The Bacillaceae family members are a good source of bacteria for bioprocessing and biotransformation involving whole cells or enzymes. In contrast to Bacillus and Geobacillus, Anoxybacillus is a relatively new genus that was proposed in the year 2000. Because these bacteria are alkali-tolerant thermophiles, they are suitable for many industrial applications. More than a decade after the first report of Anoxybacillus, knowledge accumulated from fundamental and applied studies suggests that this genus can serve as a good alternative in many applications related to starch and lignocellulosic biomasses, environmental waste treatment, enzyme technology, and possibly bioenergy production. This current review provides the first summary of past and recent discoveries regarding the isolation of Anoxybacillus, its medium requirements, its proteins that have been characterized and cloned, bioremediation applications, metabolic studies, and genomic analysis. Comparisons to some other members of Bacillaceae and possible future applications of Anoxybacillus are also discussed.
Two thermophilic bacteria (SK3-4 and DT3-1) were isolated from the Sungai Klah (SK) and Dusun Tua (DT) hot springs in Malaysia. The cells from both strains were rod-shaped, stained Gram positive and formed endospores. The optimal growth of both strains was observed at 55 degrees C and pH 7. Strain DT3-1 exhibited a higher tolerance to chloramphenicol (100 microg ml(-1)) but showed a lower tolerance to sodium chloride (2%, w/v) compared to strain SK3-4. Phylogenetic analysis based on 16S rRNA gene sequences revealed that both strains belong to the genus Anoxybacillus. High concentrations of 15:0 iso in the fatty acid profiles support the conclusion that both strains belong to the genus Anoxybacillus and exhibit unique fatty acid compositions and percentages compared to other Anoxybacillus species. The DNA G + C contents were 42.0 mol% and 41.8 mol% for strains SK3-4 and DT3-1, respectively. Strains SK3-4 and DT3-1 were able to degrade pullulan and to produce maltotriose and glucose, respectively, as their main end products. Based on phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequences, and the DNA G + C content, we propose that strains SK3-4 and DT3-1 are new pullulan-degrading Anoxybacillus strains.