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.

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Microbial Proteases Applications.

Carboxymethyl cellulase (CMCase) provides a key opportunity for achieving tremendous benefits of utilizing rice straw as cellulosic biomass. Out of total 80 microbial isolates from different ecological niches one bacterial strain, identified as Bacillus sp. 313SI, was selected for CMCase production under stationary as well as shaking conditions of growth. During two-stage pretreatment, rice straw was first treated with 0.5 M KOH to remove lignin followed by treatment with 0.1 N H2SO4 for removal of hemicellulose. The maximum carboxymethyl cellulase activity of 3.08 U/mL was obtained using 1% (w/v) pretreated rice straw with 1% (v/v) inoculum, pH 8.0 at 35°C after 60 h of growth under stationary conditions, while the same was obtained as 4.15 U/mL using 0.75% (w/v) pretreated substrate with 0.4% (v/v) inoculum, pH 8.0 at 30°C, under shaking conditions of growth for 48 h. For maximum titre of CMCase carboxymethyl cellulose was optimized as the best carbon source under both cultural conditions while ammonium sulphate and ammonium nitrate were optimized as the best nitrogen sources under stationary and shaking conditions, respectively. The present study provides the useful data about the optimized conditions for CMCase production by Bacillus sp. 313SI from pretreated rice straw.

https://downloads.hindawi.com/archive/2014/651839.pdf

Parametric Optimization of Cultural Conditions for Carboxymethyl Cellulase Production Using Pretreated Rice Straw by Bacillus sp. 313SI under Stationary and Shaking Conditions.

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.

/pdf/microbial-proteases-ubiquitous-enzymes-with-innumerable-uses-312ctmnskz.pdf

Microbial proteases: ubiquitous enzymes with innumerable uses

Our society produces a lot of voluminous waste of biomass every day, which are mainly lignocellulose in origin. It is the most abundant plant cell wall component of the biosphere and the most plentiful biological compound on terrestrial earth. The successful conversion of cellulosic waste from domestic, industrial, and municipal sources through economically feasible processes to valuable by-products has long been admitted as a desirable endeavor. The degradation of cellulosic materials has gained increasing attention due to its worldwide availability and enormous potential for transforming them into sugars, fuels, and chemical feedstocks. Enzymatic hydrolysis of cellulosic biomass holds tremendous promise due to the high specificity and production of high yields of glucose without generation of degradation products, unlike acid/alkali hydrolysis. It has lower utility cost and hydrolysis occurs under mild reaction conditions. Microorganisms that degrade cellulose are abundant and universal in nature. The enzymatic hydrolysis of cellulose requires the use of cellulase enzyme. Fungi and bacteria are the main cellulase-producing microorganisms. A “twofold” benefit could be achieved through a sustainable bioconversion of biomass by cellulase enzyme. First, it would reduce the amount of cellulosic waste and diminish its effects on our environment; and second, the bioconversion of waste would be an alternative source of fuel energy to shrink our growing dependence on fossil fuels.

Cellulase in Waste Management Applications

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 by moderately halophilic Bacillus cereus in solid state fermentation

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.

S. Jayalakshmi

Papers

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

Sachaarification of banana-agro waste and clarification of apple juice by cellulase enzyme produced from Bacillus pumilis.