Deficiency in N-acetylglucosamine transport affects the sporulation process and modifies the hemolytic

TARSITANO,JULIAN; BOCKOR SABRINA; PALOMINO MARÍA MERCEDES; FINA MARTIN, JOAQUINA; RUZAL SANDRA M.; ALLIEVI MARIANA C

REVISTA ARGENTINA DE MICROBIOLOGíA

ASOCIACION ARGENTINA MICROBIOLOGIA

Lugar: Buenos Aires; Año: 2024

0325-7541

Lysinibacillus sphaericus is a bacterium that, along with Bacillus thuringiensis var.israelensis, is considered the best biological insecticide for controlling mosquito larvaeand an eco-friendly alternative to chemical insecticides. It depends on peptidicmolecules such as N-acetylglucosamine to obtain carbon sources and possesses aphosphotransferase system (PTS) for their incorporation. Some strains carry S-layerproteins, whose involvement in metal retention and larvicidal activity against disease-carrying mosquitoes has been demonstrated. Alterations in the amino sugarincorporation system could affect the protein profile and functionality. For this study,strain ASB13052 and the isogenic mutant in the ptsH gene, predominant in the PTSsignaling pathway, were used. For the first time, the presence of N-glycosylated S-layer proteins was confirmed in both strains, with a variation in their molecular weightpattern depending on the growth phase. In the exponential phase, an S-layer proteingreater than 130 kDa was found in the ptsH mutant, absent in the wild-type strain. Themutant strain exhibited altered and incomplete sporulation processes of poor quality.Hemolysis analysis, associated with larvicidal activity, showed that the ptsH mutant hashigher lytic efficiency, correlating with the high molecular weight protein. The resultsallow us to propose the potential effects that arise because of the absence of aminosugar transport on hemolytic activity, S-layer isoforms, and the role of N-acetylglucosamine in larvicidal activity.