解磷菌的筛选及培养基成分对解磷能力的影响

Screening of Phosphate-solubilizing Strain and Effects of Medium Components on its Phosphate-solubilizing Ability

解磷菌能使土壤中难溶性或不溶性的磷转化为可被植物吸收利用的有效磷,从而提高土壤中磷的利用率.从山东夏玉米根际土壤中筛选出1株高效的解磷菌TCCC150015,经过形态学、生理生化实验、16S r DNA序列同源性比对及系统发育树的分析,确定为分散泛菌(Pantoea dispersa).以不同浓度的碳源、氮源、NaCl及pH配制培养基,研究其对分散泛菌TCCC150015解磷能力的影响.结果表明:以葡萄糖为唯一碳源时分散泛菌TCCC150015表现出最强的解磷效果,可溶性磷含量达254.10,mg/L,是对照组的24.42倍.同时研究发现,当以NH_4^+-N和NO_3^--N分别作为氮源时,可溶性磷含量分别为258.25、248.48,mg/L,显著高于以NH_4^+-N和NO_3^--N共同作为氮源的可溶性磷含量,分别是其3.56倍、3.43倍;此外,实验发现,培养基初始NaCl质量分数和p H对分散泛菌TCCC150015的解磷能力影响比较显著(P<0.05).

Phosphate-solubilizing bacteria could transform insoluble phosphorus into soluble phosphorus which can be absorbed by plants and improve the utilization of phosphorus in soil. A strain of efficient phosphate-solubilizing bacterium（TCCC150015）was isolated from summer maize rhizosphere soil samples. Based on the morphology,physiological and biochemical properties and phylogenetic analysis of 16 S r DNA sequence,strain TCCC150015,was identified as Pantoea dispersa. The effects of carbon sources,nitrogen sources,Na Cl content and p H value on the phosphate-solubilizing ability of Pantoea dispersa TCCC150015,was investigated. The results showed that TCCC150015,would achieved the highest soluble phosphorus content of 254.10,mg/L when glucose was supplied as the only carbon source,which was 24.42 times that of the control group. The soluble phosphate content was 258.25 mg/L and 248.48 mg/L respectively when NH_4~＋-N and NO_3^--N were used as nitrogen sources individually,which was 3.56 times and 3.43 times the soluble phosphate when provided with NH_4~＋-N and NO_3^--N together as nitrogen sources. It revealed that the initial p H and initial concentration of Na Cl in the medium has a siginificant effect（P〈0.05）on the capacity of phosphate-solubilization.