Characterization of Salicola sp.  IC10, a lipase- and protease-producing extreme halophile

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 degrees 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.

Comparison of prokaryotic community structure from Mediterranean and Atlantic saltern concentrator ponds by a metagenomic approach

“…By contrast, Isla Cristina saltern was built in 1955 over wetlands at the marsh of the river Carreras in the village of Isla Cristina, closely located to food-processing industries (Moreno et al, 2009). Santa Pola saltern is subjected to climatic conditions characterized by low annual rainfall and moderate temperatures, with little fluctuation between summer and winter (Rodríguez-Valera et al, 1985).…”

“…Santa Pola saltern is subjected to climatic conditions characterized by low annual rainfall and moderate temperatures, with little fluctuation between summer and winter (Rodríguez-Valera et al, 1985). However, Isla Cristina saltern is subjected to rainfall seasons, high solar radiation, and larger temperature fluctuations between day and night (Moreno et al, 2009). Although salinity has been considered the main factor involved in the structure of microbial biodiversity in saline aquatic systems, the data from our study strongly suggests that other factors may influence the composition of hypersaline aquatic microbial communities such as geographic locations (Naor et al, 2012; Zhaxybayeva et al, 2013) and environmental characteristics.…”

Halophilic Bacteria: Potentials and Applications in Biotechnology

“…On the other hand, Salicola sp. IC10 showed lipase and protease activities with optimum growth at 15-20 % (w/v) NaCl, pH 8.0 and at 40 o C. This protease hydrolyses casein, gelatin, bovine serum albumin and egg albumin, while the most specifi c substrate to the enzyme was egg albumin (de Lourdes Moreno et al 2009 ).…”

Halophiles: biology, adaptation, and their role in decontamination of hypersaline environments

“…These enzymes remain active in high-salt environments, thermotolerant and alkaliphilic (de Lourdes Moreno et al 2009), hence their popularity for use in biotechnological applications in the food and textile industries and in laundry detergents (Gomes and Steiner 2004;Setati 2010). Examples of halophilic enzymes and their tolerance towards NaCl concentration are summarized in Table 4.…”