An effective automated glucose sensor for fermentation monitoring and control.

An industrial glucose analyser was partnered to an automated injection system to evaluate glucose in the culture medium of a bioreactor. This sensor has been validated on continuous cultures ofSchizosaccharomyces pombe and continuous and fed-batch cultures ofSaccharomyces cerevisiae. In addition to the advantage of a more accurate process monitoring, the main interest of this sensor deals with the control of the substrate concentration to a prespecified reference signal.

Preparation of tritiated lipopolysaccharides from Escherichia coli K12.

Tritiated lipopolysaccharide (LPS) from E. coli K12 was prepared by coupling [3H]ethanolamine to the LPS core residue ketodeoxyoctonate (KDO) via activation of its carboxylic function with N-hydroxysuccinimide or N-hydroxy-sulfosuccinimide. Specific activities of 1.

Mechanism of enhanced oxygen transfer in fermentation using emulsified oxygen-vectors.

Limitations of oxygen transfer in fermentation can be solved using auxiliary liquids immiscible in the aqueous phase. The liquids (called oxygen-vectors) used in this study were hydrocarbon (n-dodecane) and perfluorocarbon (forane F66E) in which oxygen is highly soluble (54.9 mg/L in n-dodecane and 118 mg/L in forane F66E at 35 degrees C in contact with air at atmospheric pressure).

An inhibition enzyme-linked immunosorbent assay technique for the detection of endotoxins in proteins extracted from Escherichia coli K12 recombinant DNA.

An inhibition enzyme-linked immunosorbent assay (ELISA) was developed for the specific quantitation of rough (R) mutant E. coli K12 lipopolysaccharide (LPS). Since R-LPS binds poorly to polystyrene microplates, an LPS-BSA covalent complex was prepared following glutaraldehyde activation and used as a coating surface antigen.

Mechanism of selectivity in ion-pair high-performance liquid chromatography of aminoglycoside antibiotics using perfluorinated pairing ions.

The behaviour of perfluorinated carboxylic acids as pairing ions for the chromatography of the aminoglycoside antibiotics was studied. As with perhydrogenated pairing ions, the capacity factor can be modified according to the percentage of organic modifier and the nature and concentration of perfluorinated pairing ion in the mobile phase. The special selectivity effect observed with trifluoroacetic acid was investigated and interpreted as a concerted mechanism involving ionic and hydrophobic interactions.