Field Application Of Bacillus Amyloliquefaciens S3-1 And Technology Optimization Of Surfactin Fermentation

Abuse of Chemical fertilizer lead to a series of problems,such as environmental pollution,soil harden,intensifing salinization,soil fertility reduced and crop quality decline at the same time of promoting the development of agricultural production,which results a serious challenge to the sustainable development of agriculture.In order to reduce the use of chemical fertilizer,we screened a plant rhizosphere bacteria,named S3-1,which could promote plant growth and improve environment of the soil.Through analysis of morphology observation,physiological and biochemical experim-ents,blast of 16 S rRNA sequence found that S3-1 was identificated as Bacillus amyloliquefaciens in this study.By using the fermentation technology,we made a kind of bio-organic fertilizer through compounding S3-1 with a variety of auxiliary materials after many times.And the field experiments was taken in the form of basic fertilizer and fertilizer in tomato experimental base in Pudong district of Shanghai.Results showed that: 1)Compared with control group,after the biological organic fertilizer was applied tomato production increased by 63%,soluble protein,soluble sugar,titratable acid,vitamin C content increased by 49.36%,9.40%,6.82% and9.40% respectively,instead the content of nitrate was reduced by 13.6%.2)Application of the biological organic fertilizer made the soil urease,invertase and acid phosphatase,polyphenol oxidase,catalase activity increased by about 31.50%,44.69%,31.03%,27.27% and 4.32% respectively,and it aslo increased the number of microorganisms in soil,the microbial community structure more reasonable compared with the control group;3)Through the traditional flat coating method and PCR-DGGE technique to analyze microorganisms of soil,results showed that the diversity and abundance of rhizosphere bacteria were increased significantly of fertilization group;4)After adding biological organic fertilizer to soil,the content of available phosphorus and available potassium in soil increased by 71.1% and 69.2%respectively,and the value of the nitrate nitrogen,ammonium nitrogen was reduced by 43.4% and 55.2%.All of above indicate that the development of biological organic fertilizer could increase tomato yield,improve the quality of tomato fruit,and improve soil biological activity,promoting the transformation of organic nutrients,relief of soil salinization.In order to continue to develop the potential of S3-1,in the last part of this research,we optimized of fermentation medium components to obtainthe most of surfactin by using the response surface analysis method.Through the experiment,we Increased the amount of surfactin from 271.20 mg/L to 544.35 mg/L.This research lay a foundation for appling Bacillus amyloliquefaciens S3-1 to the practical agricultural production.