%0 Journal Article
%T Cow Dung Substrate for the Potential Production of Alkaline Proteases by Pseudomonas putida Strain AT in Solid-State Fermentation
%A Ponnuswamy Vijayaraghavan
%A Sreekumar Saranya
%A Samuel Gnana Prakash Vincent
%J Chinese Journal of Biology
%D 2014
%R 10.1155/2014/217434
%X Cow dung and agroresidues were used as the substrates for the production of alkaline proteases by Pseudomonas putida strain AT in solid-state fermentation. Among the various substrates evaluated, cow dung supported maximum ( £¿U/g) protease production. The optimum conditions for the production of alkaline proteases were a fermentation period of 48£¿h, 120% (v/w) moisture, pH 9, and the addition of 6% (v/w) inoculum, 1.5% (w/w) trehalose, and 2.0% (w/w) yeast extract to the cow dung substrate. The enzyme was active over a range of temperatures (50¨C70¡ãC) and pHs (8¨C10), with maximum activity at 60¡ãC and pH 9. These enzymes showed stability towards surfactants, detergents, and solvent and digested various natural proteins. 1. Introduction Proteases constitute one of the commercially important groups of extracellular microbial enzymes and their annual sales account for 60% of the total world enzyme market [1]. Extracellular proteases find numerous applications in industrial processes, such as detergents, leather-tanning, dairy, meat-tenderization, baking, brewery, and photographic industry [2]. From an industrial point of view, it is estimated that around 30¨C40% of the production cost of industrial enzymes can be attributed to the cost of the growth medium [3]. According to Global Food Enzymes Market Report, it is expected that the global food enzyme market will reach $2.3 billion by 2018; North America is expected to lead the market, followed by Europe and Asia-Pacific. Solid-state fermentation (SSF) is preferred over submerged fermentation, because of its lower production cost. Agroindustrial residues which included wheat bran [4]; green gram husk [5]; coffee pulp and coffee husk [6]; and Imperata cylindrica grass and potato peel [7] were widely used in SSF. In this study, cow dung substrate (referred to as dungstrate hereafter) was used as a cheap substrate for the production of alkaline proteases for various biotechnological applications. Cow dung consists of ash (13.3-13.4%), nitrogen (1.2¨C1.6%), carbon sources, ions, and growth factors. As waste, cow dung still contains high amount of nutrients [8]. A few reports were available on the use of cow dung for the production of alkaline proteases, for example, cow dung and Halomonas sp. PV1 [9] and cow dung and Bacillus subtilis VV [10]. But there might hardly be any reports on the use of cow dung for the production of proteases by Pseudomonas sp. Even though Bacillus spp. have been viewed as a promising group of organisms for protease production for various industrial applications, Pseudomonas protease has
%U http://www.hindawi.com/journals/cjb/2014/217434/