Degradation of Phenol via Meta Cleavage Pathway byPseudomonas fluorescensPU1

Abstract

<jats:p>Degradation of phenolics by members of soil microflora is an important means by which these substances are removed from the environment thus reducing environmental pollution. Biodegradation by microorganisms offers unique opportunities to destroy or render phenolic compounds. A bacterium, PU1, identified as<jats:italic>Pseudomonas fluorescens</jats:italic>PU1, was investigated for its ability to grow on and degrade phenols as sole carbon sources in aerobic shaking batch culture. The organism degraded up to 1000 ppm of phenol using meta cleavage pathway. The pathways for phenol degradation were proposed by the identification of metabolites and assay of ring cleavage enzymes in cell extracts. Phenol was degraded via catechol with subsequent metaring cleavage. Cell growth increased as the phenol concentrations increased up to 1000 ppm phenol. The biodegradation efficiency, degradation extent, and metabolic pathway of phenol were determined to provide useful clues for further application of this isolate in the engineered bioremediation systems. The paper's results suggest that<jats:italic>Pseudomonas fluorescens</jats:italic>PU1 strain could be a good candidate for remediation of phenol contaminants from heavily polluted sites.</jats:p>

Biodegradation of phenol by a novel diatom BD1IITG-kinetics and biochemical studies

“…Control incubations were carried out by heat-killed enzyme extract showing no phenol hydroxylation activity (no phenol utilization and no catechol production). Similar observations have also been reported for algae (Semple and Cain 1996), fungi (Neujhar and Gaal 1973;Páca et al 2007) and bacteria (Mahiuddin et al 2012;Ali et al 1998). Catechol can be ortho cleaved (if it follows ortho pathway) or meta cleaved (if it follows meta pathway) by catechol-1,2-dioxygenase and catechol-2,3-dioxygenase, respectively.…”

“…5f. The proposed pathway was found to have similarities with algal (Semple and Cain 1996), fungal (Tsai et al 2005;Cai et al 2007;Santos and Linardi 2004) as well as bacterial (Mahiuddin et al 2012;Ali et al 1998) catabolic mechanisms.…”

“…Comparatively higher activity of catechol-1,2-dioxygenase (0.39 U/mg) against that of catechol-2,3-dioxygenase (1.36 9 10 -2 U/mg) suggests efficiency of ortho-over meta pathway in diatom BD1IITG. Mahiuddin et al (2012) reported simultaneous activity of meta-as well as ortho pathway in Pseudomonas fluorescens PU1. They reported Fig.…”

Molecular Identification of Phenol-Degrading and Biofi lm-Forming Bacteria from Wastewater and Peat Soil

“…The method is considered effective for environmental decontamination (Tsai et al, 2005), considerably cheap, environmental friendly, and less sideproduct (Al-Thani et al, 2007;Bayoumi and Ashraf, 2010). Moreover, by using this method, pollutant is degraded completely or at least changed into less harmful products (Mahiuddin et al, 2012). Those conditions happen because microbes use phenol as a source of carbon and break it into CO 2 (Amro and Soheir, 2007;Tuah et al, 2009).…”

“…However, phenols are more commonly produced as artifi cal aromatic compounds in wastewater from many industries, such as textile, dye, oil refi nery, chemical instalation, and medical (Lee et al, 1997;Tsai et al, 2005;Al-Thani et al, 2007;Anonim, 2008). Phenol is relatively soluble in water, and the wastewater containing this compound can contaminate and accumulate in soil, surface water, and ground water (Zaki, 2006;Mahiuddin et al, 2012). This corrosive compound can be absorbed through inhalation, digestion, also skin, and may cause chemical burn, promotes tumor (Bitton, 2005;Anonim, 2008;Chakraborty et al, 2010), also affect the function of human and animal hormonal system (Aoyama et al, 2012).…”