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This content will become publicly available on December 21, 2018

Title: The complex physiology of Cellvibrio japonicus xylan degradation relies on a single cytoplasmic β-xylosidase for xylo-oligosaccharide utilization

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 in this paper, 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 themore » utilization of xylo-oligosaccharides.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ; ORCiD logo [1]
  1. Univ. of Maryland Baltimore County (UMBC), Baltimore, MD (United States). Dept. of Biological Sciences
Publication Date:
Grant/Contract Number:
SC0014183
Type:
Accepted Manuscript
Journal Name:
Molecular microbiology
Additional Journal Information:
Journal Volume: 107; Journal Issue: 5; Journal ID: ISSN 0950-382X
Publisher:
Wiley
Research Org:
Univ. of Maryland Baltimore County (UMBC), Baltimore, MD (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23). Biological Systems Science Division; USDOE
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; β-xylosidase; Cellvibrio japonicus; polysaccharide degradation; xylan; xylanase
OSTI Identifier:
1415270
Alternate Identifier(s):
OSTI ID: 1416401