Traunspurger Walter, Bergtold Matthias, Goedkoop Willem
Zoological Institute, University of Munich, Luisenstrasse 14, D-80333 Munich, Germany Fax: (+49) 89-5902-461; e-mail:
Institute of Limnology, Uppsala University, Norbyvägen 20, S-756 32 Uppsala, Sweden, , , , , , SE.
Oecologia. 1997 Sep;112(1):118-122. doi: 10.1007/s004420050291.
The effects of natural nematode communities on bacterial activity and abundance were investigated in a microcosm study. Nematodes were added at different densities to a freshwater sediment and bacterial parameters were measured after 1, 5, 9, and 17 days. Significant effects of nematode density on bacterial activity were noted on day 5. No long-term changes in bacterial activity were recorded. Bacterial abundance displayed an overall decrease in both treatments and controls. In a second experiment, the effect of nematode feeding-type on bacterial activity was studied. Microcosms were incubated with 100 individuals of a fungus-feeding (Aphelenchus avenae) or a bacteria-feeding nematode species (Caenorhabditis elegans) respectively, and bacterial activity was determined after 0, 1, 2, 4, and 7 days. Significant time and feeding-type effects were found, with consistently higher bacterial activity estimates in treatments with bacteria-feeding nematodes. These results suggest that grazing affects bacterial activity, and indicate that grazing by nematodes may be more important in stimulating bacterial activity than bioturbation or excretion. Combining these results, we conclude that natural nematode communities may have an impact on bacterial activity, and that the magnitude of this impact depends on the proportion of actively feeding bactivores within the community.
在一项微观世界研究中，研究了天然线虫群落对细菌活性和丰度的影响。将不同密度的线虫添加到淡水沉积物中，并在1天、5天、9天和17天后测量细菌参数。在第5天观察到线虫密度对细菌活性有显著影响。未记录到细菌活性的长期变化。细菌丰度在处理组和对照组中总体均呈现下降。在第二个实验中，研究了线虫摄食类型对细菌活性的影响。分别用100只食真菌线虫（燕麦真滑刃线虫）或食细菌线虫物种（秀丽隐杆线虫）对微观世界进行培养，并在0天、1天、2天、4天和7天后测定细菌活性。发现了显著的时间和摄食类型效应，食细菌线虫处理组的细菌活性估计值始终较高。这些结果表明，捕食会影响细菌活性，并表明线虫的捕食在刺激细菌活性方面可能比生物扰动或排泄更重要。综合这些结果，我们得出结论，天然线虫群落可能会对细菌活性产生影响，且这种影响的程度取决于群落中积极摄食的食细菌线虫的比例。
