Isolation, Identification and Evaluation of Enzyme Production Capacity of CGTase Producing Bacteria from Lakes Salda and Van/Turkey

Abstract

The aim of this study was isolation of CGTase positive microorganisms from lakes Salda and Van, both being extreme environments unique in character with high alkalinity pH>9.7. Four bacterial strains designated as SD5, SG2, SG3 and V3 were isolated by cultivation on selective Horikoshi agar and confirmed as CGTase producers. Microscopic inspection showed the four isolates to be Gram positive rods. Strains were identified as Bacillus based on DNA sequences of 16S rDNA region. Only the V3 and SG2 isolates could be resolved at species level identified as B. agaradhaerens and B. patagoniensis, respectively. Growth and CGTase production capacity of the strains were evaluated under shake flask conditions. All isolates achieved extracellular CGTase levels of 6-8 U/mL within 24 h of incubation. Growth curves of Bacillus sp. SG3, Bacillus sp. SD5, B. agaradhaerens V3 showed the bacteria to reach a plateau phase within 24-30 h however, extended fermentation up to 168 h showed B. patagoniensis SG2 to continue the growth cycle until the end of this period with higher CGTase activity observed. These four strains isolated which have thus been confirmed as CGTase positive bacteria can potentially be exploited as genetic sources for the synthesis of CGTase in industrial scale.