S. Dhivya

Bio: S. Dhivya is an academic researcher. The author has contributed to research in topics: Casein & Protease. The author has an hindex of 1, co-authored 1 publications receiving 13 citations.

Studies on detergent additives of protease enzyme from an estuarine bacterium Bacillus cereus

Abstract: The present study is an attempt to produce the protease enzyme from the bacterial strain Bacillus cereus . The strain was isolated from the estuarine sediment sample on casein agar medium. Various cultural conditions were optimized. Based on the results obtained from optimization the mass scale culture was made with pH 9.0; 40 0 C temperature; 35ppt of salinity; 3% of the casein as the suitable substrate. Ammonium sulphate saturation was made and the enzyme was partially purified and lyophilized. 80% saturation has given the maximum saturation of 0.9g. SDS-PAGE was made and there was the separation at 55KDa and 20KDa representing the enzyme protease. Application study was carried out with the enzyme recovered from Bacillus cereus. The purified enzyme was included in to the stain removal procedure. There was the better stain removing observation at the time of using the protease enzyme.

Microbial Proteases Applications.

Abstract: The use of chemicals around the globe in different industries has increased tremendously, affecting the health of people. The modern world intends to replace these noxious chemicals with environmental friendly products for the betterment of life on the planet. Establishing enzymatic processes in spite of chemical processes has been a prime objective of scientists. Various enzymes, specifically microbial proteases, are the most essentially used in different corporate sectors, such as textile, detergent, leather, feed, waste, and others. Proteases with respect to physiological and commercial roles hold a pivotal position. As they are performing synthetic and degradative functions, proteases are found ubiquitously, such as in plants, animals, and microbes. Among different producers of proteases, Bacillus sp. are mostly commercially exploited microbes for proteases. Proteases are successfully considered as an alternative to chemicals and an eco-friendly indicator for nature or the surroundings. The evolutionary relationship among acidic, neutral, and alkaline proteases has been analyzed based on their protein sequences, but there remains a lack of information that regulates the diversity in their specificity. Researchers are looking for microbial proteases as they can tolerate harsh conditions, ways to prevent autoproteolytic activity, stability in optimum pH, and substrate specificity. The current review focuses on the comparison among different proteases and the current problems faced during production and application at the industrial level. Deciphering these issues would enable us to promote microbial proteases economically and commercially around the world.

Microbial proteases: ubiquitous enzymes with innumerable uses

Abstract: Proteases are ubiquitous enzymes, having significant physiological roles in both synthesis and degradation. The use of microbial proteases in food fermentation is an age-old process, which is today being successfully employed in other industries with the advent of 'omics' era and innovations in genetic and protein engineering approaches. Proteases have found application in industries besides food, like leather, textiles, detergent, waste management, agriculture, animal husbandry, cosmetics, and pharmaceutics. With the rising demands and applications, researchers are exploring various approaches to discover, redesign, or artificially synthesize enzymes with better applicability in the industrial processes. These enzymes offer a sustainable and environmentally safer option, besides possessing economic and commercial value. Various bacterial and fungal proteases are already holding a commercially pivotal role in the industry. The current review summarizes the characteristics and types of proteases, microbial source, their current and prospective applications in various industries, and future challenges. Promoting these biocatalysts will prove significant in betterment of the modern world.

Amylase production by moderately halophilic Bacillus cereus in solid state fermentation

Abstract: The production of extracellular amylase by the moderately halophilic bacterium Bacillus cereus was studied in solid state fermentation (SSF). Solid substrates such as rice bran, wheat bran, sugarcane bagasse, black gram husk and green gram husk were studied for enzyme production. Growth on sugarcane bagasse gave the highest amylase activity. The time course for amylase production inferred that 48 h was the optimum duration for higher amylase production. The suitable pH, temperature and inoculum level observed for higher amylase production was pH 7.0, 40.0°C and 2.0%, respectively. The amylase production ofB. cereus was high in maltose (carbon source), yeast extract (nitrogen source), Tween 80 (surfactant) and calcium chloride (metal ion) added medium when compared to other respective sources tested. The halotolerancy of B. cereus for amylase production was 3% sodium chloride. The sugarcane bagasse can be utilized for the cheap production of amylase from Bacillus cereus. It is less expensive in comparison to synthetic media and is readily available for production purposes. Key words: Bacillus cereus, amylase, solid state fermentation (SSF), sugarcane bagasse.

Amylase Production Using Bacillus cereus Isolated from a Vermicompost Site

Abstract: Bacillus cereus strain isolated from a vermicompost site was tested for its abilities to hydrolyze the structural polysaccharides. The effect of different production parameters such as pH, temperature, carbon source, nitrogen source (Organic and inorganic) incubation time inoculum sizes and surfactants on amylase production by the isolated bacterial strain was studied. The enzyme production was assayed in submerge d fermentation (SmF) condition. The maximum amylase production was observed with maltose (216±2.6 U/ml), yeast extract (163±3.6U/ml), ammonium sulphate (70±3.0U/ml), pH 7.0 (263±4.1), temperature 40°C (152±9.1), Tween-80 (165±2.8U/ml), inoculum size level 0.5% (132±2.0U/ml) and incubation time 48 hours (172.01± 0.56U/ml) in the production medium.

Research Article PRODUCTION AND PARTIAL CHARACTERIZATION OF ALKALINE PROTEASE FROM BACILLUS TEQUILENSIS STRAINS CSGAB0139 ISOLATED FROM SPOILT COTTAGE CHEESE

Abstract: An alkaline protease producing strain was isolated from spoilt cottage cheese sample which was identified as Bacillus tequilensis strain SCSGAB0139 on the basis of morphological, cultural, biochemical characteristics and 16S rRNA sequence analysis. Primary screening for protease production was carried out by observing for zone of hydrolysis on skim milk agar, GYEA milk agar and gelatin agar plates. Physicochemical parameters like pH of the medium, incubation time and temperature, aeration and composition of the medium were optimized for maximum protease production by this isolate. Maximum yield of protease (85.67U/ml) was obtained in a medium containing peptone (5% w/v), maltose (5% w/v) and KNO3, 0.5%; K2HPO4, 0.4%; trisodium citrate, 0.4; CaCl2, 0.0002%; MgSO4·7H2O, 0.05%; Na2CO3, 1%.; 1% (v/v) of a trace element solution (NH4)6MO7O24, 0.01%; FeSO4·7H2O, 0.2%; CuSO4·5H2O, 0.02%; ZnCl2, 0.02%) having pH 10, inoculated with 1%(v/v) of pre-grown cell mass and incubated at 30°C on a rotary shaker (100rpm) for 48hrs. Absence of any one of the following salts viz. KNO3, K2HPO4, tri-sodium citrate; MgSO4, CaCl2 and Na2CO3 from optimized medium reduced the protease production by 80% to 40%. The enzyme has an optimum pH of 9 and maintained its stability over a broad pH range between 6 and 10. Its optimum temperature is 30°C, and exhibited a stability of up to 65°C. Among metal ions only Ca 2+ and Mg 2+ ions enhanced the enzyme activity up to 105% and 107% respectively while other metal ions reduced the activity by 40% where as EDTA exhibited the least inhibitory effect upon the enzyme. Protease activity was enhanced in the presence of isopropanol and marginally reduced in the presence of other organic solvents studied. The crude enzyme showed stability towards various surfactants such as Tween-20, Tween- 80, SDS and Triton X-100. It also showed excellent stability and compatibility with commonly used laundry detergents (Ariel, Surf excel and Surf Blue). The enzyme retained its activity in 2% H2O2 indicating it to be bleach-stable. The present findings show that the protease from Bacillus tequilensis strain SCSGAB0139 is alkali- and detergent- stable and hence, when this protease was applied to remove blood stains from cotton fabrics indicated its potential use in detergent formulations.