Isolation of alcohol tolerant, osmotolerant and thermotolerant yeast strains and improvement of their alcohol tolerance by UV mutagenesis
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
In this study, the yeast strains were isolated from grapes by serial dilution technique to determine their alcohol-, sugar-and thermotolerance. 34 wild type yeast strains were isolated and alcohol-, sugar-and thermotolerance of these strains were determined. The maximum alcohol tolerance was found to be 9%(v/v) in yeast strain which is named Y2. Thermotolerance behavior of 6 strains were investigated. The strains were treated with UV light with intervals of 20, 30, 40 and 50 seconds. Selected resistant colonies were investigated for alcohol tolerance. It was found that alcohol tolerance increased from 9%(v/v) to 12%(v/v) on Y2 strain.
Some properties of crude carboxymethyl cellulase of Aspergillus niger Z10 wild-type strain
Coral, Mutlu Nisa Ünaldı | Coral, Gökhan
A carboxymethyl cellulase enzyme was prepared from a wild type strain of Aspergillus niger Z10. Analyses of the enzyme preparation by SDS-PAGE revealed two protein bands showing cellulolytic activity. The molecular weight of these bands was estimated to be around 83,000 and 50,000. The optimum temperature of the enzyme was observed to be around 40 °C. It was found that the enzyme's activity has a broad pH range between 3 to 9 and 41.2% of the original activity was retained after heat treatment at 90 °C for 15 min.
Direct Liquefaction of High-Sulfur Coals: Effects of the Catalyst, the Solvent, and the Mineral Matter
Gözmen, Belgin
Two low-rank coals with high sulfur contents (Gediz subbituminous coal: 7.6 wt % S:dry basis. Çayirhan lignite: 5.7 wt% S:dry basis.) were subjected to hydroliquefaction. Liquefaction conditions included dry or solvent mediated runs under pressurized hydrogen without added catalyst or with the impregnated catalyst precursor ammonium heptamolybdate (AHM). Gediz coal having higher sulfur content gave 90% conversion in the absence of catalyst and solvent. Maximum conversion (98%) and maximum oil + gas yield (70%) from this coal were obtained by impregnating AHM onto coal and carrying out liquefaction in H2/tetralin system at 450 °C for 30 min. Under the same conditions, Çayirhan lignite gave 85% conversion and 70.5% oil + gas yield. The superior hydrodesulfurization effect of impregnated AH...