Research On Fermentation Condition Of Some Rhizosphere-soil Bacteria In Camellia

Camellia oleifera is one of four woody edible oil trees in the world.In this research,the bacteria which isolated from camellia rhizosphere soil in tongkou forest farm were studied.Four kinds of bacteria(including ammonifying bacteria,nitrogen-fixing bacteria,phosphate-solubilizing bacteria and potassium bacteria)fermentation were carried on and their activity and ability of phosphorus and potassium decomposition were analyzed.The nitrogen,phosphorus and potassium bacteria were mixed for fennentation in order to reveal the interaction between different microbial.The results are as follows.(1)The isolates with strong activity were screened by turbidimetric counting method of ammonifying bacteria for the fermentation experiments.Six aspects of the method including the culture medium,pH,inoculation amount,temperature,fluid volume and table speed were optimized.Results indicated that the optimal condition of ammonifying bacteria is in BD liquid culture medium(pH 7.6)with inoculum size 8%(4ml/50ml)at 28 ℃,180 r/min and the optimal fluid amount is 50ml/250ml.(2)The isolates with strong activity were screened by turbidimetric counting method of nitrogen fixing bacteria for the fermentation experiments.Six aspects of the method including the culture medium,pH,inoculation amount,temperature,fluid volume and table speed were optimized.Results indicated that the optimal condition of nitrogen fixing bacteria is in BP liquid culture medium(pH 7.8)with inoculum size 8%at 26 C,200 r/min and the optimal fluid amount is 50ml/250ml.(3)The isolates with strong phosphorus decomposition were screened using double flat method for the fermentation experiments.Six aspects of the method including the culture medium,pH,inoculation amount,temperature,fluid volume and table speed were optimized.Results indicated that the optimal condition of phosphate-solubilizing bacteria is in NBRIY liquid culture medium(pH 7)with inoculum size 7%at 30 ℃,160 r/min with the highest biomass and the optimal fluid amount is 50ml/250ml.(4)The isolates with strong potassium decomposition were screened using double flat method for the fermentation experiments.Six aspects of the method including the culture medium,pH,inoculation amount,temperature,fluid volume and table speed were optimized.Results indicated that the potassium bacteria has the highest biomass and the strongest potassium decomposition in N0.1 medium(pH 7.2-7.4).The optimal condition of potassium bacteria is inoculum size 7%at 30℃,200 r/min with the optimal fluid amount 50ml/250ml.(5)The ability of nitrogen fixation,phosphorus and potassium decomposition was measuered by the mixed fermentation of nitrogen,phosphorus and potassium bacteria.Result shows that:nitrogen-fixing of the mixed bacteria is:N+K>N+K+P>N+P>N>K>P+K;the ability of phosphate-solubilizing is P+ K>P>P+N>K+ P+ N>N+ K>K>N;the ability of potassium decomposition is N+P+K>K+P>K+N>K.