A comparative study on biofilm formation of a marine bacterium pseudoalteromonas sp.sf57 and its mutants

Biofilms are agglomerates of macromolecules and microorganisms, including bacteria, diatoms, fungi, and protozoa, enmeshed in a matrix of extracellular polymeric substances. The genus Pseudoalteromonas is a clade of marine bacteria that is found in a wide variety of niches. This genus attracts significant research interest because of its abundance in the marine environments and its ability to produce diverse bioactive substances. Early studies have shown that the Pseudoalteromonas sp. sf57 could affect the settlement process of marine fouling organisms including Balanus amphitrite and Hydorides elegans. However, little attention was paid on weather biofilm formation was involved in this process. In this study, a transposon mutant (named wm1) was made by Tn-10 system and screened by altered in pigmentation. Both wild type sf57 and mutant wm1 was compared with the phenotypic changes and total proteomes and metabolomes. The results showed that mutant wm1 was found different in biofilm formation. Arbitory PCR results pointed out the disrupted gene in mutant wm1 was a GspD (General Secretion Pathway Protein D), which located on the outer membrane. The LC-MS results showed that the differentially expressed proteins were mainly involved in the glycolysis/gluconeogenesis; bacterial secretion system; protein export and drug metabolism pathways