Coordinate production of cephamycin c and clavulanic acid by Streptomyces clavuligerus.

Production of cephamycin c and clavulanic acid by Streptomyces clavuligerus was investigated using different media in shake flask condition. Highest cell growth (3.8 g/L) was observed in glycerol, sucrose, proline and glutamic acid (GSPG) medium. Although, GSPG medium supported maximum growth, it was least effective for the synthesis of both cephamycin and clavulanic acid. Yield of cephamycin and clavulanic acid was maximum in dextrin and K medium, respectively. High and low level of constituents of dextrin medium, affected production of both cephamycin and clavulanic acid. Biosynthesis of clavulanic acid was associated with production of cephamycin c.

Agar immobilized yeast cells in tubular reactor for ethanol production.

Saccharomyces cerevisiae cells were immobilized in agar gel and used in a tubular reactor for conversion of cane molasses to ethanol at 30 degrees C, pH 4.5. Reactor was used in a continuous operation to test the operational stability and ethanol productivity. After 100 days of continuous fermentation at a dilution rate of 0.67 hr-1, some deactivation of cells was observed, but ethanol productivity was recovered by reactivating the cells by sparging air intermittently. It was found that intermittent reactivation during continuous operation was very important for satisfactory performance of the reactor. During operation, gel beads maintained their rigidity. Maximum ethanol concentration (94.9 g/L) was obtained with a feed containing 255 g/L reducing sugar, at a dilution rate of 0.2 hr-1. Maximum volumetric productivity (79.5 g ethanol /L/hr), specific ethanol productivity (0.58 g ethanol/g cells/hr), specific sugar uptake rate (1.12 g sugar/g cells/hr) and ethanol yield coefficient (0.43 g ethanol/g sugar) were obtained with a feed containing 195 g/L reducing sugar at a dilution rate of 1.33 hr-1.