红壤溶磷菌的筛选及溶磷机制  

SCREEING OF PHOSPHATE-SOLUBILIZING BACTERIA IN RED SOIL AND THEIR ACTING MECHANISMS

作　　者：王同[1,2] 孔令雅[1] 焦加国[1] 刘满强[1] 胡锋[1] 孙波[2] 李辉信[1] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]国家红壤改良工程技术研究中心中国科学院红壤生态实验站,江西鹰潭335211

出　　处：《土壤学报》2014年第2期373-380,共8页Acta Pedologica Sinica

基　　金：国家科技支撑计划项目(2009BADC6B03;2011BAD41B01)资助

摘　　要：采用以磷酸铝为磷源的蒙金娜（PVK）液体培养基研究了从红壤土中筛选出的4种溶磷菌的溶磷效果，选出其中的优势菌株B1，并对其溶磷机理做出初步探讨。结果表明，所筛选出的4株溶磷菌在液体培养条件下均有显著的溶磷效果，其中菌株B1在培养4d后有效溶磷量最大，达到292.8 mg L-1。各处理培养液pH在培养期间均有显著下降，pH从7.0下降至3.2~4.7。高效液相色谱测定发现，各菌株培养液中有机酸的种类与含量随培养时间变化而不同，其中菌株B1主要分泌草酸和苹果酸，培养1d后有机酸总量可达到5 mmol L-1；通过添加有机酸对磷酸铝活化的试验表明，分泌有机酸溶磷仅是菌株B1溶磷机制之一，可能还存在其他溶磷机制。菌株B1生长的适宜pH范围为5~9，最适培养温度为30℃，100ml三角瓶的最适装液量为30~40ml。经鉴定，菌株B1与苏云金芽孢杆菌有99.9%的相似性。Phosphorus solubilizing effects of four strains of phosphorus solubilizing bacteria （PSB） screened out of the red soil in Jiangxi Province were studied and compared through incubation in PVK solution containing AlPO4 as phosphorus source. Results show that all the four strains displayed significant phosphorus solubilizing effects in the solution. Among the four, Strain B1 was the most effective in dissolving phosphorus. After four days of incubation, it dissolved 292.8 mg L-1 phosphorus. Solution pH in all the treatments decreased to a varying extent from pH 7.0 to pH 3.2 ~ 4.7, during the incubation period. HPLC analysis shows that the presence of organic acids, varying in type and amount with the time of incubation, in the culture medium of all the strains. Oxalic acid and malic acid were found to the dominant organic acids in the culture medium of strain B1 and reached 5 mmol L-1 in total concentration after 1 day of incubation. The experiment of adding organic acids to activate AlPO4 indicates that B1 secreting organic acids to dissolve phosphorus is only one of the mechanisms of its phosphorus solubilizing capability. It was found that B1 favored a solution with pH varying between 5 and 9 and incubation under 30℃ and for a triangular flask （100ml）, the most suitable content of medium was 30~40 ml. Identification of strain B1 shows that the strain is 99.9% in similarity to Bacillus thuringiensis in 16S rDNA genes.

关 键 词：溶磷菌 液体培养 有机酸 溶磷机制 菌种鉴定 

分 类 号：S154.39[农业科学—土壤学]