RONAN Q. BACULI, CHERIDAN I. COLLADO AND MARIA ANGELICA D. EVANGELISTA
Abstract
Aerobic and alkaliphilic bacteria were isolated and characterized from water samples collected from a serpentinization- driven high pH spring in Poon Bato, Zambales, Philippines (pH 11.5). Seventy nine strains were initially isolated using different enrichment media. Thirteen isolates were studied in detail involving morphological and biochemical characterization, and determination of pH tolerance. These isolates were further subjected to phylogenetic analysis using 16S rRNA gene sequences and were assessed according to enzyme profile. Phylogenetic analysis revealed that most of the bacterial isolates were related to the phylum Firmicutes, containing low G+C gram-positive bacteria represented by the genera Bacillus, Exiguobacterium and Staphylococcus. Only 5 isolates were high G+C, Gram- positive bacteria associated with phylum Actinobacteria represented by the genera Brevibacterium, Microbacterium, Nesterenkonia and Microcella. Most of the bacterial isolates were alkalitolerant. Production of alkaline enzymes amylase, protease, lipase and cellulase was observed from most of the isolates, some are even multiple producers. This study demonstrates the presence of interesting groups of microorganisms capable of producing biotechnologically important enzymes.