DETERMINATION OF THE OPTIMUM CONDITIONS FOR THE PRODUCTION OF AGARASE FROM LOCAL ISOLATE BACILLUS SP. H12

Abstract

Twenty seven bacterial local isolates of Bacillus sp. were obtained from soil samples. The isolates were tested for agarase production on solid media; fourteen isolates were able to develop clear zone around the bacterial growth after floating the plates with iodine reagent (Lugol´s solution), with clear zone diameter between (1.08-1.11cm). There were further treated in submerged culture which led to selection of Bacillus sp. H12, since it was the most efficient that gave higher specific activity of agarase 11.73 unit/mg protein. The optimum conditions for agarase production using submerged cultures were 0.3% agarose as carbon source, 0.5% beef extract and peptone as nitrogen sources, 0.5% sodium chloride, at initial pH 8 and inoculum size 1×108cell/ml at 37˚C for 24 hrs using shaker incubator at 150 rpm.