Screening, isolation and molecular identification of biodegrading mycobacteria from Iranian ecosystems and analysis of their biodegradation activity

Abstract

Anthropogenic origin pollutants including pesticides, heavy metals, pharmaceuticals and industry chemicals impose many risks to human health and environment and bioremediation has been considered the strategy of choice to reduce the risk of hazardous chemicals. In the current study, we aimed to screen and characterize mycobacteria from the diverse range of Iranian aquatic and terrestrial ecosystems with harsh and unfavorable environmental conditions that can be utilized for biodegradation of target pollutants. Mycobacteria were isolated from a collection of 90 environmental samples and identified to the species level using conventional microbiological and molecular methods including the PCR amplification of hsp65 and sequence analysis of, 16S rRNA genetic markers. The growth rate of the isolates in presence of pollutants, chromatography, Gibbs and turbidometric methods were used to assess their biodegradation activity. A total of 39 mycobacterial isolates (43.3%) were recovered from 90 samples that belonged to 21 various species consisting of M. fortuitum; 6 isolates, M. flavescens and M. paragordonae; 4 isolates each, M. monacense, M. fredriksbergense and M. aurum; 2 isolates each, 7 single isolates of M. conceptionense, M. porcinum, M. simiae, M. celeriflavum, M. novocastrense, M. neoaurum, M. obuense and 12 isolates that belonged to 8 unknown potentially novel mycobacterial species. The isolates were categorized in three groups based on their bioremediation activity, i.e., 5 (12.8%) organisms without biodegradation activity, 20 (51.2%) organisms with previously reported biodegradation activity, and 14 (35.9%) organisms that showed biodegradation activity but not previously reported. Our results showed that the Iranian ecosystems harbor a good reservoir of diverse mycobacterial species with biodegrading potentiality for neutralizing environmental chemical pollutants.

<p>Species Diversity, Molecular Characterization, and Antimicrobial Susceptibility of Opportunistic Actinomycetes Isolated from Immunocompromised and Healthy Patients of Markazi Province of Iran</p>

“…Initially non-sterile samples such as wound, pus, and sputum processed by NaOH 4% and HCL 1% and other sterile samples include blood, tracheal fluid, and pleural fluid condensed with centrifugation in 3,000 ×g, then inoculated in Lowenstein Jensen (LJ) (Merk, Germany), carbon free broth, blood agar (Merk, Germany), and Sauton's media supplemented with antifungal and antibacterial antibiotics [kanamycin, nalidixic, and nystatin acid (each at 50 μg/mL)] and incubated for 8 weeks at 25, 32, and 37°C. 24 This study was approved by the ethics committee of Arak University of Medical Sciences and Social Welfare Organization under which the private and public daycare nurseries or kindergartens are organized and operate (Grant No. 3005).…”

Soil Microorganisms and Their Potential in Pesticide Biodegradation; A Review Article

“…Several microbes have developed catabolic degradative mechanisms to different organic compounds i.e. majority of degradative microbes can utilize external compounds as an energy and nutrient source (Alvarenga et al, 2018, Azadi et al, 2017, Liu et al, 2016and Wang & Xie, 2014.…”

Rubber Degrading Strains: Microtetraspora and Dactylosporangium

“…Actinobacteria are an integral part of the indigenous soil microflora, unique for their ability to degrade a large variety of organic materials, their high catabolic capacity, and their resilience in the face of unfavorable environmental conditions [13,14]. The same species of Actinobacteria growing in different locations or ecological niches are known to produce environmentally specific metabolites [15,16].…”