Secretion of an alkaline protease from a salt- tolerant and alkaliphilic, Streptomyces clavuligerus strain Mit-1

Abstract

An alkaliphilic and salt-tolerant actinomycete, Streptomyces clavuligerus strain Mit-1, was isolated from Mithapur, the western coast of India. The organism was Gram-positive, having filamentous, long thread like structure. The sporulation started after two days of growth and the optimum level of alkaline protease (130 U/ ml) was produced during the early stationary phase. The strain could grow and produce protease with 0-10% NaCl (w/v), the optimum being 5% NaCl (w/v). Growth and protease production was optimum at pH 9 with substantial decline at neutral pH. Sucrose and gelatin were the best carbon and nitrogen sources respectively, whereas gelatin broth was the preferred medium for protease production. Mit-1 produced substantial protease with various amino acids, when employed as the sole nitrogen sources. Crude substrates, such as molasses, whey and wheat flour had significant effect on enzyme production. The results are quite valuable, as only few actinomycetes, particularly salt-tolerant alkaliphilic ones, have so far been explored for their enzymatic potential and process optimization.

Optimization studies on production of a salt-tolerant protease from Pseudomonas aeruginosa strain BC1 and its application on tannery saline wastewater treatment

“…Salt tolerant proteases are highly specific in their action and their activity can be better standardized in any harsh environment. Several researchers reported the novel characteristics of salt tolerant/resistant proteases identified from different microbes (4,10,11,12,13,17,20,21,22). Such kind of enzyme characteristics encourages their application in wastewater treatment systems.…”

Genetic diversity and salt tolerance of bacterial communities from two Tunisian soils

“…Moreover, interest in microbes living in extreme environments, as arid soils has been fuelled by the discovery of novel taxa in these ecosystems and by the potential for discovery of valuable enzymes, polymeric materials, and bioactive compounds (Gould and Corry, 1980). For instances, in recent studies, salt-tolerant actinomycetes have been explored for their capacity to produce numerous bioactive molecules, particularly antibiotics (Vasavada et al, 2006), and enzymes as alkaline protease (Thumar and Singh, 2007). Finally, bacteria from saline environments may be considered models for biological salt tolerance (Lanyi, 1979).…”

Effects of Cultural Conditions on the Production of Extracellular Protease by Streptomyces albolongus and Streptomyces aburaviensis

“…Broth cultures were carried out at various culture conditions such as temperature (10, 27, 37, 45°C), initial p H of the culture media (4,5,6,7,8,9), incubation time (1, 2, 3, 4, 5, 6, 7 days), to optimize the culture conditions for the production of extracellular proteases. To determine the effects of aeration, inoculated mediums were incubated at both stationary and shaking condition (100 rpm), keeping other experimental conditions at optimum.…”

“…Although protease can be obtained from several sources, including plant, animal and microorganisms, microbial proteases are preferred in view of their rapid growth, ease of cultivation purification and genetic manipulation. A large number of microorganisms have been reported for protease production [4][5][6][7][8].…”