Functioning of a tripartite lignocellulolytic microbial consortium cultivated under two shaking conditions: a
Yanfang Wang1, Diego Javier Jiménez2, Zhenhua Zhang3
1Cluster of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands. wang-yanfang@qq.com.
Biotechnology for Biofuels and Bioproducts
|March 29, 2023
Summary
Shaking speed impacts microbial consortia. Lower speeds promote flexible metabolism in Citrobacter freundii so4 and enhance Coniochaeta sp. 2T2.1 hyphal formation and enzyme expression for lignocellulose degradation.
Area of Science:
- Microbiology
- Biotechnology
- Biochemistry
Background:
- Shaking speed significantly influences microbial consortium dynamics and lignocellulose degradation.
- A synthetic consortium of Sphingobacterium paramultivorum w15, Citrobacter freundii so4, and Coniochaeta sp. 2T2.1 was previously studied.
- Gene expression was analyzed at two shaking speeds (180 and 60 rpm) and three time points (1, 5, and 13 days).
Purpose of the Study:
- To investigate the gene expression profiles of individual strains within a lignocellulolytic microbial consortium.
- To understand the impact of different shaking speeds on microbial metabolism and enzyme activity.
- To elucidate the synergistic and alternative functional roles of the consortium members in lignocellulose degradation.
Main Methods:
- Comparative transcriptomic analysis of three microbial species (S. paramultivorum w15, C. freundii so4, Coniochaeta sp. 2T2.1).
- Cultivation of the synthetic consortium at distinct shaking speeds (180 rpm and 60 rpm).
- Sampling at multiple time points (1, 5, and 13 days) to capture dynamic changes.
Main Results:
- At 60 rpm, C. freundii so4 exhibited flexible metabolism (aerobic/microaerophilic/anaerobic) and sustained growth.
- Coniochaeta sp. 2T2.1 showed increased hyphal formation and high expression of adhesion genes at 60 rpm.
- S. paramultivorum w15 and Coniochaeta sp. 2T2.1 were key in hemicellulose degradation, with Coniochaeta sp. 2T2.1 expressing specific arabinoxylan-degrading enzymes.
- C. freundii so4 consistently expressed genes for β-xylosidase/β-glucosidase, stress response, and detoxification.
- S. paramultivorum w15 initially produced vitamin B2, with C. freundii so4 taking over this role at late stages (60 rpm).
Conclusions:
- S. paramultivorum w15 primarily degrades hemicellulose and produces vitamin B2.
- C. freundii so4 is involved in oligosaccharide degradation and detoxification.
- Coniochaeta sp. 2T2.1 degrades cellulose and xylan, and modifies lignin.
- The study enhances understanding of lignocellulose degradation synergism and functional roles in this microbial consortium.
