A Study On The Biological Characteristics And Promoting Plant Grwoth Of Silicate Bacerium In Xining Area

In the experiment, 15 Silicate bacterium strains were isolated from soil by routine separation method, which collected from South Mountain Park and Botanical Garden of west mountain in Xining .Two strains of silicate bacterium were screened, which distinctly showed the effect on the plant growth promoting. They were numbered strain GSY-1,strain GSY-3.The test of Biological Characteristics showed that strain GSY-1 and strain GSY-3 were G-.The colony of strain GSY-1 are white, round, smooth surface, even edges and stickiness. It is able to form pellicle, collarium and capsule, but it is not have precipitate or pigment in liquid medium. The colony of strain GSY-3 are white, round, smooth surface, even edges, crepe and stickiness. It is able to form pellicl , collarium and capsule , but it is not have precipitate or pigment in liquid medium. The result of nitrate reduction test, starch hydrolysis test, Indole test, gelatinlique faction test are all positive, but the result of V-P test, Citric acid test, urea hydrolysis and Phenylalanine dehydrogenase test are all negative. The strain GSY-1 and strain GSY-3 were identified as Bacillus criculans Jordan,Bacillus mucilaginosus. The conditions of fermentation optimization results showed that the best carbon source of strain GSY-1 is brown sugar,the best nitrogen source are yeast cream and NH4NO3,the best mineral salts are MgCl₂+ MgSO₄+KH₂PO₄. Optimal medium recipe of strain GSY-1: brown sugar 5.0g,yeast cream0.1g,NH4NO31.0g,MgCl₂0.1g,MgSO₄·7H₂O0.01g,KH₂PO₄0.01g,CaCO31.0g,pH 7.0,H₂O1000ml. The fermentation parameter will achieved when the pH 6.5,the temperature at 30℃, the inoculm concentration is 5%, rorate speed is200r/min, liquid volume is 150ml and the time is 72h for strain GSY-1. For strain GSY-3,the best carbon source is glucose ,the best nitrogen source are yeast cream and NH4Cl,the best mineral salts are MgCl₂+MgSO₄+KH₂PO₄.Optimal medium recipe are C₆H₁₂O₆15g,yeast cream0.1g,NH4Cl0.5g,MgCl₂0.05g,MgSO₄·7H₂O0.01g,KH₂PO₄0.05g,CaCO31.0g,pH7.0,H₂O1000ml. The fermentation parameter will achieved when the pH 6.5, the temperature at 25℃, the inoculm concentration is 3%, rorate speed is 200r/min, liquid volume is150ml and the time is 72h . The pot experiment results showed that both strain GSY-1 and strain GSY-3 can improve growth of corn.