卵孢小奥德蘑覆土中有益细菌筛选与鉴定

Screening and Identification of Beneficial Bacteria in Casing Soil of Oudemansiella raphanipes

采用稀释涂布平板法分离培养卵孢小奥德蘑(Oudemansiella raphanipes)覆土中的细菌,通过对峙培养法筛选能够促进卵孢小奥德蘑菌丝生长的细菌,并检测其溶磷、固氮、解钾及产生纤维素酶、生长激素和嗜铁素等生物活性,综合利用形态特征、生理生化特性及分子系统学方法鉴定有益细菌。结果表明:从覆土中分离获得256株细菌,其中8个属的54株细菌能够促进菌丝生长;芽孢杆菌(Bacillus)和假单胞菌(Pseudomonas)为优势属,占比分别为42.59%和25.93%;在54株细菌中,有14、8、6株细菌分别具有溶磷、固氮、解钾活性;有10、9、7株细菌分别能够产生纤维素酶、生长激素、嗜铁素。有益细菌54-14、41-60、57-71和27-17分别鉴定为荧光假单胞菌(P. fluorescens)、恶臭假单胞菌(P.putida)、粘质沙雷氏菌(Serratia marcescens)和枯草芽孢杆菌(B. subtilis)。

Using the dilution plating method,bacteria in casing soil of Oudemansiella raphanipes were isolated,and then those with mycelium growth promotion activity on O.raphanipes were screened by confrontation culture analysis.The beneficial bacterial strains were determined for biological activities,including phosphorus solubilization,nitrogen fixation,potassium releasing,cellulose production,siderophore production,and indoleacetic acid production.Four of the beneficial bacterial strains were then identified based on morphological features,physio-biochemical characteristics,and molecular phylogeny.The results showed that a total of 256 bacterial strains were isolated from the casing soil samples,among which,54 strains belonging to 8 genus showed mycelium-promoting activity.The dominant genera were Bacillus and Pseudomonas,accounting for 42.59%and 25.93%,respectively.Among the 54 bacterial strains,14,8 and 6 strains showed phosphorus solubilization,nitrogen fixation and potassium releasing activity,respectively.There were 10,9,and 7 strains capable of producing cellulose,indoleacetic acid and siderophore,respectively.The beneficial strains 54-14,41-60,57-71 and 27-17 were identified as P.fluorescens,P.putida,Serratia marcescens and B.subtilis,respectively.This study provided a theoretical basis for exploring the biological function of bacteria in casing soil of O.raphanipes.