Characterization of halophilic Archaea isolated from different hypersaline ecosystems

Halobacterial representatives were isolated from salted fish, naturally occurring salt pans as well as artificial saline pools in the Mediterranean area. The isolation techniques experimented proved successful, allowing halophilic archaea to be retrieved in almost 72% of analysed samples. About 65% of strains could be presumptively ascribed to the species Haloarcula marismortui by RFLP (Restriction Fragment Length Polymorphism) grouping and 16S rRNA gene sequence comparison. Nevertheless, cluster analysis of RAPD-PCR patterns revealed a wide heterogeneity among isolated strains. Biochemical features of technological interest, such as proteolytic, lipolytic and decarboxylase activity, were investigated in order to elucidate the role of archaea during ripening of salted anchovies. Proteolytic activity was only evidenced on the sarcoplasmic fraction extracted from fresh anchovies and for only four strains out of 21. No strain revealed either lipolytic capability on cod liver oil or proteolytic activity on fresh anchovies myofibrillar extract. Finally, only one strain exhibited decarboxylase activity, minimizing the potential responsibility for the spoilage of salted anchovies, since little direct evidence of the degradation process is provided. However, the possible pro-technological contribution of proteolytic strains to improve the quality of salted anchovies needs further investigation.