A Simple Scheme for the Identification of Marine Heterotrophic Bacteria

A scheme has been proposed to identify the marine heterotrophic bacterial genera based on the minimum biochemical tests. Fifteen gram negative and six gram positive marine bacterial genera could be identified with this proposed scheme which involves staining, morphology, motility and some major biochemical tests INTRODUCTION A number of reports are available on key characters for the identification of heterotrophic bacteria (Simidu and Aiso, 1962; Baumann et al.,1972; Buchanan and Gibbons, 1974; Starr et al.,1981; Sneath, 1986), and in particular for the marine heterotrophic bacteria (Baumann et al.,1972; Oliver, 1982). But, most of the schemes are based on several time consuming biochemical tests. In spite of performing all the laborious biochemical tests, sometimes, the isolates are misidentified. Oliver (1982) proposed a key for the identification of gramnegative bacteria and Jensen and Fenical (1995) for gram-positive bacteria and these are widely followed. More bacterial genera have been reported from the marine environment, and these are not included in those schemes. Hence, in the present study an attempt has been made to simplify and modify these schemes to include the recently reported marine heterotrophic bacteria and to propose a collated scheme for the identification of marine bacterial genera (both gram negative and gram positive) based on minimum biochemical tests. The scheme relies on the information given by Shewan (1963), Okami and Okazaki (1972), Buchanan and Gibbons (1974), Starr et al. (1981), Oliver (1982), Jensen and Fenical (1995) and Cappuccino and Sherman (2001). Centre of Advanced Study in Marine Biology, Annamalai University Parangipettai608 502, Tamil Nadu, India *E-mail: [email protected] Tel: +91-4144-243223 ext. 220; Fax: +91-4144-243555 Thalassas, 2007, 23 (2): 17-21 An International Journal of Marine Sciences