1株高产铁载体菌株的筛选鉴定以及化感作用的验证

Screening and identification of a high-yielding siderophore strain and verification of allelopathic effect

为了探究铁载体在生物化感作用中的影响,从种植地黄的3种土壤样品中,分离纯化具有产铁载体能力的细菌菌株,进行形态学观察以及分子生物学鉴定,测定菌株产铁载体的生长曲线,通过单因素试验和正交试验确定最优产铁载体条件,在此基础上通过薄层层析和硅胶柱层析分离纯化铁载体,并以拟南芥种子为材料,分析铁载体对植物生长发育的影响。结果表明,经形态学和分子生物学鉴定,筛选出高产铁载体菌株为恶臭假单胞菌(Pseudomonas putida)S2。该菌株产铁载体最优发酵条件为26℃,180 r·min^(-1),pH值为10.0,培养时间48 h,此时产铁载体含量为64.37%,分离纯化出大极性和小极性共2种铁载体,大极性铁载体能有效抑制拟南芥主根的生长,根长度由1.80 cm减小到0.76 cm。

In order to explore the influence of siderophore on the biological allelopathy,the bacterial strains with siderophore-producing ability were isolated and purified from the three soil samples planted with Rehmannia glutinosa.Morphological observation and molecular biological identification were performed to determine the growth curve of siderophore-producing strains.The optimal siderophore production conditions were determined by single factor test and orthogonal test.On this basis,siderophores were separated and purified by thin-layer chromatography and silica gel column chromatography,and the effects of siderophores on plant growth and development were analyzed by taking Arabidopsis seeds as materials.The results showed that the selecting high-producing siderophore strain was identified as Pseudomonas putida S2 through morphological and molecular biological identification.The optimal fermentation conditions for siderophore production of this bacteria were 26℃,180 r·min^(-1),pH value of 10.0,and culture time of 48 h.At this time,the amount of siderophore production was 64.37%and the two kinds of siderophores contained large and small polarities were separated and purified.The large polar siderophore could effectively inhibit the growth of Arabidopsis main roots,and the root length was reduced from 1.80 cm to 0.76 cm.