Distribution of Hydrocarbon-Degrading Bacteria in the Soil Environment and Their Contribution to Bioremediation

Abstract

A real-time PCR quantification method for indigenous hydrocarbon-degrading bacteria (HDB) carrying the alkB gene in the soil environment was developed to investigate their distribution in soil. The detection limit of indigenous HDB by the method was 1 × 10(6) cells/g-soil. The indigenous HDB were widely distributed throughout the soil environment and ranged from 3.7 × 10(7) to 5.0 × 10(8) cells/g-soil, and the ratio to total bacteria was 0.1-4.3 %. The dynamics of total bacteria, indigenous HDB, and Rhodococcus erythropolis NDKK6 (carrying alkB R2) during bioremediation were analyzed. During bioremediation with an inorganic nutrient treatment, the numbers of these bacteria were slightly increased. The numbers of HDB (both indigenous bacteria and strain NDKK6) were gradually decreased from the middle stage of bioremediation. Meanwhile, the numbers of these bacteria were highly increased and were maintained during bioremediation with an organic nutrient. The organic treatment led to activation of not only the soil bacteria but also the HDB, so an efficient bioremediation was carried out.

Analysis of the Alkane Hydroxylase Gene and Long-Chain Cyclic Alkane Degradation in <i>Rhodococcus</i>

“…c-alkane-degrading bacteria belonging to the genus Rhodococcus isolated from their natural habitats in our previous study were closely related to R. erythropolis and strains harboring alkB R2 type [33]. Although many c-alkane-degrading…”

“…Moreover, alkB varies among species of the genus Rhodococcus, and oxidizable substrates differ depending on the alkB gene type [32]. For example, Fukuhara et al [33] revealed that the R. erythropolis strain NDKK6, carrying the alkB R2 type, showed a high c-alkane degradation ability. Furthermore, the carbon number of the alkyl side chain seemed to influence c-alkane degradation [34] [35] [36] [37].…”

From Functional Potential of Soil Bacterial Communities Towards Petroleum Hydrocarbons Bioremediation

“…However, biodegradation of hydrocarbons occurs naturally and is found in most types of soils (Pinholt et al 1979;Whitby & Skovhus 2009). In fact, microbes which have the potential to degrade hydrocarbons are widely distributed in the environment (Bamforth & Singleton 2005;Head et al 2006;Whitby & Skovhus 2009;Fukuhara et al 2013;Boon et al 2014) and exposure to hydrocarbons result in changes in the microbial community structure. During this process, genes encoding for a variety of metabolizing enzyme are critical for the ability of microorganisms to biodegrade hydrocarbons (Liu et al 2015).…”

Assessment of the Hydrocarbon Degrading Abilities of Three Bioaugmentation Agents for the Bioremediation of Crude Oil Tank Bottom Sludge Contaminated Libyan Soil

“…COTBS contains a mixture of hydrocarbon fractions ranging from alkanes to polycyclic aromatic hydrocarbons (PAHs), [5] and heavy molecular weight hydrocarbons (HMWHCs) above C 40 [6]. Some fractions such as PAHs (a significant component of COTBS [7]) have carcinogenic and mutagenic characteristics to living organisms [8].…”