东北黑土氨基糖的矿化动态及其对外源物质添加的响应

采用间歇淋洗好气培养法研究了东北黑土中3种不同微生物来源氨基糖(氨基葡萄糖、胞壁酸和氨基半乳糖)的矿化动态以及对葡萄糖添加和葡萄糖与氮肥配施的响应.结果表明:土壤中不同种类的氨基糖具有不同的矿化特征.培养期间胞壁酸含量减少25.4%而氨基葡萄糖含量降低7.1%,表明细菌来源的胞壁酸在土壤中的矿化速率快于真菌来源的氨基葡萄糖,但氨基葡萄糖的矿化数量(68.4 mg·kg^-1)显著高于胞壁酸(15.4 mg·kg^-1).葡萄糖添加以及葡萄糖与氮肥配施均显著提高了土壤中氨基葡萄糖和胞壁酸的含量,但两种处理的影响有所不同.相比之下,氨基半乳糖在土壤中矿化较慢,并且受外源物质的影响较小,表现出较高的稳定性.

Amino sugars mineralization and its responses to exogenous substances in black soil of Northeast China

By the method of intermittent leaching aerobic incubation, this paper studied the mineralization of three kinds of microbes-derived amino sugar (glucosamine, muramic acid, and galactosamine) in black soil of Northeast China, and the responses to glucose addition and glucose plus nitrogen amendment. The mineralization of the amino sugars was compound-specific. During incubation period, the content of muramic acid decreased by 25.4%, while that of glucosamine decreased by 7.1%, suggesting that bacteria-derived muramic acid was more inclined to be mineralized, compared with fungi-originated glucosamine. However, the mineralized amount of glucosamine (68.4 mg·kg^-1) was greater than that of muramic acid (15.4 mg·kg^-1). Both glucose addition and glucose plus nitrogen amendment improved the contents of glucosamine and muramicacid significantly, butthe effect varied. The mineralization of galactosamine was much slower, and less affected by exogenous substances addition, indicating that galactosamine was more stable in test soil.