Genetic and physiological analysis of biofilm formation on different plastic surfaces by Sphingomonas sp. strain S2M10 reveals an essential function of sphingan biosynthesis

Abstract

Alphaproteobacteria belonging to the group of the sphingomonads are frequently found in biofilms colonizing pure-water systems, where they cause technical and hygienic problems. In this study, physiological properties of sphingomonads for biofilm formation on plastic surfaces were analysed. Sphingomonas sp. strain S2M10 was isolated from a used water-filtration membrane and submitted to transposon mutagenesis for isolating mutants with altered biofilm formation. Mutants showing strongly decreased biofilm formation carried transposon insertions in genes for the biosynthesis of the polysaccharide sphingan and for flagellar motility. Flagella-mediated attachment was apparently important for biofilm formation on plastic materials of intermediate hydrophobicity, while a mutant with defect in spnB, encoding the first enzyme in sphingan biosynthesis, showed no biofilm formation on all tested materials. Sphingan-dependent biofilm formation was induced in the presence of specific carbon sources while it was not induced in complex medium with yeast extract and tryptone. The regulation of sphingan-based biofilm formation was investigated by interfering with the CckA/ChpT/CtrA phosphorelay, a central signal-transduction pathway in most Alphaproteobacteria. Construction and ectopic expression of a kinase-deficient histidine kinase CckA caused cell elongation and massive sphingan-dependent cell aggregation. In addition, it caused increased activity of the promotor of spnB. In conclusion, these results indicate that sphingan-based biofilm formation by sphingomonads might be triggered by specific carbon sources under prototrophic conditions resembling a milieu that often prevails in pure-water systems.

Hybrid Histidine Kinase WelA of Sphingomonas sp. WG Contributes to WL Gum Biosynthesis and Motility

“…WG was similar to that of the sphingan - producing Sphingomonas sp. strain S2M10 ( Czieborowski et al, 2020 ). However, it was different from that in Sphingomonas melonis ( Francez-Charlot et al, 2015 ) and Sphingomonas A1 ( Maruyama et al, 2015 ).…”

“…In Sphingomonas sp. strain S2M10, the mutant of FlaQ, the homolog of FlaEY, was proved to enhance the expression of fliC and reduce the expression of flgI and a hypothetical protein ( Czieborowski et al, 2020 ). Therefore, the more expressed master regulators might participate in the regulation of flagellar biogenesis; however, the flagellar regulatory cascade remains unclear.…”

Wastewater treatment alters microbial colonization of microplastics

“…Finally, sequences from the genus Sphingomonas and its family Sphingomonadaceae were 10-fold more abundant on effluent microplastic compared to sewage microplastic. Bacteria from the genus Sphingomonas are able to degrade various complex organic compounds, including polycyclic aromatic hydrocarbons [91], the plasticizer bisphenol A [92] and plastic monomers [93,94], and they produce a polysaccharide that enhances biofilm formation on plastic surfaces [95]. The observed increases in Klebsiella, Pseudomonas, and Sphingomonas on microplastics in effluent suggests some specific selection for these organisms on plastic within WWTPs, perhaps related to the surface as a growth substrate and their capacity to break down plastic polymers.…”

Causes, Factors, and Control Measures of Opportunistic Premise Plumbing Pathogens—A Critical Review

“…It is important to acknowledge that the overall performance of these pathogens are not the same. Falkinham [2] writes that Mycobacterium avium is clearly the most resistant to chlorine and only Pseudomonas aeruginosa can grow under anaerobic conditions [143].…”