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Title: Genetic engineering and improvement of a Zymomonas mobilis for arabinose utilization and its performance on pretreated corn stover hydrolyzate

In this paper, a glucose, xylose and arabinose utilizing Zymomonas mobilis strain was constructed by incorporating arabinose catabolic pathway genes, araBAD encoding L-ribulokinase, L-arabinose isomerase and L-ribulose-5-phosphate- 4-epimerase in a glucose, xylose co-fermenting host, 8b, using a transposition integration approach. Further improvement on this arabinose-capable integrant, 33C was achieved by applying a second transposition to create a genomic knockout (KO) mutant library. Using arabinose as a sole carbon source and a selection pressure, the KO library was subjected to a growth-enrichment process involving continuous sub-culturing for over 120 generations. Strain 13-1-17, isolated from such process demonstrated significant improvement in metabolizing arabinose in a dilute acid pretreated, saccharified corn stover slurry. Through Next Generation Sequencing (NGS) analysis, integration sites of the transposons were identified. Furthermore, multiple additional point mutations (SNPs: Single Nucleotide Polymorphisms) were discovered in 13-1-17, affecting genes araB and RpiB in the genome. Finally, we speculate that these mutations may have impacted the expression of the enzymes coded by these genes, ribulokinase and Ribose 5-P-isomerase, thus attributing to the improvement of the arabinose utilization.
 [1] ;  [1] ;  [1] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 2155-952X
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Biotechnology & Biomaterials
Additional Journal Information:
Journal Volume: 5; Journal Issue: 2; Journal ID: ISSN 2155-952X
OMICS International
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B)
Country of Publication:
United States
09 BIOMASS FUELS; Zymomonas mobilis; arabinose; araBAD; transposition; knockout library; Cre-Lox recombination; next generation sequencing (NGS)