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

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.

Formation and analysis of mannosylerythritol lipids secreted by Pseudozyma aphidis.

Pseudozyma aphidis DSM 70725 was found to be a novel producer of mannosylerythritol lipids (MELs). The MELs were quantified by HPLC. Glucose as carbon source for precultivation supported growth well.

Double diastereoselection in aldol reactions mediated by dicyclohexylchloroborane between L-erythrulose derivatives and chiral aldehydes. The Felkin-Anh versus Cornforth dichotomy.

Both matched and mismatched diastereoselections have been observed in aldol reactions of the B,B-dicyclohexylboron enolate of a protected l-erythrulose derivative with a range of chiral aldehydes. The stereochemical outcome of reactions with alpha-methyl aldehydes can be adequately explained within the Felkin-Anh paradigm. In the case of alpha-oxygenated aldehydes, however, strict adherence to this model does not allow for a satisfactory account of the observed results.