Recently, returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution. Meanwhile, the slow decomposition of straw may harm the growth of the next crop. This study aimed to determine the effects of rumen microorganisms (RMs) on straw decomposition, bacterial microbial community structure, soil properties, and soil enzyme activity. The results showed that RMs significantly enhanced the degradation rate of straw in the soil, reaching 39.52%, which was 41.37% higher than that of the control on the 30th day after straw return. After 30 d, straw degradation showed a significant slower trend in both the control and the experimental groups. According to the soil physicochemical parameters, the application of rumen fluid expedited soil matter transformation and nutrient buildup, and increased the urease, sucrase, and cellulase activity by 10%‒20%. The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid. The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability, which was the main reason for the accelerated straw decomposition. Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw, proposing a viable solution to the problem of sluggish straw decomposition.
Animals ; Rumen/metabolism* ; Agriculture/methods* ; Soil/chemistry* ; Microbiota ; Bacteria/metabolism* ; Oryza/metabolism* ; Soil Microbiology ; Cellulose

In order to investigate the enzyme production mechanism of yak rumen-derived anaerobic fungus Orpinomyces sp. YF3 under the induction of different carbon sources, anaerobic culture tubes were used for in vitro fermentation. 8 g/L of glucose (Glu), filter paper (Flp) and avicel (Avi) were respectively added to 10 mL of basic culture medium as the sole carbon source. The activity of fiber-degrading enzyme and the concentration of volatile fatty acid in the fermentation liquid were detected, and the enzyme producing mechanism of Orpinomyces sp. YF3 was explored by transcriptomics. It was found that, in glucose-induced fermentation solution, the activities of carboxymethyl cellulase, microcrystalline cellulase, filter paper enzyme, xylanase and the proportion of acetate were significantly increased (P < 0.05), the proportion of propionate, butyrate, isobutyrate were significantly decreased (P < 0.05). The results of transcriptome analysis showed that there were 5 949 differentially expressed genes (DEGs) between the Glu group and the Flp group, 10 970 DEGs between the Glu group and the Avi group, and 6 057 DEGs between the Flp group and the Avi group. It was found that the DEGs associated with fiber degrading enzymes were significantly up-regulated in the Glu group. Gene ontology (GO) function enrichment analysis identified that DEGs were mainly associated with the xylan catabolic process, hemicellulose metabolic process, β-glucan metabolic process, cellulase activity, endo-1,4-β-xylanase activity, cell wall polysaccharide metabolic process, carbohydrate catabolic process, glucan catabolic process and carbohydrate metabolic process. Moreover, the differentially expressed pathways associated with fiber degrading enzymes enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were mainly starch and sucrose metabolic pathways and other glycan degradation pathways. In conclusion, Orpinomyces sp. YF3 with glucose as carbon source substrate significantly increased the activity of cellulose degrading enzyme and the proportion of acetate, decreased the proportion of propionate, butyrate and isobutyrate. Furthermore, the degradation ability and energy utilization efficiency of fungus in the presence of glucose were improved by means of regulating the expression of cellulose degrading enzyme gene and participating in starch and sucrose metabolism pathway, and other glycan degradation pathways, which provides a theoretical basis for the application of Orpinomyces sp. YF3 in practical production and facilitates the application of Orpinomyces sp. YF3 in the future.
Animals ; Cattle ; Neocallimastigales/metabolism* ; Anaerobiosis ; Rumen/microbiology* ; Propionates/metabolism* ; Isobutyrates/metabolism* ; Cellulose/metabolism* ; Fungi ; Starch/metabolism* ; Glucose/metabolism* ; Acetates ; Sucrose/metabolism* ; Cellulases ; Cellulase

Gluconacetobacter xylinus is a primary strain producing bacterial cellulose (BC). In G. xylinus, BcsD is a subunit of cellulose synthase and is participated in the assembly process of BC. A series of G. xylinus with different expression levels of the bcsD gene were obtained by using the CRISPR/dCas9 technique. Analysis of the structural characteristics of BC showed that the crystallinity and porosity of BC changed with the expression of bcsD. The porosity varied from 59.95%-84.05%, and the crystallinity varied from 74.26%-93.75%, while the yield of BC did not decrease significantly upon changing the expression levels of bcsD. The results showed that the porosity of bacterial cellulose significantly increased, while the crystallinity was positively correlated with the expression of bcsD, when the expression level of bcsD was below 55.34%. By altering the expression level of the bcsD gene, obtaining BC with different structures but stable yield through a one-step fermentation of G. xylinus was achieved.
Cellulose/chemistry* ; Clustered Regularly Interspaced Short Palindromic Repeats ; Fermentation ; Gluconacetobacter xylinus/metabolism*

The phenomenon that waste of fungus-growing materials in the planting process of Gastrodia elata is very common. It has been proved by practice that the used fungus-growing materials planted with G. elata can be used to plant Phallus impudicus. But the mechanism is unclear. In this study, we compared the different infested-capacity of Armillaria gallica and Phallus impudicus by morphological anatomy of the used fungus-growing materials. We also compared the differences on the two fungi consumed the main contents of fungus-growing materials, cellulose, lignin and hemicellulose, by using nitric acid-95% ethanol method, sulfuric acid method and tetrabromide method respectively, so that to explore the mechanism of A. gallica and P. impudicus recycle the fungus-growing materials, and to provide scientific basis for recycling the used fungus-growing materials of G. elata. The results showed that A. gallica had a strong ability to invade some parts outside the vascular cambium, but it had a weak ability to invade some parts inside the vascular cambium, while P. impudicus had a strong ability to invade the same parts. The contents of lignin and cellulose, which from inside and outside the vascular cambium of fungus-growing materials were significantly different. In the parts of outside the vascular cambium of fungus-growing materials, A. gallica degraded more lignin and cellulose, while P. impudicus degraded more hemicellulose. In the parts of inside the vascular cambium of fungus-growing materials, A. gallica degraded more cellulose, while P. impudicus degraded more hemicellulose. The present results suggested that A. gallica and P. impudicus made differential utilization of the carbon source in the fungus-growing materials to realize that P. impudicus recycle the used fungus-growing materials of G. elata. A. gallica used lignin and cellulose as the main carbon source, while P. impudicus used hemicellulose as the main carbon source.
Agaricales/growth & development* ; Armillaria/growth & development* ; Cellulose/metabolism* ; Lignin/metabolism* ; Polysaccharides/metabolism*

In order to clarify dynamic change of microbial community composition and to identify key functional bacteria in the cellulose degradation consortium, we studied several aspects of the biodegradation of filter papers and rice straws by the microbial consortium, the change of substrate degradation, microbial biomass and pH of fermentation broth. We extracted total DNA of the microbial consortium in different degradation stages for high-throughput sequencing of amplicons of bacterial 16 S rRNA genes. Based on the decomposition characteristics test, we defined the 12th, 72nd and 168th hours after inoculation as the initial stage, peak stage and end stage of degradation, respectively. The microbial consortium was mainly composed of 1 phylum, 2 classes, 2 orders, 7 families and 11 genera. With cellulose degradation, bacteria in the consortium showed different growth trends. The relative abundance of Brevibacillus and Caloramator decreased gradually. The relative abundance of Clostridium, Bacillus, Geobacillus and Cohnella increased gradually. The relative abundance of Ureibacillus, Tissierella, Epulopiscium was the highest in peak stage. The relative abundance of Paenibacillus and Ruminococcus did not change obviously in each stage. Above-mentioned 11 main genera all belonged to Firmicutes, which are thermophilic, broad pH adaptable and cellulose or hemicellulose degradable. During cellulose degradation by the microbial consortium, aerobic bacteria were dominant functional bacteria in the initial stage. However, the relative abundance of anaerobic bacteria increased gradually in middle and end stage, and replaced aerobic bacteria to become main bacteria to degrade cellulose.
Bacteria ; classification ; metabolism ; Biodegradation, Environmental ; Cellulose ; metabolism ; DNA, Bacterial ; genetics ; Microbial Consortia ; RNA, Ribosomal, 16S ; genetics

Residue of Mori Cortex was studied to optimize its enzymatic hydrolysis process, and explore its potential as a carbon source for biochemistry and biofuel production. The cellulose content of diluted acid pretreated (DAP) and non-pretreated from Mori Cortex were measured in this study, and the results showed that the cellulose content of DAP and non-pretreated from Mori Cortex were 52.5% and 47%, respectively. This higher cellulose content indicated that residue of Mori Cortex had the potential to act as a carbon source for biochemistry and biofuel production. Enzymatic hydrolysis of pretreated and non-pretreated from Mori Cortex was conducted under different enzyme loading amount. 40 FPU·(g DW）⁻¹ enzyme loading was determined as the optimal amount by comparing the yield of sugar and the rate of enzymolysis. Under this condition, the concentrations of glucose, xylose, arabinose sugar were 23.82, 4.84, 3.6 g·L⁻¹, and the corresponding enzymatic hydrolysis rate was 45.33% which was 2.3 times higher than that of non-pretreated from Morus alba residues. Fed-batch enzymatic hydrolysis was conducted finally to get higher sugar yield, and the final glucose concentration reached up to 38 g·L⁻¹ with the enzymatic hydrolysis rate of 36.19%. The results indicated that Mori Cortex residue had higher cellulose and hemicellulose contents, so it had the potential to become a carbon source to produce the bio-chemicals and biofuels. Through enzymatic hydrolysis, it can be converted into microbial available monosaccharides; and through fermentation, it can be converted into high value-added chemicals, biofuels, etc., to solve the problem of residue pollution, and achieve the sustainable development and greening of Chinese pharmaceutical production process.
Carbohydrates ; Cellulose ; chemistry ; Enzymes ; metabolism ; Fermentation ; Hydrolysis ; Morus ; chemistry

The expensive production of bioethanol is because it has not yet reached the 'THREE-HIGH' (High-titer, high-conversion and high-productivity) technical levels of starchy ethanol production. To cope with it, it is necessary to implement a high-gravity mash bioethanol production (HMBP), in which sugar hydrolysates are thick and fermentation-inhibitive compounds are negligible. In this work, HMBP from an atmospheric glycerol autocatalytic organosolv pretreated wheat straw was carried out with different fermentation strategies. Under an optimized condition (15% substrate concentration, 10 g/L (NH4)2SO4, 30 FPU/g dry matter, 10% (V/V) inoculum ratio), HMBP was at 31.2 g/L with a shaking simultaneous saccharification and fermentation (SSF) at 37 degrees C for 72 h, and achieved with a conversion of 73% and a productivity of 0.43 g/(L x h). Further by a semi-SFF with pre-hydrolysis time of 24 h, HMBP reached 33.7 g/L, the conversion and productivity of which was 79% and 0.47 g/(L x h), respectively. During the SSF and semi-SSF, more than 90% of the cellulose in both substrates were hydrolyzed into fermentable sugars. Finally, a fed-batch semi-SFF was developed with an initial substrate concentration of 15%, in which dried substrate (= the weight of the initial substrate) was divided into three portions and added into the conical flask once each 8 h during the first 24 h. HMBP achieved at 51.2 g/L for 72 h with a high productivity of 0.71 g/(L x h) while a low cellulose conversion of 62%. Interestingly, the fermentation inhibitive compound was mainly acetic acid, less than 3.0 g/L, and there were no other inhibitors detected, commonly furfural and hydroxymethyl furfural existing in the slurry. The data indicate that the lignocellulosic substrate subjected to the atmospheric glycerol autocatalytic organosolv pretreatment is very applicable for HMBP. The fed-batch semi-SFF is effective and desirable to realize an HMBP.
Biofuels ; Carbohydrates ; chemistry ; Cellulose ; chemistry ; Ethanol ; metabolism ; Fermentation ; Furaldehyde ; chemistry ; Glycerol ; chemistry ; Hydrolysis ; Triticum

Acanthamoeba cysts are resistant to unfavorable physiological conditions and various disinfectants. Acanthamoeba cysts have 2 walls containing various sugar moieties, and in particular, one third of the inner wall is composed of cellulose. In this study, it has been shown that down-regulation of cellulose synthase by small interfering RNA (siRNA) significantly inhibits the formation of mature Acanthamoeba castellanii cysts. Calcofluor white staining and transmission electron microscopy revealed that siRNA transfected amoeba failed to form an inner wall during encystation and thus are likely to be more vulnerable. In addition, the expression of xylose isomerase, which is involved in cyst wall formation, was not altered in cellulose synthase down-regulated amoeba, indicating that cellulose synthase is a crucial factor for inner wall formation by Acanthamoeba during encystation.
Acanthamoeba castellanii/*enzymology/genetics/metabolism ; Aldose-Ketose Isomerases/*biosynthesis ; Amebiasis/*pathology ; Benzenesulfonates ; Cell Wall/chemistry/genetics/*metabolism ; Cellulose/biosynthesis ; Down-Regulation ; Encephalitis/parasitology ; Glucosyltransferases/*biosynthesis/genetics ; Keratitis/parasitology ; Microscopy, Electron, Transmission ; RNA Interference ; RNA, Small Interfering

Sugarcane bagasse modified by polyethylenimine (PEI) and glutaraldehyde (GA) was used as a carrier to immobilize Clostridium acetobutylicum XY16 in the process of butanol production. The effects of chemically modified sugarcane bagasse on batch and repeat-batch fermentations were investigated. Batch fermentation was conducted with an addition of 10 g/L modified sugarcane bagasse and 60 g/L glucose, resulting in a high solvent concentration of 21.67 g/L and productivity of 0.60 g/(L x h) with the treatment of 4 g/L PEI and 1 g/L GA. Compared to the fermentations by free cells and immobilized cells on unmodified sugarcane bagasse, the productivity increased 130.8% and 66.7%, respectively. The fibrous-bed bioreactor also maintained a stable butanol production during repeat-batch fermentations, achieving a maximum productivity of 0.83 g/(L x h) with a high yield of 0.42 g/g.
Batch Cell Culture Techniques ; Bioreactors ; Butanols ; metabolism ; Cells, Immobilized ; Cellulose ; metabolism ; Clostridium acetobutylicum ; metabolism ; Fermentation ; Saccharum ; chemistry

In this study, we constructed a yeast consortium surface-display expression system by using Flo1 as an anchor protein. Endoglucanase II (EGII) and cellobiohydrolase II (CBHII) from Trichoderma reesei, and β3-glucosidase 1 (BGLI) from Aspergillus aculeatus were immobilized on Saccharomyces cerevisiae Y5. We constructed the cellulose-displaying expression yeast consortium (Y5/fEGII:Y5/fCBHII:Y5/fBGLI = 1:1:1) and investigated the enzymatic ability and ethanol fermentation. The displayed cellulolytic enzymes was stabile during the 96-h fermentation. The yeast consortium produced 0.77 g/L ethanol from 10 g/L phosphoric acid swollen cellulose (PASC) within 96 h. The yield (in grams of ethanol produced per gram of carbohydrate consumed) was 0.35 g/g, which correspond to 68.6% of the theoretical yield.
Aspergillus ; enzymology ; Cellulase ; genetics ; Cellulose ; metabolism ; Cellulose 1,4-beta-Cellobiosidase ; genetics ; Enzymes, Immobilized ; genetics ; Ethanol ; metabolism ; Fermentation ; Glucosidases ; genetics ; Mannose-Binding Lectins ; metabolism ; Protein Binding ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; metabolism ; Trichoderma ; enzymology