Proteases are the hydrolytic enzymes which hydrolyzes peptide bond between proteins with paramount applications in pharmaceutical and industrial sector. Therefore production of proteases with efficient characteristics of biotechnological interest from novel strain is significant. Hence, in this study, an alkaline serine protease produced by Bacillus cereus strain S8 (MTCC NO 11901) was purified and characterized. The alkaline protease was purified by ammonium sulfate precipitation (50%), ion exchange (DEAE-Cellulose) and gel filtration (Sephadex G-100) chromatographic techniques. As a result of this purification, a protein with specific activity of 300U/mg protein was obtained with purification fold 17.04 and recovery percentage of 34.6%. The molecular weight of the purified protease was determined using SDS-PAGE under non-reducing (71 kDa) and reducing conditions (35 kDa and 22 kDa). Zymogram analysis revealed that proteolytic activity was only associated with 22 kDa. These results indicate that existence of the enzyme as dimer in its native state. The molecular weight of the protease (22 kDa) was also determined by gel filtration (Sephadex G-200) chromatography and it was calculated as 21.8 kDa. The optimum activity of the protease was observed at pH 10.0 and temperature 70 °C with great stability towards pH and temperature with casein as a specific substrate. The enzyme was completely inhibited by PMSF and TLCK indicating that it is a serine protease of trypsin type. The enzyme exhibits a great stability towards organic solvents, oxidizing and bleaching agents and it is negatively influenced by Li2+ and Co2+ metal ions. The purified protein was further characterized by Matrix Assisted Laser Desorption Ionization/Mass Spectroscopy (MALDI/MS) analysis which reveals that total number of amino acids is 208 with isoelectric point 9.52.

Dissolved organic carbon (DOC) and nitrogen (DON) were measured in 27 major and medium monsoonal estuaries along the Indian coast during southwest monsoon in order to understand the spatial variability in their concentrations and fluxes to the northern Indian Ocean. A strong spatial variability (~20‐fold) in DOC and DON was observed in the Indian monsoonal estuaries due to variable characteristics of the catchment area and volume of discharge. It is estimated that the Indian monsoonal estuaries transport ~2.37 ± 0.47 Tg (1 Tg = 1012 g) of DOC and ~0.41 ± 0.08 Tg of DON during wet period to the northern Indian Ocean. The Bay of Bengal receives 3 times higher DOC and DON (1.82 and 0.30 Tg, respectively) than the Arabian Sea (0.55 and 0.11 Tg). Catchment area normalized fluxes of DOC and DON were found to be higher in the estuaries located in the southwestern than the estuaries from other regions of India. It was attributed to relatively higher soil organic carbon, biomass carbon, and heavy rainfall in catchment areas of the rivers from the former region. It has been noticed that neither catchment area nor discharge volume of the river controls the fluxes of DOC and DON to the northern Indian Ocean. Since the total load of DOC and DON is strongly linked to the volume of discharge, alterations in the freshwater discharge due to natural or anthropogenic activities may have significant influence on organic matter fluxes to the Indian coastal waters and its impact on microbial food web dynamics needs further evaluation.

Citation: Suribabu K, Lalitha Govardhan T, Hemalatha KPJ (2014) Strain Improvement of Brevibacillus borostelensis R1 for Optimization of α-Amylase Production by Mutagens. J Microb Biochem Technol 6: 123-127. doi:10.4172/1948-5948.1000132 Copyright: © 2014 Suribabu K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited AbstractPhysical and chemical mutagens are promising and are used for screening of high yielding strains. The exponential increase in the application of amylases in various fields has placed stress and demand in both qualitative improvement and quantitative enhancement through strain improvement. Ultraviolet light exerts its mutagenic effect by exciting electrons in molecules. The potent UV mutants which showed more than 20 mm zone of starch hydrolysis were screened and selected at 42% of survival time at 80minutes of exposure. The wild strain with fixed parameters yielded (3000 U/ml). The major findings of the strain improvement were out of ten mutants isolated, two (UV-3 and UV-10) showed 3000-4000 U/ml of amylase activity. The % of survival of Brevibacillus borstelensis R1 in Pikovskaya's medium was 25.75% at 120 minutes of exposure. Ten mutants (HNO 2 -10, HNO 2 -30, EMS-4, EtBr-40, EtBr-50, Acr-1, Acr-20, Acr-30, Acr-4 and 5′-FU-50) out of fifty mutants isolated showed 3000-4300U/ml of amylase activity, which was higher than the wild strain. The potent Bacillus species screened from marine water was Brevibacillus borstelensis R1. The α-amylase was found to be useful in bakery, food, fodder for poultry, automation dishwashing and laundry industries.

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