Open AccessCharacterization of Salicola sp. IC10, a lipase‐ and protease‐producing extreme halophile
Author(s) -
De Lourdes Moreno María,
García María Teresa,
Ventosa Antonio,
Mellado Encarnación
Publication year - 2009
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2009.00651.x
Subject(s) - halophile , haloarchaea , biology , lipase , protease , biochemistry , extreme environment , casein , amylase , halobacteriaceae , microbiology and biotechnology , halobacterium , enzyme , archaea , bacteria , halobacterium salinarum , genetics , gene
Abstract In order to explore the diversity of extreme halophiles able to produce different hydrolytic enzymes (amylase, protease, lipase and DNAse) in hypersaline habitats of South Spain, a screening program was performed. A total of 43 extreme halophiles showing hydrolytic activities have been isolated and characterized. The isolated strains were able to grow optimally in media with 15–20% (w/v) total salts and in most cases, growth was detected up to 30% (w/v) total salts. Most hydrolase producers were assigned to the family Halobacteriaceae , belonging to the genera Halorubrum (22 strains), Haloarcula (nine strains) and Halobacterium (nine strains), and three isolates were characterized as extremely halophilic bacteria (genera Salicola, Salinibacter and Pseudomonas ). An extremely halophilic isolate, strain IC10, showing lipase and protease activities and identified as a Salicola strain of potential biotechnological interest, was further studied. The optimum growth conditions for this strain were 15–20% (w/v) NaCl, pH 8.0, and 37 °C. Zymographic analysis of strain IC10 detected the lipolytic activity in the intracellular fraction, showing the highest activity against p ‐nitrophenyl‐butyrate as a substrate in a colorimetric assay, whereas the proteolytic activity was detected in the extracellular fraction. This protease degraded casein, gelatin, bovine serum albumin and egg albumin.