本文選題：解淀粉芽孢桿菌 + 細菌性條斑病��； 參考：《廣西大學(xué)》2017年碩士論文

【摘要】：解淀粉芽孢桿菌物種豐富,廣泛分布在土壤和植物表面。近年來隨著解淀粉芽孢桿菌具有抑制多種植物病原菌能力的發(fā)現(xiàn),使其成為了具有生物農(nóng)藥發(fā)展?jié)摿Φ奈⑸�。從湖南、廣西等地水稻田采取土壤樣品,經(jīng)分離、純化得到9763株芽孢桿菌,采用牛津杯法測定分離菌株對水稻細菌性條斑病菌的拮抗能力,篩選得到具有拮抗能力的芽孢桿菌310株,經(jīng)過多次重復(fù)篩選,最終得到拮抗能力強且穩(wěn)定的菌株JF48,其對水稻細菌性條斑病的抑菌圈直徑達37±3 mm。通過對該菌株的形態(tài)、生理生化以及16SrDNA序列進行分析,鑒定該菌株為解淀粉芽孢桿菌(Bacillus amyloliquefaciens)。通過搖瓶培養(yǎng)試驗,研究了不同碳源、氮源、無機鹽種類、搖瓶裝液量、轉(zhuǎn)速、起始pH、發(fā)酵培養(yǎng)溫度、接種量對解淀粉芽胞桿菌JF48菌株芽孢產(chǎn)量及芽孢轉(zhuǎn)化率的影響。然后通過Plackett-Burman試驗從單因素試驗得到的最佳因素中篩選出三個顯著影響因子,分別為玉米粉、豆粕粉、發(fā)酵培養(yǎng)溫度。最后,經(jīng)響應(yīng)面法優(yōu)化后的最佳發(fā)酵培養(yǎng)條件為:玉米粉14.69g/L、豆粕粉 9.54g/L、CaC122g/L、NaCl5g/L、MgS04lg/L、裝液量50mL/250mL、轉(zhuǎn)速為200rpm、初始pH7.5、溫度38℃、接種量1%。在此發(fā)酵培養(yǎng)條件下,芽孢產(chǎn)量達到3.6×109cffu/mL,與優(yōu)化前相比提高了105 倍。通過單因素試驗,確定解淀粉芽孢桿菌JF48菌株可濕性粉劑的最佳配方如下:載體硅藻土 10%、助劑聚乙二醇(PEG-8000)10%、穩(wěn)定劑K2HPO42%、紫外保護劑抗壞血酸(VC)0.1%。使用該配方制成的解淀粉芽孢桿菌JF48菌株的可濕性粉劑芽孢含量為5.6×109cfu/g,懸浮率為76%,濕潤時間為56s。使用JF48菌株培養(yǎng)液進行盆栽防治試驗,試驗組的水稻發(fā)病等級均明顯低于對照組。這表明解淀粉芽孢桿菌JF48菌株對水稻細菌性條斑病具有明顯的防治效果。
[Abstract]:Bacillus amylolyticus is abundant in species and widely distributed on soil and plant surfaces. In recent years, with the discovery of Bacillus amylolyticus which has the ability to inhibit many plant pathogens, it has become a potential microorganism with biological pesticide development. 9763 strains of Bacillus spp were isolated from paddy fields of Hunan and Guangxi provinces. The antagonistic ability of the isolated strains against bacterial spot bacteria of rice was determined by Oxford Cup method. 310 strains of Bacillus with antagonistic ability were screened. After repeated screening for many times, the strain JF48 with strong antagonistic ability and stability was obtained. The diameter of inhibition circle against bacterial streak disease of rice was 37 鹵3 mm. The strain was identified as Bacillus amylolique faciensus by analyzing its morphology, physiology and biochemistry and 16SrDNA sequence. The effects of different carbon sources, nitrogen sources, inorganic salt species, liquid volume, rotation speed, initial pH, fermentation temperature and inoculation amount on spores yield and spores conversion of Bacillus amylolyticus JF48 strain were studied by shaking flask culture experiment. Then through Plackett-Burman test, three significant influencing factors were screened out from the best factors obtained by single factor test, which were corn flour, soybean meal powder and fermentation temperature. Finally, the optimum fermentation conditions were as follows: corn flour 14.69 g / L, soybean meal 9.54 g / L, CaC122g / L, NaCl5g / L, MgS04lg / L, 50 mL / L, rotational speed 200rpm, initial pH 7.5, temperature 38 鈩，

本文編號：1945202