Naphthalene-utilizing and mercury-resistant bacteria isolated from an acidic environment

Abstract

Soil samples were taken from areas of low pH (2.5-3.5) surrounding an outdoor coal storage pile. These samples were added to medium with naphthalene as the sole carbon source to enrich for organisms capable of degrading polycyclic aromatic hydrocarbons (PAH) at low pH. Five such bacterial strains were isolated. Sequencing of the 16S rDNA showed them to be members of the genera Clavibacter, Arthrobacter and Acidocella. These organisms were all capable of growth with naphthalene as a sole carbon source at low pH. The genes nahAc, nahAd, phnAc, nahH, xylE or GST, which are known to be associated with PAH degradation were not detected. Isolate 10, the Acidocella strain, tolerated high levels of mercury. PCR amplification and sequencing of genes from the mer operon from isolate 10 DNA suggested that mercury is transported into the bacterial cell and subsequently detoxified since the enzymes encoded by genes in this operon are involved in these processes.

Two naphthalene degrading bacteria belonging to the genera Paenibacillus and Pseudomonas isolated from a highly polluted lagoon perform different sensitivities to the organic and heavy metal contaminants

“…Most of these bacteria were isolated from extreme environments such as naphthalene-utilizing and mercury-resistant bacteria isolated from an acidic environment (Dore et al 2003). The presence of heavy metals may suppress or reduce PAH degradation (Insam et al 1996;Wild et al 1991).…”

“…Therefore, it gains importance in studies on the physiology of bacteria growing in the presence of organic pollutants and of toxic elements. However, next to reports on the toxicity of organic compounds and metals, observations of the effects of different contaminants on microbial cells are relatively rare (Dore et al 2003).…”

Characterization of acidophilic bacteria related to Acidiphilium cryptum from a coal-mining-impacted river of South Brazil

“…These features also contribute to make the isolation process more difficult (Johnson et al, 1993). The isolation of a small group of bacterial strains from acid environments was also reported by Kishimoto et al (1993) and Dore et al (2003), although this may vary accordingly to the culture media employed (Kishimoto & Tano 1987).…”

“…Another problem associated with coal is the presence of polyaromatic hydrocarbons (PAHs) (Dore et al, 2003;Jacques et al, 2007). These organic compounds bear two or more benzene rings arranged in a linear or angular form, and are poor soluble in water, which contributes to its persistence in the environment (Fuentes et al, 2014).…”

Isolation of hydrocarbonoclastic bacteria from bilge oil contaminated water

“…The catabolic genes checked were C12O and C23O (Sei et al, 1999), pdo (Krivobok et al, 2003), p3-24 (Dore et al, 2003), ndo (Teramoto et al, 2009), nidA (Brenza et al, 2003, phn (Jennifer et al, 2007) and all benzene,toluene, ethyl benzene and xylene (BTEX) catabolic genes as mentioned in Hendrickx et al (2006). The reaction mixture (50 µL) contained 1X taq buffer, 2.5 mM MgCl2, 200 mM concentration of each deoxynucleoside triphosphate, 50 pmol of each primer, 2.5 U of Taq DNA polymerase (Sigma Aldrich, Mumbai, India) and 1 µL of DNA template.…”