红壤区油茶根际解磷细菌的筛选、鉴定及其解磷能力
Screening, Identification and Phosphate Solubilizing Capability of Phosphate Solubilizing Bacteria in Rhizosphere of Camellia oleifera Abel at Red Soil Region
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摘要: 研究油茶根际解无机磷细菌的解磷能力对提高红壤丘陵区土壤磷素利用效率具有重要的指导意义。本研究从油茶根际分离筛选出97株具有解无机磷能力的菌株, 采用NBRI-BPB培养基进行复筛获得5株解磷能力较强的解无机磷细菌, 并测定其在NBRIP培养基中有效磷含量, 采用形态特征、生理生化、Biolog系统和16SrDNA序列分析鉴定细菌种类, 确定WB38为耳假单胞菌(Pseudomonas auricularis), WB39(WB75)为杓兰果胶杆菌(Pectobacterium cypripedii), WB53(WB68)为路德维希肠杆菌(Enterobacter ludwigii)。研究了解磷菌株WB38在不同条件对解磷能力的影响, 结果表明:不同因子对该菌株解磷能力均有显著影响, 其中温度对其解磷能力影响最大;该菌株培养的最适碳源和氮源分别为葡萄糖和NH4NO3;解磷细菌WB38解磷的最佳培养条件为A2B1C1D1, 即温度28℃, 初始pH值6.5, 接种量1%, 溶氧量25 mL。Abstract: The phosphate solubilizing capability of phosphate solubilizing bacteria (PSB) in rhizosphere of Camellia oleifera Abel apparently affects the Phosphorus use efficiency in red soil. 97 phosphate-solubilizing bacterial strains were isolated from the Camellia oleifera rhizosphere soil of Hu'nan Province, the high effective PSB were further screened using NBRI-BPB medium, and the molybdenum-anti-spectrophotometric method was applied to determine the phosphate-dissolving ability of the high effective PSB after four days' fermentation in NBRIP medium. The bacteria were identified by their morphological, physiological and biochemical characteristics with Biolog system and 16S rDNA gene sequence analysis. The high effective PSB of WB38, WB39 (WB75), WB53 (WB68) were identified as Pseudomonas auricularis, Pectobacterium cypripedii, and Enterobacter ludwigii, respectively. Experiments were conducted to study the phosphate-solubilizing capability of WB38 under different culture conditions. Every factor has a significant influence on phosphate-solubilizing ability of WB38, and the greatest influence factor on phosphate-solubilizing ability was the temperature. The optimum carbon source and nitrogen source were glucose and NH4NO3. WB38 displayed a better phosphate-solubilizing capability at the temperature of 28℃, the medium initial pH was 6.5, the inoculation quantity was 1% and the aeration quantity was 25 mL.