Purification and Characterization of Halophilic Organic Solvent Tolerant Protease from Marine Bacillus sp. APCMST-RS7 and Its Antioxidant Potentials

Abstract

Halophilic organic solvent tolerant proteolytic bacterium was isolated from the marine sediment of Rajakkamankalam estuary and identified as Bacillus sp. APCMST-RS7. The alkaline protease synthesized by Bacillus sp. APCMST-RS7 was purified by using ammonium sulphate precipitation, dialysis and DEAE-Sepharose Fast Flow column. The purified protease showed 6.60-fold purity, 26.02 U/mg specific activity with 24.30 % yield. The molecular weight of the purified alkaline protease was 32 kDa. This purified protease registered maximum activity at pH 8 and it was stable between pH 8-9 after 1.30 h of incubation. The optimum temperature registered was 50°C and it was stable between 30 and 40°C even after 1.30 h of incubation. This enzyme also showed maximum activity at 1.5 M NaCl concentration. The Km and V max values registered were, 0.0002 g/l and 1428.57 U/ml, respectively. Further, magnesium chloride, barium chloride and copper sulphate influenced this enzyme activity remarkably and it was also found to be enhanced by many of the tested surfactants and solvents. Here, the serine protease inhibitor totally inhibited the enzyme activity; hence it is of serine protease family. The candidate bacterium effectively deproteinized the shrimp shell waste with maximum protease activity. The shrimp shell hydrolysate also exhibited maximum antioxidant activity.

Detergent‐Compatible Robust Alkaline Protease from Newly Isolated Halotolerant Salinicoccus sp. UN‐12

“…The optimum temperature of the studied protease was higher than those previously reported for proteases from halophilic/halotolerant bacteria [15,18,[22][23][24]. The outcomes related to the enhancement of protease activity in the presence of calcium ions are in agreement with former reports on the thermal stability of temperature-sensitive proteases by the addition of Ca 2?…”

“…The studied protease retained maximal protease activity in the presence of Nirma detergent powder and retained greater than 90% activity in Rin, Surf Excel, Tide, and Ghari. Previously, the stability of protease from several halophilic and other microbes in commercial detergents was reported [17,24,37]. To our knowledge, this is the first report of a multifaceted protease from Salinicoccus genus tested for its suitability with commercial detergents.…”

“…Similarly, proteases obtained from halophilic/halotolerant Bacillus aquimaris VITP4 [23], Bacillus sp. APCMST-RS7 [24], and Bacillus firmus CAS-7 [29] strain also showed highest activity against casein. These outcomes suggest the applicability of the protease for removal of proteinaceous stains generated by sweat, milk, and blood.…”

“…Proteases have been reported to play a significant role in non-aqueous enzymology and were particularly suitable for peptide and ester synthesis by employing various organic solvents [24]. High concentrations of salts and presence of organic solvents reduce the water activity of a system, hence the hypersaline environments are comparable with non-aqueous media (organic solvent-containing reaction medium) [55].…”

Production of Protease Showing Antibacterial Activity by Bacillus subtilis VCDA Associated with Tropical Marine Sponge Callyspongia diffusa

“…The protease production by the marine sponge isolate B. subtilis VCDA was also affected by changes in the salt concentration in which an enhanced activity of 38 U/ml was detected at 1.5% concentration of NaCl and a similar report was observed in case Bacillus sp. APCMST-RST with maximum activity at 1.5% NaCl and an reduced protease activity was noted with incearse in salt concentration [26].…”