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

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

【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1-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128.308μmolα-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KLBMP 4820产IAA含量最显著。

[Objective] In order to obtain plant growth promoting strains of production 1-aminocyclopropane-l-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 gmol a-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 ofJatropha 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 （Bacillus） had the strongest ability of IAA production respectively.