Carboxymethyl Cellulase Research Articles

Dark septate endophytes improved the performance of Isatis indigotica by enhancing the degradation of lignocellulosic residues

To evaluate the lignocellulose degradation ability of dark septate endophytes (DSE) and the utilization efficiency of agricultural waste in medicinal plant cultivation, in this study, 44 DSE strains (isolated from various plots and plants) were inoculated on the medium with sodium carboxymethyl cellulose, xylan, and citrus pectin as the single carbon source or with additional guaiacol, and found that both DSE strains can selectively degrade different lignocellulose component (mainly cellulose, hemicellulose, and pectin), while the specificity of fungal genus was the main factor affecting the lignocellulosic degradation ability. Further, corn straw and licorice residue, were used as lignocellulosic residues (LR) in solid state fermentation to demonstrate the cellulase production ability of DSE. Among them, the activities of filter paper cellulase, carboxymethyl cellulase, and β-glucosidase of Paraphoma chlamydocopiosa were the highest at 0.721-2.055, 1.435-3.102, and 1.245-2.976 U/g, respectively, and followed by Paraboeremia selaginellae at 0.347-1.644, 1.386-2.864, and 1.068-2.878 U/g, respectively. In addition, P. chlamydocopiosa and P. selaginellae exhibited the Isatis indigotica growth promotion which could increase the shoot, root, and total biomass by 56.3%, 93%, and 58.4% and 58.4%, 139.8%, 64.9% respectively. Further the two-factor pot experiment investigated the synergetic effects of the two DSE strains plus LR on I. indigotica. Two strains improved the LR utilization efficiency by mobilizing soil C-hydrolytic enzyme activities. These results highlight potential DSE applications in medicinal plant cultivation under LR return.

Ganoderma lucidum driven fermentation of Rosa roxburghii pomace: Effects on noodle physicochemical properties, digestion, and gut microbiota

Rosa roxburghii pomace (RRP) is a high dietary fiber byproduct that is underutilized. This study investigated the effects of Ganoderma lucidum fermented Rosa roxburghii pomace (FRRP) on noodle cooking characteristics, texture, structure, in vitro digestion, and fermentation. The results showed that soluble dietary fiber, active components (polysaccharides, triterpenoids and dietary flavonoids), and the total cellulase (Filter paper enzymes, Carboxymethyl cellulase), β-glucosidase and laccase activity were significantly increased in FRRP (p < 0.05). FRRP improved the cooking and sensory properties of noodles and inhibited starch hydrolysis during in vitro digestion. The resistant starch content in noodles with 15 % FRRP increased by 12.63 %, and the predicted glycemic index decreased by 9.34 %. Moreover, the intestinal microbiota structure was significantly improved, promoting the growth of beneficial bacteria such as Bifidobacterium and Lactobacillus. This study contributed to the high-value and environmentally friendly utilization of RRP and provided new insights into the development of efficient noodles.

Co-fermentation of dark septate endophytes and Trichoderma viride can effectively degrade cellulose in different Chinese medicinal herbal residues

Chinese medicinal herbal residues (CMHRs) are currently a widely overlooked renewable biomass resource, and developing controllable microbial fermentation technology for CMHRs will help achieve the resource utilization of CMHRs. In this study, the activity of various cellulases, reducing sugar content and cellulose degradation rate were combined to evaluate the solid state fermentation (SSF) potential of dark septate endophytes (DSE) and Trichoderma viride in separate fermentation and co-fermentation of different CMHRs (single Astragalus mongolicus residue and compound residues of Panax notoginseng and Salvia miltiorrhiza). The results showed that the cellulase activity of some DSE strains was higher than that of T. viride. T. viride fermentation alone could increase the content of substrate reducing sugars, while DSE fermentation could reduce the content of substrate reducing sugars. DSE strains such as Macrophomina pseudophaseoline, Paraboeremia selaginellae, Paraphoma chlamydocopiosa and Paraphoma radicina had the potential to co-ferment with T. viride. Optimization of the fermentation process by inoculation of T. viride after 3 d or 6 d of DSE effectively increased the cellulase activity of co-fermented CMHRs. After optimization, the activities of filter paper cellulase, carboxymethyl cellulase, and β-glucosidase in different fermentation combinations reached 2.51–5.61, 2.86–4.72 and 12.85–32.35 U/g, respectively. Further, the co-fermentation of DSE and T. viride effectively degraded cellulose in different CMHRs with a degradation rate of 54.43%–67.38%. Scanning electron microscope confirmed that the co-fermentation of DSE and T. viride could increase the external surface area and porosity of CMHRs, and destroy the structure of CMHRs. The results of this study both provided a basis for the microbial degradation of single and compound CMHR, which is of great significance for solving the treatment of waste such as Chinese herbal residue and further resource utilization.

Correction: Optimization of Carboxymethyl Cellulase Production by Bacillus sp. NAB37 and Biocatalytic Potential in Saccharification of Acid-Alkali Pretreated Parthenium Hysterophorus

Correction: Optimization of Carboxymethyl Cellulase Production by Bacillus sp. NAB37 and Biocatalytic Potential in Saccharification of Acid-Alkali Pretreated Parthenium Hysterophorus

Bioprospecting of novel and biologically active compounds and enzymes from a new fungal biobank for industrial biotechnology

Here, we present methods for screening any newly isolated microbial biobank for enzymes, antioxidants, and additional secondary metabolites. Bioactive compounds and enzymes produced by fungi have many applications in industry as valuable leads for pharmaceuticals, nutraceuticals, and potential strains for industrial biotechnology. In this study, fungi collected from Irish habitats were purified and identified by sequencing Internal Transcribed Spacer (ITS) ribosomal DNA regions. Reducing sugars released because of enzyme hydrolysis was used to estimate the relative enzyme activity for carboxymethyl cellulase, pectinase, β-xylanase, arabinoxylanase, mannanase, and galacto-mannanase in the fungal extracts and was normalized against the crude protein content to express relative enzyme activity/milligram. The best enzyme producers were as follows: F1 Clonostachys rosea demonstrated 351.63 U/mg β-xylanase and 645.50 U/mg arabinoxylanase activity; F2 Penicillium expansum had 25 U/mg cellulase and 112.5 U/mg pectinase activity; F3 Fusarium avenaceum had 139.36 U/mg arabinoxylanase, 52.33 U/mg galacto-mannanase, and 45 U/mg mannanase activity; and F9 Trichoderma koningii had 372.15 U/mg β-xylanase and 655.18 U/mg arabinoxylanase activity. In addition to enzyme activity, these strains also exhibited antioxidant activity when tested in Oxygen radical absorbance capacity (ORAC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric ion reducing antioxidant power (FRAP) assays, with activity expressed as μmol Trolox equivalents (TE) per gram of dried fungal extract. In results from the ORAC assay, F1 C. rosea reported 655,669 µmol TE/g; F2 P. expansum had 636,889 µmol TE/g; and F3 F. avenaceum had 4,488,035 µmol TE/g. High DPPH activity was observed for F1 C. rosea at 12,572 µmol TE/g, F3 F. avenaceum at 22,646 µmol TE/g, and F9 T. koningii at 22,558 µmol TE/g. F1 C. rosea, F3: F. avenaceum, and F9 T. koningii also reported high FRAP activity at 36,019 µmol TE/g, 69,325 µmol TE/g, and 25,812 µmol TE/g, respectively. In terms of secondary metabolites, the main compounds detected for the isolates were F1 C. rosea produced benzoic acid, 3-pyridinepropionic acid, and cyclo(-Gly-Phe); F2 P. expansum produced Cyclo(-Gly-Phe) and prenitremone A; F3 F. avenaceum produced cyclo(-Leu-Leu) and p-anisaldehyde; and F9 T. koningii produced cyclo(-Gly-Phe), canescin, citreoviridin X, and cyclopaldic acid. These selected isolates indicate that Irish fungi are a potential source of enzymes and novel biologically active compounds useful in industrial biotechnology and bioproduction supporting sustainability and responsible environmental management.

Bioactive Potential of Actinobacteria Strains Isolated from the Rhizosphere of Lavender, Lemon Balm, and Oregano

The objective of this study was to isolate and characterize actinobacteria from the rhizosphere of medicinal and aromatic plants, specifically lavender (Lavandula angustifolia Mill.), lemon balm (Melissa officinalis L.), and oregano (Origanum vulgare L.). Rhizospheric soil samples revealed a high abundance of culturable actinobacteria (6.97–7.23 log10 CFU/g). Six isolates were selected for their promising enzymatic activities (lignin peroxidase, carboxymethyl cellulase) and antimicrobial properties. Isolates M345 and M162 exhibited the highest cellulase activity indices (3.19 ± 0.71 and 2.54 ± 0.22, respectively), with five isolates producing lignin peroxidase. These actinobacteria also demonstrated plant growth-promoting traits such as phosphate solubilization and nitrogen fixation, along with strong antimicrobial activity against Gram-negative bacteria and phytopathogenic fungi. Additionally, they significantly enhanced maize seed germination, increasing the vigor index from 4283.33 ± 1264.37 to 6248.28 ± 1661.94 compared to that of the control. These results indicate that the isolated actinobacteria strains hold potential as microbial inoculants for sustainable agriculture, contributing to soil health, plant growth, and pathogen management.

Optimization of Cellulase Production from Agri-Industrial Residues by Aspergillus terreus NIH2624

The objective of this study was to assess the cellulase production of four fungi: Aspergillus terreus NIH2624, Aspergillus clavatus NRRL1, Aspergillus versicolor CBS583.65 and Aspergillus phoenicis ATCC3157, under submerged cultivation conditions. When these fungi were cultured in shake flasks using Mandels and Weber’s minimal medium with 1% sugarcane bagasse as a carbon source and 1.8 g/L of rice bran extract as a nitrogen source, A. terreus showed maximum cellulase production (filter paper activity (FPase) 3.35 U/mL; carboxymethyl cellulase activity (CMCase) 1.69 U/mL). Consequently, A. terreus was selected for the optimization study for cellulase production. Among the different tested carbon sources, A. terreus showed higher CMCase activity when it was cultivated on delignified sugarcane bagasse (1.64 U/mL) and higher FPase activity on sugarcane straw (7.95 U/mL). Regarding the nitrogen sources, the maximum FPase activity was observed when using rice bran (FPase, 8.90 U/mL) and soybean meal (FPase, 9.63 U/mL). The optimized fermentation medium (minimal medium with delignified sugarcane bagasse and rice bran as carbon and nitrogen sources, respectively) resulted in an enzymatic cocktail mainly composed of xylanases, with a maximum activity of 1701.85 U/mL for beechwood xylan, 77.12 U/mL for endoglucanase and 21.02 U/mL for cellobiohydrolase. Additionally, the enzymatic cocktail showed efficient activities for β-glucosidase, β-xylanase, arabinofuranosidase and lytic polysaccharide monoxygenases (LPMOs). This cellulase enzyme solution has the potential to efficiently hydrolyze lignocellulosic biomass, producing second-generation sugars in biorefineries.

Optimization of Carboxymethyl Cellulase Production by Bacillus sp. NAB37 and Biocatalytic Potential in Saccharification of Acid-Alkali Pretreated Parthenium Hysterophorus

Optimization of Carboxymethyl Cellulase Production by Bacillus sp. NAB37 and Biocatalytic Potential in Saccharification of Acid-Alkali Pretreated Parthenium Hysterophorus

Efficacy of zinc nanoparticle supplementation on ruminal environment in lambs

BackgroundZinc nanoparticles (NPs) are characterized by high bioavailability, small size, and high absorbability. The purpose of this experiment was to determine the effect of Zn-NP feed supplementation on ruminal fermentation, microbiota, and histopathology in lambs. In vitro (24 h), short-term (STE, 28 d), and long-term (LTE, 70 d) experiments were performed. The lambs in STE were fed a basal diet (BD) composed of 350 g/d ground barley and 700 g/d meadow hay (Control), BD enriched with ZnO-NPs (80 mg Zn/kg of diet, ZnO-NPs), and BD enriched with Zn phosphate-based NPs (80 mg Zn/kg of diet, ZnP-NP). The in vitro gas production technique was used in incubated rumen fluid from STE. The lambs in LTE were fed BD (Control), BD enriched with ZnO-NPs (40 mg Zn/kg of diet, ZnO-NP40), BD enriched with ZnO-NPs (80 mg Zn/kg of diet, ZnO-NP80) and BD enriched with ZnO (80 mg Zn/kg of diet, ZnO-80).ResultsAfter 24 h of incubation, dry matter digestibility was higher for ZnO-NP and ZnP-NP substrates than the control in an in vitro experiment (P < 0.001). The total bacterial population in the STE was lower (P < 0.001) in the ZnP-NP group than in the control and ZnO-NP groups, but the protozoan populations were not significantly different. The ammonia-N concentration in LTE was lowest in the ZnO-NP80 group (P = 0.002), but the activities of carboxymethyl cellulase (P < 0.001) and xylanase (P = 0.002) were higher in the ZnO-NP40, ZnO-NP80, and ZnO-80 groups than in the control group. Morphological observation after STE and LTE revealed histological changes (e.g. inflammation of the epithelium or edema of the connective tissue) in the rumen of lambs.ConclusionZn-NP supplementation up to 70 d improved feed-use efficiency and influenced ammonia-N concentration and activities of hydrolases in the rumen. The active ruminal fermentation affected the health of the ruminal papillae and epithelium in the lambs, regardless of the application's form, dose, or duration. However, by affecting rumen microbial fermentation, Zn-NPs could alter fermentation patterns, thereby increasing the capacity of host rumen epithelial cells to transport short-chain fatty acids.

Transcriptome Analysis Reveals the Effect of Oyster Mushroom Spherical Virus Infection in Pleurotus ostreatus.

Oyster mushroom spherical virus (OMSV) is a mycovirus that inhibits mycelial growth, induces malformation symptoms, and decreases the yield of fruiting bodies in Pleurotus ostreatus. However, the pathogenic mechanism of OMSV infection in P. ostreatus is poorly understood. In this study, RNA sequencing (RNA-seq) was conducted, identifying 354 differentially expressed genes (DEGs) in the mycelium of P. ostreatus during OMSV infection. Verifying the RNA-seq data through quantitative real-time polymerase chain reaction on 15 DEGs confirmed the consistency of gene expression trends. Both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses highlighted the pivotal role of primary metabolic pathways in OMSV infection. Additionally, significant changes were noted in the gene expression levels of carbohydrate-active enzymes (CAZymes), which are crucial for providing the carbohydrates needed for fungal growth, development, and reproduction by degrading renewable lignocellulose. The activities of carboxymethyl cellulase, laccase, and amylase decreased, whereas chitinase activity increased, suggesting a potential mechanism by which OMSV influenced mycelial growth through modulating CAZyme activities. Therefore, this study provided insights into the pathogenic mechanisms triggered by OMSV in P. ostreatus.

A carboxymethyl cellulase from the yeast Cryptococcus gattii WM276: Expression, purification and characterisation

Cryptococcus gattii and its medical implications have been extensively studied. There is, however, a significant knowledge gap regarding cryptococcal survival in its environmental niche, namely woody material, which is glaring given that infection is linked to environmental populations. A gene from C. gattii (WM276), the predominant global molecular type (VGI), has been sequenced and annotated as a putative cellulase. It is therefore, of both medical and industrial intertest to delineate the structure and function of this enzyme. A homology model of the enzyme was constructed as a fusion protein to a maltose binding protein (MBP). The CGB_E4160W gene was overexpressed as an MBP fusion enzyme in Escherichia coli T7 cells and purified to homogeneity using amylose affinity chromatography. The structural and functional character of the enzyme was investigated using fluorescence spectroscopy and enzyme activity assays, respectively. The optimal enzyme pH and temperature were found to be 6.0 and 50 °C, respectively, with an optimal salt concentration of 500 mM. Secondary structure analysis using Far-UV CD reveals that the MBP fusion protein is primarily α-helical with some β-sheets. Intrinsic tryptophan fluorescence illustrates that the MBP-cellulase undergoes a conformational change in the presence of its substrate, CMC-Na+. The thermotolerant and halotolerant nature of this particular cellulase, makes it useful for industrial applications, and adds to our understanding of the pathogen's environmental physiology.

Fibrobacter sp. HC4, a newly isolated strain, demonstrates a high cellulolytic activity as revealed by enzymatic measurements and in vitro assay.

Despite their low quantity and abundance, the cellulolytic bacteria that inhabit the equine large intestine are vital to their host, as they enable the crucial use of forage-based diets. Fibrobacter succinogenes is one of the most important intestinal cellulolytic bacteria. In this study, Fibrobacter sp. HC4, one cellulolytic strain newly isolated from the horse cecum, was characterized for its ability to utilize plant cell wall fibers. Fibrobacter sp. HC4 consumed only cellulose, cellobiose, and glucose and produced succinate and acetate in equal amounts. Among genes coding for CAZymes, 26% of the detected glycoside hydrolases (GHs) were involved in cellulolysis. These cellulases belong to the GH5, GH8, GH9, GH44, GH45, and GH51 families. Both carboxymethyl cellulase and xylanase activities of Fibrobacter sp. HC4 were detected using the Congo red method and were higher than those of F. succinogenes S85, the type strain. The in vitro addition of Fibrobacter sp. HC4 to a fecal microbial ecosystem of horses with large intestinal acidosis significantly enhanced fibrolytic activity as measured by the increase in gas and volatile fatty acids production during the first 48 h. According to this, the pH decreased and the disappearance of dry matter increased at a faster rate with Fibrobacter sp. HC4. Our data suggest a high specialization of the new strain in cellulose degradation. Such a strain could be of interest for future exploitation of its probiotic potential, which needs to be further determined by in vivo studies.IMPORTANCECellulose is the most abundant of plant cell wall fiber and can only be degraded by the large intestine microbiota, resulting in the production of volatile fatty acids that are essential for the host nutrition and health. Consequently, cellulolytic bacteria are of major importance to herbivores. However, these bacteria are challenged by various factors, such as high starch diets, which acidify the ecosystem and reduce their numbers and activity. This can lead to an imbalance in the gut microbiota and digestive problems such as colic, a major cause of mortality in horses. In this work, we characterized a newly isolated cellulolytic strain, Fibrobacter sp. HC4, from the equine intestinal microbiota. Due to its high cellulolytic capacity, reintroduction of this strain into an equine fecal ecosystem stimulates hay fermentation in vitro. Isolating and describing cellulolytic bacteria is a prerequisite for using them as probiotics to restore intestinal balance.

Enhanced reducing sugar production by blending hydrolytic enzymes from Aspergillus fumigatus to improve sugarcane bagasse hydrolysis.

Biomass pretreatment for the production of second-generation (2G) ethanol and biochemical products is a challenging process. The present study investigated the synergistic efficiency of purified carboxymethyl cellulase (CMCase), β-glucosidase, and xylanase from Aspergillus fumigatus JCM 10253 in the hydrolysis of alkaline-pretreated sugarcane bagasse (SCB). The saccharification of pretreated SCB was optimised using a combination of CMCase and β-glucosidase (C + β; 1:1) and addition of xylanase (C + β + xyl; 1:1:1). Independent and dependent variables influencing enzymatic hydrolysis were investigated using response surface methodology (RSM). Hydrolysis using purified CMCase and β-glucosidase achieved yields of 18.72mg/mL glucose and 6.98mg/mL xylose. Incorporation of xylanase in saccharification increased the titres of glucose (22.83mg/mL) and xylose (9.54mg/mL). Furthermore, characterisation of SCB biomass by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy respectively confirmed efficient structural disintegration and revealed the degree of crystallinity and spectral characteristics. Therefore, depolymerisation of lignin to produce high-value chemicals is essential for sustainable and competitive biorefinery development.

Isolation and Characterization of Cellulolytic Pseudomonas Aeruginosa from Teak Forest Soil for its Cellulase Production and Cellulolytic Activity

A cellulolytic bacterium was isolated from Tectona forest soil and provisionally identified as Pseudomonas aeruginosa. The bacterium showed the highest level of reducing sugar and extracellular protein production when incubated for 3 days at 40°C, pH 8.5 in Winstead’s broth having 1.5% carboxymethyl cellulose (CMC) and 0.2% Yeast Extract as carbon and nitrogen sources, respectively. The bacterium produced the maximum 462 µg/ml reducing sugar and 450 µg/ml extracellular proteins. Crude cellulase produced by the bacterium showed the highest carboxymethyl cellulase (CMCase) activity rather than filter paperase (FPase), Avicelase and β-Glucosidase activities. The crude cellulase showed highest CMCase activity when incubated for 90 minutes at pH 8.5, 25°C using CMC and Yeast Extract as carbon and nitrogen sources, respectively as well as in presence of Hg2+ ion and SDS (inhibitor and reductant). The highest enzyme activity was found to be 315 U/ml. The molecular weight of the crude cellulase was found as 33 kDa through SDS PAGE analysis. According to Worthington Enzyme Manual it may be Endoglucanase IV. The Chittagong Univ. J. B. Sci., Vol. 10(1 &amp;2):167-179, 2020

Gut microorganisms of Locusta migratoria in various life stages and its possible influence on cellulose digestibility.

Cellulose is the most abundant and cheapest renewable resource in nature, but its degradation is difficult, so finding efficient cellulose degradation methods is an urgent challenge. Locusta migratoria is a large group of agricultural pests, and the large number of microorganisms that inhabit their intestinal tracts play an important role in cellulose degradation. We analyzed the dynamics of Locusta migratoria gut microbial communities and cellulose digestibility using a combination of high-throughput sequencing technology and anthrone colorimetry. The results revealed that the gut microbial diversity and cellulose digestibility were dynamically changed at different life stages. In addition, we explored the intestinal bacterial community of Locusta migratoria across life stages and its correlation with cellulose digestibility. The dominant bacterial genera at different life stages of Locusta migratoria were uncovered and their carboxymethyl cellulase activity (CMCA) and filter paper activity (FPA) were determined. This study provides a new avenue for screening cellulolytic bacteria and lays the foundation for developing insects with significant biomass into cellulose-degrading bioreactors.

Enhancing soil amendment for salt stress using pretreated rice straw and cellulolytic fungi

Rice straw breakdown is sluggish, which makes agricultural waste management difficult, however pretreatment procedures and cellulolytic fungi can address this issue. Through ITS sequencing, Chaetomium globosum C1, Aspergillus sp. F2, and Ascomycota sp. SM2 were identified from diverse sources. Ascomycota sp. SM2 exhibited the highest carboxymethyl cellulase (CMCase) activity (0.86 IU/mL) and filter-paper cellulase (FPase) activity (1.054 FPU/mL), while Aspergillus sp. F2 showed the highest CMCase activity (0.185 IU/mL) after various pretreatments of rice straw. These fungi thrived across a wide pH range, with Ascomycota sp. SM2 from pH 4 to 9, Aspergillus sp. F2, and Chaetomium globosum C1 thriving in alkaline conditions (pH 9). FTIR spectroscopy revealed significant structural changes in rice straw after enzymatic hydrolysis and solid-state fermentation, indicating lignin, cellulose, and hemicellulose degradation. Soil amendments with pretreated rice straw, cow manure, biochar, and these fungi increased root growth and soil nutrient availability, even under severe salt stress (up to 9.3 dS/m). The study emphasizes the need for a better understanding of Ascomycota sp. degradation capabilities and proposes that using cellulolytic fungus and pretreatment rice straw into soil amendments could mitigate salt-related difficulties and improve nutrient availability in salty soils.

Carbon fixation mechanism of fungal community bypass strategy in rice straw composting combined with functional microbes: inhibition from cellobiose to glucose pathway

Composting offers an eco-friendly approach, converting organic solid waste into valuable soil enhancer products. Three experimental treatments were designed to explore the microbial mechanisms influencing lignocellulose loss in rice straw composting: CK (the control), B4 (inoculated with Bacillus subtilis), and Z1 (inoculated with Aspergillus fumigatus). The results showed significant increases in carboxymethyl cellulase, cellobiohydrolase, laccase, and xylanase activities during B4 and Z1composting. However, lignin peroxidase and manganese peroxidase were not significantly affected, and β-glucosidase was inhibited. Additionally, microbial inoculation stimulated lignin loss, with B4 and Z1 composting increasing degradation by 14.42% and 16.29%, respectively, compared to the CK. Simultaneously, humic substance content increased as microbial inoculation inhibited β-glucosidase, causing cellobiose to accumulate and divert into a pathway that forms humic substances. The random forest model showed that Symmetrospora and Phaeosphaeria significantly boosted lignocellulose loss in B4 and Z1 composting by promoting fungi functional aggregation, thus accelerating the degradation and transformation process. This study explored the microbial mechanism of lignocellulose loss and provided new insights into lignocellulose conversion and carbon fixation.

Fungal co-culture enabled co-fermentation of food waste for production of endoglucanase enzyme

The primary scenarios of biochemical industries include diverse applications with high demand and the costly manufacturing of microbial cellulolytic enzymes. Using these enzymes to turn cellulosic waste into fuel is one of the prime applications of these enzymes to produce green fuel. Nevertheless, low production and weak functional abilities make these enzymes expensive and technically non-viable. This study presents multifactor bioprocess approaches to enhance cellulolytic enzyme production and efficiency using a low-cost strategy. Co-fermentation of pea pods (PPs) and potato peel (PP) wastes as food wastes has been conducted for solid-state fermentation (SSF) using fungal strain-based co-culture. To set the SSF, the nutrient medium and moisture balance of SSF have been maintained using an extract of PPs and PP waste, which are found to be rich in sugar and starch composition. Starch may function as a natural inducer in the SSF process to alleviate enzyme production in the presence of sugar composition. At 37 oC and pH 5.0, a maximum of 2.4 U/mL FPA (filter paper activity) has been produced at a substrate ratio of 4:04 (PPs:PP) using 50% of the moisture content on day 5 of the harvesting period. Additionally, 24.7 IU/mL of CMCase (carboxymethyl cellulase) in day 8 and 18.8 IU/mL of BGL (β-Glucosidase) in day 7 have been obtained. A temperature of 37 oC was found to be optimal, while a pH range of 5.0–9.0 was noticed to be optimal for maximum CMCase activity. Thus, the study may provide a sustainable approach to valorizing domestic solid food waste for the economic production of hydrolytic enzymes.

Effects of yak rumen anaerobic fungus Orpinomyces sp. YF3 fermented on in vitro wheat straw fermentation and microbial communities in dairy goat rumen fluid, with and without fungal flora.

Rumen fungi play an essential role in the breakdown of dietary fibrous components, facilitating the provision of nutrients and energy to the host animals. This study investigated the fermentation characteristics and effects on rumen microbiota of yak rumen anaerobic fungus Orpinomyces sp. YF3 in goat rumen fluid, both with and without fungal flora, utilizing anaerobic fermentation bottles. Crushed and air-dried wheat straw served as the fermentation substrate, and cycloheximide was used to eradicate microorganisms from the rumen fluid of dairy goats. The experiment compromised four treatment groups (2×2 factorial design): control (C); yak fungus group (CF, Orpinomyces sp. YF3); goat fungi eliminated group (CA, antibiotic: 0.25 mg/mL cycloheximide); goat fungi eliminated+yak fungus group (CAF). Each treatment had six replicates. Fermentation characteristics and microbial composition of the fermentation media were analyzed using one-way analysis of variance and high-throughput sequencing technology. The findings revealed that in the Orpinomyces sp. YF3 addition group (CF and CAF groups), there were significant increases in ammonia nitrogen concentration by 70%, total volatile fatty acids (VFA) by 53%, as well as acetate, isobutyrate, and valerate concentrations, and the ratio of acetate to propionate (p < 0.05), while the propionate proportion declined by 13%, alongside a reduction of butyrate concentration (p < 0.05). Similarly, in the CF and CAF groups, there were a notable increase in the relative abundance of Bacteroidota, Synergistota, Desulfobacterota, Actinobacteria, and Fusobacteriota, alongside a decrease in the relative abundance of Fibrobacterota and Proteobacteria (p < 0.05). Bacteria exhibiting increased relative abundance were positively correlated with the activity of carboxymethyl cellulase and avicelase, total VFA concentration, and acetate proportion, while showing a negatively correlation with propionate proportion. In conclusion, supplementing rumen fermentation media with yak rumen anaerobic fungus Orpinomyces sp. YF3 led to an increase in bacteria associated with fibre degradation and acetic acid production, a decrease in propionate-producing bacteria, enhanced the activity of plant cell wall degrading enzymes, and promoted cellulose degradation, ultimately elevating total VAF concentration and acetate proportion. This presents a novel approach to enhance roughage utilization in ruminants.

Isobutyramide and Slow-Release Urea as Substitutes for Soybean Meal in the Finishing Diet of Beef Cattle.

Two experiments were conducted to investigate the effects of isobutyramide (IBA) and slow-release urea (SRU) as substitutes for soybean meal (SBM) in the finishing diet of beef cattle. The completely randomized design in vitro experiment with five treatments, i.e., control, 0.9% SRU group, 0.6% SRU + 0.3% IBA group (SRU-I), 0.3% SRU + 0.6% IBA group (IBA-S), 0.9% IBA group was conducted. The results showed that the IBA-S and IBA increased (p ≤ 0.05) substrate disappearance of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), total gas, and total volatile fatty acids (TVFA). The SRU group had the highest (p < 0.01) crude protein disappearance and ammonia nitrogen concentration, but the IBA contrarily decreased (p < 0.01) them compared with the control. Inclusion of IBA increased isobutyrate concentrations (p = 0.01) with the highest value for the IBA group. Then, an 84-day replicate 4 × 4 Latin square design with 8 Angus steers and four treatments, i.e., control, SRU, SRU-I, IBA-S was performed. The results showed that the treatments did not affect DM intake (p > 0.05) but tended (p = 0.09) to increase average daily gain. The inclusion of IBA increased (p < 0.05) the apparent digestibility of DM, organic matter, NDF, ADF, TVFA, and microbial crude protein with the highest values for the IBA-S group. The IBA-contained groups also increased (p ≤ 0.01) isobutyrate concentration, activities of carboxymethyl cellulase and xylanase, and the relative abundance of Butyrivibrio fibrisolvens with the highest values for the IBA-S group. The SRU had no effect on animal growth and nutrient apparent digestibility. In conclusion, IBA was developed as a new substitute for SBM in the finishing diet of beef cattle, and the optimal strategy was the isonitrogenous substitution of SBM with 0.3% SRU and 0.6% IBA of the diet.