Screening,Identification And Optimization Of Bacterium And Microalgae For High Yield Of Auxin

There are many kinds of microorganisms,the distribution area is very wide,it contains a variety of nutrients,such as plant hormones,flammable oils,proteins,amino acids,etc.In this paper,the microorganism is the main research object,through the process of extracting,enriching,screening,identifying and optimizing the culture of microorganisms in nature,we focus on the production capacity of auxin in plant hormones.Finally,in the 69 soil samples and 23 water samples,we screened 8 strains bacterium and 4 strainsmicroalgae with high yield of auxin.8 strains of IAA-overproducing bacteria are identified as follows,3-2,N1-3 and T311-1 are Bacillus badius,7-1 is Escherichia vulneris,9-1 is Bacillus cereus,7-2 and S318-2 are Enterobacter cloacae,and N6-1 is Bacillus encimensis.Four species of IAA-overproducing microalgae is that Z1-2 is Dunallella salina,Z8-1 is Uncultured cyanobacterium,ZN5-3 and ZS307-2 is Chlorella sp.,respectively.In the results of bacteria,the production of auxin concentration of 7-1 reached 199.88 mg/L,and S318-2 reached 185.86 mg/L.3-2,7-2 and S318-2 grew best in alkaline(pH=8)conditions,even better,the 9-1 grew best under acidic(pH=5)conditions.3-2,N1-3 and T311-1 had better salt tolerance,and the best growth was 4%.It can be seen that the addition of tryptophan can significantly improve the yield of auxin.In the results of microalgae,we found that a salt tolerant algae,Z1-2,grew well under the condition of salt concentration of 2%,and the yield of auxin was as high as 32.88 mg/L.Moreover,the production of auxin concentration of ZN5-3 also reached 41.54 mg/L.