Influence of phenanthrene and fluoranthene on the degradation of fluorene and glucose by Sphingomonas sp. strain LB126 in chemostat cultures

Abstract

Since bacteria degrading polycyclic aromatic hydrocarbon compounds (PAHs) in polluted soils are generally exposed to mixtures of PAHs, we examined the influence of simple PAH mixtures on the degradation activity of Sphingomonas sp. strain LB126. Fluorene serves as sole carbon and energy source for the strain LB126 and phenanthrene and fluoranthene are cometabolically degraded by this species. Chemostat cultures of the strain LB126 were used to study a potential inhibiting effect of phenanthrene and fluoranthene on the degradation of fluorene that was previously observed in batch cultures. We also looked at the effect of phenanthrene on the degradation of glucose in a chemostat culture to see if this effect was specific for the PAH-metabolic pathway or for the total metabolism of the strain. The co-substrates were supplied in a 5% to 30% fraction of fluorene. Phenanthrene and fluoranthene had no significant influence on growth. However, fluorene degradation was inhibited by both phenanthrene and fluoranthene. The effect of phenanthrene was about 10 times stronger than the effect of fluoranthene. Nevertheless, more than 95% removal of fluorene took place together with more than 95% removal of either phenanthrene or fluoranthene. The effect of phenanthrene on the strain LB126 could be ascribed to both toxicity and competitive inhibition, but the effect observed at steady state was due to competitive inhibition only. It appeared that the strain LB126 adapts to the toxicity of phenanthrene within five generations. The inhibitory effects observed previously in batch cultures of the strain LB126 should mainly be ascribed to the toxic effect of phenanthrene.

Life cycle responses of the midge Chironomus riparius to polycyclic aromatic compound exposure

“…For all test compounds, actual concentrations at the beginning of the experiment after correcting for recovery ranged from 70% to 91% of the nominal value. The concentrations of anthracene, phenanthrene, acridine and phenanthridine in the test sediment decreased by 25%, 42%, 18% and 55% respectively during the experiment, probably due to microbial degradation (Van Herwijnen et al, 2003;Johnsen et al, 2005). Actual concentrations of acridone and phenanthridone in the sediment remained nearly constant during the experiment, indicating that these transformation products were not further degraded.…”

Degradation of phenanthrene by Burkholderia sp. C3: initial 1,2- and 3,4-dioxygenation and meta- and ortho-cleavage of naphthalene-1,2-diol

“…Many bacterial species capable of PAH degradation have been isolated and belong to the genera of Arthrobacter (Samanta et al 1999), Pseudomonas (Balashova et al 1999), Rhodococcus (Dean-Ross et al 2002), Mycobacterium (Dean-Ross et al 2002;Kim et al 2005;Moody et al 2001), Sphingomonas (Pinyakong et al 2000;van Herwijnen et al 2003), and Stenotrophomonas (Juhasz et al 2000). In addition, Burkholderia sp.…”

Pesticide relevance and their microbial degradation: a-state-of-art

“…JS19b1 can break down diazinon, pirimiphos-methyl, and temephos. Other genera Burkholderia (Kang et al 2003), Pseudomonas (Prabha and Phale 2003), Sphingomonas (Ye et al 1996;Van Herwijnen et al 2003) and Stenotrophomonas as Gram negative and Mycobacterium and Rhodococcus as Gram positive were so isolated and characterized for biodegradation of PAHs varying from two-ring PAHs to five ring PAHs (Beate et al 1993;Moody et al 2004). Arthrobacter, Agrobacterium, Burkholderia, Enterobacter (Cui et al 2001;Johnsen et al 2005;Bhadbhade et al 2002;Pipke and Amrhein 1988) Plesiomonas and Pseudomonas (Horne et al 2002a, b) have ability to degrade of a highly toxic and powerful inhibitory acetylecholinesterase organophosphorus pesticides (OPS) such as chlorpyrifos (Singh et al 2003), coumaphos, diazinon, fenitrothion monocrotophos and parathion (Cui et al 2001) (Table 3).…”

“…In these processes fungi and bacteria are involved producing intracellular or extra cellular enzymes including hydrolytic enzymes, peroxidases, oxygenases, etc. (Van Herwijnen et al 2003;Ortiz-Hernández et al 2011).…”