两株解磷菌的GFP标记及其在复垦土壤中的定殖

Two Phosphate-solubilizing Strains Tagged by GFP and Their Colonization in Reclaimed Soil

为研究从土壤中筛选的2株解磷菌w134和w137在复垦土壤中的存活能力与定殖特性,利用电击转化法将含绿色荧光蛋白(GFP)的质粒电转至解磷菌中,经荧光显微观察和质粒检测,获得发光稳定的标记菌株w134GFP和w137GFP。对标记菌和野生菌的生长曲线和解磷能力进行比较,结果发现,二者无明显差别。对标记菌在复垦土壤中的定殖动态观察结果表明,接种7 d时,w134GFP和w137GFP的菌量从初始的5.0×10^(7)cfu/g分别增到7.6×10^(8)、9.8×10^(9)cfu/g;之后定殖数量逐渐降低,35~42 d时,2株菌的数量在4.5×10^(4)cfu/g;93 d降至10~20 cfu/g;在接菌的前28 d,灭菌土壤中标记菌的定殖数量高于未灭菌土壤,随后土壤灭菌和不灭菌对定殖的影响逐渐减小,到58 d时,定殖数量基本没有差别;此外,在接菌的0~58 d内,添加有机肥处理的标记菌定殖数量高于对应不施肥处理,添加有机肥促进了菌株的定殖。研究表明,解磷细菌w134和w137可以在复垦土壤中有效定殖,这为后期研究其在矿区复垦中的实际解磷效果提供了基础。

To investigate the colonization characteristics of the two phosphate-solubilizing strains isolated by our laboratory in reclaimed soil,the plasmid containing green fluorescent protein(GFP)was electroporated into phosphate-solubilizing bacteria to obtain the stable GFP-marked strains,named w134GFP and w137GFP,using fluorescence detection and plasmid expression.The results of growth curve and P solubilization capacity showed that there were no significant differences between the wild strains and the GFP-marked strains.The colonization of the GFP-tagged strains in reclaimed soil observations showed that 7 d after inoculation,the populations of w134GFP and w137GFP increased from 5.0×10^(7)cfu/g to 7.6×10^(8),9.8×10^(9)cfu/g,respectively.After that,the number of colonization decreased gradually.The numbers of two strains were about 4.5×10^(4)cfu/g during 35-42 d.Until 93 d,the numbers dropped to 10-20 cfu/g.In the first 28 d of inoculation,the populations of GFP-marked strains in sterilized soil were higher than those in no-sterilized soil.And then,the influence of soil sterilization and non-sterilization on colonization gradually decreased.There was almost no difference in populations on 58 d.Additionally,the numbers of GFP-tagged strains in the treatments with organic fertilizer were higher than those in the treatments without fertilizer before 58th day of inoculation,which indicated that organic fertilizer could promote the colonization of strains.This study showed that w134 and w137 could effectively colonize in reclaimed soil,which provided a basis for further study on their practical phosphorus solubilizing capacity in coal mining area.