ESTIMATION OF THE INTRINSIC BIODIVERSITY AMONG POLY(3-HYDROXYALKANOATES) DEGRADING STREPTOMYCETES USING GAS-CHROMATOGRAPHIC ANALYSIS OF FATTY-ACIDS

One hundred and twenty three poly(3-hydroxyalkanoates) degrading strep tomycetes (referred to as PHA strains) from soils, composts, natural w aters, and some other sources were characterized by gas chromatographi c analysis of their methylated cellular fatty acids. They were compare d to reference strains of the genera streptomyces (48 strains) and Str eptoverticillium (9 strains) by numerical analysis. Saturated iso- and anteiso-branched fatty acids of between 14 and 18 carbons constituted the major components in the fatty acid profiles of most of the strain s. In the dendrogram, obtained by unweighted average linkage clusterin g of the Euclidean distances Delta, calculated between each pair of fa tty acid profiles, all strains were linked at Delta = 43. At Delta = 1 1, 18 clusters, consisting each of 2 to 63 strains, could be delineate d, and 16 strains remained unclustered. The clusters could also be rec ognized by principal-component analysis, although small overlaps betwe en some clusters were evident. Most clusters could be differentiated f rom each other by their fatty acid compositions. The PHA strains were scattered over 14 different clusters, 11 of which also contained refer ence strains, and 9 PHA strains remained unclustered. In addition to t he PHA strains, 29 of the 46 reference strains of Streptomyces were al so shown to degrade poly(3-hydroxybutyrate) in vitro. Poly(3-hydroxybu tyrate-co-10%3-hydroxyvalerate) was degraded in vitro by all 56 PHA st rains tested. The study demonstrates the biodiversity of streptomycete s involved in the degradation of poly(3-hydroxyalkanoates) in differen t habitats. The numerical analysis of fatty acid profiles confirms the homogeneity of the Streptomyces albidoflavus group, and the heterogen eity of the Streptomyces cyaneus and Streptomyces anulatus groups, and supports the reunification of the genera Streptomyces and Streptovert icillium.