The Thermoanaerobacter glycobiome reveals mechanisms of pentose and hexose co-utilization in bacteria.
Thermoanaerobic bacteria are of interest in cellulosic-biofuel production, due to their simultaneous pentose and hexose utilization (co-utilization) and thermophilic nature. In this study, we experimentally reconstructed the structure and dynamics of the first genome-wide carbon utilization network of thermoanaerobes. The network uncovers numerous novel pathways and identifies previously unrecognized but crucial pathway interactions and the associated key junctions. First, glucose, xylose, fructose, and cellobiose catabolism are each featured in distinct functional modules; the transport systems of hexose and pentose are apparently both regulated by transcriptional antiterminators of the BglG family, which is consistent with pentose and hexose co-utilization. Second, glucose and xylose modules cooperate in that the activity of the former promotes the activity of the latter via activating xylose transport and catabolism, while xylose delays cell lysis by sustaining coenzyme and ion metabolism. Third, the vitamin B₁₂ pathway appears to promote ethanologenesis through ethanolamine and 1, 2-propanediol, while the arginine deiminase pathway probably contributes to cell survival in stationary phase. Moreover, by experimentally validating the distinct yet collaborative nature of glucose and xylose catabolism, we demonstrated that these novel network-derived features can be rationally exploited for product-yield enhancement via optimized timing and balanced loading of the carbon supply in a substrate-specific manner. Thus, this thermoanaerobic glycobiome reveals novel genetic features in carbon catabolism that may have immediate industrial implications and provides novel strategies and targets for fermentation and genome engineering.
CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics and BioEnergy Genome Center, Qingdao Institute of BioEnergy and BioProcess Technology, Chinese Academy of Sciences, Qingdao, China.
Lu
L
Lin
Houhui
H
Song
Qichao
Q
Tu
Yujia
Y
Qin
Aifen
A
Zhou
Wenbin
W
Liu
Zhili
Z
He
Jizhong
J
Zhou
Jian
J
Xu
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D056804:Biofuels; D002475:Cellobiose / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry / Q000378:metabolism; D019856:Ethanolamine / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D054794:Glycomics; D006601:Hexoses / Q000378:metabolism*; D010429:Pentoses / Q000378:metabolism*; D010802:Phylogeny; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D046968:Thermoanaerobacter / Q000235:genetics* / Q000378:metabolism*; D014805:Vitamin B 12 / Q000737:chemistry / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
D001426:Bacterial Proteins; D056804:Biofuels; D006601:Hexoses; D010429:Pentoses; D016601:RNA-Binding Proteins; C064872:antiterminator proteins, Bacteria; D002475:Cellobiose; D000431:Ethanol; D019856:Ethanolamine; D002482:Cellulose; D014994:Xylose; D005947:Glucose; D014805:Vitamin B 12