枯草芽孢杆菌（Ｂａｃｉｌｕｓｓｕｂｔｉｌｉｓ）Ｂ０３４分离自水稻叶面，对水稻白叶枯病菌具有较强的拮抗能力。除去菌体培养液以７０％饱和度硫酸铵沉淀所得的拮抗物粗提液对热稳定，对胰蛋白酶不敏感，对蛋白酶Ｋ、链霉蛋白酶Ｅ部分敏感，对氯仿部分敏感，其作用的活性ｐＨ范围低至４，高至１２以上，比较耐碱性。粗提液经ＰｈｅｎｙｌＳｅｐｈａｒｏｓｅＣＬ４Ｂ柱层析、ＤＥＡＥＳｅｐｈａｃｅｌ柱层析和ＨＰＬＣ的Ｓｕｐｅｒｄｅｘ７５ＨＲ１０／３０柱层析，得到二个拮抗活性峰：Ｐ１和Ｐ２。Ｐ２经ＳＤＳＰＡＧＥ和ＰＡＧＥＩＥＦ电泳显示为单一蛋白带，分子量５０３ｋＤ，等电点６２５。自动Ｅｄｍａｎ降解法从Ｐ２的Ｎ端测出残基序列为ＩｌｅＳｅｒＡｓｎＰｒｏＸＩｌｅＡｓｐＶａｌ Bacillus subtilis B034 was isolated from the leaf surface of rice and had a strong antagonistic activity against Xanthomonas oryzae. The crude extract of the antagonist obtained by the precipitation of 70% saturation ammonium sulfate was removed from the culture medium and was not sensitive to trypsin, sensitive to protease K and pronase E, partially sensitive to chloroform, and its activity As low as 4 pH range, up to 12 or more, more alkaline resistance. The crude extract was separated by Phenyl Sepharose CL 4B column chromatography, DEAE Sephacel column chromatography and HPLC Superdex75HR10 / 30 column chromatography to obtain two antagonistic activity peaks: P1 and P2. P2 by SDS  PAGE and PAGE  IEF electrophoresis showed a single protein band, molecular weight 50  3kD, isoelectric point 6  25. Automatic Edman Degradation Method The residual sequence was detected from the N-terminal of P2 as Ile-Ser-Asn-Pro-X-Ile-Asp-Val