Abstract
Toluene can enter the environment due to various industrial activities. Toluene exposure may cause serious health risks to human and other living organisms. Thus, removal of toluene from the environment is exceptionally important in toluene-contaminated habitats. The aim of present study was to isolate and characterize toluene-utilizing bacteria from contaminated soil surrounding car body repair and painting workshops in Irbid industrial city, Jordan. Therefore, polluted soil samples (10 g) were transferred to flasks containing 99 ml of Stanier’s medium supplemented with 1% toluene and aerobically incubated at 30°C for 72 h. Subsequently, four morphologically different toluene-utilizing bacteria, designated as T1, T2, T3, and T4, were isolated. The cells of T1, T2 and T3 were Gram-positive, rod-shaped, aerobic, and positive for oxidase and catalase. However, the cells of T4 were Gram-negative, round-shaped, aerobic, negative for oxidase, and positive for catalase. Based on 16S rDNA sequencing data, isolates T1, T2 and T3 had high homology (97% - 98%) with Lysinibacillus boronitolerans, Bacillus subtilis and Rhodococcus pyridinivorans, respectively, whereas the isolate T4 had a homology of 89% with Acinetobacter schindleri, and could represent a distinct lineage within the genus Acinetobacter. The generated 16S rDNA sequences were deposited in GenBank database. After testing different physicochemical conditions, the isolates appeared to grow best at 1% toluene, 30°C and pH 6.8, with the generation times ranged between 8 - 11 h. In conclusion, we reported for the first time the identification of four novel soil bacterial species with the capacity to utilize toluene as sole source of carbon and energy from soil sites surrounding car painting workshops. The beneficial effect of the four isolates in the bioremediation of toluene from toluene polluted soil areas must be examined under in situ and ex situ conditions.
Highlights
Toluene is an aromatic compound that exhibits water-insolubility and low chemical reactivity due to the delocalized π electron system and the resonance energy of the aromatic ring [1]
Soil samples were collected from sites surrounding car body repair and painting workshops in Irbid industrial city, Jordan
To the best of our knowledge, this is the first report of isolation and identification of four novel bacterial species from polluted soil samples collected from sites in close vicinity to auto body repair and spray painting workshops in industrial city of Irbid, Jordan
Summary
Toluene is an aromatic compound that exhibits water-insolubility and low chemical reactivity due to the delocalized π electron system and the resonance energy of the aromatic ring [1]. It has an n-octanol:water partition coefficient (Kow) of 2.69. Toluene is daily released in large quantities in the environment due to crude oil spills following oil tanker accidents and pipeline disruption It can be released into the environment due to extensive use in agricultural and industrial activities such as production paints, lacquers, thinners, pesticides, cigarette, polymers, as well as from automobile and car spray painting workshops and others [5] [6]. When toluene enters the soil, some of it will adhere to soil particles through the process of adsorption, and some of it will reach groundwater
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
