DETECTION OF METHANOTROPHIC BACTERIA IN ENVIRONMENTAL-SAMPLES WITH THE PCR

We designed PCR primers by using the DNA sequences of the soluble meth ane monooxygenase gene clusters of Methylosinus trichosporium OB3b and Methylococcus capsulatus (Bath), and these primers were found to be s pecific for four of the five structural genes in the soluble methane m onooxygenase gene clusters of several methanotrophs. We also designed primers for the gram-negative methylotroph-specific methanol dehydroge nase gene moxF. The specificity of these primers was confirmed by hybr idizing and sequencing the PCR products obtained. The primers were the n used to amplify methanotroph DNAs in samples obtained from various a quatic and terrestrial environments. Our sequencing data suggest that a large number of different methanotrophs are present in peat samples and also that there is a high level of variability in the mmoC gene, w hich codes for the reductase component of the soluble methane monooxyg enase, while the mmoX gene, which codes for the alpha subunit of the h ydroxylase component of this enzyme complex, appears to be highly cons erved in methanotrophs.