Physicochemical characterization of actinomycetes isolated from decayed cedar wood: contact angle measurement

Physicochemical characterization of microorganism is very important in a wide range of scientific and technological fields. In this study, we reported the isolation and the molecular identification of actinomycetes recovered from cedar wood decay. The isolates named H5 and H8 were identified by 16S rDNA sequencing and were shown to belong to the genus Nocardia and Streptomyces, respectively. Furthermore, physicochemical proprieties including hydrophobicity, electron donor/acceptor, and the Lifshitz–van der Waals (γLW) of these strains were evaluated using contact angle measurements. The results showed that Nocardia sp. (H5) had a hydrophobic (ΔGiwi = −78.56 mJ/m2) and a weak electron donor/acceptor character. In contrast, results from contact angle measurements showed that the surface free energy of Streptomyces strains (H2, H3, and H8) were ΔGiwi = 20.71 mJ/m2, ΔGiwi = 30.63 mJ/m2, and ΔGiwi = 15.35 mJ/m2, respectively, classifying these microorganisms as hydrophilic bacterium. Moreover, the three strains were predominantly electron donating (γ– ) and exhibit a weak electron-accepting (γ+) character.