Project description:Purpose:The goals of this study are to clarify the B. subtilis NBRC 16449 response to soybeans. Methods: B. subtilis NBRC 16449 cells were aerobically cultured in liquid LB, LB solidified with agar, or on surface of boiled soybeans to logarithmic growth phase. Total RNAs were extracted from bacterial cells by Hot-Phenol method. Samples for RNA-seq were prepared according to Illmina protocol available from the manufacture. The sequence reads that passed quality filters were analyzed at the transcript isoform level with bowtie v0.11.2. Results: Using an optimized data analysis workflow, we mapped around 15 million sequence reads per sample to the whole genome of B. subtilis BEST195 and identified 4271 transcripts in B. subtilis NBRC 16449 with Bowtie aligner. Read count per genome was extracted from known gene annotations with HTSeq program. Compared the transcriptomes of B. subtilis NBRC 16449 grown on LB solidified with agar to that grown on surface of boiled soybeans, about 5% of genes showed the different expression levels.
Project description:Investigation of whole genome gene expression level changes in a Gluconacetobacter xylinus NBRC 3288 delta-fnrG mutant, compared to the wild-type strain.
Project description:In marine Vibrio species, chitin-induced natural transformation enables bacteria to take up DNA from the external environment and integrate it into their genome via homologous recombination. Expression of the master competence regulator TfoX bypasses the need for chitin induction and drives expression of the genes required for competence in several Vibrio species. Here, we show that TfoX expression in two Vibrio campbellii strains, DS40M4 and NBRC 15631, enables high frequencies of natural transformation. Conversely, transformation was not achieved in the model quorum-sensing strain V. campbellii BB120 (previously classified as Vibrio harveyi). Surprisingly, we find that quorum sensing is not required for transformation in V. campbellii DS40M4. This result is in contrast to Vibrio cholerae that requires the quorum-sensing regulator HapR to activate the competence regulator QstR. However, similar to V. cholerae, QstR is necessary for transformation in DS40M4. To investigate the difference in transformation frequencies between BB120 and DS40M4, we used previously studied V. cholerae competence genes to inform a comparative genomics analysis coupled with transcriptomics. BB120 encodes homologs of all known competence genes, but most of these genes were not induced by ectopic expression of TfoX, which likely accounts for the non-functional natural transformation in this strain. Comparison of transformation frequencies among Vibrio species indicates a wide disparity among even closely related strains, with Vibrio vulnificus having the lowest functional transformation frequency. We show that ectopic expression of both TfoX and QstR is sufficient to produce a significant increase in transformation frequency in Vibrio vulnificus.
