European Journal of Biomedical and Pharmaceutical Sciences

INFLUENCE OF CARBON, NITROGEN AND METAL SALTS ON ?-AMYLASE PRODUCTION BY BACILLUS MEGATERIUM KLMI 4 USING AGRO-WASTES

Masarath Irfana and Lingappa K.*

ABSTRACT

Maximum activity of α-amylase was observed with fructose 375.0 IU, closely followed by that with supplementation of maltose (360 IU/ml). Several sugars like dextrin 275.0 IU, glucose 170.0 IU, glycerol 178.0 IU, trehalose 140 IU and xylose 148 IU and medium amended with starch 210 IU caused lower enzyme activity but higher than that in the controls: The non-metabolizable sugars like arabinose, raffinose, meso-inositol, sucrose and galactose do not support α-amylase production as indicated by enzyme activities much lower than that in the control, whereas with lactose lower enzyme activity is observed as the organism is basically a non-lactose fermenter. Addition of peptone proved to be beneficial for enzyme production, enzyme yield at 48 h increased gradually as peptone concentration increased upto 1.5% and thereafter it decreased as peptone concentration increased, the enzyme yield being suppressed at 3.5 and 4.0% peptone concentrations. The highest yield of α-amylase 214.0 IU was obtained with 1.5% peptone. Amongst all the organic nitrogen sources supplemented, peptone was observed to be most beneficial for α-amylase production with an yield of 215.0 IU. Urea tended to suppress the yield of the enzyme. The order of beneficiality of the sources is in the following manner: peptone>beef extract>tryptone>yeast extract> hydrolysed casein>corn steep liquor and soluble casein. Ammonium bisulphate was observed to be most beneficial, α-amylase activity of 195.0 IU after 48 h of incubation period was recorded. Amongst other salts, only ammonium nitrate and ammonium sulfate were beneficial. Other salts were slightly suppressive. Amongst the metal salts supplemented, zinc sulphate, mangenese sulphate and ferrous sulphate were observed to exhibit suppressive action on α-amylase production by the bacterium. Other salts enhanced α-amylase production, maximum yield 198.0 IU being observed with calcium sulphate. The beneficial influence of these salts was observed to be in the following order : calcium sulphate>calcium chloride >magnesium sulphate >copper sulphate. The enzyme activity was 65.0 IU at 24 h and it rose sharply to 513.0 IU at 48 h, almost eight times as that at 24 h. Thereafter it declined very sharply, recording 160.0 IU and 35.0 IU at 72 and 96 h, respectively.

Keywords: Bacillus megaterium KLMI 4, Alpha-amylase production, Agro-wastes (substrate), influence of carbon, nitrogen, metal salts.