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Key Words:
Anthropogenic disturbance
Landfill
Leachate
Microbial diversity
DGGE
ABSTRACT
The ecological balance of an ecosystem has a relation to its biodiversity. Although it has been established that biodiversity and ecological stability are related, generalization about the exact nature of this relation remains elusive and more so in microbial diversity. A growing volume of studies has indicated that anthropogenic activities impact biodiversity, but it is difficult to generalize the impact of anthropogenic activities on microbial diversity. Landfilling by municipal solid waste is one such activity where microbes play a major role, and leachates are released from the landfill, altering the soil's physical and chemical nature. Change in factors like carbon source, pH, and toxicity of the soil is most likely to affect the indigenous microflora of the soil. The present study was undertaken to compare the microbial diversity of soil receiving landfill leachate with that of the soil not receiving any landfill leachate to assess the impact of the landfilling activity on microbial diversity. The landfill site selected for the study was that of Kamrup Metro District of Assam, located at Boragaon, near the Ramsar wetland called Deeporbeel. By using the Denaturing Gradient Gel Electrophoresis (DGGE) method, it has been found that the microbial diversity of the soil receiving leachate was higher than that of the soil not receiving any leachate from the landfill.
INTRODUCTION
Most biodiversity studies have focused mostly on plants and animals. Ecological theories have been developed by studying aboveground ecosystems but have neglected the below-ground systems, despite the latter's importance to global nutrient cycling and life on the Earth (Lynch et al. 2004). The study of microbial diversity by culture-dependent methods had been limited earlier because only 1% of the total microflora can be cultured under lab conditions. Recent use of culture-independent methods like DGGE and metagenomics has brought newer insights into microbial ecology. Despite these advances, the link between microbial diversity and soil functions is still a major challenge. Several field studies have examined how disturbance affects microbial diversity, but the findings of different studies contradict each other. The lack of consensus on how disturbance affects microbial diversity highlights the need for more studies in this field.
In general ecology, Wilhm (1967) observed that benthic diversity was depressed in...