ABSTRACT
The effect of different concentrations of carbon source (lactose) and inducer (glycerol) on biomass and glycerophosphate oxidase (GPO) production by mutant strain of Aerococcus viridans 1509 was tested. The best combination of lactose and glycerol concentrations for good enzyme productivity was 0.5% lactose and 2.5% glycerol. Further improvement of GPO levels was achieved after scaling-up of the bioprocess and cultivation of the cells in a 3 liter laboratory bioreactor. Using 4.5 x 10(-5) m3 s-1 air flow rate during growth, GPO activity increased 20-times in comparison with cultivation in flasks.
Subject(s)
Glycerol/pharmacology , Glycerolphosphate Dehydrogenase/biosynthesis , Lactose/pharmacology , Streptococcaceae/enzymology , Culture Media , Dose-Response Relationship, Drug , Mutation , Streptococcaceae/geneticsABSTRACT
Protein synthesis in an aqueous two-phase system is reported here as a novel type of extractive bioconversion. Translation of BMV RNA was studied using either rabbit reticulocyte lysate or wheat-germ extract in aqueous dextran-PEG systems. Both polymers inhibited protein synthesis and the translation system partitioned into both phases. In the rabbit reticulocyte two-phase system, protein synthesis reached 30% of that in free solution, while in wheat-germ extract it was 60% of that in free solution. Protein was found mainly in the dextran (lower) phase but its partitioning was related to the polymer concentration, and molecular weight, as well as the ionic strength of the system. Protein synthesis was highly influenced by PEG concentration, potassium chloride concentration, and dextran molecular weight.
