Bacillus Research Paper

2.3 BACILLUS SPECIES

The bacillus genus comprises of gram-positive aerobic or facultative anaerobic endospore-forming rod-shaped bacteria that includes both mesophiles and extremophiles (Priest, 1993). Bacillus species are ubiquitous and environmentally diverse, they include thermophilic, psychrophilic, acidophilic, alkalophilic and halophilic bacteria. The bacteria produce spores under unfavourable environmental conditions. Spores produced are resistant to heat, drying, disinfectants and other destructive agents thus remain viable for long periods (Nicholson, Munakata, Horneck, Melosh, & Setlow, 2000). Spores may be oval or cylindrical in shape and may be located centrally, sub terminally or terminally. Spores, resting and inactive survival

Higher numbers of the species occur at coastal waters with increasing temperature and depth. Predominant species in seawater includes B. licheniformis followed by B. subtilis and B. plumilus (Bonde, 1981). Species of the genus bacillus found in fresh water represents most of bacteria of soil origin (Austin and Allen-Austin, 1983). Species are in fresh waters are common in sediments and include B. cereus, B. firmis, B. megaterium, and B. pumilus (Allen et al, 1983).

Various species of the genus bacillus have been isolated from the faeces of animals. They occur in the alimentary tract of animals (Gibson and Gordon, 1974). Bacillus species are important members of the rumen ecosystem as they assist in the nutrition of the host. Species isolated from the rumen of ruminants include B. licheniformis, B. circulans, B. coagulans, and B. laterosporus (Williams and Withers, 1981, 1983). Bacillus species are not commonly associated with leaves but are occasionally isolated from olive tree leaves (Ercolani, 1978). Large populations of bacillus are found in the rhizosphere and rhizoplane including B. macerans, B. polymyxa and sporolactobacillus which grow at the expense of root exudates. Conversely, some species of the genus provide plants with nitrate in nitrogen deficient soils (Rhodes-Roberts, 1981). Bacillus flora present in food is related to the distribution

Enzymes produced include the function such as oxidizing or reducing, hydrolyzing and metabolic in nature. Relative amount as well as catalytic property of the various individual enzymes produced varies between species and even between strains of the same species (Outtrup and Jorgensen, 2002). Enzymes produced by bacillus species make up about 50% of the total enzyme market (Schallmey et al, 2004). The enzymes alkaline proteinase and α-amylase dominate the industrial market. Alkaline proteinase is used extensively as detergent additives and α-amylase are used in the starch industry (Tomazee and Klibanov, 1988). Similarly, the enzyme glucose isomerase produced using B. coagulan is used to convert glucose to fructose in the production of high fructose corn