Журнал биопереработки и биотехники

 The study investigated the parameter optimization for anthocyanin extraction from egg plant (Solanum melongena) with the approach response surface methodology. Extractions were carried out using acid–ethanol with the temperature range (60–90°C), time (30–90 min) and solid–liquid ratio (1:15–1:30). Three level three factor Box-Behnken design was followed to observe the anthocyanin yield for the studied parameters. The maximum yield of anthocyanin was observed at the temperature 76.5°C in 70 min in the ratio of 1:26.

 Jadomycin is a novel antibiotic that has shown activities against bacteria, yeasts and fungi as well as cytotoxic properties to cancer cells. Because of the wide range of its inhibitory actions, jadomycin shows promise as a novel antibiotic and cancer treatment drug. Streptomyces venezuelae are aerobic bacteria that are capable of producing jadomycin when shocked by alcohol in a nutrient deprived amino acid rich medium. The size of the bacterial population that is transferred from the growth medium to the production medium can significantly affect the jadomycin yield. Therefore, the number of transferred bacteria must be accurately measured. In this study, a dehydrogenase activity measurement test was developed for S. venezuelae using triphenyl tetrazolium chloride (TTC) to measure the cell growth and activity in maltose-yeast extract-malt extract (MYM) broth. The dehydrogenase activity was determined by measuring the visible color changes of the TTC to triphenyl formazan (TF). The test conditions which included extraction solvent, number of extractions, incubation time, incubation temperature and medium pH were evaluated. The results showed that the triphenyl formazan was related to the number of cells. Methanol was better able to permeate the cells and extract higher amount of TF than ethanol. The amount of TF increased with the number of extractions for both solvents. A lower medium pH and/or lower temperature produced the highest amount of TF. The best test conditions that produced the highest TF yield were three extractions using methanol after an incubation time of 1 hour at a temperature of 30ºC and a medium pH of 6.