Monitoring Eubacterial Communities During Salted Anchovy (Engraulis anchoita) Ripening.

CAROLINA BELFIORE; ELINA VIHAVAINEN; JOHANNA BJÖRKROTH; GRACIELA VIGNOLO

Bologna, Italia

Congreso; Foodmicro 2006. Food safety and food biotechnology: diversity and global impact.; 2006

International Commitee on Food Microbiology and Hygiene

Salting and curing of anchovy is a traditional process used to obtain a tender product with a specific pleasant aroma and taste as a result of biological activities on the fish flesh. To identify the dominant bacterial species, a polyphasic approach, including classical phenotyping, 16S/23S rDNA RFLP, RAPD and 16S rDNA sequence analysis was used. Bacterial counts on MRS + 7% NaCl showed an initial value of 103 CFU/g then decreasing to 10 CFU/g at five months of ripening. Isolated strains were identified to species level using 16 and 23 rDNA HindIII RFLP (ribotyping) database. The HindIII ribopatterns showed the presence of nine clusters among the isolates tested, three of these including lactic acid bacteria. The first group included the type strain of Leuconostoc mesenteroides subsp. dextranicum, the second Leuconostoc mesenteroides subsp. cremoris and the third Leuconostoc carnosum. In order to assess the biodiversity within Leuconostoc species all isolates were analyzed by RAPD. Two primers were used and the presence of six different biotypes was observed. By means of 16S rDNA gene sequence analysis, catalase positive cocci isolates were identified as Staphylococcus warneri. Due to the increase in NaCl concentration, a pattern of succession was observed during anchovy ripening process, in which Leuconostoc was displaced by Staphylococcus population, this remaining until the final stages of ripening.