Enzymology Characteristics Of Some Important Enzymes From Bacillus Sp.

Enzyme is a kind of biological macromolecule which has the biological catalytic function.So we call it biological catalyst.As a catalyst,it can accelerate the rate of biochemical reactions,but it doesn't change the direction and products.Enzymes mainly come from animals,plants and microbes.In the reaction,it can use low dosage enzymes to catalytic high efficiency and high speed reactions.In many fields it can be active with the high efficiency and low cost aim,thus enzymes have become a hot topic in the research field.Moreover,the kinds of enzyme is numerous but its amount is less with difficulty to be extracted.Also,the activity of enzyme can be deactivated easily.These may hinder the enzyme development for industrial production.Compared with microbes,there are less enzymes in animals or plants and the extraction process is very difficult,so microbial enzyme production will become the research focus.In the numerous microbial groups,however,Bacillus is famous for its various species,high security,wide range of sources and high resistance to environment.Therefore,studying the enzyme characteristics of Bacillus will be a base for the industrial production.Many specific domestic and international scholars have carried on a deep research to enzymes secreted from 20 kinds of Bacillus including Bacillus subtilis.In this paper we chose 118 strains of Bacillus-like genus which contain 114 species as our experimental materials which were preserved in the Agricultural Bio-Resources Institute,Fujian Academy of Agricultural Sciences.We used the method of shaping transparent circle to detect the production of Xylanase,Protease,Pectinase,Pullulanase,Chitinase and Phytase,all of these enzymes come from the above species.And we also analyzed the six kinds of enzymes on enzymatic properties.By the preliminary screening,we got 37 species which can produce Xylanase,54 species which can produce Protease,42 species which can produce Pectinase,46 Pullulanase producing species,10 Chitinase and 16 Phytase producing species.So we can see that different kinds Bacillus have much different enzyme producing characteristics.Further screening,we got some species which can produce high yield enzyme.These included Bacillus safensis(FJAT-14260)and B.amyloliquefaciens(FJAT-2349).We optimized their fermentation conditions for enzyme production.For the B.safensis FJAT-14260 species,we measured the enzyme activity was 24597.65(U·mL-1)in the original Xylanase fermentation medium.Having optimized by single factor and orthogonal experiment we got the optimal fermentation conditions:Yeast extract 7 g/L,Peptone 9 g/L,Xylan concentration 10 g/L,Culture temperature 30?,Initial PH=8,Loading liquid quantity 30 mL/250 mL.In this condition,after 32 h,we measured the enzyme activity was 113585.78(U/mL)in FJAT-14260 species.This is 4.62 times higher than before optimization.Then for B.safensis FJAT-14260,we measured the enzyme activity was 32.32(U·mL-1)in the original Protease fermentation medium.Also we optimized fermentation conditions by single factor experiment and got the optimal condition as follows:Soluble starch 10g·L-1,Soya bean meal 5g·L"1,Carbon Nitrogen ratio 3:1,Optimal temperature 35 ?,190 r/min,PH=8.In this condition,after 32 h culturing,we measured the enzyme activity was 69.26(U/mL)in FJAT-14260 species.This is 2.14 times higher than before optimization.For B.amyloliquefaciens FJAT-2349,we measured the enzyme activity was 31.06(U·mL-1)in the original Pectinase fermentation medium.After optimized fermentation conditions by single factor experiment,we got the optimal fermentation conditions:Maltose 10.0 g/L,Beef extract 5.0 g/L,Carbon Nitrogen ratio 3:1,Optimal temperature 35 ?,150 r/min,PH=6.In this condition,after 40 h culturing,the enzyme activity achieved to 154.28(U·mL-1)which was 4.97 times higher than before optimization.When B.amyloliquefaciens FJAT-2349 in the original Pullulanase fermentation medium the enzyme activity was 42.27(U-mL-1).Also optimized fermentation conditions by single factor experiment,we got the optimal fermentation conditions:Yeast extract 10.0 g/L,Peptone 5.0 g/L,Carbon Nitrogen ratio 2:1,Optimal temperature 35 ?,190 r/min,Initial PH=8.After 48 h culturing,the enzyme achieved to the the highest activity 86.40(U·mL-1)which was 2.04 times higher than before optimization.