一株高效解磷细菌的紫外诱变选育及其在红壤稻田施用效果

红壤对磷有强大吸附固定力,磷肥易被土壤中活性铁、铝固定而使有效态磷转化为各种形态的非有效磷,从而大大降低磷肥的利用率。解磷菌能使土壤中难溶性或不溶性的磷转化为易于被植物吸收利用的磷。通过对江西鹰潭红壤分离筛选并经过紫外诱变获得一株性状稳定的高效解磷细菌Y8。经鉴定,菌株Y8为蜡状芽孢杆菌（Bacillus cereus）。通过与生产中应用的徐州华龙高效复合菌肥厂的解磷细菌X3相比,菌株Y8降解有机磷、溶解Ca3（PO4）2的能力均比较高,分别为155.3mg·L^-1和240.1mg·L^-1。研究各种理化因子对菌株Y8解磷能力的影响,确定了菌株Y8的最佳培养条件为葡萄糖20g·L^-1、NH4（SO4）21.5g·L^-1、pH7.0、温度为35℃,在该条件下菌株Y8溶解Ca3（PO4）2的量为295.6mg·L^-1。在江西鹰潭红壤稻田的施用试验表明,将菌株Y8制成微生物菌剂施用于水稻田可起到减施化肥的作用。

Mutagenesis of a phosphate dissolving bacterial strain by UV and its application to rice cultivation in red soil

Available phosphorous in phosphate fertilizers was transformed readily to unavailable phosphorous by the high content of iron and aluminum in red soil,thus reducing fertilizer utilization efficiency.Phosphate-dissolving bacteria solubilized sparingly insoluble phosphate into available phosphorus that can be easily utilized by crops.In this study several phosphate-dissolving bacterial strains were isolated and screened from red soil from Yingtan,Jiangxi Province.Of these,a stable,and the most efficient phosphate-solubilizing bacterial strain,was selected for UV mutagenesis.This strain after UV treatment showed higher phosphate solubilization capacity than strain X3 from Xuzhou Hua Long Efficient Compound Microbial Fertilizer Factory.This isolate was named strain Y8 and identified as Bacillus cereus.Strain Y8 dissolved 155.3 mg·L^-1 phosphorous from lecithin and 240.11 mg·L^-1 phosphorous from Ca3（PO4）2 in a flask with shaking.The physical-chemical factors on the growth of Y8 were used to optimize the culturing conditions.Under optimal conditions（glucose 20 g·L^-1,NH4（SO4）2 1.5 g·L^-1,pH 7.0,and 35 ℃）Y8 dissolved 295.6 mg·L^-1 phosphorous from Ca3（PO4）2.Strain Y8 was applied as a living bacteria agent to rice a field in Yingtan,Jiangxi Province.The initial results suggested that the living bacteria agent containing Y8 strain maintain rice growth,increasing yield while reducing chemical fertilizer usage.