解磷微生物的分离与筛选

磷是植物体内有机化合物的主要成分,为生物固氮所必需,土壤中大部分磷以难溶态存在,不能被植物直接吸收利用,解磷微生物可以促进土壤难溶磷向有效磷的转化。基于目前耕地有效磷缺乏的现状,通过对解磷微生物初筛、复筛培养基的研究,探索了解磷微生物的筛选模型以及各地解磷微生物的多样性,对不同类型土壤中分离出的2000多株解磷微生物的溶磷效果进行了研究。结果表明:菜园土中有机质含量高,解磷微生物最多,从全国各地土样及种子表皮中分离出芽孢杆菌P17菌株、短杆菌P10菌株和红酵母Y3菌株等解磷微生物;不同地域、同种地区不同类型土壤中溶解难溶性无机磷和有机磷微生物的种类和数量存在显著差异;无机磷平板初筛模型可以有效分离样品中的解磷微生物,溶磷效果需结合复筛模型进行确定。

Isolation and selection of P-dissolving microbes

Phosphorus is the main component of organic compounds in plant and necessary for the biological nitrogen fixation.Most of the phosphorus is insoluble in soil,which cannot be absorbed by plants directly.P-dissolving microbes can promote the transformation of insoluble phosphorus to available phosphorus in soil.The study was centered on the current situation of effective phosphorus deficiency in cultivated land.Diversity of P-dissolving microbes was explored by construction of screening model during the study of initial screening medium and re-screening culture medium.More than 2000 strains of P-dissolving microbes were isolated from different soil samples by solid plate method .Results are shown as follows.P-dissolving microbes are most in vegetable garden soil because of its high content of organic matter.Quantity and kinds of P-dissolving microbes are different in soil from different area.Bacillus P17,Brevibacterium P10,Rhodotorula Y3 are isolated and identified.P-dissolving microbes could be isolated with the screening model by solid plate method,but P-dissolving effect is still needed to be determined combined with liquid screening model.