Rhamnolipid biosurfactant is a kind of biological metabolic properties produced by Pseudomonas and Burkholderia bacteria. At the same time, it is also a kind of biological surface active agent which has the longest time and the most mature application technology. It exists naturally in soil, water and plants. It belongs to a kind of glycolipid anionic surfactants.
1. Application in the field of petroleum
Rhamnolipid, as a biosurfactant, has the function of reducing the interfacial tension of oil and water. It has been applied to the three production technology after the first and the two oil recovery. The main principles are as follows.
(1) as a sacrificial agent used to reduce the amount of expensive oil displacement agent or in the formation of the loss, and other oil displacement agent has the advantages of oil flooding effect, effective time is long, but adding rhamnolipid effectively reduces the oil displacement agent, greatly reducing the cost.
(2) biological surfactant has typical biological activity. It can activate the original microorganism in the formation and play the role of synergistic oil recovery. In the field test water samples of the oilfield, it is found that the bacterial content in the water sample increased by 2-3 orders of magnitude after six months after injection.
(3) as an active agent, rhamnolipid itself is a surfactant, which can reduce the interfacial tension of oil and water. After mixing, the oil and water interfacial tension of the flooding agent can reach the level of 10-3mN/m, thus improving the efficiency of crude oil displacement.
Two. Application of Agriculture
A lot of researches and practical applications have proved that rhamnolipid can be applied to crops, vegetables, fruits and flowers to stimulate growth, assist nutrition absorption, increase pesticide and fertilizer effect, and has proved that it has no toxic side effects on humans and animals.
Rhamnolipid biosurfactant can be used as a wetting agent in the production of foliar fertilizer. Because many plants are covered with a layer of wax layer, the blade surface as a protective surface, rhamnolipid bio surfactant can be used as wetting agent, added to the foliar fertilizer, on the surface of hydrophobic groups by dispersion forces adsorbed on the wax layer, the hydrophilic group extends to the fertilizer solution forming directional adsorption film instead of the hydrophobic wax layer, improve the wetting condition of foliar fertilizer in waxy layer, so that the full fertilizer spreading, promote fertilizer nutrients are absorbed by the maximum.
Rhamnolipid bioactive agent has the function of chelating some trace elements. The carboxyl group which is ionized under weak alkaline environment can fix the trace elements around the roots, reduce the possibility of rapid loss of trace elements in soil, and ensure the long-term effectiveness of fertilizers. (Root Uptake of Lipophilic Zinc#Rhamnolipid Complexes, J. Agric. Food Chem. 2008, 56, 2112-2117)
It can play an effective role in improving the alkaline soil environment, and it is a good additive for alkaline soil. Using Rh to ionize Rh- and H+ under alkaline conditions, improving OH-'s neutralization in alkaline soil and improving soil alkalinity, thus changing the environmental conditions of soil compaction.
Because rhamnolipid has the effect of wetting agent and good surface activity, it can be applied to the wetting, spreading and permeating of the pesticide. In addition, rhamnolipid has the ability to degrade some of the pesticide residues.
In addition, rhamnolipid has good antifungal effect (published in the literature, mentioned several times) for crop seed dressing and inhibit fungi, mildew experiment has been confirmed.
The use of Shu Li glycols in agriculture is more common abroad. The Environmental Protection Bureau of New York, United States, has passed the registration test of the biologic drug containing Shu Li sugar and fat. (EPA, registration number 72431-1)
Three. Application of environmental field
Rhamnolipid can be used to treat polycyclic aromatic hydrocarbons (PAHs), such as polycyclic aromatic hydrocarbons released in the Gulf of Mexico oil spill accident, for the treatment of COD, and heavy metal pollution.
Rhamnolipid can repair environmental pollution caused by human beings, including soil, water, coastline and oil, metal or other pollutants in the seabed. Rhamnolipid with metal chelating ability ("Stability Constants for the Complexation of Various Metals with a Rhamnolipid Biosurfactant", J. ENVIRON. QUAL., VOL. 30, MARCH-APRIL 2001), it can replace EDTA as a chelating agent, used to remove heavy metal pollutants in soil, water and other liquids. It can also be used as a way to deal with soil by using plant method to absorb heavy metal ions in soil. It is a good way for plant technology to process heavy metal contaminated soil in situ.
Cause for pesticides or toxic pesticides in soil or water pollution, rhamnolipid and its production of Pseudomonas aeruginosa has repair effect, according to the data ("EFFECT OF RHAMNOLIPID POTENTIAL ON BIODEGRADATION OF ENDOSULFAN BY Pseudomonas aeruginosa IN BATCH STUDIES. Arunkumar Mani, J Biosci Tech, Vol 2 (3), 2011268-278), 2 glycolipids can promote the degradation of endosulfan by Pseudomonas aeruginosa package, to repair the toxic pollution of soil or water.
Rhamnolipid, as a biosurfactant, has the characteristics of non-toxic and two affinity. When the concentration increases to critical concentration, it will play a significant role in enhancing the capacity of PAHs. Polychlorinated biphenyls can be eluted and HLB of polychlorinated biphenyls can be changed so that they can be easily absorbed and degraded by Pseudomonas. (rhamnolipid preparation and its application in the remediation of polychlorinated biphenyls contaminated soil, Ma Manying, Doctoral Dissertation of Hunan University)
Four, the application of the food field

At present, rhamnolipids are used as food expanding and expanding agents and seasoning agents. Their edible safety has passed the EPA food safety certification.

Five, application in the field of daily chemistry
Besides its good surface activity, rhamnolipid also has good cell permeability, which is derived from organisms and has good nontoxic and biodegradable properties. These features make it widely used in a variety of daily products.
The cosmetics industry uses a large number of surfactants, which almost exist in 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, moisturizing agent, soap, eye shadow, wet towel and perfume. The most commonly used are SLES (twelve alkyl ether sulfates) and SLS (twelve alkyl sulfate).
Regulators have accused SLES of the inclusion of a carcinogen, 1.4- two oxane. 1.4- two oxane is a by-product of SLES production and is usually not completely removed from SLES products. SLS has been proved to be irritating to the skin at high concentrations. Although the traditional production of SLS comes from coconut or palm oil, some of the SLS are produced from petroleum and petroleum by-products. Rhamnolipid is a natural product. It will replace most of the surfactants and emulsifiers derived from oil, shampoo, soap and most of the cosmetics listed above, such as SLS, SDS or NADS.
Rhamnolipid can spread the substance by dispersing and wetting properties. To help retain water, lubricate, produce foam, as a kind of cleaning agent. It can maintain the stability of the mixture, control the viscosity of the product, and emulsify the oil in the pores to reduce the occurrence of acne.
Six. Application in the field of Medicine
Rhamnolipid can be used to deal with skin burns and partial dermatosis, and can also be used as a basic drug.