. The research parameters included the number of leaves, leaf length, number of roots, root length, plant height, fresh weight, and plant dry weight. The results of this study showed that the treatment of 3 mL/L Ecoenzyme showed potential in increasing the number of leaves by 4 pieces: at the same time the optimal concentration of the combination of Ecoenzyme and NBs was 2 mL/L plus 5 mL NBs N2 in increasing the number of roots by 10 pieces, and the optimal concentration of NBs was 5 mL in increasing the root length by 7.07 cm, plant height by 17.10 cm leaf. length, plant weight by 4.16 g and dry weight by 0.85 g in Phalaenopsis orchids.

Compositional and temporal division of labor modulates mixed sugar fermentation by an engineered yeast consortium

Synthetic microbial communities have emerged as an attractive route for chemical bioprocessing. They are argued to be superior to single strains through microbial division of labor (DOL), but the exact mechanism by which DOL confers advantages remains unclear. Here, we utilize a synthetic Saccharomyces cerevisiae consortium along with mathematical modeling to achieve tunable mixed sugar fermentation to overcome the limitations of single-strain fermentation. The consortium involves two strains with each specializing in glucose or xylose utilization for ethanol production. By controlling initial community composition, DOL allows fine tuning of fermentation dynamics and product generation. By altering inoculation delay, DOL provides additional programmability to parallelly regulate fermentation characteristics and product yield. Mathematical models capture observed experimental findings and further offer guidance for subsequent fermentation optimization. This study demonstrates the functional potential of DOL in bioprocessing and provides insight into the rational design of engineered ecosystems for various applications.

Cloning of AA9 Polysaccharide Monooxygenase gene AN3860 into pEX2B for expression in Aspergillus oryzae

Polysaccharide monooxygenases (PMOs) catalyze oxidative degradation of recalcitrant carbohydrate chains in cellulose, starch, and chitin. In biofuel industry, the conversion of rich lignocellulose source to fermentable sugars by hydrolytic cellulases can be synergistically boosted by cellulose-active PMOs (AA9 PMOs) found in a vast number of fungi that grow on biomass. Aspergillus nidulans, a filamentous fungus, possess a dozen of PMO-encoding genes, but only the AN3860 is expressed at a high level when cultured with wheat straw as the sole carbon source. Bioinformatic analysis indicates that AN3860 belongs to type 3 AA9 PMO subfamily that is capable of hydroxylating both C1 and C4 of the glycosidic linkages. Therefore, AN3860 may be a potential enzyme to improve cellulose hydrolysis efficiency, which has not been characterized. In this study, we describe the AN3860 cloning into Aspergillus oryzae AUT1-PlD. To facilitate the purification of AN3860, we added a CBM20 tag to its C-terminal. The recombinant vector was designed and constructed successfully. Simultaneously, we have obtained the clone of A. oryzae carrying the target gene by the ATMT method. Further expression optimization and characterization of AN3860 by both activity assays and spectroscopic techniques are underway.