CHARACTERIZATION OF INDIGENOUS MICROORGANISMS AT A FORMER MANUFACTURED GAS PLANT

摘要

A multidisciplinary field study of a former Manufactured Gas Plant in Portadown, Northern Ireland, was carried out prior to the installation of a Permeable Reactive Barrier (Biological). Trial pits (44) at various depths and multilevel boreholes (8) were characterized for microbial numbers. Total viable cell numbers varied from 4.5 x 105 to 8.0 x 107 across the site. Naphthalene and phenol degraders represent 0.74% and 2.33% of the total viable cell counts, respectively, although when thiocyanate was used as the sole source of nitrogen these numbers drop to 0.17% and 0.46%. Molecular based techniques have revolutionized our knowledge of environmental microbiology. It is well known that only a small proportion of indigenous microorganisms are culturable in a laboratory environment (0.1-10%) and replication of in-situ conditions is almost impossible with “bias” playing a significant role in the cultivation of mixed microbial populations. Consequently the determination of species composition and the abundance of microorganisms across the site was achieved using molecular techniques (16S rRNA gene sequencing, total counts). Changes in microbial structure across the site was monitored by TGGE analysis and revealed an increase in biodiversity in conjunction with increasing contamination levels, probable due to a wide range of carbon substrates being made accessible. Evidence for the implementation of a biological PRB is provided.