[Objective] The aim was to study the characteristics of microbial community in the rhizosphere soil of Dongxiang wild rice（Oryza rufipogon Griff.）.[Method] The microbial biomass carbon and nitrogen was estimated by the chloroform fumigation extraction method;the microbial community composition and Nitrogen cycling microbial functional groups were investigated by the Dilution plate culture method and the most probable number methods respectively.[Result] The microbial biomass carbon and nitrogen,in rhizosphere soil of Dongxiang Wild Rice was 83.02±18.23 mg/kg soil and 16.98±2.54 mg/kg soil,which was lower than that of ordinary cultivated rice;The relationship between the number of culturable microbial groups was bacteriaactinomycetesfungi,and the Nitrogen cycling microbial physiological groups was as the following：ammonifying bacteriaaerobic azotobacteriadenitrobacteriaanaerobic azotobacterianitrobacterianitrosobacteria.[Conclusion] The microbial community in the rhizosphere soil of Dongxiang Wild Rice was different from that of the ordinary cultivated rice.
Objective] This study aimed to determine the effects of medium composi-tion and fermentation condition on the production of antibiotics from an actinomycete antagonistic to Penicil ium viridicatum, which was isolated from soil and identified primarily as Streptomyces anandi . [Method] Single-factor experiments and orthogonal array designs were used to optimize the medium composition and fermentation con-ditions. [Result] Culture medium composition and fermentation conditions showed sig-nificant influence on the antibiotic production from S. anandi . The optimum culture medium consisted of soluble starch 10 g/L, soybean cake powder 15 g/L, KH2PO4 0.5 g/L and MgSO4·7H2O 0.1 g/L. The optimized fermentation conditions were tem-perature 30 ℃, initial pH value 7.7, culture medium amount 40 ml/250 ml flask, and fermentation time 144 h. The titer of fermentation broth reached 452.7 U/ml when the S. anandi was cultured under the optimal fermentation medium and conditions. [Conclusion] The study may lay the foundation on further isolation and purification of the antibiotic from S. anandi JXNU02.
