Evaluation of waste products in the synthesis of surfactants by yeasts

• Published in: Chemical Papers
• Main Authors: Dzięgielewska, Ewelina, Adamczak, Marek
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer Science and Business Media LLC 2013
• Subjects: Materials Chemistry; Industrial and Manufacturing Engineering; General Chemical Engineering; Biochemistry; General Chemistry; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.2478/s11696-013-0349-1; http://link.springer.com/content/pdf/10.2478/s11696-013-0349-1

Abstract The highest yields of biosurfactants were obtained by: (i) Pseudozyma antarctica (107.2 g L−1) cultivated in a medium containing post-refining waste; (ii) Pseudozyma aphidis (77.7 g L−1); and (iii) Starmerella bombicola (93.8 g L−1) both cultivated in a medium with soapstock; (iv)Pichia jadinii (67.3 g L−1) cultivated in a medium supplemented with waste frying oil. It was found that the biosurfactant synthesis yield increased in all strains when the cell surface hydrophobicity reached 70–80 %, enabling the microbial cells to make good contact with hydrophobic substrates. The lowest surface tension of the post-cultivation medium was from 32.0 mN m−1 to 37.8 mN m−1. However, this parameter (which was also determined by a drop collapse assay) was of limited use in monitoring biosurfactant synthesis in this study. The crude glycerol was not a good substrate for biosurfactant synthesis although, in the case of P. aphidis, 67.4 g L−1 of biosurfactants were obtained after cultivation in the medium supplemented with glycerol fraction (GF2). In a low-cost medium containing soapstock and whey permeate or molasses, about 90 g L−1 of mannosylerythritol lipids were synthesised by P. aphidis and approximately 40 g L−1 by P. antarctica.