Location: Renewable Product Technology ResearchTitle: The yajC gene from Lactobacillus buchneri and Escherichia coli and its role in ethanol tolerance
Submitted to: Journal of Industrial Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/24/2015
Publication Date: 1/20/2016
Citation: Liu, S., Skory, C., Qureshi, N., Hughes, S. 2016. The yajC gene from Lactobacillus buchneri and Escherichia coli and its role in ethanol tolerance. Journal of Industrial Microbiology and Biotechnology. 43(4):441-450. doi: 10.1007/s10295-015-1730-6.
Interpretive Summary: The Lactobacillus buchneri NRRL B-30929 strain shows high tolerance to environmental ethanol concentrations. The yajC gene (Lbuc_0921) from L. buchneri NRRL B-30929 was found highly responsive to ethanol by proteomics analyses. In this study, the L. buchneri yajC gene was cloned and over-expressed in E. coli. The recombinant strain produced yajC after Isopropyl ß-D-1-thiogalactopyranoside induction and showed tolerance to 4% ethanol. This is the first report linking yajC to ethanol stress and tolerance. These results can be used to guide genetic modifications to increase ethanol tolerance in industrial biocatalysts.
Technical Abstract: The yajC gene (Lbuc_0921)from Lactobacillus buchneri NRRL B-30929 was identified from proteomics analyses in response to ethanol treatment. This protein’s expression level was increased by 15 fold in response to 10% vs 0% ethanol. The yajC encodes the smaller subunit of the preprotein translocase complex, which interacts with secD and secF of the secD operon to coordinate protein transport and secretion across cytoplasmic membrane in Escherichia coli. The yajC protein was linked to sensitivity to growth temperatures in E. coli, involved in translocation of virulence factors during Listeria infection, and stimulating a T cell-mediated response of Brucella abortus. In this study, the L. buchneri yajC gene was over-expressed in E. coli. The strain carrying pET28byajC that produces yajC after Isopropyl ß-D-1-thiogalactopyranoside induction showed tolerance to 4% ethanol in growth media, compared to the control carrying pET28b vector alone. This is the first report linking yajC to ethanol stress and tolerance.