Chemostat study of citric acid production from glycerol by Yarrowia lipolytica.

The aim of the study was to examine how the dilution rate and the chemical composition of the production medium impacts on the synthesis of citric acid by the Yarrowia lipolytica strain Wratislavia AWG7 from glycerol in a chemostat culture. The yeast Y. lipolytica Wratislavia AWG7, an acetate (acet(-)) and morphological (fil(-)) mutant, was cultured in a nitrogen- and phosphorus-limited medium at the dilution rate of 0.

RAPD with microsatellite as a tool for differentiation of Candida genus yeasts isolated in brewing.

Fifteen wild yeast strains were isolated in two factories of a lager brewing company in Poland. Their identification with API 32C system showed mainly the presence of Candida sake species (7/15). To differentiate the isolates, randomly amplified polymorphic DNA (RAPD) with (GTG)(5), (GAC)(5), (GACA)(4) microsatellite primers and M13 core sequence (5'-GAG GGT GGC GGT TCT-3') were chosen.

Factors affecting killer activity of some yeast species occurring in Rokpol cheese.

Fourteen strains of Candida famata and 7 strains of C. sphaerica originating from blue-veined Rokpol cheese were studied for their ability to produce killer toxins against 3 strains of Yarrowia lipolytica selected as potential starter cultures for cheesemaking. All tested strains revealed killer activity in the presence of salt, at 14 degrees C and pH 4.

Identification and biochemical characteristics of yeast microflora of Rokpol cheese.

Yeast microflora on the surface and interior of Rokpol cheese was examined for cheeses produced at three dairies located in Lower Silesia, Poland. Yeast populations on the surface of the cheeses ranged from 10(5)-10(9) cfu/g, but were 10-100 times lower for interior samples. The occurrence and proportions of yeast species varied, depending on the dairy plant and cheese sample.

Comparison of different strains of the yeast Yarrowia lipolytica for citric acid production from glucose hydrol.

Four commercial strains and two mutants of the yeast species Yarrowia lipolytica were screened using batch fermentation. Strain Y. lipolytica A-101-1.