Fed-batch bioreactor production of mannosylerythritol lipids secreted by Pseudozyma aphidis

Abstract

Two strains of Pseudozyma aphidis, DSM 70725 and DSM 14930, were used for the bioreactor production of mannosylerythritol lipids (MELs). Foam formation interfered substantially with the cultivation process. Soybean oil was simultaneously employed as both carbon source and anti-foam agent. Primary MEL formation occurred after nitrate limitation. After a first short time-period of nitrate limitation and further nitrate addition, MELs were secreted in spite of nitrate excess. The sedimentation of MEL-enriched beads indicated enhanced product formation. Maximum yield, productivity and yield coefficient of 165 g l(-1), 13.9 g l(-1) day(-1) and 0.92 g g(-1) were achieved using strain DSM 14930 with additional substrate-feeding (glucose, sodium nitrate, yeast extract) and a foam-controlled soybean oil supply.

Produção de biossurfactante por levedura

“…O rendimento foi 2,6 vezes maior que o rendimento obtido na produção deste por batelada simples (37g/L). 13 Rau et al 17 produziram biossurfactante por Pseudozyma aphidis utilizando óleo de soja e glicose, em batelada alimentada, obtendo uma alta produção de biossurfactante (168 g/L) ao final de 11 dias de fermentação.…”

Getting Lipids for Biodiesel Production from Oleaginous Fungi

“…Therefore, while the first investigations on oleaginous fungi most commonly employed glucose as carbon source, nowadays the production of single-cell oils is predominantly addressed to transformation of raw materials, by-products and surplus. Glucose is the carbon source most commonly employed for growth of oleaginous fungi and lipid production (Boulton & Ratledge, 1984;Hansson & Dostalek, 1986;Hassan et al, 1993;Heredia & Ratledge, 1988;Jacob, 1991;Jacob, 1992;Johnson et al, 1992;Li et al, 2007;Pan et al, 1986;Ratledge, 2004;Rau et al, 2005;Saxena et al, 2008;Zhao et al, 2008). High glucose concentrations enhance the carbon flow that is directed toward TAG production, thus improving lipid production in several yeasts.…”

Identification of Pseudozyma graminicola CBS 10092 as a Producer of Glycolipid Biosurfactants, Mannosylerythritol Lipids

“…MEL-A is the most J. Oleo Sci. 57, (2) 123-131 (2008) intensively studied MEL due to its high production yield from different carbon sources 17,18) , and exhibits versatile interfacial and biochemical properties 2,6) . However, the "diacetylated" MEL shows low hydrophilicity and/or watersolubility; this partially limits its range of applications.…”

“…In addition, they show high binding affinity toward different immunoglobulins 12,13) and lectins 14) . On conventional high-level MEL producers such as P. antarctica T-34 2,15) , P. aphidis DSM 70725 16,17) and P. rugu- 18) , the product is consistently a mixture of MEL-A, -B and -C ( ); MEL-A is the major component and comprises more than 70% of all the MELs. However, MEL-A has a drawback in handling of the aqueous solution due to its very low water-solubility and/or hydrophilicity: this has partially limited practical application of MELs.…”