African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5211

Full Length Research Paper

Isolation and characterization of bacterial producers of optically pure D(-) and L(+) lactic acid

Marcela Piassi Bernardo1, Luciana Fontes Coelho1, Cristian J. Bolner de Lima1, Cynara de Melo Rodovalho2, Paola Monteiro de Oliveira1, Fabricio C. de Paula1 and Jonas Contiero1*
1Department of Biochemistry and Microbiology, Biological Sciences Institute, UNESP–University. Estadual Paulista, Rio Claro, SP, Brazil. 2UNESP – Univ. Estadual Paulista, Centro de Estudos de Insetos Sociais, Rio Claro, São Paulo, Brazil.
Email: [email protected]

  •  Accepted: 03 May 2013
  •  Published: 21 May 2013


The aim of the present study was to isolate and characterize bacterial producers of optically pure D(-) and L(+) lactic acid for use in the synthesis of polymers employed in the production of resistive and biodegradable materials. Four hundred microorganisms were isolated. Of these strains, 20 had high capacity for production of only one lactic acid isomer which was selected for characterization. D(-) lactic acid producers were identified as Weissella paramesenteroides (25%), Leuconostoc mesenteroides (6.25%),Leuconostoc lactis (6.25%) and Lactobacillus delbrueckii (6.25%). L(+) lactic acid producers were identified as Lactobacillus casei (12.5%), Enterococcus sp. (18.75%),Lactobacillus paracasei (6.25%), Streptococcus sp. (6.25%) and Lactobacillus sp. (12.5%). The most promising isolate for L(+) lactic acid production was Ke8, in the presence of sucrose. Otherwise, Ke6 and Ke11 were the best producers, by using glucose as the carbon source. The best microorganism for the production of D(-) lactic acid was isolated from fermented milk (L. delbrueckii Y15C). However, the growth of this microorganism is easily inhibited on media containing sugar concentration greater than 60 g/L.


Key words: Lactic acid bacteria, identification, characterization, carbon sources, lactic acid, optimization.