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Gaur S, Gupta S, Jha PN, Jain A. Rhamnolipid production by Pseudomonas aeruginosa (SSL-4) on waste engine oil (WEO): Taguchi optimization, soil remediation, and phytotoxicity investigation. ENVIRONMENTAL TECHNOLOGY 2024; 45:4536-4549. [PMID: 37682050 DOI: 10.1080/09593330.2023.2257915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/31/2023] [Indexed: 09/09/2023]
Abstract
ABSTRACTEnvironmental concerns and rising biosurfactant demand emphasize the need for this study. The objective is to maximize rhamnolipid-biosurfactant production by Pseudomonas aeruginosa (SSL-4) utilizing waste engine oil (WEO) as the sole substrate for use in soil bioremediation and commercial production. Using an L16 Taguchi orthogonal array, a signal-to-noise ratio, and an analysis of variance (ANOVA), the effects of environmental (pH, incubation temperature) and dietary parameters (carbon source concentration, carbon/nitrogen (C/N) and carbon/phosphorus (C/P) ratio) are examined. Variations of the following parameters were made within a carefully selected range: incubation temperature of 25-40℃, pH range of 5-11, WEO concentration of 1-7% (v/v), and C/N and C/P ratios of 10-40. Response variables in this batch study include surface tension reduction (mN/m), dry cell biomass (DCBM) (g/L), and rhamnolipids yield based on substrate consumption, YP/S (g/g). Rhamnolipid was synthesized under optimal conditions, providing a yield of 21.42 g/g. The oil recovery of 74.05 ± 1.481% was achieved from oil-contaminated soil at a CMC of ∼70 mg/L. FTIR, 1H NMR, and UPLC-MS techniques were utilized for the characterization of rhamnolipids, and AAS for determining heavy metals concentration in WEO and residual waste engine oil (RWEO). The Germination Index (GI) of ∼82.55% indicated no phytotoxicity associated with synthesized rhamnolipid.
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Affiliation(s)
- Shailee Gaur
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Suresh Gupta
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Prabhat N Jha
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Amit Jain
- Department of Chemical Engineering, Birla Institute of Technology and Science, Pilani, Rajasthan, India
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Zhou J, Liu S, Xie B, Wang W, Xu N, Xu A, Dong W, Jiang M. Enhancing rhamnolipid production through a two-stage fermentation control strategy based on metabolic engineering and nitrate feeding. BIORESOURCE TECHNOLOGY 2023; 388:129716. [PMID: 37689118 DOI: 10.1016/j.biortech.2023.129716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/21/2023] [Accepted: 09/04/2023] [Indexed: 09/11/2023]
Abstract
Nitrate plays a crucial role in the high-efficient fermentation production of rhamnolipids (RLs). However, the underlying mechanism remains unclear. Firstly, by knocking out the restriction endonuclease PaeKI and utilizatiing the endogenous CRISPR-Cas-mediated single-plasmid recombineering system, a genome editing system for P. aeruginosa KT1115 has been established. Secondly, an engineered strain KT1115ΔpaeKIΔnirS was obtained with a 87% of reduction in nitric oxide (NO) accumulation and a 93% of reduction in RLs production, revealing the crucial role of NO signaling molecule produced from nitrate metabolism in RLs production. Finally, by combining metabolic engineering of the nitrate metabolism pathway with nitrogen feeding, a new two-stage fermentation process was developed. The fermentation production period was reduced from 168 h to 120 h while achieving a high yield of 0.8 g/g, and the average productivity increased by 55%. In all, this study provides a novel insights in the RLs biosynthesis and fermentation control strategy.
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Affiliation(s)
- Jie Zhou
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211800, PR China
| | - Shixun Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Bin Xie
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Wenyao Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Ning Xu
- Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology, Huaiyin Normal University, Huai'an 223300, PR China
| | - Anming Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211800, PR China.
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, PR China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing 211800, PR China
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Efficient isolation of biosurfactant rhamnolipids from fermentation broth via aqueous two-phase extraction with 2-propanol/ammonium sulfate system. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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