MCCP136 a new cold-active microcin produced by a psychrophylic Serratia sp. (poster)

SÁNCHEZ LA; FARIÑA JI; DELGADO OD

Pucón

Congreso; XVIII Congreso Latinoamericano de Microbiología; 2006

Asociación Latinoamericana de Microbiología (ALAM)

Antimicrobial peptides are molecules widespread in life forms to mediate competition, and their industrial production could be important for the potential use as preservatives in food, cosmetics and pharmaceutical industries. Cold environments could be a suitable source of microorganisms with ability to produce cold-active antimicrobials of biotechnological interest. A new psychrophilic Serratia sp. producing a new cold-active microcin was isolated from Isla de los Estados (Tierra del Fuego, Argentina) soil samples. The aim of the study was to produce the antimicrobial compound in a batch culture and its partial characterization. The isolate was identified by partial sequencing of the 16S rDNA and gyrB gene. Batch fermentations were carried out in a BIOFLO III bioreactor under pH, temperature and D.O. controlled conditions. Trypsin, proteinase K, pronase E, catalase, peroxidase, lipase and á-amylase were used to determine the antimicrobial nature. Antimicrobial Mw was estimated by the free cell supernatant flow through a dialysis membrane. The protein net-charge was determined by agarose gel electrophoresis and the activity was visualized by tricine-PAGE. The antimicrobial compound is a thermo-stable low Mw protein, produced during the stationary growth phase. It has a broad range of pH activity (1-13) and inhibitor effect against both Gram (+) and Gram (-). Mitomycin C has not induction effect.