Change of Endoglucanase Activity and Rumen Microbial Community During Biodegradation of Cellulose Using Rumen Microbiota

Abstract

Treatment with rumen microorganisms improves the methane fermentation of undegradable lignocellulosic biomass; however, the role of endoglucanase in lignocellulose digestion remains unclear. This study was conducted to investigate endoglucanases contributing to cellulose degradation during treatment with rumen microorganisms, using carboxymethyl cellulose (CMC) as a substrate. The rate of CMC degradation increased for the first 24 h of treatment. Zymogram analysis revealed that endoglucanases of 52 and 53 kDa exhibited high enzyme activity for the first 12 h, whereas endoglucanases of 42, 50, and 101 kDa exhibited high enzyme activities from 12 to 24 h. This indicates that the activities of these five endoglucanases shifted and contributed to efficient CMC degradation. Metagenomic analysis revealed that the relative abundances of Selenomonas, Eudiplodinium, and Metadinium decreased after 12 h, which was positively correlated with the 52- and 53-kDa endoglucanases. Additionally, the relative abundances of Porphyromonas, Didinium, unclassified Bacteroidetes, Clostridiales family XI, Lachnospiraceae and Sphingobacteriaceae increased for the first 24 h, which was positively correlated with endoglucanases of 42, 50, and 101 kDa. This study suggests that uncharacterized and non-dominant microorganisms produce and/or contribute to activity of 40, 50, 52, 53, and 101 kDa endoglucanases, enhancing CMC degradation during treatment with rumen microorganisms.

Effect of liquid volume and microflora source on degradation rate and microbial community in corn stover degradation

“…In this study, endo-glucanase was used as an important basis to judge the ability of cellulase. The results showed that liquid volume had a significant effect on endo-glucanase activity, and endo-glucanase was closely related to degradation rate, which is supported by previous works (Takizawa et al 2020 ; Wang et al 2004 ). This indicated that the lower dissolved oxygen environment caused by a higher liquid volume promote the activity of anaerobic lignocellulose degrading bacteria.…”

Effect of Liquid Volume And Microflora Source On Degradation Rate And Microbial Community In Corn Stover Degradation

“…In this study, endo-glucanase was used as an important basis to judge the ability of cellulase. The results showed that liquid volume had a signi cant effect on endo-glucanase activity, and endo-glucanase was closely related to degradation rate, which is supported by previous works (Takizawa et al 2020;Wang et al 2004). This indicated that the lower dissolved oxygen environment caused by a higher liquid volume promote the activity of anaerobic lignocellulose degrading bacteria.…”

Defining the Frontiers of Synergism between Cellulolytic Enzymes for Improved Hydrolysis of Lignocellulosic Feedstocks

“…Five endoglucanases of the ruminant bacterial symbionts were detected, and their molecular weights were 42, 50, 52, 53, and 101 kDa [66]. Even though the 52 and 53 kDa EGs were more active compared to three other proteins, the authors did not classify these EGs into different GH families.…”