# US 9,434,755 B2 · Process for the isolation of rhamnolipids

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- Number: US 9,434,755 B2
- Document ID: US9434755B2
- Status: Granted
- Kind: B2
- Application number: 14/089,168
- Filed: 2013-11-25
- Published: 2014-05-29
- Granted: 2016-09-06
- Earliest claimed: 2012-11-26
- Assignees: Evonik Degussa GmbH
- Applicants: Martin Schilling; Marius Ruetering; Verena Dahl; Fabien Cabirol
- Inventors: Martin Schilling; Marius Ruetering; Verena Dahl; Fabien Cabirol
- Web page: https://patentgrep.com/patent/US9434755B2

## CPC

- C07H 15/04: attached to an oxygen atom of the saccharide radical
- C11B 1/10: by extracting
- C11B 1/108: {after-treatment, e.g. of miscellae}
- C07H: SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS (derivatives of aldonic or saccharic acids C07C, C07D; aldonic acids, saccharic acids C07C59/105, C07C59/285; cyanohydrins C07C255/16; glycals C07D; compounds of unknown constitution C07G; polysaccharides, derivatives thereof C08B; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; sugar industry C13)
- C11B: PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES (drying-oils C09F)

## Abstract

A process for isolating rhamnolipids is provided. The process includes providing an aqueous medium containing at least one rhamnolipid and having a pH of less than 6. Next, the aqueous medium is brought into contact with at least one organic solvent to provide a multiphase system and then the aqueous phase is separated off. The pH is then increased to a value of 6 or more to provide a multiphase organic system. Next, a rhamnolipid-enriched organic phase is separated off. An optional step of further purifying the rhamnolipid may be performed.

## Claims

### Claim 1

A process for the isolation of rhamnolipids, said process comprising:
A) providing an aqueous medium containing at least one rhamnolipid and having a pH of less than 6, wherein the aqueous medium comprises between 10 g/l and 300 g/l of the at least one rhamnolipid,
B) i) bringing the aqueous medium into contact with at least one organic solvent to provide a multiphase system X, wherein the at least one organic solvent dissolved in the aqueous medium is in an amount from 0.1 to 30% by weight of the multiphase system X, ii) separating off the aqueous phase from multiphase system X, to provide an organic phase Y,
C) increasing the pH of the organic phase Y, to a value of 6 or more to provide a multiphase system Z comprising at least two organic phases, and
D) separating off a rhamnolipid-enriched organic phase from the multiphase system Z.

### Claim 2 (depends on 1)

The process according to claim 1, wherein said pH of said aqueous medium in process step A) is from 2 to 4.5.

### Claim 3 (depends on 1)

The process according to claim 1, wherein the at least one organic solvent of process step B) is selected from methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isoamyl acetate, butan-1-ol, butan-2-ol and diethyl ether.

### Claim 4 (depends on 1)

The process according to claim 1, wherein a volume ratio of the aqueous medium to the at least one organic solvent prior to bringing them into contact is from 0.2:1 to 5:1.

### Claim 5 (depends on 1)

The process according to claim 1, wherein in process step C) the pH is increased to 6.1 to 9.

### Claim 6 (depends on 1)

The process according to claim 1, wherein in process step C) the pH is increased by means of an inorganic base.

### Claim 7 (depends on 1)

The process according to claim 1, wherein process steps B), C) and D) are carried out in a temperature range from 10 to 50° C.

### Claim 8 (depends on 1)

The process according to claim 1, further comprising:
E) further purify the rhamnolipid within the rhamnolipid-rich phase.

### Claim 9 (depends on 8)

The process according to claim 8, wherein an organic solvent is used in process step E) to separated off from the rhamnolipid by means of at least partial evaporation.