Zymomonas mobilis CCT 4494 imobilized in alginate-chitosan hybrid system for levan production

• Grant number: 11/15475-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2011
• End date: July 31, 2012
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Crispin Humberto Garcia Cruz
• Grantee: Gabriella Duarte Nascimento
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

Use of immobilized cells in products of industrial interest biosynthesis, such as levan gum is a promising alternative to increase efficiency of conventional processes that use free cells during fermentation. Levan is a polysaccharide composed by fructose units linked by ² bonds (2.6) and can be produced by various microorganisms, among which stands out Zymomonas mobilis. Among different holders in the literature, the use of alginate and chitosan have shown satisfactory results such as increased production of biomass and greater protection against adverse medium conditions. Therefore, this study will aim to establish a protocol for immobilization into the cells of Zymomonas mobilis CCT4494 using technique of trapping in a mixture of alginate and chitosan as holder; evaluate the production of levan obtained by immobilized cells using different concentrations of sucrose and monitor cell growth in the holder, testing different values of pH, determine the temperature that maximizes the production of levan and finally evaluating the ability to reuse beads in subsequent processes.(AU)