Co-Utilization of Canola Oil and Glucose on the Production of a Surfactant by Candida lipolytica Leonie A. Sarubbo, 1,2 Charles B. B. Farias, 2 Galba Maria Campos-Takaki 1,2 1 Departamento de Química, Universidade Católica de Pernambuco, Rua do Príncipe, n. 526, Bl D, Boa Vista Cep 50050-900, Recife-Pernambuco, Brasil 2 Nfflcleo de Pesquisas em CiÞncias Ambientais (NPCIAMB), Universidade Católica de Pernambuco, Rua Nunes Machado, n.42, Bl J, TØrreo, Boa Vista Cep, 50050-590, Recife-Pernambuco, Brasil Received: 10 August 2006 / Accepted: 4 October 2006 Abstract. Candida lipolytica synthesized a surfactant in a cultivation medium supplemented with ca- nola oil and glucose as carbon sources. Measurements of biosurfactant production and surface tension indicated that the biosurfactant was produced at 48 h of fermentation. The surface-active species is constituted by the protein–lipid–polysaccharide complex in nature. The cell-free broth was particularly influenced by the addition of salt, the pH and temperature depending on the emulsified substrate (hexadecane or a vegetable oil). After comparison between ethyl acetate and mixtures of chloroform and methanol as solvent systems for surfactant recovery, it was found that ethyl acetate was able to extract crude surfactant material with high product recovery (8.0 g/L). The isolated biosurfactant decreased the surface tension to values of 30 mN/m at the critical micelle concentration. Emulsification properties of the biosurfactant produced were compared to those of commercial emulsifiers and other microbial surfactants. Surfactants are used in various industries like textile, paper, polymer, plastic, cosmetics, pharmaceuticals; food, and machinery manufacturing [14]. They are also one of the most frequently used chemicals in our daily lives. For instance, they play an indispensable role even in ballpoint pens and in canned coffee. The rapid development of the chemical industry that began in the 1960s led to the development of a wide variety of petroleum-based chemical surfactants. On the other hand, natural surfactants produced from animal or plant materials, such as soap, lecithin, and saponin, have long been consumed for home and industries before chemical surfactants were produced and used widespread [12]. The increase of the environmental awareness and strict legislation has made environmental compatibility of surfactants an important factor in their application for various uses. Among natural surfactants, ones of micro- bial origin, so-called biosurfactants, have gained attention because of their biodegradability, low toxicity, ecological acceptability, and ability to be produced from renewable and less expensive substrates [17]. Some bacteria, yeasts, and fungi are able to produce biosurfactants. The molec- ular structures of these compounds comprise a hydro- philic portion, which might consist of monosaccharides, oligosaccharides, or polysaccharides, amino acids or peptides, or carboxylate or phosphate groups, and a hydrophobic portion, which is composed of saturated or unsaturated (hydroxy) fatty acids or fatty alcohols. The main classes of biosurfactant are glycolipids, lipoamino acids and lipopeptides, polymers (lipoproteins, lipopoly- saccharides), phospholipids, monoglycerides and digly- cerides, and fatty acids [15]. World production of oils and fats is about 2.5–3 million tons, 75% of which is derived from plants [10]. Most oils and fats are used in the food industry, which generates great quantities of waste tallow, lard, marine oils or soap stick, and free fatty acids from the extraction of seed oils. Waste disposal is a growing problem, which explains the increasing interest in the use of waste in microbial transformation [18]. Many works have investigated the production of biosurfactants using domestic vegetable oils in order to Correspondence to: Leonie A. Sarubbo; email: leonie@unicap.br CURRENT MICROBIOLOGY Vol. 54 (2007), pp. 68–73 DOI: 10.1007/s00284-006-0412-z Current Microbiology An International Journal ª Springer Science+Business Media, Inc. 2006