The availability of the complete sequence of the Bacillus subtilis chromosome (F. Kunst et al., Nature 390:249-256, 1997) makes possible the construction of genome-wide DNA arrays and the study of this organism on a global scale. Because we have a long-standing interest in the effects of scoC on late-stage developmental phenomena as they relate to aprE expression, we studied the genome-wide effects of a scoC null mutant with the goal of furthering the understanding of the role of scoC in growth and developmental processes. In the present work we compared the expression patterns of isogenic B. subtilis strains, one of which carries a null mutation in the scoC locus (scoC4). The results obtained indicate that scoC regulates, either directly or indirectly, the expression of at least 560 genes in the B. subtilis genome. ScoC appeared to repress as well as activate gene expression. Changes in expression were observed in genes encoding transport and binding proteins, those involved in amino acid, carbohydrate, and nucleotide and/or nucleoside metabolism, and those associated with motility, sporulation, and adaptation to atypical conditions. Changes in gene expression were also observed for transcriptional regulators, along with sigma factors, regulatory phosphatases and kinases, and members of sensor regulator systems. In this report, we discuss some of the phenotypes associated with the scoC mutant in light of the transcriptome changes observed.

The initiation of sporulation in Bacillus subtilis is under control of the transcriptional factor Spo0A. Most Spo0A mutants fail to initiate the sporulation process and aH the sporulation initiated processes such as the synthesis of subtilisin.However, the product of spoOd9V, one of the several spo0A mutants characterized, distinguishes itself in the fact that, while it appears to effectively repress abrB, it fails to activate the spollA operon. The aim of this study was to examine the effect of the spoOA9V mutation on aprE expression and we found that in different genetic backgrounds, the spoOA9V mutation has a negative effect on aprE: :lacZ expression.

A gene from Bacillus thuringiensis subsp. kurstaki that codes for a Lepidoptera-specific insecticidal toxin (delta-endotoxin) was engineered for expression in Bacillus subtilis. A low-copy-number plasmid vector that replicates in Escherichia coli and B. subtilis was constructed to transform B. subtilis with gene fusions first isolated and characterized in E. coli. Naturally occurring promoter sequences from B. subtilis (43, veg, ctc, and spoVG) were inserted upstream from the plasmid-borne structural gene. In the most prolific case, when the sporulation-specific spoVG promoter was fused to the heterologous toxin gene, the toxin product accumulated during postexponential growth to >25% of the total cell protein. However, the resulting specific activity of the insecticidal toxin product was not commensurate with the abundance of the protein.

We used the sequence-specific endonucleases EcoRI, SmaI, BamHI, HsuI, and HaeIII as identification tools in following the conjugal transfer of the well-studied R plasmids Sa, R388, RP4, and R6K. Transfers were both intergeneric and intrageneric. Plasmid fingerprints were generated from both singleand combination-enzyme digests. The Sa transconjugants yielded plasmids showing consistent fingerprints for each of the respective endonucleases used, whereas the three other R-plasmid transconjugants showed fingerprint changes. 1070 on August 1, 2020 by guest