Project description:The goal of this study is to find novel regulatory details of plant biomass-degrading enzymes in filamentous fungus Trichoderma guizhouense NJAU4742. Strain NJAU4742 and its mutants (∆Tgxyr1,∆Tgace1 and ∆Tgace2) were firstly incubated using 2% glucose, and then transfered into the medium containing different polysaccharides (xylan or cellulose) or carbon starvation. After 0h, 4h, 24h or 72h, samples were extracted and used for transcriptome sequencing in Illumina platform.
Project description:The genome of the lignocellulose-degrading, extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus encodes genes comprising clusters of glycoside hydrolases, ABC transporters and metabolic enzymes that are transcriptionally responsive to carbohydrates. Transcriptomic and biosolubilization analyses were used to determine if C. saccharolyticus could be deployed as a probe to assess the characteristics of plant biomass feedstocks and efficacy of pre-treatment methods, as these both relate to deconstruction strategies for biofuels production. Based on the response of C. saccharolyticus to plant cell wall polysaccharides, genomic loci were identified that reflected the availability of cellulose, glucomannan, pectin and xylan in biomass to microbial degradation. Furthermore, these loci were useful in assessing how various plant biomass feedstocks (genetically and chemically modified Populus sp., unpretreated Populus sp., and chemically modified switchgrass) were amenable C. saccharolyticus solubilization.
Project description:Lignocellulose degradation by microbes plays a central role in global carbon cycling, human gut metabolism, and renewable energy technologies While considerable effort has been put into understanding the biochemical aspects of lignocellulose degradation, much less work has been done to understand how these enzymes work in an in vivo context Here, we report a systems level study of xylan degradation in the saprophytic bacterium Cellvibrio japonicus Transcriptome analysis indicated seven genes that encode carbohydrate active enzymes were up-regulated during growth with xylan containing media In-frame deletion analysis of these genes found that only gly43F is critical for utilization of xylo-oligosaccharides, xylan, and arabinoxylan Heterologous expression of gly43F was sufficient for the utilization of xylo-oligosaccharides in Escherichia coli Additional analysis found that the xyn11A, xyn11B, abf43L, abf43K, and abf51A gene products were critical for utilization of arabinoxylan Furthermore, a predicted transporter (CJA_1315) was required for effective utilization of xylan substrates, and we propose this unannotated gene be called xntA (xylan transporter A) Our major findings are 1) C japonicus employs both secreted and surface associated enzymes for xylan degradation, which differs from the strategy used for cellulose degradation, and 2) a single cytoplasmic β-xylosidase is essential for the utilization of xylo-oligosaccharides
