Industrial applications of alkaliphiles and their enzymes--past, present and future.
Alkaliphiles are microorganisms that can grow in alkaline environments, i.e. pH >9.0. Their enzymes, especially extracellular enzymes, are able to function in their catalytic activities under high alkaline pH values because of their stability under these conditions. Proteases, protein degrading enzymes, are one of the most produced enzymes in industry. Among proteases, alkaline proteases, which are added to some detergents, are the most produced. Other alkaline enzymes, e.g. alkaline cellulases, alkaline amylases, and alkaline lipases, are also adjuncts to detergents for improving cleaning efficiency. Alkaline enzymes often show activities in a broad pH range, thermostability, and tolerance to oxidants compared to neutral enzymes. Alkaliphilic Bacillus species are the most characterized organisms among alkaliphiles. They produce so many extracellular alkaline-adapted enzymes that they are often good sources for industrial enzymes. As a patent strain, the whole genome sequence of alkaliphilic Bacillus halodurans C-125 has been sequenced for the first time. In addition, an increasing number of whole genomic sequences and structural analyses of proteins in alkaliphiles, development of genetic engineering techniques and physiological analyses will reveal the alkaline adaptation mechanisms of alkaliphilic Bacillus species and the structural basis of their enzymatic functions. This information opens up the possibility of new applications. In this paper we describe, first, the physiologies of environmental adaptations, and then the applications of enzymes and microorganisms themselves in alkaliphilic Bacillus species.
Fujinami
Shun
S
NITE Bioresource Information Center, Department of Biotechnology, National Institute of Technology and Evaluation, 2-10-49 Nishihara, Shibuya-ku, Tokyo 151-0066, Japan.
Fujisawa
Makoto
M
D000681:Amylases; D001407:Bacillus / Q000201:enzymology / Q000378:metabolism*; D003505:Cyclodextrins; D043364:Endo-1,4-beta Xylanases; D007218:Industrial Microbiology / Q000379:methods*; D012697:Serine Endopeptidases
D003505:Cyclodextrins; D000681:Amylases; D043364:Endo-1,4-beta Xylanases; D012697:Serine Endopeptidases; C032923:microbial serine proteinases