Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes.
Project description:The general assumption is that when bacteria run out of nutrients they become dormant or form spores. Here we show, using a new technique, that under deep starvation conditions non-sporulating Bacillus subtilis cells do not become dormant but continue to grow. B. subtilis can form (endo)spores and this has been regarded as the principal mechanism through which it survives long periods of nutrient depletion. However, in this study we demonstrate that non-sporulating B. subtilis cells can survive deep starvation conditions for many months. During this period, cells adopt an almost coccoid shape and become tolerant to antibiotics and oxidative stress. Interestingly, these cells appeared to be metabolically active, and transcriptome analyses indicated that their gene-expression profile differs substantially from both stationary phase cells, and exponentially growing cells. Surprisingly, using an inhibitor for cell division, we discovered that these coccoid-like B. subtilis cells are not dormant but actually grow and divide, albeit with a doubling time of ~4 days. It emerged that secreted proteases, allowing acquisition of nutrients from lysed brethren, are essential for this growth mode. In fact, nutrient levels comparable to 10,000 times diluted LB (Lysogeny broth) appeared to be sufficient to sustain this growth. The very slow growth provides an alternative strategy for B. subtilis to survive nutrient depletion and environmental stresses. We propose to call this the oligotrophic growth state. This state might be common among bacterial species to survive deep starvation conditions.
Project description:Transcriptome comparison of Bacillus subtilis Natto under sliding permissive (0.7% agar) and restrictive (1.5% agar or spo0A mutant strain) conditions.
Project description:Bacillus subtilis is exposed to a wide range of transitory stress and starvation conditions. Here we investigate the expression changes observed in the B. subtilis wild type strain 168 and its isogenic sigB mutant(BSM29) with respect to each stress condition tested.
Project description:Identification of the specific WalR (YycF) binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the WalRK regulon in Bacillus subtilis and its role in cell wall metabolism, as well as implying a role in several other cellular processes. For each sample analyzed in this study three biological replicates were performed. Three different samples were taken from a strain expressing the WalR-SPA protein as well as from wild-type (168) without a tagged WalR. Samples were taken from exponentially growing cells in low phosphate medium (LPDM) as well as from phosphate-limited cells (T2). Each sample compares ChIP DNA vs. Total DNA from the same cells.
Project description:Identification of the specific PhoP binding regions on the B. subtilis chromosome during exponential and phosphate starvation growth phases. The data serves to extend the PhoPR regulon in Bacillus subtilis and its role in adaptation to phosphate-limiting conditions and cell wall metabolism, as well as implying a role in several other cellular processes.
Project description:Bacillus subtilis is exposed to a wide range of transitory stress and starvation conditions. Here we investigate the expression changes observed in the B. subtilis wild type strain 168 and its isogenic sigB mutant(BSM29) with respect to each stress condition tested. Gene expression was queried for the stress conditions: ethanol-, butanol-, osmotic- and oxidative stress, heat shock, low temperature growth, glucose as well as oxygen limitation. For butanol-, ethanol-, osmotic-, and oxidative stress as well as heat shock : time points (0min, 5min, 10min, 15min and 20min) ; for glucose limitation and oxygen limitation : time points (0min, 15min, 30min, 45min, 60min or 90min) and for low temperature growth, samples for recording of expression values were taken during mid-exponential growth at OD540 0.9 and 1.0.
Project description:Transcriptome comparison of Bacillus subtilis Natto under sliding permissive (0.7% agar) and restrictive (1.5% agar or spo0A mutant strain) conditions. B subtilis Natto wild type cells were grown on the top of LB solid medium with 1.5% and 0.7% agar concentration (samples 1-4). B subtilis Natto wild type and spo0A derivative were grown on top of LB solid medium with 0.7% agar concentration (Sample 5-7). In first experiment, 4 biological replicates were used, while in the second experiment 3 biological replicates included. Dye swaps are included in both experiments.
Project description:The sigma(B)-dependent general stress response in the common soil bacterium Bacillus subtilis can be elicited by a range of stress factors, such as starvation or an ethanol-, salt-, or heat-shock, via a complex upstream signaling cascade. Additionally, sigma(B) can be activated by blue light, via the phototropin homologue YtvA, a component of the environmental branch of the signaling cascade. The genome-wide transcriptomes of B. subtilis reported here show that sigma(B) can activated by blue as well as red light via RsbP/RspQ, the energy branch of sigma(B) upstream signaling cascade. A 16 chip genome-wide expression study using RNA recovered from B.subtilis strain PB565/pYtvA under light and dark conditions before and after induction with IPTG, and from B.subtilis strain PB565 under light and dark conditions. Each B.subtilis subsp. subtilis strain 168 NC_000964 chip measures the expression level of 4,104 genes in two-fold from with eight 60-mer probe pairs (PM/MM) per gene.