[Formation of the taxa of methane-oxidizing bacteria by numerical analysis methods]

Obligate methane oxidizing bacteria were classified within groups using numerical analysis and computer techniques. Employment of properties coinciding for all the species of the bacterial group under study was found to result in an insignificant (5--10%) change in the degree of similarity rather than in the redistribution of interrelationship; it had no effect on the formation of phenons. The Smirnov taxonomical analysis according to which the weight of a property is inversely proportional to its frequency has a number of advantages over other numerical methods where all the properties are assumed to be of equal value. Comparative evaluation of the data obtained by different methods which have been used by us to calculate the coefficients for coupled similarity of species (the coefficient of association, the coefficient of correlation, the index of distance, the coefficient of taxonomic ratio) shows that similar results are found in all the cases with respect to group division of the species belonging to the family Methylomonadaceae Leadbetter 1974. The species of methane oxidizing bacteria should be divided into the following genera: Methylosinus Whittenbury, Phillips a. Wilkinson 1970, Methylocystis Whittenbury, Phillips a. Wilkinson 1970, Methylococcus Foster a. Davis 1966, Methylomonas Leadbetter 1974.