Comparative genomics and secretome profiling of Enterobacter cloacae SBP-8

Here, we report the comprehensive genome analysis of Enterobacter cloacae SBP-8 and its pan-genome comparison to other Enterobacter species. Genome comparison was performed by the BioRing Image Generator Tool, which predicted its genome similarity to other closest strains. Detailed annotations of the genome revealed different families of carbohydrate-degrading enzymes (CAZymes) that might be involved in the degradation of decaying plant materials with industrial significance for biomass research and the food industry. Moreover, the microbial secretome contains a number of proteins that generally interact with other microbes, environmental space, and the host. The secretion of proteins is performed by the secretory system present in the bacterial cell, however, only a few secretome proteins have been studied in limited bacterial strains. Therefore, we explored the secretome analysis of E. cloacae SBP-8 by nano LC-MS/MS and identified 776 proteins that provide insight into the role of these proteins in bacterial adaptation to different environments. The secretome proteins were classified into molecular, biological, and cellular functions using Blast2GO, whereas the subcellular localization was predicted by the PSORB tool. Many of the secretome proteins belonged to virulence proteins including Type VI secretion system (T6SS) proteins, chemotaxis fimbriae formation proteins, outer membrane proteins (OMPs), and exotoxin secretion. Moreover, STRING analysis showed the interaction among the identified proteins. The detailed investigations of secretome proteins may provide an understanding of the possible pathogenicity of test organism E. cloacae SBP-8, and is also clinically important for the development of biomarkers and therapeutic approaches.