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

This study was aimed to investigate the mechanism of leukemia cell apoptosis induced by histone deacetylase inhibitor (HDACI). Flow cytometry was used to detect the apoptosis of leukemia cell lines NB4, U937 and Jurkat, and the changes of mRNA and protein expressions of TRAIL, DR4 and DR5 were detected by Western blot and RT-PCR respectively. The results showed that both TRAIL and DR5 protein and mRNA expressions in NB4, U937 and Jurkat cells increased after treated with sodium butyrate (SB) and in time-dependent manner. However, DR4 mRNA in leukemia cells was not significantly changed after treated with SB. It is concluded that the apoptosis mechanism of leukemic cell lines NB4, U937 and Jurkat induced by SB is closely related to the protein and mRNA expressions up-regulating TRAIL and DR5, but the DR4 may not participate in the apoptosis induced by SB.
Apoptosis ; drug effects ; Cell Line, Tumor ; Histone Deacetylase Inhibitors ; pharmacology ; Humans ; Isobutyrates ; pharmacology ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; metabolism ; TNF-Related Apoptosis-Inducing Ligand ; metabolism