Alkalihalobacillus lehensis M136, a Novel Alkaliphilic, Cyclodextrin Glucanotransferase (CGTase)-producing Isolate from Manleluag Hyperalkaline Spring in Pangasinan, Philippines.

A cyclodextrin glucanotransferase (CGTase)-producing bacterium was isolated from Manleluag hyperalkaline spring, Pangasinan, the first to be reported from a hyperalkaline environment in the Philippines. The isolate, M136, had the highest CGTase enzyme activity (46.01 U/mL) out of the forty-one similar bacterial isolates and exceeds the CGTase activity of the reference strain, Paenibacillus sp. JCM 9143. Using whole genome analysis, M136 was identified as Alkalihalobacillus lehensis. The CGTase enzyme produced by Alkalihalobacillus lehensis M136 was partially purified with 73.97% recovery and post-purification activity of 49.52 U/mL. The enzyme has an estimated molecular weight of 78.64 kDa and an isoelectric point of 4.72. Enzyme characterization revealed that it was stable at 30-80 °C (optimal activity at 70 °C), pH 4.0-10.0 (optimal activity at pH 6.0), and in the presence of different metal ions and reagents such as zinc, calcium, magnesium, and manganese, ethylenediaminetetraacetic acid, iodoacetic acid, sodium dodecyl sulfate, and phenylmethylsulfonyl fluoride. [ABSTRACT FROM AUTHOR]