Occurrence and growth potentials of hydrocarbon degrading bacteria on the phylloplane of some tropical plants

Abstract

The surface of leaf samples from ten tropical plants, Anthocleista, Sarcophrynium, Canna, Colocassia, Musa, Cola, Citrus, Mangifera, Terminalia and Annona were cultured for the estimation of total heterotrophic and hydrocarbon utilizing bacteria. The total heterotrophic bacteria ranged from 0.75 x 10⁷ to 0.98 x 10⁷ (cfu/cm²) while the hydrocarbon utilisers ranged from 0.86 x 10⁶ to 2.12 x 16⁶ (cfu/cm²). The percentages of hydrocarbon degraders were highest on Mangifera and lowest on Colocassia. Hydrocarbon degraders identified as Acinetobacter, Flavobacterium, and Micrococcus were obtained. Most of the organisms grew well on diesel. Pseudomonas sp. grew luxuriantly on diesel and kerosene while Bacillus sp. did not grow on kerosene. Optimal growth on the hydrocarbon occurred between the 8^th and 14^th day. It was therefore concluded that bacteria with ability to utilize hydrocarbons could be obtained from leaf surfaces. Such organisms could serve as seeds for bioaugmentation during remediation of polluted environments.

Keywords: Phylloplane, bacteria, hydrocarbon, degradation, kerosene, diesel, lubricant