The usefulness of the enzyme preparation Fyre-Zyme (trade name) for purification of hydrocarbon-contaminated soil was investigated under laboratory conditions. Parallelly, its influence on the dynamics of soil microflora has been tested. Fyre-Zyme, which does not currently have a certificate in Poland, was the most effective during the first 6 hours of experiment. At this time, in comparison to control soil (without Fyre Zyme), the content of petroleum substance decreased by 29% and after 60 days by 52%. Fyre-Zyme preparation assisted the degradation of n-aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) but did not affect in loss of mono-aromatic hydrocarbons (BTEX). The changes of soil biotic relations were observed at presence of Fyre-Zyme – decrease of the number eukaryotic microflora and increase of prokaryotic microflora during 60 days of process. However, the enzyme preparation had no influence on the number of hexadecane degrading microorganisms.

This research aims at determining which yeast types can be encountered in the following home products: pickled cucumbers, sauerkraut and mixed pickled vegetables. Seventy-five strains of yeast have been isolated from the pickles selected for the research. These strains have been identified on the basis of API tests (bioMerieux), amplification of the selected regions of rDNA genes (NS3-ITS4) and restrictive analysis, as well as genome scanning, performed in order to detect microsatellite sequences. Yeast Saccharomyces cerevisiae (38.7% isolates) and Yarrowia lipolytica (25.6% isolates) have been determined as a dominant microflora for the pickles. There have been also isolated strains belonging to the following types: Pichia etchellsii, P. ohmerii, Candida holmii, C. pelliculosa and Shizosaccharomyces japonicus. With the use of API 32C, some isolates have been identified merely in accordance to their type, and due to a limited data base of model strains, not all the isolates have been possible to be classified on the level on their type with the support of molecular techniques. The obtained results of the research allowed to supply the database with new yeast strains (strains of different restrictive profiles), which should consequently facilitate conducting the identifying works.

Erythritol, a four-carbon polyhydric alcohol, is a sweetener presently more often used as sucrose replacement. Its production on commercial scale is performed only in biotechnological processes. The aim of this study was to compare yield and dynamics of erythritol production from glycerol, derived from biodiesel production, by strain Wratislavia K1-UV21 of Y. lipolytica in batch, fed-batch and repeated-batch cultures. The cultivations were performed in Biostat B Plus bioreactor. The total concentration of glycerol was 150 and 250 g∙dm^-3, in batch and fed-batch culture, respectively. The repeated-batch culture was started as fed-batch culture. Next, after glycerol depletion, from the bioreactor 40% of culture broth was withdrawn and replaced by the same amount of fresh medium, in which glycerol concentration was 100 g∙dm^-3. Such cycle was repeated four times. In batch and fed-batch cultures yeast produced 84.1 and 136 g∙dm^-3 of erythritol, respectively. The production yield was similar (0.53 g∙g^-1) in both processes. However, volumetric productivity and specific erythritol production rate were higher in batch cultivation. In repeated-batch culture high yield (0.51–0.55 g∙g^-1) and dynamics of erythritol production (0.80–1.05 g·dm^-3h^-1) was achieved during first three cycles.