Isolation and selection of thermotolerant bacteria potentially producing stereoisomers of lactic acid

• Grant number: 12/21679-9
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2013
• Effective date (End): December 31, 2013
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal researcher: Jonas Contiero
• Grantee: Regiane Alves de Oliveira
• Home Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

Currently, lactic acid is a compound widely used in food, pharmaceutical, medical and chemical indutries, occurring naturally in form of two optical isomers, D (-) and L (+) lactic acid. These isomers, when used together, provide different characteristics to the lactic acid polymer, in comparison to the polymer synthesized by only L (+). Thus, the project aims at the isolation and selection of thermophilic bacterias producers of lactic acid, mainly isomers D (-) and L (+) which are used in the synthesis of polymers used in the production of a wide range of materials resistant and biodegradable. Bacteria will be isolated from different rhizospheres in the state of São Paulo. With these isolates, fermentations will be conducted at 50oC from different substrates and sugars such as sugar cane juice, cheese whey, sucrose, glycerol, cottonseed, corn steep liquor and yeast autolysate. After defining the best bacteria and substrate, it will be make a central composite experimental design with four replicates at the central point for optimization of the component concentrations of the means of production. In all experiments are sampled at different times to evaluate the production of lactic acid, biomass and substrate consumption. (AU)