Characterization of up-regulated proteases in an industrial recombinant Escherichia coli fermentation (original) (raw)

Detection, quantification, and characterization of proteases in recombinant Escherichia coli

Biotechnology Techniques, 1993

Electrophoresis of crude cell exlracts on PAGE gels in the presence of SDS copolymerized with a nonspecific protease substrate has been used to detect, characterize, and quantify intracellular proteases in recombinant Escherichia coli. After electrophoresis, the gels are incubated, SDS is removed, and protease activity is revealed by clear zones on the stained gel due to proteolysis of the nonspecific protease substrate (gelatin or casein). The method differentiates proteases based on activity and molecular weight.

Biotechnological Perspectives of Microbial Proteases

The review briefly elucidates the importance of proteases in living organisms and their wide range of potential applications in the vast areas of research and biotechnology. The important features of the proteases are also exploited in a number of ways and can be used to serve various applications in different industries. Apart from their natural potential of performing various important operations in living tissues, various microbial proteases have potential applications in a number of industries. In cellular environment, proteases are involved in the breakdown of the proteins' peptide bonds and transform them into smaller fragments of amino acids and peptides which are prerequisite for the differentiation and cellular growth. Proteases have also vast applications in a range of industrial procedures such as food, pharmaceutical, dairy and detergent. Microbial proteases have dominated roles in the industrial sectors. Microbial proteases are exploited for their characteristic feature of hydrolyzing the protein and the rest of the components of wheat and soy beans in the production of soy sauce. The production of proteases can be enhanced via substantiated fermentation methods. The variation in the composition of growth media such as changes in carbon and nitrogen ratio and some other features affecting microbial growth are significant in the evaluating the fermentation procedures. The production of microbial proteases is advantageous because they can be generated rapidly, their production is cost effective and the manipulation of microbial enzymes is quite easy. Proteolytic enzymes can be produced by either submerged fermentation (SmF) or solid state fermentation (SSF). But the latter is far more advantageous because it direct towards many potential benefits for the protease production. The review mainly focuses on the microbial protease production, their functional and structural aspects and the application of these proteolytic enzymes in different industries.

An overview of microbial proteases for industrial application

Microorganisms are attractive sources of proteases as they can be artificially cultured in large quantities in a relatively short time by established fermentation methods. Microbial proteases have been and will continue to gain global significant prominence, particularly in commercial industries. Microbial alkaline proteases dominates the world enzyme market, accounting for a nearly two-thirds share of the detergent industry. Screening and characterization of these proteases from different sources serves many advantages from both environmental and industrial points of view. Most of the microbial proteases of significant application in detergent industry are bacterial alkaline proteases from genus Bacillus. The major bottleneck has been the screening of wild-type biocatalyst that would be detergent compatible with increase efficiency than what is seen today. Given their role in commercial industries; it is deemed imperative to gather the disperse literature on the current state of the art describing the sources, classification, application and biosynthetic regulation of bacterial proteases. Special emphasis has been given to bacterial alkaline proteases that are detergent compatible.