Simultaneous optimization of biomass and protease biosynthesis by a local isolated Pseudomonas sp. Part 1. Selection of main medium components and operating conditions

AGÜERO MARÍA VICTORIA; KOTLAR CATALINA; ROURA SARA INES

Industrial Biotechnology

Mary Ann Liebert Inc. Publishers

Lugar: Nueva York; Año: 2011 vol. 7 p. 364 - 373

1550 9087

The kinetics of cell growth and protease production, substrate specificity, morphology, motility, and antimicrobial effects against food pathogens were evaluated for a Pseudomonas strain recently isolated from fresh cabbage. Protease and biomass production in batch fermentation were tested in relation to different medium com¬ponents (glucose, meat peptone, NaCl, Ca2+, and Mg2+ content) and in different pH, temperature, and agitation-speed conditions, first by a rapid prescreening assay and then a Plackett-Burman (PB) experi¬mental design. The prescreening assay aimed to determine optimal lower and upper values of each one of the above variables, thereby avoiding estimations or reliance on published data on other known Pseudomonas strains. The combination of prescreening and the PB design allowed determination not only of optimal ranges for each of the studied variables but also the significant relevance of each, in rapid, economical fashion. Results showed that temperature, agitation speed, NaCl, and pH had the greatest effects on proteolytic activity, while temperature, glucose, pH, peptone, and agitation speed most significantly affected microorganism growth. This information is useful for maximizing Pseudomonas sp. Growth and protease production through optimal operating conditions and media composition. The significant factors identified in this work have been evaluated in a previously published study of medium opti¬mization through use of response surface optimization (Kotlar et al, Ind Biotechnol 6[6] 364-374 [2010]).