ABSTRACT
While most thermophilic species generally are isolated only from hot springs, solfataras or geothermally heated soils, thermophilic species of Bacillus may be isolated from a wide range of both thermophilic and mesophilic environments. All of the heterotrophic thermophilic species of Bacillus grow heterotrophically on complex media such as nutrient agar, or tryptone soya bean agar or L agar. Biochemical and physiological characterization was carried out together with analysis of DNA homology with B. stearothermophilus strains and a wide range of mesophilic Bacilli. Physiological tests indicate B. thermoleovorans has a similar pattern of carbohydrate utilization to B. thermoglucosidasius. In normal batch fermentation most Bacillus species form spores as the population enters stationary phase. The maximum rate of synthesis of many extracellular enzymes occurs during late exponential or early stationary phase growth as the cells become committed to sporulation.
