Sucrose metabolism by Lactobacillus curvatus CRL705

L. C. TERÁN; CECILIA ARISTIMUÑO; S. FADDA; R. RAYA

Rosario

Congreso; Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2014

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Lactobacillus curvatus CRL705 is a meat starter culture that ferments sucrose and produces a potent bacteriocin (lactocin Lac705); these two important phenotypes are associated, respectively, with plasmids pRC18 (18,664 bp) and pRC12 (12,342 bp). In this work, the capacity to utilize sucrose by L. curvatus CRL705 (pRC12 and pRC18) and two CRL705-derivatives, strains Sac7 (pRC18) and 28B (pRC12), was studied. Sucrose fermentation was observed in CRL705 and 28B, but not in Sac7, and only when cells were incubated under anaerobic conditions during 48 h at 30 °C. Genes related to the sucrose metabolism, such as the PTS system, fructokinase, permease and a sucrose 6-phosphate hydrolase, are present in the genome of strain CRL705, but the presence of an invertase function that could explain the sucrose positive phenotype was not detected. Nucleotide sequence analysis of plasmid pRC12 indicates that this plasmid has fourteen putative ORF. Two of these genes are potential candidates related with sucrose fermentation: hyd, which encodes a protein of 934 aa with a hydrolase-like domain, and ca-atp, which encodes a protein of 434 aa that has a COG02726 domain related with carbohydrate transport and metabolism. The involvement of genes hyd and ca-atp in the capacity of sucrose fermentation by L. curvatus CRL705 is currently being investigated.