Insights into polyaromatic hydrocarbon biodegradation by Pseudomonas stutzeri CECT 930: operation at bioreactor scale and metabolic pathways

Abstract

Contamination of the environment with polycyclic aromatic hydrocarbons is one of the major problems facing the industrialized nations today. In this work, Pseudomonas stutzeri CET 930 was studied for the first time as bioremediation agent for the degradation of effluents containing phenanthrene, pyrene and benzanthracene, both individually and mixed. The promising results of degradation obtained at flask scale (92, 63 and 94 % in 7 days, respectively) marks the onset of the operation at bench scale bioreactor. The overall biotransformation of phenanthrene, pyrene and benzanthracene in batch operation mode was 95, 78 and 82 % when present individually, and 100, 98 and 100 % when carrying out the biological process in cometabolic conditions, respectively. We have demonstrated the great versatility of this strain for the degradation of structurally different contaminants, such as metal working fluids, polycyclic aromatic hydrocarbons or insecticides such as chlorpyrifos, which makes it a suitable candidate to be applied at industrial scale. In all cases, the experimental data were successfully fitted to models, which turned out to be valuable tools to classify the metabolites involved in the biodegradation process as biomass-related. Since a complete mineralization was pursued, the metabolic pathways of the studied contaminants have been proposed based on gas chromatography-mass spectrometry data.

Bioremediation of polycyclic aromatic hydrocarbon (PAH) compounds: (acenaphthene and fluorene) in water using indigenous bacterial species isolated from the Diep and Plankenburg rivers, Western Cape, South Africa

“…This was attributed to the possibility that the microorganisms had utilised all the contaminants (serving as carbon sources) and hence, stopped replicating abundantly. Apart from substrate depletion, another plausible explanation for the drastic decline in microbial numbers is that toxic intermediates and by-products such as salicylate as well as oxy-PAHs; including PAH-ketones, quinones and coumarins 32 , 33 , 34 , 35 might have been produced and accumulated in the reactors thereby causing the death of the bacterial cells.…”

Biodegradation of Anthracene and Phenanthrene by Pseudomonas stutzeri (BUK_BTEG1) Isolated from Petrochemical Contaminated Soil

“…These findings suggested that the PAHs degradation route by strain BUK BTEG1 followed a similar course to that described for Pseudomonas sp. strain Jpyr-1 and strain CECT 930 (Moscoso et al, 2015) Pseudomonas otitidis strain P4 (Singh and Tiwary, 2016) and Pseudomonas stutzeri P2 (Singh and Tiwary, 2017).…”

Enhancement of mixture pollutant biodegradation efficiency using a bacterial consortium under static magnetic field

“…A recent study showed that P . stutzeri has the capacity to degrade phenanthrene, pyrene and benzo(a)anthracene in a bioreactor with 95,78 and 82% of removal, respectively [28]. The studies mentioned above show that P .…”