At present, it is widely used in petroleum industry, green agriculture and ecological environment, and also has great application potential in food industry, cosmetics and medical care. Rhamnolipid, as a biosurfactant, can reduce the interfacial tension between oil and water. Used in tertiary oil recovery technology after primary oil recovery and secondary oil recovery, its main action principle is as follows:
(1) is used as a sacrificial agent to reduce the amount of expensive oil displacement agent or the loss in the formation. After compounding with other oil displacement agents, the oil displacement effect is good and the action time is long, but the addition of rhamnolipid effectively reduces the amount of oil displacement agent and greatly reduces the cost.
(2) Biosurfactants have typical biological activity, which can activate indigenous microorganisms in the formation and play a role in collaborative oil recovery. It is found in the field test water samples of oil field that the bacterial content in oil well water samples has increased by 2-3 orders of magnitude after 6 months of injection.
(3) Rhamnolipid, as an active agent, is itself a surfactant, which can reduce the interfacial tension between oil and water. After compounding, the interfacial tension between oil and water can reach 10-3mN/m, thus improving the oil displacement efficiency. A large number of studies and practical applications have proved that rhamnolipid can be used in crops, vegetables, fruits and flowers to stimulate growth, assist nutrient absorption and increase the effects of pesticides and fertilizers, and it has been proved that it has no toxic and side effects on people and animals.
Rhamnolipid biosurfactant can be used as wetting agent in the production of foliar fertilizer. Because the leaves of many plants are covered with a layer of wax, the surface of the leaves becomes a protective surface. Rhamnolipid biosurfactant can be used as wetting agent and added to foliar fertilizer. Hydrophobic groups are adsorbed on the surface of the wax layer through dispersion force, and hydrophilic groups extend into the fertilizer solution, forming a directional adsorption film to replace the hydrophobic wax layer, improving the wetting condition of foliar fertilizer in the wax layer, fully spreading the fertilizer, and promoting the maximum absorption and utilization of fertilizer nutrients.
Rhamnolipid biosurfactant has the function of chelating some trace elements, and the ionized carboxyl group can fix trace elements around the root system in weak alkaline environment, which reduces the possibility of rapid loss of trace elements in soil and ensures the long-term effect of fertilizer. Root absorption of lipophilic zinc # rhamnolipid complex, J. Agric. Food Chemistry. 2008, 56, 2 1 12–2 1 17)
It can effectively improve the alkaline soil environment and is a good additive for improving alkaline soil. Using the property that Rh ionizes Rh- and H+ under alkaline conditions, it neutralizes with OH- in alkaline soil, thus improving the alkalinity of soil, thus changing the environmental conditions of soil hardening.
Rhamnolipid has the function of wetting agent and good surface activity, so it can be applied to the wetting, spreading and penetration of pesticides. In addition, rhamnolipid has the ability to degrade some pesticide residues.
In addition, rhamnolipid has a good inhibitory effect on fungi (mentioned many times in the published literature), and it has been proved to be used in the experiments of dressing crops and inhibiting fungi and molds.
The application of rhamnolipid in agriculture is quite common abroad, and the New York State Environmental Protection Bureau has passed the registration test of biological drugs containing rhamnolipid. (EPA, registration number 7243 1- 1) Rhamnolipid can be used to treat polycyclic aromatic hydrocarbons (PAHs), such as polycyclic aromatic hydrocarbons released by the oil spill in the Gulf of Mexico, refractory COD in water, heavy metal pollution and so on.
Rhamnolipid can repair environmental pollution caused by human beings, including oil, metal or other pollutants in soil, water, coastline and seabed. Rhamnolipid has a certain metal chelating ability ("Stability Constant of Complexation of Various Metals with Rhamnolipid Biosurfactant", J. Environ. Qual。 , Vol. 30, March–April 2001), which can be used as a chelating agent to remove heavy metal pollutants from soil, sewage and other liquids. It can also be used to treat soil by absorbing heavy metal ions in soil by plant method, which is a good method to treat heavy metal contaminated soil in situ by plant technology.
Rhamnolipid and its producer Pseudomonas aeruginosa can repair the soil or water pollution caused by pesticides or highly toxic pesticides. According to the data ("Effect of rhamnolipid potential on biodegradation of endosulfan by Pseudomonas aeruginosa in batch study." Arun Kumarmani, J BIOS Citech, Vol.2 (3), 20 1 1, 268-278) showed that rhamnolipid could promote Pseudomonas aeruginosa to degrade endosulfan, thus repairing highly toxic polluted soil or water.
Rhamnolipid, as a biosurfactant, is non-toxic and amphiphilic. When the concentration increases to the critical concentration, it will obviously compatibilize polycyclic aromatic hydrocarbons. It can elute PCBs, change the HLB of PCBs, and make them easily absorbed and degraded by Pseudomonas. Preparation of Rhamnolipid and Its Application in Remediation of PCB Contaminated Soil, Ma, Ph.D. Thesis of Hunan University) Rhamnolipid not only has good surface activity, but also has good cell permeability. Derived from biology, it has good non-toxic and degradable characteristics. These characteristics make it widely used in various daily chemical products.
Surfactants are widely used in cosmetics industry, which are found in almost every product. Different products containing surfactants include anti-dandruff products, skin cream, hair dye, shampoo and conditioner, toothpaste, mascara, nail polish, lipstick, antiperspirant, baby products, shaving cream, humectant, soap, eye shadow, wet wipes and perfume. SLES (dodecyl ether sulfate) and SLS (dodecyl sulfate) are the most commonly used.
The regulator accused SLES of containing carcinogen 1.4- dioxane. 1.4- dioxane is a by-product of SLES production and cannot be completely removed from SLES products. SLS has been proved to be irritating to the skin at high concentration. Although traditional SLS products come from coconut oil or palm oil, some SLS are made from petroleum and petroleum by-products. Rhamnolipid is a natural product, which will replace petroleum surfactants and emulsifiers, such as SLS, SDS or NADS, in moisturizers, shampoos, soaps and most cosmetics listed above.
Rhamnolipid can diffuse substances through dispersion and wetting properties. Helps keep moisture, lubricate and foam, as a cleaner. It can keep the system of the mixture stable, control the viscosity of the product, emulsify the oil in the pores and reduce the occurrence of acne. Rhamnolipid can be used to treat skin burns and some skin diseases, and can also be used as a basic medicine. Relevant research and clinical evidence come from Croatia and the United States:
In the 1990s, researchers from Yugoslavia Institute accidentally discovered that rhamnolipid and Pseudomonas aeruginosa had a good effect on skin burns, and people began to study the application of rhamnolipid in medicine. ("using dirhamnolipid Tamara Stipcevic to enhance the healing of full-thickness burn wounds", Ante Piljac and Goran Piljac Taj Co., Inc., 2323 Shasta Drive # 40, Davis, CA 956 16, USA) comprehensively expounded the role of rhamnolipid in treating skin burns, and gained valuable clinical application experience.
In addition, Piljac et al. in the United States applied for and obtained the patent of "Pharmaceutical Preparation Based on Rhamnolipid" on June 3rd (US5455232), which further promoted the application research of Rhamnolipid in medicine.