Bacterial and chemical properties of Japanese traditional anchovy product, salted Etari

Abstract

We analyzed the bacterial flora and chemical properties of the Japanese traditional anchovy product called salted Etari, which is distributed in Nagasaki Prefecture in the western part of Japan. The pH and NaCl concentrations ranged from 6.4 to 6.6 and from 9.6% to 13.9%, respectively. The lactic acid and total free amino acid concentrations were determined to be between 122 and 344 mg/100 g of sample and between 2850 and 4783 mg/100 g of sample. The bacterial cell counts were determined to be 10³–10⁸ and 10⁴–10⁸ cells/g under aerobic and anaerobic conditions using a plate medium containing 10% NaCl, respectively. The isolates were classified into six groups on the basis of the results of PCR-restriction fragment length polymorphism (RFLP) analysis targeting the 16S rRNA gene. According to the results of 16S rRNA gene sequencing, the predominant PCR–RFLP group was identified as the halophilic lactic acid bacterium Tetragenococcus halophilus, and the remaining groups were identified as bacteria belonging to the genera Chromohalobacter, Halomonas, and Staphylococcus. The results of culture-independent analysis, namely, terminal restriction fragment length polymorphism (T-RFLP) analysis targeting the 16S rRNA gene, indicated that T. halophilus is the bacterium commonly found in salted Etari.