Purification and characterization of an acetyl esterase fromAspergillus niger

Applied Biochemistry and Biotechnology - Optimized acetyl esterase enzyme production conditions usingAspergillus niger ATCC 10864 in 14-L fermentation jars were determined to be 33?C, 1.5 vvm...     

Mass spectrometric monitoring of 2-oxoglutaric acid in fermentation broth

A mass spectrometric method for monitoring 2-oxoglutarie acid (an essentially nonvolatile compound) in aqueous solutions is described. Silicone rubber membranes are used for mass spectrometric sampling; the acid is esterified with methanol. The assay was applied to monitoring 2-oxoglutarie acid in penicillin fermentation broths. Three ion peaks of the ester were suitable for measurements. Preliminary work on faster esterification with diazomethane in diethyl ether is reported.