Short communication -: Classification of soil microorganisms based on growth properties:: a critical view of some commonly used terms

The theory that soil microorganisms can be classified on the basis of their growth characteristics, nutritional versatility, and affinity for substrate has surfaced in various forms and at various times throughout the 20(th) century (Bottomley, 1999; Sylvia et al., 1999). Therefore, reading today's scientific literature, one can find several different definitions for categorizing soil organisms by trophic characteristics. The authors, however, not always give their exact meaning. Some definition pairs are often used interchangeably and, in other cases, different fields use the same definition. Such a situation causes uncertainty, and confuses the reader. For this reason, we aim to discuss the appropriate usage of three, from the angle of soil microbiology important and commonly used definition pairs in this paper. We try to clarify the origin of certain definitions, which are sometimes used incorrectly and attempt to give suggestions for a proper use of the definitions discussed. So we would like to start a discussion about these terms within the scientific community rather than to give strict guidelines. Figure 1 gives a theoretical survey about the relationship among the terms discussed.