Rhamnolipids have been the subject of substantial research. This listing is to give an overview of references on the research. The list is organized by basic application as well as pointers to general references to rhamnolipids andPseudomonas aeruginosa and other rhamnolipid producing bacteria.

Some references include short abstracts or key findings and/or links from which the full paper can be retrieved.

Microbiology and Pseudomonas aeruginosa

There is a chapter devoted to P. Aeruginosa in Todar’s Online Textbook of Bacteriology. A search on “aeruginosa” brings up over 30 pages of information.

Pseudomonas and Nonfermenters [PPT] Lecture notes about attributes of Pseudomonas and similar bacteria and the infections they cause from the UMD course BSCI 424 Pathogenic Microbiology.

Complete genome sequence of Pseudomonas aeruginosa PA01, an opportunistic pathogen. Nature. 2000 Aug 31;406(6799):959-64. The complete sequence of P. aeruginosa strain PAO1 with its 6.3 million base pairs. the sequence provides insights into the basis of the versatility and intrinsic drug resistance of P. aeruginosa. Consistent with its larger genome size and environmental adaptability, P. aeruginosa contains the highest proportion of regulatory genes observed for a bacterial genome and a large number of genes involved in the catabolism, transport and efflux of organic compounds.

The Pseudomonas Genome Database – sponsored by the Cystic Foundation Therapeutics Inc.

Anaerobic Survival of Pseudomonas aeruginosa by Pyruvate Fermentation Requires an Usp-Type Stress Protein Journal of Bacteriology, January 2006, p. 659-668, Vol. 188, No. 2 Anaerobic long-term survival of P. aeruginosamight be essential for survival in deeper layers of a biofilm and the persistent infection of anaerobic mucus plaques in the cystic fibrosis lung.

Basic Rhamnolipid Discovery and Analysis

Bacterial Lipids – Kates M. – Advanced Lipid Research 2:17-90, 1964 A review of prior research on lipids produced by bacteria and an attempt to group bacteria based on those lipids.

Bacterial Glycolipids – Shaw N – Bacteriological Review. 1970 December; 34(4): 365–377. A summary of the sources and structure of various known glycolipids including rhamnolipids.

Characterization of Rhamnolipid Produced by Pseudomonas aeruginosaIsolate Bs20 – AM Abdel-Mawgoud MM Aboulwafa NAH Hassouna – Journal Applied Biochemistry and Biotechnology June 2008

Surfactant Theory
The Orientation of Molecules in the Surfaces of Liquids, the Energy Relations at Surfaces, Solubility, Adsorbtion, and the Effect of Acids and Bases on Interfacial Tension WD Harkins ECH Davies GL Clark – J Am Chem Soc – 1917, 39, 541-596

A quantitative kinetic theory of emulsion type, I. Physical chemistry of the emulsifying agent – Gas/Liquid and Liquid/Liquid Interface. – Davies JT – Proceedings of the International Congress of Surface Activity (1957): 426-438 – a discussion on the behavior of emulsifiers and a proposal on how to calculate HLB – the hydrophilic-lipophilic balance.

Binary and Multicomponent Solutions of Amphiphilic Compounds. Solubization and the Formation, Structure, and Theoretical Significance of Liquid Crystalline Solutions – PA Winsor – Chemical Reviews V68, N1, Jan 1968. – a discussion of amphiphilic compounds, solubilization, micelles considering thermodynamics and the various micellular structures.

Rhamnolipid Production

Rhamnolipid production by Pseudomonas aeruginosa under denitrification: effects of limiting nutrients and carbon substrates. Chayabutra, C; Wu, J; Ju, LK, Biotechnology-Bioengineering. 2001 Jan 5; 72(1): 25-33 – Being biosurfactants, rhamnolipids create severe foaming when produced in aerobicPseudomonas aeruginosa fermentation. The necessary reduction of aeration causes oxygen limitation and restricts cell and product concentrations.

US Patent 7202063 – Processes for the production of rhamnolipids – producing rhamnolipids involving culturing Pseudomonas chlororaphis strain NRRL B-30761 USDA This is from a study in the production of rhamnolipids using a bacteria that is not considered a pathogen.

Production of rhamnolipids by Pseudomonas aeruginosa – G Soberon-Chavez F Lepine E Deziel – Applied Microbiological Biotechnology – 2005 V68 7i8-725 – a discussion of the chemical processes used by P. aeruginosato produce rhamnolipids.

Environmental importance of rhamnolipid production from molasses as a carbon source – H. Rashedi, M. Mazaheri Assadi, B. Bonakdarpour, E. Jamshidi International Journal of Environmental Science and Technology, Vol. 2, No. 1, Spring, 2005, pp. 59-62 – This study used molasses which is a waste product from sugar industry as carbon source to produce rhamnolipid. The yield of rhamnolipid per biomass with 2%, 4%, 6%, 8% and 10% molasses are 0.003, 0.009, 0.053, 0.041 and 0.213 respectively. The production of rhamnolipid (0.0531 g. rhamnolipid/g biomass) is higher compared to the culture grown in aerobic conditions (0.04 g. rhamnolipid/g biomass).

Pseudomonas Strains as Source of Microbial Surface-Active Molecules – S Bhattacharyya et al – Journal of Oleo Science Vol. 52 (2003) , No. 4 221-224 – Two new strains of Pseudomonas putida are isolated and their lipids extracted which are long chain polyunsaturated fatty acids producing surface tensions in the range of 32-40 mN/m.

Microbial production of surfactants and their commercial potential. – J D Desai and I M Banat – Microbiology and Molecular Biology Reviews. 1997 March; 61(1): 47–64

Fermentative production of a glycolipid biosurfactant-rhamnolipid – Kuei-Ling Yeh – 2007-07-05 – Masters Thesis – This paper is an analysis of the rhamnolipids produced by a P. aeruginosa EM1 isolated a oil contaminated site and methodology to increase rhamnolipid production.

Pilot Plant Production of Rhamnolipid Biosurfactant by Pseudomonas aeruginosa – HE Reiling, U Thanei-Wyss, LH Guerra-Santos, R Hirt, O Kappelli, A Feichter – Applied and Environmental Microbiology – May 1986, Vol. 51, No. 5, p. 985-989

Rhamnolipid biosurfactants produced by Renibacterium salmoninarum27BN – N Christova B Tuleva Z Lalchev A Jordanova B Jordanov – Bulgaria Naturforsch, 59c, 70-74 (2004)

Pseudomonas aeruginosa rhamnolipids: biosynthesis and potential applications – RM Maier G Soberón-Chávez – Applied Microbiol Biotechnology. 2000 Nov 54(5):625-33

References on microbiology and Pseudomonas aeruginosa

Text Book of Bacteriology Chapter on Pseudomonas

Pseudomonas Genome Database

Rhamnolipid Pharmacology

Di-rhamnolipid from Pseudomonas aeruginosa displays differential effects on human keratinocyte and fibroblast cultures. T Stipcevic T Piljac RR. Isseroff – Journal of Dermatological Science 2005 November; 40(2): 141–143.

Production and properties of heat-stable extracellular hemolysin fromPseudomonas aeruginosa – MK Johnson D Boese-Marazzo – Infections and Immunology 1980;29:1028–1033

US Patent 5466675 – Immunological activity of rhamnolipids – G Piljac V Piljac

US Patent 5455232 – Pharmaceutical preparation based on rhamnolipid G Piljac V Piljac – European Patent EP0630252 – Pharmaceutical Preparation Based On Rhamnolipid Against Dermatological Diseases

BioSurfactant References

Types, Production and Application of Biosurfactants – CN Mulligan, BF Gibbs – Proc. Indian National Science Academy. B70 No. 1 pp 31-55 (2004) – an overview of biosurfactant uses, attributes, and production.

Effect of Rhamnolipid (Biosurfactant) Structure on Solubilization and Biodegradation of n-Alkanes – Y Zhang RM Miller – Applied and Environmental Microbiology – June 1995 p. 2247-2251 – This study quantifies the rhamnolipids biosurfactant structure on alkanes.

High- and low-molecular-mass microbial surfactants – Rosenberg E, Ron EZ – Applied Microbiology and Biotechnology 1999 Aug;52(2):154-62.- Microorganisms synthesize a wide variety of high- and low-molecular-mass bioemulsifiers which are analyzed for their potential use.

Bioremediation References
Effectiveness of bioremediation for the Exxon Valdez oil spill – JR Bragg RC Prince EJ Harner RM. Atlas – Nature 368, 413 – 418 (31 March 1994)

Using Oil Spill Dispersants on the Sea, Committee on Effectiveness of Oil Spill Dispersants, Marine Board, Commission on Engineering and Technical Systems, National Research Council, National Academy Press, Washington, D.C. 1989

A Rhamnolipid Biosurfactant Reduces Cadmium Toxicity during Naphthalene Biodegradation – Todd R. Sandrin, Andrea M. Chech, and Raina M. Maier – Applied and Environmental Microbiology. 2000 October; 66(10): 4585–4588

Lipid Biotechnology by Tsung Min Kuo, Harold W. Gardner, CRC press 2002 – pg647

Stability constants for the complexation of various metals with a rhamnolipid biosurfactant, FJ Ochoa-Loza JF Artiola RM Maier – Journal of environmental quality, 2001, vol. 30, no2, pp. 479-485 – This analysis indicates that rhamnolipids are very effective for removing metal pollutants..

Effect of clays, metal oxides, and organic matter on rhamnolipid biosurfactant sorption by soil – FJ Ochoa-Loza WH Noordman DB Jannsen ML Brusseau RM Maier – Chemosphere, 2007, vol. 66, no9, pp. 1634-1642

Fertilizer Facilitation

Root Uptake of Lipophilic Zinc-Rhamnolipid Complexes – SP Stacey MJ Mclaughlin I Cakmak GM Hettiarachchi KG Scheckel M Karkkainen – Journal of agricultural and food chemistry, 2008, vol. 56, no6, pp. 2112-2117 – In a calcareous soil, rhamnolipids increased dry matter production and Zn concentrations in Wheat.

Enhanced Oil Recovery

Some Physicochemical Aspects of Microemulsion Flooding: A Review – RL Reed, RN Healy – Improved Oil Recovery by Surfactant and Polymer Flooding – 1977 – An overview of using surfactants in emulsifying oil reserves.

The fundamental basis for the action of a chemical dehydrant. Influence of the physical and chemical formation on the stability of an emulsion. – JL Salager – International Chemical Engineering 1990 30 103-116 – A discussion of how to remove water and surfactants after secondary oil recovery.

The stability of O/W Type Emulsions as Functions of Temperature and the HLB of Emulsifiers: The Emulsification by PIT – methods – K Shinoda H Saito – J. of Colloid and Interface Science Vol 30, No. 2, June 1969, 258-263

The Comparison of the PIT system and the HLB-value system to emulsifier selection – K Shinoda – Proc. of 5th Int. Cong. of Surface Activity – V2, 275-283 1969.

Emulsion Optimization by use of the Phase Inversion Temperature (PIT) – Zenitech – A Lecture on the use of Phase Inversion Temperature

The Correlation between Phase Inversion Temperature In Emulsion and Cloud Point in Solution of Nonionic Emulsifier – K Shinoda H Arai – J. of Physical Chemistry V68, N12 3485-3490 Dec 1964 – The longer the hydrophilic chain, the higher the cloud point and/or phase inversion temperature.

The HLB System – a time-saving guide to emulsifier selection – ICI America

Engineering bacteria for production of rhamnolipid as an agent for enhanced oil recovery Qinhong Wang et al, Biotechnology and Bioengineering. 2007; 98: 842-853. Genetic Engineering to produce rhamnolipids for EOR.

Recent Advances in Petroleum Microbiology – Jonathan D. Van Hamme, Ajay Singh, and Owen P. Ward – Microbiol Mol Biol Rev. 2003 December; 67(4): 503–549 – Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons.

Biological References

“Di-rhamnolipid from Pseudomonas aeruginosa displays differential effects on human keratinocyte and fibroblast cultures“. ST, Piljac RR Isseroff – Journal of Dermatological. Science – Nov 2005 – V40 (2): 141–3.

Rhamnolipid Surfactant Production Affects Biofilm Architecture inPseudomonas aeruginosa PAO1 – ME Davey NC Caiazza GA O’Toole – Journal of Bacteriology. 2003 February; 185(3): 1027–1036

Rhamnolipids Are Virulence Factors That Promote Early Infiltration of Primary Human Airway Epithelia by Pseudomonas aeruginosa – Laurence Zulianello et al – Infection and Immunity. 2006 June; 74(6): 3134–3147

US Patent 5514661 – Immunological activity of rhamnolipids – Goran Piljac et al

US Patent 5455232 – Pharmaceutical preparation based on rhamnolipid – Goran Piljac et al

Rhamnolipids mediate detachment of Pseudomonas aeruginosa from biofilms – BR Boles M Thoendel PK Singh – Molecular Microbiology Jul 2005 V57 I5, 1210 – 1223 – Research how rhamnolipids help bacteria leave biofilms to enter a planktonic state.

Rhamnolipids Modulate Swarming Motility Patterns of Pseudomonas aeruginosa – NC Caiazza, RMQ Shanks, GA O’Toole – Journal of Bacteriology, November 2005, p. 7351-7361, Vol. 187, No. 21