化感物质对枯草芽孢杆菌(Bacillus subtilis)在厌氧条件下的生长及反硝化作用的影响

研究由秸秆腐解产生的化感物质 :阿魏酸 ( t-FA)、对羟基苯甲酸 ( p-HA)和苯甲酸 ( BA)在不同浓度下对厌氧培养的枯草芽孢杆菌 ( Bacillussubtilis)的生长及其反硝化活性的影响。结果表明 ,3种浓度的阿魏酸 ( 5.1 5、2 .58、0 .2 6mmol/L)均表现出对枯草芽孢杆菌的生长有抑制作用。对羟基苯甲酸 ( 0 .3 6、3 .62、7.2 4 mmol/L )对生长影响不明显。 8.1 9mmol/L和 4 .0 9mmol/L的苯甲酸有一定的刺激作用 ,而 0 .4 1 mmol/L的苯甲酸与对照无差别。实验表明枯草芽孢秆菌不仅能转化 NO- 3生成 NO- 2 ,而且还能转化 NO- 2 生成 N2 O。 3种化感物质对 NO- 3的转化均表现抑制作用 ,其抑制作用强弱依次为阿魏酸 >对羟基苯甲酸 >苯甲酸。高浓度的抑制作用强于低浓度。阿魏酸在 5.1 5mmol/L和 2 .58mmol/L浓度下 ,其抑制作用的差异显著性分别为 P<0 .0 1 ,P<0 .0 5。 NO- 2 的生成与 NO- 3的减少相互有关联 ,第 3天测定时 ,各处理中NO- 3急剧减少 ,而 NO- 2 急剧增加。在阿魏酸、苯甲酸处理中的 NO- 2 积累高峰在第 3天、第 4天 ,然后下降。而在对羟基苯甲酸的处理中 NO- 2 的积累一直上升 ,在第 6天的观察中仍未出现下降趋势。 3种化感物质均能抑制 N2 O的生成 ,至于在田间的抑制效果尚需进一步试验

Effects of allelochemicals on growth of Bacillus subtilis and its denitrification under anaerobic condition

The effects of allelochmicals,such as trans\|ferulic acid(t\|FA),phydroxbenzoic acid(p\|HA)and benzoic acid(BA),isolated from decomposed wheat straw on the growth of Bacillus subtilis and its denitrification were investigated.The growth and denitrification of Bacillus subtilis was significantly inhibited by t\|FA at the concentrations of 5.149mmol/L,2.575mmol/L and 0.257mmol/L respectively.However,the effects of p HA at concentrations of 0.362,3.620,7.240mmol/L on growth of Bacillus subtilis were not observed.The growth of B.subtilis was stimulated by BA at concentrations of 4.09 and 8 189mmol/L. The denitrification of B.subtilis was inhibited by both of p HA and BA.The sequence of their inhibition was t\|FA>p\|HA>BA.The inhibition of allelochemicals at a higher concentration was stronger than that at the lower one.Emission of N 2O was inhibited by the above three allelochemicals.The effects of inhibition of allelochemicals in the field remain to be investigated.