Abstract
A study was performed on the biodiversity of actinomycetes in the Gravel Bed Hydroponic (GBH) system constructed wetland for industrial wastewater treatment. Identification of 102 actinomycete isolates recovered from the biofilm of the treatment system revealed high taxonomic diversity. Forty species belonging to ten genera were identified: Streptomyces, Nocardioides, Micromonospora, Nocardiopsis, Nocardia, Actinomadura, Pseudonocardia, Planobispora, Kineosporia and Kitasatospora. The later four genera have never been isolated from biological wastewater treatment systems. The biodiversity of actinomycetes generally increased down the system, where 21 species were recorded at the end of the bed compared to 16 species at its top. Streptomyces and Nocardioides were the most dominant genera in the bed. Numerical analysis of the studied isolates showed a sharp separation of the GBH actinomycete isolates from the corresponding type strains. Actinomycetes from the GBH are suggested to have valuable degradation activities.
