南极乔治王岛南端的菲尔德斯半岛被认为是研究南极生态与生物资源的理想之地.本研究从该半岛全岛范围采集了3类不同类型的土壤样品,采用传统最大或然法(MPN)对其所含氮循环各类群微生物的总量进行了测定,同时利用常规Griess试剂、纳氏试剂等显色法初步估算了各菌群的功能活性强度,并结合土壤理化性质和采样点生态等进行了初步分析.目的是对该半岛土壤氮循环微生物进行先期初步了解,为进一步深入研究它们的其他特性奠定基础.结果表明:13个土样中所含氮循环微生物总量趋势为氨化菌>反硝化菌>硝化菌和固氮菌(活菌数),除极个别样品外均具有不同程度的硝化、反硝化、氨化活性.其中,所有土壤样品均具有比较高的氨化菌含量及氨化活性强度;丘陵山坡土壤的反硝化菌含量与反硝化活性强度要高于动、植物区土壤(极个别样品除外);动物区和植物区土壤的硝化菌含量较少,但硝化活性强度较高,预示着可能存在高效功能菌株;而丘陵山坡土壤的硝化菌含量及硝化活性强度则表现得高低不一.本结果为进一步深入研究该地区氮循环微生物提供了前期参考.%Fildes Peninsula is located at the southern end of King George Island in Antarctica. It is an ideal place to study Antarctic ecology and biological resources because of its unique geographical location and ecolog-ical environment. In this study, three different soil sample types were collected from the peninsula. The population sizes of soil nitrogen cycle microbes and their functional activities were determined using the Most Probable Number (MPN) and conventional Griess and Nessler's active color test methods. The expe-rimental results were also comprehensively analyzed regarding the ecology and physicochemical properties of the soil. The objectives were to develop a preliminary understanding of the soil nitrogen cycle microbes of Fildes Peninsula, and to prepare a scientific foundation for further study within this area. The results showed that the population sizes of nitrogen cycle microbes in the 13 collected soil samples in descending order were ammonification bacteria > denitrifying bacteria > nitrobacteria or nitrogen-fixing bacteria. Ex-cept for a few samples, most exhibited differing degrees of nitrification, denitrification, and ammonification activity. Furthermore, all soil samples had relatively high levels of ammonification bacteria and ammonifi-cation activity. The population sizes of denitrifying bacteria and the denitrifying activity of hillslope soils were higher than soils occupied by animals and plants. Although lower levels of nitrobacteria existed in soils occupied by animals and plants, they showed higher nitrifying activity, which might indicate the existence of strains with efficient function. Furthermore, the population sizes of nitrobacteria and the nitrifying activity of hillslope soils varied. This study provides a preliminary reference for further research of the characteris-tics of nitrogen cycling microbes in Antarctica.
展开▼
