The Screening And Incubation Of Bacillus Sp. Stain Producing Alginate Lyase And Researches On Its Properties

A Bacillus sp. Stain screened from soil was cultured and screened in the solid medium with the sodium alginate as the sole carbon source. Finally a strain S1 which could produce the extra-cell alginate lyase was chosen as the initial strain for the following experiment. The strain S1 was identified as Bacillus subtilis . The research has found that the optimum conditions of producing alginate lyase are as follows. The nitrogen sources were peptone and urea. The optimal content of sodium alginate was 0.5 ~ 0.6%. The alginate lyase was well produced with initial pH 7.5 of liquid medium under the temperature 32℃and rotation rate 180r/min after fermentation for 84- 108hr.The enzyme activity reaches 18.79U/mL under the conditions above.After UV and EMS mutagenizing on the strain S1 the alginate lyase secreted by the mutant strain EMS-50 with pretty stable biological characters reached 43.22U/mL higher than the original one (18.94 U/mL).The alginate lyase produced by EMS-50 is extra-cellular induced enzyme. It could be induced by sodium alginate and mannose while the lyase was produced better in the presence of glucose. The results of orthogonal test showed the optimum alginate lyase producing medium is that with 0.6% sodium alginate, 0.6%urea, 0.6%peptone, 2%glucose, 0.4% yeast extract, 0.5%NaCl and0.4% KH2PO4.And the optimum culture conditions containing the initial medium pH, amount of...