Presumptive Identification of Heterotrophic Thermophilic Bacteria From Surface Waters of Balabagon Boiling Lake in Manito, Albay

Abstract

Water samples from the surface waters of Balabagon Boiling Lake in Manito, Albay in December 2002 were passed through a membrane filtration device with membranes with 0.45 pm pore size. The membranes were placed in TGYE plates and incubated at 50°C for 48 hours. The isolates were purified and subjected to various morphological and physiological tests for the purposes of presumptive identification. A total of fifty-two heterotrophic bacterial strains were isolated. They were found to be thermophilic and/or thermotolerant strains of Bacillus species, namely Bacillus acidocaldarius, B. brevis, B. circulans, B. coagulans, B. laterosporus, B. Hcheniforniis, B pumilits, B. sphaericus, B. stearothermophilus, and B. subtilis The ubiquity of Bacillus species is attributed to its endospores, which are heat-resistant, disperse easily, and are able to survive in extreme conditions. The proximity of the sampling to the shoreline may account for the identified Bacillus species commonly of soil origins. The absence of other probable organisms may be due to limiting factors in the collection and cultivation procedures.