Production of four interfacial active rhamnolipids from n-alkanes or glycerol by resting cells of Pseudomonas species DSM 2874.
In a simple phosphate buffer or a sodium chloride solution resting cells of Pseudomonas spec. DSM 2874 produced up to 15 g/l of different rhamnolipids. The rhamnolipid composition of the organic crude extract depended on the temperature during the cultivation and on the C-source. The optimal sodium chloride concentration for rhamnolipid formation was about 100 mM/l and the optimal phosphate buffer concentration about 65 mM/l. The optimal pH-value for the production of rhamnolipids from n-alkanes or glycerol was in the range pH 6.0-7.2. While rhamnolipid formation with glycerol as the sole C-source showed a wide optimum ranging from 27 degrees up to 37 degrees C, production of rhamnolipids from n-alkanes had a sharp optimum at 37 degrees C. The addition of multivalent cations, different N-sources and EDTA caused an inhibition of rhamnolipid formation, while the n-alkane concentration had no influence. Specific rhamnolipid formation decreased with increasing cell concentration. Various C-sources were suitable for the formation of rhamnolipids by resting cells of Pseudomonas spec. DSM 2874. Yields, which were comparable to those obtained on n-alkanes or glycerol, were found for stearic acid, fatty alcohols and vegetable oils. A study of the time course of glycolipid production of resting cells was carried out in a 20 1-bioreactor with an intensor system and with n-tetradecane as the sole C-source.
D000473:Alkanes / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism*; D006017:Glycolipids / Q000096:biosynthesis* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D011549:Pseudomonas / Q000254:growth & development / Q000378:metabolism*; D012210:Rhamnose / Q000096:biosynthesis* / Q000302:isolation & purification; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature
D000473:Alkanes; D006017:Glycolipids; D012965:Sodium Chloride; D004492:Edetic Acid; D007501:Iron; D008274:Magnesium; D005990:Glycerol; D012210:Rhamnose; D002118:Calcium