Biodegradation of polycyclic aromatic hydrocarbons, phenol and sodium sulfate by Nocardia species isolated and characterized from Iranian ecosystems

Abstract

Anthropogenic pollutants are known to have adverse effect on ecosystem, biodiversity and human health. Bioremediation is an option that has been widely used to remediate organic contaminants and reduce the risk of these hazardous materials. Microorganisms are readily available to screen and can be rapidly characterized to be applied in many extreme environmental conditions. Actinomycetes have a great potential for the production of bioactive secondary metabolites which have biodegradation activity. This study aimed to screen and characterize Nocardia species with biodegradation potential from diverse Iranian ecosystems. The isolates were screened from 90 collected environmental samples, identified and characterized using conventional and molecular microbiological methods including the PCR amplification and sequencing analysis of 16S rRNA and rpoB genetic markers. Growth rate in presence of pollutants, chromatography, Gibbs and turbidometric methods were used to determine bioremediation ability. A total of 19 Nocardia isolates were recovered from the cultured samples (21.1%) that belonged to 10 various species. The most prevalent Nocardia species was N. farcinica; 4 isolates (21%), followed by N. cyriacigeorgica and N. cashijiensis like; 3 isolates each (15.7%) and N. asteroides and N. kroppenstedtii; 2 isolates each (10.5%). Our results showed that various Nocardia species have great potential for bioremediation purposes, although they have not received much attention of the scholars for such significant usage.

Polycyclic aromatic hydrocarbons accumulation in soil horizons of different temperate forest stands

“…Biodegradation of these pollutants depends primarily on the moisture, pH, soil temperature and bioavailability of the organic matter contained in the soil (Johnsen et al, 2005). The biological breakdown of persistent organic pollutants by microorganisms is one of the most important and effective methods of removing PAHs from the environment (Azadi & Shojaei, 2020; Ghosal et al, 2016). The rate of biodegradation changes is influenced by the composition and activity of the microorganisms and the contamination's properties and age (Lors et al, 2012).…”

Biodegradation of chlorpyrifos using isolates from contaminated agricultural soil, its kinetic studies

“…Biodegradation is considered best option for in situ restoration operations 6 . Soils contaminated with polycyclic aromatic hydrocarbon was successfully restored by Nocardia farcinica , Nocardia asteroids and Nocardia cashijiensis 27 . Chlorpyrifos is widely used on cotton and vegetables to control pests.…”

First isolation of biodegradable polycyclic aromatic hydrocarbons Mycobacterium porcinum and Mycobacterium celeriflavum from oil-polluted ecosystems

“…Microflora develops in the regions where they can survive in the presence of such undigested materials and can use these compounds as an energy and carbon sources and they grow and appear as the predominant microbial population of the area (14). Several studies conducted in this field showed that numerous aquatic and soil bacterial species can degrade and consume pollutants as a sole carbon and energy source, such as Polaromonas, Pseudomonas, Burkholderia, Bacillus, Sphingomonas, Nocardia, and Mycobacterium (15,16). Mycobacterium genera are reported to not only have a high intrinsic resistance to stressful condition but also have the potential for degradation of environmental pollutants including crude oil, hydrocarbons, chlorophenols, polychlorinated biphenyls polychlorophenols, heavy metals, and diverse PAH alkanes (17).…”