枣根际解磷细菌的分离筛选及16S rDNA鉴定

Screening and 16S rDNA identification of phosphate-solubilizing bacteria in rhizosphere soils of jujube

以新疆红枣根际土壤为材料,采用溶磷圈初筛和摇瓶复筛法筛选出土样中的解磷细菌,并对解磷细菌的16S r DNA进行测序,通过Blast检索同源序列,鉴定解磷细菌的分类。结果表明,在磷酸三钙无机磷培养基中,所筛选出的20个菌株在摇瓶培养下均有溶磷效果,其中P7,P13的能力最强,解磷量达到300 mg·L^(-1)以上,pH值在培养期间均有显著下降,菌株解磷量与培养液pH值呈极显著负相关;在蒙金娜有机磷培养基中,仅有少数几个菌株对卵磷脂有较强的解磷能力,P_3,P_7,P_9与对照间差异显著,培养液的pH值维持在一个较高水平,菌株解磷量与培养液的p H值呈极显著负相关,16S rDNA序列分析,筛选出的解磷细菌主要为Bacillus sp.,Acinetobacter sp.,Pseudomonas sp.,Enterobacter sp.等4个属的细菌。本试验最终确定的最佳解磷细菌为P_7,Bacillus sp.。

To obtain strains of phosphate solubilization from jujube rhizosphere soils in Xinjiang,phosphate-solubilizing bacteria were screened from rhizosphere soils by using phosphate-solubilizing circle and molybdenum stibium anti-color methods. The 16 S r DNA of phosphate-solubilizing bacteria was sequenced and searched against the public database. The results showed that 20 strains displayed significant phosphorus-solubilizing effects in the solution. Among them,Ca_3（ PO_4）_2 solution,containing strain P7,P13,were the most effective in dissolving phosphorus. After four days of incubation,it dissolved 300 mg·L^（-1）phosphorus. Solution pH in all the treatments decreased to a varying extent,and the final p H values were found to be significantly negatively correlated to the amounts of dissolved phosphorus; PVK solution,containing only a few strains,displayed significant phosphorus-solubilizing effects,and P_3,P_7,P_9 were the most effective strains in dissolving phosphorus. Solution p H in all the treatments maintained a higher level,and the final pH values were found to be significantly negativelycorrelated to the amounts of dissolved phosphorus. The 20 strains identified by 16 S rDNA gene sequencing analysis belong to four species,Bacillus sp.,Acinetobacter sp.,Pseudomonas sp.,and Enterobacter sp.,and strain P_7 was supposed to be the most suitable strain to dissolue phosphorus.