1
|
Hou N, Zhao X, Han Z, Jiang X, Fang Y, Chen Y, Li D. Dodecenylsuccinic anhydride-modified oxalate decarboxylase loaded with magnetic nano-Fe 3O 4@SiO 2 for demulsification of oil-in-water emulsions. CHEMOSPHERE 2022; 308:136595. [PMID: 36167213 DOI: 10.1016/j.chemosphere.2022.136595] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/19/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The inability to demulsify oil-in-water emulsions via green and efficient processes is a challenging problem in many industrial processes. As a novel biodemulsifier, protein demulsifiers display excellent dispersibility and stability, but their demulsification mechanisms are not clear, which severely restricts their large-scale production and application. In this study, the demulsification mechanism of the high-efficiency protein biodemulsifier oxalate decarboxylase (Bacm OxdC), which is secreted by the Bacillus mojavensis XH1 strain, for an oil-in-water emulsion was analyzed. The results showed that Bacm OxdC was spontaneously adsorbed at the oil-water interface and turned its hydrophobic amino acids outward to increase its hydrophobicity and break the emulsified system. Furthermore, it effectively reduced the oil-water interfacial tension and interfacial film strength, thereby reducing the oil-water interfacial energy and finally enabling demulsification. To further improve the demulsification efficiency and reusability, Fe3O4@SiO2@OxdC-DDSA was prepared. This method provided a magnetic response for Bacm OxdC and enabled efficient demulsification. The demulsification rate of Fe3O4@SiO2@OxdC-DDSA reached 98.1% at 24 h, which was 30.7% higher than that of the original Bacm OxdC. After three cycles, the demulsification rate still reached 89.3%, proving it has excellent recyclability. This work is the first study on the demulsification mechanism of protein biodemulsifiers and provides useful insights into the demulsification mechanism of biodemulsifiers for oil-in-water emulsions. In addition, a promising high-efficiency modification technique for protein biodemulsifiers was proposed, which provided information for the development of biodemulsifiers for oil-water separation.
Collapse
Affiliation(s)
- Ning Hou
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China
| | - Xin Zhao
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China
| | - Ziyi Han
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China
| | - Xinxin Jiang
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China
| | - Yongping Fang
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China
| | - Yun Chen
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China
| | - Dapeng Li
- College of Resources and Environment, Northeast Agricultural University, No. 600 Changjiang Street, Harbin, Heilongjiang, 150030, PR China.
| |
Collapse
|
2
|
Dhandhi Y, Chaudhari RK, Naiya TK. Development in separation of oilfield emulsion toward green technology – A comprehensive review. SEP SCI TECHNOL 2021. [DOI: 10.1080/01496395.2021.1995427] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Yogesh Dhandhi
- Department of Petroleum Engineering, Indian Institute of Technology (ISM), Dhanbad, India
| | - Ronak Kumar Chaudhari
- Department of Petroleum Engineering, Indian Institute of Technology (ISM), Dhanbad, India
| | - Tarun Kumar Naiya
- Department of Petroleum Engineering, Indian Institute of Technology (ISM), Dhanbad, India
| |
Collapse
|
3
|
Sha D, Zheng R, Wang B, Xu J, Shi K, Yang X, Ji X. Superhydrophilic polyvinyl alcohol-formaldehyde composite sponges with hierachical pore structure for oil/water emulsion separation. REACT FUNCT POLYM 2021. [DOI: 10.1016/j.reactfunctpolym.2021.104975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
4
|
Hou N, Wang Q, Sun Y, Li X, Song Q, Jiang X, Li B, Zhao X, Zang H, Li D, Li C. A novel biodemulsifier of Bacillus mojavensis XH1 - Oxalate decarboxylase with the potential for demulsification of oilfield emulsion. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124737. [PMID: 33321372 DOI: 10.1016/j.jhazmat.2020.124737] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/25/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
In recent years, special attention has been devoted to biodemulsifiers as a new type of environment-friendly demulsifiers. A novel biodemulsifying oxalate decarboxylase (OxdC) secreted by Bacillus mojavensis XH1 is reported in the present study. A genome-wide comparison showed that strains with high demulsification efficiencies all possess alkane degradation genes. An analysis of the differentially expressed genes and proteins induced by different substrates showed that OxdC secreted by XH1 was an effective demulsifier. Moreover, the demulsification ability was verified by prokaryotic gene expression, knockout and complementation analyses. OxdC from XH1 exhibited a strong demulsification capacity and significantly outperformed the model protein Bacillus subtilis 168 OxdC (Yvrk), which shared a high amino acid similarity but showed limited demulsification ability. Based on a comparison of the structural characteristics, the hydrophobic amino acids on the surface of OxdC were identified as a key factor driving the favorable demulsification activity of XH1. The metabolic pathways of XH1 used liquid paraffin and glucose as substrates, illustrating that hydrocarbons are necessary for biodemulsifier secretion. The present study provides new insight into the application of OxdC as an additional genetic resource in biodemulsification.
Collapse
Affiliation(s)
- Ning Hou
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Qiaoruo Wang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Yang Sun
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Xianyue Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Qiuying Song
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Xinxin Jiang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Baoxin Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Xinyue Zhao
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Hailian Zang
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Dapeng Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
| | - Chunyan Li
- College of Resources and Environment, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China.
| |
Collapse
|
5
|
Onaizi SA. Demulsification of crude oil/water nanoemulsions stabilized by rhamnolipid biosurfactant using enzymes and pH-swing. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.118060] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
6
|
Sha D, Zheng R, Wang B, Shi K, Yang X, Liu X, Liu Z, Ji X. Three-dimensional superhydrophilic polyvinyl alcohol–formaldehyde composite sponges with suitable pore sizes for high efficiency emulsion separation. NEW J CHEM 2021. [DOI: 10.1039/d1nj02780h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PVA/PVF and PVA–COOH/PVF composite sponges with excellent emulsion separation performance.
Collapse
Affiliation(s)
- Di Sha
- University of Science and Technology of China, Hefei 230026, People's Republic of China
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Run Zheng
- University of Science and Technology of China, Hefei 230026, People's Republic of China
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Baolong Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Kai Shi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Xu Yang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Xue Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Zhi Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Xiangling Ji
- University of Science and Technology of China, Hefei 230026, People's Republic of China
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| |
Collapse
|
7
|
Corti-Monzón G, Nisenbaum M, Villegas-Plazas M, Junca H, Murialdo S. Enrichment and characterization of a bilge microbial consortium with oil in water-emulsions breaking ability for oily wastewater treatment. Biodegradation 2020; 31:57-72. [DOI: 10.1007/s10532-020-09894-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 03/05/2020] [Indexed: 01/09/2023]
|
8
|
Cai Q, Zhu Z, Chen B, Zhang B. Oil-in-water emulsion breaking marine bacteria for demulsifying oily wastewater. WATER RESEARCH 2019; 149:292-301. [PMID: 30465987 DOI: 10.1016/j.watres.2018.11.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/06/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Oily wastewater is a large waste stream produced by a number of industries. This wastewater often forms stable oil-in-water (O/W) emulsion. These emulsions require demulsification in order to effectively treat the water prior to release. Although biological demulsification of O/W emulsion has advantages over traditional approaches, its development is at a preliminary stage with few demulsifying bacteria reported and a need for effective screening methods for such bacteria. In this study, thirty-seven marine O/W emulsion demulsifying bacterial strains belonging to 5 genera and 15 species were reported. Cell hydrophobicity and interfacial activity played key roles in the emulsion breaking. One of the highly effective demulsifying bacteria, Halomonas venusta strain N3-2A was identified and characterized. Both its extracellular biosurfactant and cell surface contributed to demulsification resulting in breaking of 92.5% of the emulsion within 24 h. A high throughput and effective screening strategy targeting O/W emulsion breaking bacteria using oil spreading test coupled with cell hydrophobicity test was proposed. In addition, the 37 demulsifying bacteria showed a certain degree of species/genus specific patterns of surface activity and cell hydrophobicity. The reported bacteria and the screening strategy have promising potential for the biological demulsification of O/W emulsions and oily wastewater treatment.
Collapse
Affiliation(s)
- Qinhong Cai
- The Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X5, Canada
| | - Zhiwen Zhu
- The Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X5, Canada
| | - Bing Chen
- The Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X5, Canada
| | - Baiyu Zhang
- The Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X5, Canada.
| |
Collapse
|
9
|
Rocha e Silva FCP, Roque BAC, Rocha e Silva NMP, Rufino RD, Luna JM, Santos VA, Banat IM, Sarubbo LA. Yeasts and bacterial biosurfactants as demulsifiers for petroleum derivative in seawater emulsions. AMB Express 2017; 7:202. [PMID: 29143238 PMCID: PMC5688055 DOI: 10.1186/s13568-017-0499-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 10/26/2017] [Indexed: 11/10/2022] Open
Abstract
Oil sludge or waste generated in transport, storage or refining forms highly stable mixtures due to the presence and additives with surfactant properties and water forming complex emulsions. Thus, demulsification is necessary to separate this residual oil from the aqueous phase for oil processing and water treatment/disposal. Most used chemical demulsifiers, although effective, are environmental contaminants and do not meet the desired levels of biodegradation. We investigated the application of microbial biosurfactants as potential natural demulsifiers of petroleum derivatives in water emulsions. Biosurfactants crude extracts, produced by yeasts (Candida guilliermondii, Candida lipolytica and Candida sphaerica) and bacteria (Pseudomonas aeruginosa, Pseudomonas cepacia and Bacillus sp.) grown in industrial residues, were tested for demulsification capacity in their crude and pure forms. The best results obtained were for bacterial biosurfactants, which were able to recover about 65% of the seawater emulsified with motor oil compared to 35–40% only for yeasts products. Biosurfactants were also tested with oil-in-water (O/W) and water-in-oil (W/O) kerosene model emulsions. No relationship between interfacial tension, cell hydrophobicity and demulsification ratios was observed with all the biosurfactants tested. Microscopic illustrations of the emulsions in the presence of the biosurfactants showed the aspects of the emulsion and demulsification process. The results obtained demonstrate the potential of these agents as demulsifiers in marine environments.
Collapse
|
10
|
Vallejo-Cardona AA, Martínez-Palou R, Chávez-Gómez B, García-Caloca G, Guerra-Camacho J, Cerón-Camacho R, Reyes-Ávila J, Karamath JR, Aburto J. Demulsification of crude oil-in-water emulsions by means of fungal spores. PLoS One 2017; 12:e0170985. [PMID: 28234917 PMCID: PMC5325188 DOI: 10.1371/journal.pone.0170985] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 01/13/2017] [Indexed: 11/23/2022] Open
Abstract
The present feature describes for the first time the application of spores from Aspergillus sp. IMPMS7 to break out crude oil-in-water emulsions (O/W). The fungal spores were isolated from marine sediments polluted with petroleum hydrocarbons. The spores exhibited the ability to destabilize different O/W emulsions prepared with medium, heavy or extra-heavy Mexican crude oils with specific gravities between 10.1 and 21.2°API. The isolated fungal spores showed a high hydrophobic power of 89.3 ± 1.9% and with 2 g of spores per liter of emulsion, the half-life for emulsion destabilization was roughly 3.5 and 0.7 h for extra-heavy and medium crude oil, respectively. Then, the kinetics of water separation and the breaking of the O/W emulsion prepared with heavy oil through a spectrofluorometric technique were studied. A decrease in the fluorescence ratio at 339 and 326 nm (I339/I326) was observed in emulsions treated with spores, which is similar to previously reported results using chemical demulsifiers.
Collapse
Affiliation(s)
- Alba Adriana Vallejo-Cardona
- CONACYT-Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C., Av. Normalistas 800, Colinas de la Normal, C.P., Guadalajara, Jalisco, México
| | - Rafael Martínez-Palou
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - Benjamín Chávez-Gómez
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - Graciela García-Caloca
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - Jairo Guerra-Camacho
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - Ricardo Cerón-Camacho
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - Jesús Reyes-Ávila
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - James Robert Karamath
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
| | - Jorge Aburto
- Dirección de Investigación en Transformación de Hidrocarburos. Gerencia de Transformación de Biomasa. Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas Norte 152, CP, Mexico City, Mexico
- * E-mail:
| |
Collapse
|
11
|
Zhang Y, Liu J, Huang X, Lu L, Peng K. Chemically modified surface functional groups of Alcaligenes sp. S-XJ-1 to enhance its demulsifying capability. Appl Microbiol Biotechnol 2017; 101:3839-3848. [PMID: 28091790 DOI: 10.1007/s00253-017-8111-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 12/20/2016] [Accepted: 12/29/2016] [Indexed: 11/30/2022]
Abstract
Cell-surface functional groups (amino, carboxyl, hydroxyl, as well as phosphate) were chemically modified in various ways to enhance the demulsification capability of the demulsifying bacteria Alcaligenes sp. S-XJ-1. Results demonstrated that the demulsifying activity was significantly inhibited by amino enrichment with cetyl trimethyl ammonium bromide, amino methylation, hydroxyl acetylation, and phosphate esterification, but was gradually promoted by carboxyl blocking with increasing the extents of esterification. Compared with the raw biomass, an optimal esterification of carboxyl moieties enhanced the demulsification ratio by 26.5% and shortened the emulsion half-life from 24 to 8.8 h. The demulsification boost was found to be dominated by strengthened hydrophobicity (from 53° to 74°) and weakened electronegativity (from -34.6 to -4.3 mV at pH 7.0) of the cell surface, allowing the rapid dispersion and adsorption of cells onto the oil-water interface. The chemical modification of the functional groups on the biomass surface is a promising tool for the creation of a high-performance bacterial demulsifier.
Collapse
Affiliation(s)
- Yuyan Zhang
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education, Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, 200092, China
| | - Jia Liu
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education, Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, 200092, China
| | - Xiangfeng Huang
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education, Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, 200092, China
| | - Lijun Lu
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education, Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai, 200092, China
| | - Kaiming Peng
- Post-Doctoral Research Station, Tongji University, Shanghai, 200092, China.
| |
Collapse
|
12
|
Zolfaghari R, Fakhru’l-Razi A, Abdullah LC, Elnashaie SS, Pendashteh A. Demulsification techniques of water-in-oil and oil-in-water emulsions in petroleum industry. Sep Purif Technol 2016. [DOI: 10.1016/j.seppur.2016.06.026] [Citation(s) in RCA: 363] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
13
|
Mnif I, Ghribi D. Review lipopeptides biosurfactants: Mean classes and new insights for industrial, biomedical, and environmental applications. Biopolymers 2016; 104:129-47. [PMID: 25808118 DOI: 10.1002/bip.22630] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 01/09/2015] [Accepted: 02/23/2015] [Indexed: 11/10/2022]
Abstract
Lipopeptides are microbial surface active compounds produced by a wide variety of bacteria, fungi, and yeast. They are characterized by high structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface, respectively. Surfactin, iturin, and fengycin of Bacillus subtilis are among the most popular lipopeptides. Lipopepetides can be applied in diverse domains as food and cosmetic industries for their emulsification/de-emulsification capacity, dispersing, foaming, moisturizing, and dispersing properties. Also, they are qualified as viscosity reducers, hydrocarbon solubilizing and mobilizing agents, and metal sequestering candidates for application in environment and bioremediation. Moreover, their ability to form pores and destabilize biological membrane permits their use as antimicrobial, hemolytic, antiviral, antitumor, and insecticide agents. Furthermore, lipopeptides can act at the surface and can modulate enzymes activity permitting the enhancement of the activity of certain enzymes ameliorating microbial process or the inhibition of certain other enzymes permitting their use as antifungal agents. This article will present a detailed classification of lipopeptides biosurfactant along with their producing strain and biological activities and will discuss their functional properties and related applications.
Collapse
Affiliation(s)
- Inès Mnif
- Higher Institute of Biotechnology, Sfax, Tunisia.,Unit Enzymes and Bioconversion, National School of Engineers, Tunisia
| | - Dhouha Ghribi
- Higher Institute of Biotechnology, Sfax, Tunisia.,Unit Enzymes and Bioconversion, National School of Engineers, Tunisia
| |
Collapse
|
14
|
Luna JM, Rufino RD, Jara AMA, Brasileiro PP, Sarubbo LA. Environmental applications of the biosurfactant produced by Candida sphaerica cultivated in low-cost substrates. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2014.12.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
15
|
High molecular weight bioemulsifiers, main properties and potential environmental and biomedical applications. World J Microbiol Biotechnol 2015; 31:691-706. [PMID: 25739564 DOI: 10.1007/s11274-015-1830-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/22/2015] [Indexed: 12/31/2022]
Abstract
High molecular weight bioemulsifiers are amphipathic polysaccharides, proteins, lipopolysaccharides, lipoproteins, or complex mixtures of these biopolymers, produced by a wide variety of microorganisms. They are characterized by highly structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface respectively and/or emulsify hydrophobic compounds. Emulsan, fatty acids, phospholipids, neutral lipids, exopolysaccharides, vesicles and fimbriae are among the most popular high molecular weight bioemulsifiers. They have great physic-chemical properties like tolerance to extreme conditions of pH, temperature and salinity, low toxicity and biodegradability. Owing their emulsion forming and breaking capacities, solubilization, mobilization and dispersion activities and their viscosity reduction activity; they possess great environmental application as enhancer of hydrocarbon biodegradation and for microbial enhanced oil recovery. Besides, they are applied in biomedical fields for their antimicrobial and anti-adhesive activities and involvement in immune responses.
Collapse
|
16
|
Hou N, Feng F, Shi Y, Cao H, Li C, Cao Z, Cheng Y. Characterization of the extracellular biodemulsifiers secreted by Bacillus cereus LH-6 and the enhancement of demulsifying efficiency by optimizing the cultivation conditions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:10386-10398. [PMID: 24777330 DOI: 10.1007/s11356-014-2931-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/15/2014] [Indexed: 06/03/2023]
Abstract
A highly efficient demulsifying strain, LH-6, was isolated from petroleum-contaminated soil and identified as Bacillus cereus by 16S rDNA gene analysis. It achieved 95.61 and 95.40 % demulsifying ratios within 12 h for water-in-oil (W/O) and oil-in-water (O/W) model emulsions, respectively. Fourier transform infrared spectroscopy (FT-IR) and thin-layer chromatography (TLC) detections indicated that the LH-6's extracellular biodemulsifiers were different types of lipopeptides for the W/O and O/W emulsions. Optimization of the culture medium composition was conducted to improve the biosynthesis and demulsifying efficiency of the biodemulsifier. The optimal carbon source was liquid paraffin, while waste frying oil could also be an alternative carbon source. The optimal nitrogen sources were ammonium sulfate and yeast extract. To further enhance the biodemulsifier efficiency, the optimal cultivation conditions were determined using response surface methodology (RSM) based on central composite rotation design (CCRD). Using the optimized cultivation conditions, the demulsifying ratios increased to 98.23 and 97.65 % for the W/O and O/W model emulsions, respectively.
Collapse
Affiliation(s)
- Ning Hou
- College of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | | | | | | | | | | | | |
Collapse
|
17
|
Li G, Zhang H, Ma T. Electrochemical Studies on De-Emulsification: Effect of a Biosurfactant Produced by Bacillus subtilisMO-1. J DISPER SCI TECHNOL 2014. [DOI: 10.1080/01932691.2013.807738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
18
|
Huang X, Peng K, Lu L, Wang R, Liu J. Carbon source dependence of cell surface composition and demulsifying capability of Alcaligenes sp. S-XJ-1. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3056-3064. [PMID: 24476023 DOI: 10.1021/es404636j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Biodemulsifiers are environmentally friendly agents used in recycling oil or purifying water from emulsion, yet the demulsifying feature of cell-surface composition remains unclear. In this study, potentiometric titration, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry were combined to characterize cell-surface chemical composition of demulsifying strain Alcaligenes sp. S-XJ-1 cultivated with different carbon sources. Cells cultivated with alkane contained abundant elemental nitrogen and basic functional groups, indicating that their surface was rich in proteins or peptides, which contributed to their highest demulsifying efficiency. For cells cultivated with fatty acid ester, the relatively abundant surface lipid contributed to a 50% demulsification ratio owing to the presence of more acidic functional group. The cells cultivated with glucose exhibited a high oxygen concentration (O/C ∼0.28), which indicated the presence of more polysaccharides on the cell surface. This induced the lowest demulsification ratio of 30%. It can be concluded that cell surface-associated proteins or lipids other than the polysaccharide of the demulsifying strain played a positive role in the demulsification activity. In addition, the cell-surface oligoglutamate compounds identified in situ were crucial to the demulsifying capability.
Collapse
Affiliation(s)
- Xiangfeng Huang
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University , Shanghai 200092, People's Republic of China
| | | | | | | | | |
Collapse
|
19
|
Amirabadi S, Jahanmiri A, Rahimpour M, nia BR, Darvishi P, Niazi A. Investigation of Paenibacillus alvei ARN63 ability for biodemulsifier production: Medium optimization to break heavy crude oil emulsion. Colloids Surf B Biointerfaces 2013; 109:244-52. [DOI: 10.1016/j.colsurfb.2013.03.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Revised: 03/22/2013] [Accepted: 03/25/2013] [Indexed: 10/27/2022]
|
20
|
Huang X, Peng K, Feng Y, Liu J, Lu L. Separation and characterization of effective demulsifying substances from surface of Alcaligenes sp. S-XJ-1 and its application in water-in-kerosene emulsion. BIORESOURCE TECHNOLOGY 2013; 139:257-264. [PMID: 23665685 DOI: 10.1016/j.biortech.2013.04.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 04/11/2013] [Accepted: 04/11/2013] [Indexed: 06/02/2023]
Abstract
The main goal of this work was to analyze the effect of surface substances on demulsifying capability of the demulsifying strain Alcaligenes sp. S-XJ-1. The demulsifying substances were successfully separated from the cell surface with dichloromethane-alkali treatment, and exhibited 67.5% of the demulsification ratio for water-in-kerosene emulsions at a dosage of 356mg/L. FT-IR, TLC and ESI-MS analysis confirmed the presence of a carbohydrate-protein-lipid complex in the demulsifying substances with the major molecular ions from mass-to-charge ratio (m/z) 165 to 814. After the substances separated, the cell morphology changed from aggregated to dispersed, and the concentration of cell surface functional groups decreased. Cell surface hydrophobicity and the ability of cell adhesion to hydrophobic surface of the treated cells was also reduced compared with original cell. It was proved that the demulsifying substances had a significant effect on cell surface properties and accordingly with demulsifying capability of Alcaligenes sp. S-XJ-1.
Collapse
Affiliation(s)
- Xiangfeng Huang
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China
| | | | | | | | | |
Collapse
|
21
|
Coutinho JOPA, Silva MPS, Moraes PM, Monteiro AS, Barcelos JCC, Siqueira EP, Santos VL. Demulsifying properties of extracellular products and cells of Pseudomonas aeruginosa MSJ isolated from petroleum-contaminated soil. BIORESOURCE TECHNOLOGY 2013; 128:646-654. [PMID: 23220111 DOI: 10.1016/j.biortech.2012.09.137] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 08/02/2012] [Accepted: 09/11/2012] [Indexed: 06/01/2023]
Abstract
A strain of Pseudomonas aeruginosa isolated from a site contaminated with refined oil products exhibited demulsification capabilities against Tween 80-Span 80 stabilized oil-in-water (O/W), Tween 80-stabilized water-in-oil (W/O) model emulsions (kerosene-water), and an industrial emulsion (Daido Dairoll PA-5A). GC-MS analysis confirmed the presence of fatty acids and carbohydrates in the extracellular biodemulsifier. The demulsifying activity of cells and culture supernatants was favored by growth in media containing 1% diesel oil. There was a correlation between culture age, de-emulsification and cellular hydrophobicity, and highest activities were observed for cells and supernatants from 96-h cultures. Activity increased with addition of up to 60 mg cells or 300 μL supernatant to emulsions. The activity was relatively stable at 20-40 °C and to freezing, but was reduced by 69% by washing the cells with chloroform-methanol-water. This demulsifier has potential for application in biotreatment of emulsified oily wastewaters to promote recovery and/or degradation of oil.
Collapse
Affiliation(s)
- J O P A Coutinho
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP 486, 31270-901 Belo Horizonte, MG, Brazil
| | | | | | | | | | | | | |
Collapse
|
22
|
Efficient breaking of water/oil emulsions by a newly isolated de-emulsifying bacterium, Ochrobactrum anthropi strain RIPI5-1. Colloids Surf B Biointerfaces 2012; 98:120-8. [DOI: 10.1016/j.colsurfb.2012.04.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Revised: 04/16/2012] [Accepted: 04/23/2012] [Indexed: 11/23/2022]
|
23
|
Potential applications of bioprocess technology in petroleum industry. Biodegradation 2012; 23:865-80. [DOI: 10.1007/s10532-012-9577-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/17/2012] [Indexed: 11/25/2022]
|
24
|
Li X, Li A, Liu C, Yang J, Ma F, Hou N, Xu Y, Ren N. Characterization of the extracellular biodemulsifier of Bacillus mojavensis XH1 and the enhancement of demulsifying efficiency by optimization of the production medium composition. Process Biochem 2012. [DOI: 10.1016/j.procbio.2012.01.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
25
|
Liu J, Lu LJ, Huang XF, Shang JJ, Li MX, Xu JC, Deng HP. Relationship between surface physicochemical properties and its demulsifying ability of an alkaliphilic strain of Alcaligenes sp. S-XJ-1. Process Biochem 2011. [DOI: 10.1016/j.procbio.2011.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
26
|
Liu J, Peng K, Huang X, Lu L, Cheng H, Yang D, Zhou Q, Deng H. Application of waste frying oils in the biosynthesis of biodemulsifier by a demulsifying strain Alcaligenes sp. S-XJ-1. J Environ Sci (China) 2011; 23:1020-1026. [PMID: 22066226 DOI: 10.1016/s1001-0742(10)60508-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Exploration of biodemulsifiers has become a new research aspect. Using waste frying oils (WFOs) as carbon source to synthesize biodemulsifiers has a potential prospect to decrease production cost and to improve the application of biodemulsifiers in the oilfield. In this study, a demulsifying strain, Alcaligenes sp. S-XJ-1, was investigated to synthesize a biodemulsifier using waste frying oils as carbon source. It was found that the increase of initial pH of culture medium could increase the biodemulsifier yield but decrease the demulsification ratio compared to that using paraffin as carbon source. In addition, a biodemulsifier produced by waste frying oils and paraffin as mixed carbon source had a lower demulsification capability compared with that produced by paraffin or waste frying oil as sole carbon source. Fed-batch fermentation of biodemulsifier using waste frying oils as supplementary carbon source was found to be a suitable method. Mechanism of waste frying oils utilization was studied by using tripalmitin, olein and tristearin as sole carbon sources to synthesize biodemulsifier. The results showed saturated long-chain fatty acid was difficult for S-XJ-1 to utilize but could effectively enhance the demulsification ability of the produced biodemulsifier. Moreover, FT-IR result showed that the demulsification capability of biodemulsifiers was associated with the content of C=O group and nitrogen element.
Collapse
Affiliation(s)
- Jia Liu
- Tongji University, Shanghai 200092, China.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Liu J, Huang XF, Lu LJ, Xu JC, Wen Y, Yang DH, Zhou Q. Optimization of biodemulsifier production from Alcaligenes sp. S-XJ-1 and its application in breaking crude oil emulsion. JOURNAL OF HAZARDOUS MATERIALS 2010; 183:466-473. [PMID: 20702035 DOI: 10.1016/j.jhazmat.2010.07.047] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 06/04/2010] [Accepted: 07/14/2010] [Indexed: 05/29/2023]
Abstract
A biodemulsifier-producing strain of Alcaligenes sp. S-XJ-1, isolated from petroleum-contaminated soil of the Karamay Oilfield, exhibited excellent demulsifying ability. The application of this biodemulsifier significantly improved the quality of separated water compared with the chemical demulsifier, polyether, which clearly indicates that it has potential applications in the crude oil extraction industry. To optimize its biosynthesis, the impacts of carbon sources, nitrogen sources and pH were studied in detail. Paraffin, a hydrophobic carbon source, favored the synthesis of this cell wall associated biodemulsifier. The nitrogen source ammonium citrate stimulated the production and demulsifying performance of the biodemulsifier. An alkaline environment (pH 9.5) of the initial culture medium favored the strain's growth and improved its demulsifying ability. The results showed paraffin, ammonium citrate and pH had significant effects on the production of the biodemulsifier. These three variables were further investigated using a response surface methodology based on a central composite design to optimize the biodemulsifier yield. The optimal yield conditions were found at a paraffin concentration of 4.01%, an ammonium citrate concentration of 8.08 g/L and a pH of 9.35. Under optimal conditions, the biodemulsifier yield from Alcaligenes sp. S-XJ-1 was increased to 3.42 g/L.
Collapse
Affiliation(s)
- Jia Liu
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | | | | | | | | | | | | |
Collapse
|
28
|
Microbial biosurfactants and biodegradation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 672:65-74. [PMID: 20545274 DOI: 10.1007/978-1-4419-5979-9_5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microbial biosurfactants are amphipathic molecules having typical molecular weights of 500-1500 Da, made up of peptides, saccharides or lipids or their combinations. In biodegradation processes they mediate solubilisation, mobilization and/or accession of hydrophobic substrates to microbes. They may be located on the cell surface or be secreted into the extracellular medium and they facilitate uptake of hydrophobic molecules through direct cellular contact with hydrophobic solids or droplets or through micellarisation. They are also involved in cell physiological processes such as biofilm formation and detachment, and in diverse biofilm associated processes such as wastewater treatment and microbial pathogenesis. The protection of contaminants in biosurfactants micelles may also inhibit uptake of contaminants by microbes. In bioremediation processes biosurfactants may facilitate release of contaminants from soil, but soils also tend to bind surfactants strongly which makes their role in contaminant desorption more complex. A greater understanding of the underlying roles played by biosurfactants in microbial physiology and in biodegradative processes is developing through advances in cell and molecular biology.
Collapse
|
29
|
Liu J, Huang XF, Lu LJ, Xu JC, Wen Y, Yang DH, Zhou Q. Comparison between waste frying oil and paraffin as carbon source in the production of biodemulsifier by Dietzia sp. S-JS-1. BIORESOURCE TECHNOLOGY 2009; 100:6481-6487. [PMID: 19643603 DOI: 10.1016/j.biortech.2009.07.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 07/05/2009] [Accepted: 07/06/2009] [Indexed: 05/28/2023]
Abstract
In order to lower the production cost, waste frying oils were used in the biosynthesis of demulsifier by Dietzia sp. S-JS-1, which was isolated from petroleum contaminated soil. After 7 days of cultivation, the biomass concentration of the most suitable waste frying oil (WFO II) culture reached 3.78 g/L, which was 2.4 times the concentration of paraffin culture. The biodemulsifier produced with WFO II culture broke the emulsions more efficiently than that produced with paraffin culture, given the same volume ratio of carbon source in the culture medium and the same cultivation conditions. It achieved 88.3% of oil separation ratio in W/O emulsion and 76.4% of water separation ratio in O/W emulsion within 5 h. With the aid of thin layer chromatography (TLC) and Fourier transform infrared (FTIR) spectrometry, biodemulsifiers produced from both paraffin and WFO II were identified as a mixture of lipopeptide homologues. The subtle variation in the distribution of these homologues and high biomass concentration of WFO II cultures may account for the afore-mentioned good demulsification performance.
Collapse
Affiliation(s)
- Jia Liu
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, 200092, China
| | | | | | | | | | | | | |
Collapse
|
30
|
Huang XF, Liu J, Lu LJ, Wen Y, Xu JC, Yang DH, Zhou Q. Evaluation of screening methods for demulsifying bacteria and characterization of lipopeptide bio-demulsifier produced by Alcaligenes sp. BIORESOURCE TECHNOLOGY 2009; 100:1358-1365. [PMID: 18799309 DOI: 10.1016/j.biortech.2008.08.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 08/04/2008] [Accepted: 08/05/2008] [Indexed: 05/26/2023]
Abstract
In this paper, surface tension measurement, oil-spreading test and blood-plate hemolysis test were attempted in the screening of demulsifying bacteria. After the comparison to the screening results obtained in demulsification test, 50 mN/m of surface tension of culture was proposed as a preliminary screening standard for potential demulsifying bacteria. For the identification of efficient demulsifying strains, surface tension level was set at 40 mN/m. The detected strains were further verified in demulsification test. Compared to using demulsification test alone as screening method, the proposed screening protocol would be more efficient. From the screening, a highly efficient demulsifying stain, S-XJ-1, was isolated from petroleum-contaminated soil and identified as Alcaligenes sp. by 16S rRNA gene and physiological test. It achieved 96.5% and 49.8% of emulsion breaking ratio in W/O and O/W kerosene emulsion within 24h, respectively, and also showed 95% of water separation ratio in oilfield petroleum emulsion within 2h. The bio-demulsifier was found to be cell-wall combined. After soxhlet extraction and purification through silicon-gel column, the bio-demulsifier was then identified as lipopeptide biosurfactant by TLC and FT-IR.
Collapse
Affiliation(s)
- Xiang-Feng Huang
- College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.
| | | | | | | | | | | | | |
Collapse
|
31
|
Singh A, Van Hamme JD, Ward OP. Surfactants in microbiology and biotechnology: Part 2. Application aspects. Biotechnol Adv 2006; 25:99-121. [PMID: 17156965 DOI: 10.1016/j.biotechadv.2006.10.004] [Citation(s) in RCA: 336] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 10/25/2006] [Accepted: 10/25/2006] [Indexed: 10/24/2022]
Abstract
Surfactants are amphiphilic compounds which can reduce surface and interfacial tensions by accumulating at the interface of immiscible fluids and increase the solubility, mobility, bioavailability and subsequent biodegradation of hydrophobic or insoluble organic compounds. Chemically synthesized surfactants are commonly used in the petroleum, food and pharmaceutical industries as emulsifiers and wetting agents. Biosurfactants produced by some microorganisms are becoming important biotechnology products for industrial and medical applications due to their specific modes of action, low toxicity, relative ease of preparation and widespread applicability. They can be used as emulsifiers, de-emulsifiers, wetting and foaming agents, functional food ingredients and as detergents in petroleum, petrochemicals, environmental management, agrochemicals, foods and beverages, cosmetics and pharmaceuticals, and in the mining and metallurgical industries. Addition of a surfactant of chemical or biological origin accelerates or sometimes inhibits the bioremediation of pollutants. Surfactants also play an important role in enhanced oil recovery by increasing the apparent solubility of petroleum components and effectively reducing the interfacial tensions of oil and water in situ. However, the effects of surfactants on bioremediation cannot be predicted in the absence of empirical evidence because surfactants sometimes stimulate bioremediation and sometimes inhibit it. For medical applications, biosurfactants are useful as antimicrobial agents and immunomodulatory molecules. Beneficial applications of chemical surfactants and biosurfactants in various industries are discussed in this review.
Collapse
Affiliation(s)
- Ajay Singh
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | | | | |
Collapse
|
32
|
|
33
|
Abstract
Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times (<60 s) are being used effectively. Microbes are being injected into partially spent petroleum reservoirs to enhance oil recovery. However, these microbial processes have not exhibited consistent and effective performance, primarily because of our inability to control conditions in the subsurface environment. Microbes may be exploited to break stable oilfield emulsions to produce pipeline quality oil. There is interest in replacing physical oil desulfurization processes with biodesulfurization methods through promotion of selective sulfur removal without degradation of associated carbon moieties. However, since microbes require an environment containing some water, a two-phase oil-water system must be established to optimize contact between the microbes and the hydrocarbon, and such an emulsion is not easily created with viscous crude oil. This challenge may be circumvented by application of the technology to more refined gasoline and diesel substrates, where aqueous-hydrocarbon emulsions are more easily generated. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H(2)S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments.
Collapse
Affiliation(s)
- Jonathan D Van Hamme
- Department of Biological Sciences, The University College of the Cariboo, Kamloops, British Columbia V2C 5N3
| | | | | |
Collapse
|
34
|
|