Construction And Characterization Of A Null Allele Of The Hfq Gene Of The Dissimilatory Metal Reducing Bacterium Shewanella Oneidensis

Shewanella oneidensis is a dissimilatory metal reducing bacterium that can utilize a range of terminal electron acceptors when grown under anaerobic conditions. Our primary goal is to identify and characterize genes that encode small regulatory non‐coding RNAs (sRNAs) in S. oneidensis . sRNA genes are regulated by changes in environmental conditions and can themselves regulate other genes by inexact base pairing to their mRNA targets. We are particularly interested in sRNAs that may regulate the process of metal reduction. The highly conserved RNA chaperone protein Hfq has been widely implicated in bacterial sRNA function. We have constructed a null allele of the S. oneidensis hfq gene. The S. oneidensis hfq mutant has a modest delayed growth phenotype. In addition, our mutant displays reduced survival in stationary phase. Our hfq mutant also exhibits a decreased rate of Cr(VI) reduction when grown under anaerobic conditions compared to the rate of Cr(VI) reduction by wild type S. oneidensis . We are currently evaluating the growth and survival of the Shewanella hfq null mutant. We are also investigating the mutant's sensitivity to a variety of physical stresses, evaluating the capacity of the hfq mutant to reduce metals other than Cr(VI), and determining the role of Shewanella hfq in sRNA function. This research is funded by a grant from the RI‐INBRE program, award # P20RR016457‐10.