Efficiency of naphthalene biodegradation by Pseudomonas putida G7 in soil

Abstract

The efficiency of naphthalene degradation by Pseudomonas putida G7 in soil was assessed using a mathematical model. The number of microorganisms and the concentration of naphthalene in soil samples were monitored. The feasibility of a spectrofluorometric method for naphthalene assay in soil samples was compared with high pressure liquid chromatography. A proposed mathematical model described the growth of the naphthalene-degrading strains and the consumption of substrates (naphthalene, naphthalene degradation intermediates and soil organic substances) in soil. To describe the growth kinetics of microorganisms having high affinity to substrates with low solubility, two differential equations with substrate exponent 2/3 were proposed. These equations were used to describe utilization of soil organic matter. The model parameters characterize the growth rates for different substrates and respective yield coefficients, specific bacterial death and adaptation rates, and also the rates of PAHs degradation and evaporation. These characteristics can be used in choosing the bacterial strains for biopreparations and efficient clean-up biotechnology of polluted soils.

Naphthalene degradation by Pseudomonas sp. HOB1: In vitro studies and assessment of naphthalene degradation efficiency in simulated microcosms

“…3) and this can be attributed to growth of biomass on naphthalene intermediates. Filonov et al [18] reported a similar observation of growth of naphthalene degrading culture on their catabolic intermediates.…”

“…Costerton and Lappin-Scott [36] had stated that the planktonic single species laboratory culture exerts a powerful selective pressure on a bacterial genome that eventually produces a cell that lacks protective and adhesive surface structures that cannot survive in natural environments where adhesion and protection is of paramount importance. Filonov et al [18,37] showed naphthalene degradation for the concentration of 1 mg/g and 2.5 mg/g in soil model systems in 8 days and 3 days respectively. Pseudomonas sp.…”

“…Simulated microcosms were prepared by method of Filonov et al [18] with certain modifications. Simulated microcosms were set up in triplicates in glass Petri dish (90 mm diameter).…”

“…Preliminary laboratory studies like characterization of physiological traits and determining the efficiency of the degrading strains are obligatory to increase the probability of success of field tests that are performed by introducing the microbes in the environment [18]. Besides, experiments using soil model systems must also be conducted to study the behavior and efficiency of the introduced microbes in the soil model system.…”

Assessment of naphthalene biodegradation efficiency of Pseudomonas and Burkholderia strains tested in soil model systems

“…Moreover, model systems which closely approximate the conditions at field sites, including soil microcosms, are now frequently used to test potential remediation strategies 1. Modeling of natural processes under laboratory conditions necessitates the development of new model systems, methods for control of vital microbial functions and degradation of xenobiotics, and rapid methods for the quantitative detection of xenobiotics in soil and aqueous solutions 2…”