紫色土硅酸盐细菌的表型特征及溶磷解钾能力

对40株分离自四川、重庆等地的代表笥紫色土中的硅酸盐细菌和1株参照菌株进行了52个表型性状的数值分析，探讨了硅酸盐细菌液体振荡培养后pH值、菌数变化与溶磷、解钾量之间的关系，结果表明：紫色土硅酸盐细菌绝大部分属于胶胨样芽孢杆菌（Bacillus mucilaginosus），但在个体和群体生长特征、碳氮源利用、硝酸盐还原能力、耐Ⅰ菌株在86％相似水平分为2个亚群，不同的硅酸盐细菌菌株的溶磷、解钾特性差异较大，具有溶磷解钾双重特性的菌株约占供试菌株（含参考菌株）的22％，只具溶磷特性的约占29％,其溶磷效果较显著（有效磷增加最高达40.64%），而解钾效果不明显（有效钾增加最多的只有7.9%）。供试紫色土硅酸盐细菌的溶磷、解钾特性与菌株生长过程中产酸有关，其溶磷、解钾量与培养液中pH值的降低呈正相关，图5表3参20。

PHENOTYPIC ASPECTS AND PHOSPHORUS-RELEASING AND POTASSIUM-RELEASING ABILITY OF SILICATE BACTERIA ISOLATED FROM PURPLE SOILS

Forty silicate bacteria, isolated from purple soils in different sites of Sichuan and Chongqing, China, together with the representative strain (Bacillus muciloginasus AS1.232), were tested by numerical analysis of 52 phenotypic characteristics. The results indicated that they were very diverse with their physiological and biochemical aspects, such as shape and size of bacteria, utilization of sole carbon and nitrogen sources, tolerance of NaCl, etc. All strains tested were classified into four clusters at the level of 80% similarity, and cluster I were further divided into 2 subclusters at the level of 86% similarity. The phosphorus-releasing ability and potassium-releasing ability was significantly different among the silicate bacteria. 22% strains had the ability to release both phosphorus and potassium mineral, while 29% strains had phosphorus-releasing ability only. However, the potassium-releasing ability of these strains was low. The phosphorus-releasing and potassium-releasing ability was positively related to the decreasing of pH value during culture process. Fig 5, Tab 3, Ref 20