Isolation and characterization of four novel Gram-positive bacteria associated with the rhizosphere of two endemorelict plants capable of degrading a broad range of aromatic substrates |
| |
Authors: | Djokic Lidija Narancic Tanja Nikodinovic-Runic Jasmina Savic Miloje Vasiljevic Branka |
| |
Institution: | (1) Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia; |
| |
Abstract: | Four new Gram-positive, phenol-degrading strains were isolated from the rhizospheres of endemorelict plants Ramonda serbica and Ramonda nathaliae known to exude high amounts of phenolics in the soil. Isolates were designated Bacillus sp. PS1, Bacillus sp. PS11, Streptomyces sp. PS12, and Streptomyces sp. PN1 based on 16S rDNA sequence and biochemical analysis. In addition to their ability to tolerate and utilize high amounts
of phenol of either up to 800 or up to 1,400 mg l−1 without apparent inhibition in growth, all four strains were also able to degrade a broad range of aromatic substrates including
benzene, toluene, ethylbenzene, xylenes, styrene, halogenated benzenes, and naphthalene. Isolates were able to grow in pure
culture and in defined mixed culture on phenol and on the mixture of BTEX (benzene, toluene, ethylbenzene, and xylenes) compounds
as a sole source of carbon and energy. Pure culture of Bacillus sp. PS11 yielded 1.5-fold higher biomass amounts in comparison to mixed culture, under all conditions. Strains successfully
degraded phenol in the soil model system (2 g kg−1) within 6 days. Activities of phenol hydroxylase, catechol 1,2-dioxygenase, and catechol 2,3-dioxygenase were detected and
analyzed from the crude cell extract of the isolates. While all four strains use ortho degradation pathway, enzyme indicative of meta degradation pathway (catechol 2,3-dioxygenase) was also detected in Bacillus sp. PS11 and Streptomyces sp. PN1. Phenol degradation activities were induced 2 h after supplementation by phenol, but not by catechol. Catechol slightly
inhibited activity of catechol 2,3-dioxygenase in strains PS11 and PN1. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|