Characterization of the Central Metabolic Pathways in Thermoanaerobacter sp. Strain X514 via Isotopomer-Assisted Metabolite Analysis

Author:

Feng Xueyang1,Mouttaki Housna2,Lin Lu23,Huang Rick1,Wu Bing1,Hemme Christopher L.2,He Zhili2,Zhang Baichen4,Hicks Leslie M.4,Xu Jian3,Zhou Jizhong2,Tang Yinjie J.1

Affiliation:

1. Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, Missouri 63130

2. Institute for Environmental Genomics and Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma 73019

3. Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, People's Republic of China

4. Donald Danforth Plant Science Center, 975 N. Warson Rd., St. Louis, Missouri 63132

Abstract

ABSTRACT Thermoanaerobacter sp. strain X514 has great potential in biotechnology due to its capacity to ferment a range of C 5 and C 6 sugars to ethanol and other metabolites under thermophilic conditions. This study investigated the central metabolism of strain X514 via 13 C-labeled tracer experiments using either glucose or pyruvate as both carbon and energy sources. X514 grew on minimal medium and thus contains complete biosynthesis pathways for all macromolecule building blocks. Based on genome annotation and isotopic analysis of amino acids, three observations can be obtained about the central metabolic pathways in X514. First, the oxidative pentose phosphate pathway in X514 is not functional, and the tricarboxylic acid cycle is incomplete under fermentative growth conditions. Second, X514 contains ( Re )-type citrate synthase activity, although no gene homologous to the recently characterized ( Re )-type citrate synthase of Clostridium kluyveri was found. Third, the isoleucine in X514 is derived from acetyl coenzyme A and pyruvate via the citramalate pathway rather than being synthesized from threonine via threonine ammonia-lyase. The functionality of the citramalate synthase gene ( cimA [Teth514_1204]) has been confirmed by enzymatic activity assays, while the presence of intracellular citramalate has been detected by mass spectrometry. This study demonstrates the merits of combining 13 C-assisted metabolite analysis, enzyme assays, and metabolite detection not only to examine genome sequence annotations but also to discover novel enzyme activities.

Publisher

American Society for Microbiology

Subject

Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3