Isocitrate dehydrogenase of Bacillus cereus is involved in biofilm formation

In this study, we scanned the genome ofB. cereus 0-9 and found a gene encoding isocitrate dehydrogenase (FRY47_22620) namedicdH. The IcdH protein was expressed and purified. The enzyme activity assay showed that the protein had IDH activity dependent on NADP+, indicating that this gene encoded an IDH. The ΔicdH mutant and its complemented strains were obtained by a homologous recombination strategy, and crystal violet data and CLSM were measured. The results showed that the biofilm yield of the mutant ΔicdH decreased, and the biofilm morphology also changed, while the growth of ΔicdH was not affected. The extracellular pH and citric acid content results showed that the ΔicdH mutant exhibited citric acid accumulation and acidification of the extracellular matrix. In addition, the addition of excess Fe3+ restored the biofilm formation of the ΔicdH mutant. It is speculated that IDH inB. cereus may regulate biofilm formation by modulating intracellular redox homeostasis. In addition, we found that theicdH deletion ofB. cereus 0-9 could result in a reduced sporulation rate, which was significantly different from sporulation inB. subtilis caused by interruption of the stage I sporulation process due toicdH loss. All the above results provide us with new insights for further research on IDH.
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research