低氧条件适用性硅酸盐细菌的分离及对水稻幼苗生长影响

Isolation of silicate bacteria from paddy field and determination of activity of the strain

从湖南地区水稻田土样中分离适用于水田作物的硅酸盐细菌,得到在亚历山大罗夫培养基上符合硅酸盐细菌菌落特征的菌株1株,编号为菌株s-3。通过一系列的生理生化试验,菌体形态及菌落特征的观察以及16S r DNA序列分析对菌株s-3进行菌种鉴定,初步鉴定菌株s-3属于硅酸盐细菌的一种——环状芽孢杆菌(Bacillus circulans)。通过在不同供氧条件下测定菌株s-3的解钾能力,发现在微氧条件下菌株s-3仍能保持较高的活性。通过水培试验,测定菌株s-3作为生物肥料对水稻植株幼苗的促生长能力,发现施用菌株s-3培养液后,可大幅增加植株的钾总量,促进植株生长,具有作为生物肥料进一步研究的潜力。

From the soil samples of paddy field in Hunan area, several silicated bacteria strains had been isolated, which could be used as a kind of biological fertilize applied to paddy-field. As a result, a strain named s-3 which was similar to the silicate bacteria was obtained. Then the strain was identified by morphological and culture features observation, a series of physiological and biochemical experiments and 16 S r DNA sequence analysis. Based on the results, strain s-3 was identified as Bacillus circulans, a kind of silicate bacteria. The ability of strain s-3 to release potassium at different levels of oxygen dissolution was determined. As a result, we found that on the condition of low oxygen dissolution, strain s-3 still had a certain level of activity of releasing potassium. And then the activities of strain s-3 as a biological fertilizer to release potassium nutrient and to promote rice growth were determined through hydroponic experiment. As a result, we found that the culture fluid of strain s-3 had a certain level of activity to increase the content of K in rice and promote rice growth, which indicated its potential as a bio-fertilizer.