Enhanced biodegradation and valorization of drilling wastewater via simultaneous production of biosurfactants and polyhydroxyalkanoates by Pseudomonas citronellolis SJTE-3

• Published in: Bioresource technology Vol. 340; p. 125679
• Main Authors: Koutinas, Michalis, Kyriakou, Maria, Andreou, Kostas, Hadjicharalambous, Michalis, Kaliviotis, Efstathios, Pasias, Dimitris, Kazamias, George, Varavvas, Costas, Vyrides, Ioannis
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2021
• Subjects: Biosurfactant; Drilling waste; Polycyclic aromatic hydrocarbons; Polyhydroxyalkanoate; Total petroleum hydrocarbons; Biosurfactant; Drilling waste; Polycyclic aromatic hydrocarbons; Total petroleum hydrocarbons; Polyhydroxyalkanoate
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.125679

[Display omitted] •A microorganism metabolizing hazardous drilling fluids and oily mud was isolated.•SJTE-3 efficiently biodegraded COD, n-dodecane, n-tetradecane and naphthalene.•Biosurfactant and medium-chain-length PHA formation enabled pollutants valorization.•The biosurfactant exhibited useful properties and 24% of cell weight comprised PHA.•Transcription from multiple pathways indicated stimulation of putisolvin synthesis. Pseudomonas citronellolis SJTE-3 was isolated as a highly efficient microorganism for biodegradation and valorization of drilling fluids (DF) wastewater. The strain metabolised DF and oily mud exhibiting up to 93%, 86%, 85% and 88% of chemical oxygen demand (COD), n-dodecane, n-tetradecane and naphthalene removal efficiency respectively. Enhanced bioconversion was enabled through production of biosurfactants that reduced the surface tension of water by 53% and resulted in 43.3% emulsification index (E24), while synthesizing 24% of dry cell weight (DCW) as medium-chain-length polyhydroxyalkanoates (PHA). Expression from the main pathways for alkanes and naphthalene biodegradation as well as biosurfactants and PHA biosynthesis revealed that although the alkanes and naphthalene biodegradation routes were actively expressed even at stationary phase, PHA production was stimulated at late stationary phase and putisolvin could comprise the biosurfactant synthesized. The bioconversion of toxic petrochemical residues to added-value thermoelastomers and biosurfactants indicate the high industrial significance of P. citronellolis SJTE-3.