具有ACC脱氨酶活性的麻疯树根际促生菌(PGPR)的分离筛选及系统发育分析

目的]获得具有产ACC、IAA,铁载体,能固氮或解磷的潜在促生菌株.方法]通过稀释涂布的方法,从麻疯树根际土壤中分离得到98株细菌,从中选取28株以产l-氨基环丙烷-1-羧酸(ACC)脱氨酶为主要促生指标进行筛选,同时检测了其产吲哚乙酸(IAA)、固氮、解磷及铁载体等促生指标的能力.结果]结果显示,46％的菌株能产ACC脱氨酶,其含量最高可达到128.308 μmol α-KA/(mg.h),68％的菌株能产生IAA,54％的菌株有固氮的能力,32％的菌株有解磷的能力.少量菌株同时具有产ACC脱氨酶、IAA,固氮,解磷等能力.挑选代表性菌株进行16S rRNA序列分析,这些菌株属于芽孢杆菌属(Bacillus)、节杆菌属(Arthrobacter)、假单胞菌属(Pseudomonas)和产碱杆菌属(Advenella)等8个属,其中多数菌株(50％)属于芽孢杆菌属,系统发育分析表明菌株KLBMP 4817、KLBMP 4821和KLBMP 4824为窄食单胞菌属(Stenotrophomonas)和类芽孢杆菌属(Paenibacillus)的潜在新种.结论]攀枝花麻疯树根际土壤细菌中含有丰富的遗传多样性,且存在大量的促生菌株.其中,菌株KLBMP 4804产ACC脱氨酶含量最高.菌株KLBMP4820产IAA含量最显著.

solation, screening and phylogenetic analysis of plant growth-promoting rhizobacteria (PGPR) containing ACC deaminase from Jatropha curcas L.

Objective] In order to obtain plant growth promoting strains of production 1-aminocyclopropane-1-carboxylic acid(ACC) deaminase,nitrogen fixation,phosphate solubi-lization,and production of indoleacetic acid and siderophore.Methods] 98 rhizobacteria from Jatropha curcas L.were isolated by the method of grinding separation and 28 isolates were selected for the detection of plant growth promoting index of production ACC deaminase,ni-trogen fixation,phosphate solubilization,and production of indoleacetic acid and siderophore.Results] The results showed that 46% of the isolates produced ACC with the maximum ACC deaminase was 128.308 μmol α-KA/(mg·h),68% of the isolates produced IAA,54% had ni-trogen fixation ability and 32% of them had phosphate solubilization ability.Some of the rep-resentative isolates were seleceted for the 16S rRNA gene sequencing and analyzing.The rep-resentative strains belonged to 8 different genera including Bacillus,Arthrobacter,Pseudo-monas and Alcaligenes,with Bacillus as the predominant genus(50%).Phylogenetic analysis demonstrated that strain KLBMP 4817、KLBMP 4821 and KLBMP 4824 could be potential novel species of the genera Stenotrophomonas and Paenibacillus.Conclusion] The rhizobac-teria of Jatropha curcas L.in Panzhihua City contain a variety of bacteria as well as source of new taxa.Some of them had the ability of plant growth promoting.Among them,strain KLBMP 4804(Bacillus) had the strongest ACC deaminase activity.Strain KLBMP 4820(Ba-cillus) had the strongest ability of IAA production respectively.