Evaluation of di-rhamnolipid biosurfactants production by a novel Pseudomonas sp. S1WB: Optimization, characterization and effect on petroleum-hydrocarbon degradation

• Published in: Ecotoxicology and environmental safety Vol. 242; p. 113892
• Main Authors: Phulpoto, Irfan Ali, Yu, Zhisheng, Li, Jinmei, Ndayisenga, Fabrice, Hu, Bowen, Qazi, Muneer Ahmed, Yang, Xiaosong
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-09-2022; Elsevier
• Subjects: Biodegradation; Di- rhamnolipids; High stability; Optimization; Petroleum-hydrocarbon pollutants; Pseudomonas sp; Biodegradation; Di- rhamnolipids; Petroleum-hydrocarbon pollutants; Pseudomonas sp; High stability; Optimization
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.113892

Rhamnolipid biosurfactants are multifunctional compounds that can play an indispensable role in biotechnological, biomedical, and environmental bioremediation-related fields, and have attracted significant attention in recent years. Herein, a novel strain Pseudomonas sp. S1WB was isolated from an oil-contaminated water sample. The biosurfactants produced by this strain have capabilities to reduce surface tension (SFT) at 32.75 ± 1.63 mN/m and emulsified 50.2 ± 1.13 % in liquid media containing 1 % used engine oil (UEO) as the sole carbon source. However, the lowest SFT reduction (28.25 ± 0.21), highest emulsification index (60.15 ± 0.07), and the maximum yields (900 mg/L) were achieved under optimized conditions; where, the glucose/urea and glycerol/urea combinations were found efficient carbon and nitrogen substrates for improved biosurfactants production. Biosurfactants product was characterized using ultra-high performance liquid chromatography-mass spectrometry (UHPLC- MS) and detected various di- rhamnolipids congeners. In addition, the di-rhamnolipids produced by S1WB strain was found highly stable in terms of surface activity and EI indices at different environmental factors i.e. temperature, pH and various NaCl concentrations, where, emulsifying property was found high stable till 30 days of incubation. Moreover, the stain was capable to degrade hydrocarbon at 42.2 ± 0.04 %, and the Gas chromatography- mass spectrometry (GC-MS) profile showed the majority of peak intensities of hydrocarbons have been completely degraded compared to control.
[Display omitted]
•The strain Pseudomonas sp. S1WB was isolated from oil-contaminated water sample.•Glucose and urea were found efficient C/N substrates for biosurfactants production.•Maximum bioproduction yield was achieved 900 mg/L under optimized condition.•UHPLC-MS profile revealed the strain was capable to produce di-rhamnolipids congeners.•The strain degraded majority of peak intensities of hydrocarbon based on GC-MS results.