Alkaliphiles in estuarine mangrove regions of Goa, (central west coast of India)

Obligate alkaliphilic bacteria (28 strains) were isolated from various estuarine ecosystems of Goa, India. Most of these strains were found to be Gram positive, motile rods, capable of growth in aerobic condition upto pH 12, exhibiting optimum growth at pH 10.5. Isolates exhibited high buffering capacity confirming their alkaliphilic nature. Significantly high difference was noted in the buffering capacities of the alkaliphiles and the neutrophile indicating their ability to maintain their internal pH. The obligate alkaliphile A52 exhibited highest cytoplasmic buffering capacity of 8,500 nanomoles OH- ions/pH unit/mg protein. The isolates also showed amylase (39%), protease (50%) and lipase (100%) activity under alkaline conditions. The present study depicts that such alkaliphilic bacteria also play an important role in the mineralization of organic matter under high pH conditions in natural ecosystems.