Jihai Zhou Xiangwu Sun Jiaguo Jiao Manqiang Liu Feng Hu Huixin Li. Dynamic changes of bacterial community under the influence of bacterial-feeding nematodes grazing in prometryne contaminated soil.Applied Soil Ecology201364: 70–76.

Abstract

Microcosm experiments were carried out to study the effects of bacterial-feeding nematodes and prometryne on soil bacterial communities in contaminated soil. Prometryne (5 or 10 mg kg⁻¹ dry soil that is P5 or P10) and bacterial-feeding nematodes (5 or 10 individuals g⁻¹ dry soil that is N5 or N10) singly and in combination (P5N5 P5N10 P10N5 P10N10) were added to a nematode-free soil. An uncontaminated nematode-free soil was studied for comparison (Control). Bacterial-feeding nematode grazing boosted soil enzyme activities in contaminated soils thus speeding up prometryne degradation. In the initial stage of the experiment prometryne enhanced the soil enzyme activities too but served the opposite purpose later. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that prometryne contamination and nematode grazing over the incubation period exerted an obvious impact on Species richness (S) Shannon–Wiener index (H′) and Evenness (E_H) of soil bacteria which increased initially then decreased and increased again later. The cluster analysis of DGGE profiles showed that the similarity of soil bacterial communities in all treatments with indigenous microbes P5 P5N5 P5N10 P10 P10N5 and P10N10 and the Control was 75% 44% 78% and 49% at Day 0 Day 8 Day 18 and Day 30 respectively. Compared to the Control DGGE profiles displayed a varying characteristic bands pattern in all treatments over the incubation period with certain bands present in the treatments while not in the Control and vice versa suggesting that bacterial-feeding nematode grazing and prometryne contamination affected soil bacterial communities evidently. Consequently when added to contaminated soil bacterial-feeding nematodes can contribute to restoration of contaminated sites by degrading toxic compounds like prometryne through enhanced microbial activity.