Abstract: Sequencing Batch Reactor（SBR）was used to enrich short-cut denitrifying phosphorus accumulating bacteria（SDPB）. The strain was isolated，purified and identified. Response surface methodology was applied to optimize the medium of bacteria. Results showed that Si was isolated and purified from SBR. Morphological/physiological/biochemical indicators and the phylogenic tree of 16S rDNA gene sequence measurements demonstrated that Si is similar to Acinetobacter beijerinckii. Biochemical properties also demonstrated that Si has the function of short denitrifying and phosphorus accumulating. Acinetobacter beijerinckii is a kind of SDPB. Through the analyses of response surface methodology，the order of key factors affecting the growth of Si is pH≈carbon source＞nitrogen source. The best medium of Si is carbon source of 4060mg/L，nitrogen source of 1090 mg/L with pH 8.0. The average turbidity of bacteria is 0.867.

摘要： 利用序批式反应器（SBR）富集短程反硝化聚磷菌，并对其进行分离纯化及鉴定，同时采用计算机响应面方法进行培养基的优化。结果表明：SBR系统中分离纯化得到菌株Si，细菌形态观察、生理生化指标和16S rDNA系统发育树表明Si菌与Acinetobacter beijerinckii最相似，同时生理生化指标显示Si菌具有短程反硝化和聚磷功能，因此Acinetobacter　beijerinckii是短程反硝化聚磷菌；影响Si生长的关键因素次序为pH值≈碳源＞氮源；Si菌最佳培养基中碳源为4060mg/L，氮源为1090 mg/L，pH值为8，此时菌浊平均值为0.867。