Amongs three strains: H. annosus, T. versicolor and C. unicolor, tested for laccase production, C.unicolor was chosen as the best producer of the enzyme. The effective method of cultivation was developed that resulted in high laccase activity and low protease amount. The following scheme was suggested: slant – inoculum with silica gel as additive in broth – two successive cultivations with silica gel in broth. It was found that the culture should be stopped between 10 and 12 day. Filtrated enzyme fluid was used for immobilization on various carriers: wood shavings (pine, birch, oak) and commercial supports (Eupergit C, Dowex Marathon, Amberlite IRA 900, DEAE-Granocel-2000, BA/EGDMA). Physical adsorption and covalent attachment were applied as testing methods of immobilization. The best results were obtained when DEAE-Granocel-2000, activated with divinyl sulfone was used as the carrier (measured activity 22.1 U^.ml^-1). The optimization of immobilization conditions showed that the highest enzymatic activity of laccase was observed in pH 7.0 of coupling mixture without NaCl.

In this paper we examined nine strains of filamentous fungi belonging to Aspergillus, Trichoderma and Rhizopus genus for their ability to phytases biosynthesis and accompanying celulase and xylanase enzymes in medium with wheat bran as a soul carbone source. In 8-days submerged fermentations eight strains were able to synthesize phytases and the activity of those enzymes was generally increasing during the process. The most effective producers of phytases were Aspergillus niger KB and Aspergillus niger 551: the activity was 24,45 nkat g^-1 and 17,7 nkat g^-1, respectively. In the experimental conditions not all strains revealed celulase and xylanase activity. In solid state fermentation with A. niger 551 there was observed the important increase of phytases specific activity in comparison to submerged fermentation. The optimum parameters for phytases of A. niger 551 activity were 45 °C and pH 5,6.

In this paper eight strains of Geotrichum candidum were examined for their ability to produce lipases in mineral medium containing different concentration of residues oil – waste product from fatty industry, as a carbone source. Residue oil was used in 1%, 2%, 3% concentration. Mineral medium with addition of 1% of glucose or 1% rapeseed oil was used for comparison. Activities of lipases were tested against olive oil (JL_O) and glycerol tributyrate (JL_T) used as substrates. All tested strains differed in intra- and extracellular lipase activity, depending on the concentration of oil residue as well as incubation time and the substrate type used in enzymatic analysis. Generally, enzymes of tested strains showed higher specifity to olive oil, then to glycerol tributyrate. The highest production of lipases appeared as early as the 3-th day of incubation. Higher level of lipases in presence of residue oil or rapeseed oil in comparison with control medium (containing 1% glucose as carbon source) indicates inductive character of their biosynthesis. Culture medium containing 1% of residue oil appeared to be the most effective for enzyme synthesis and G. candidum X5 strain showed the highest extracellular activity (195 JL_O mL^-1) in given conditions.

The influence of ethanolic extracts of Capsicum annuum and Levisticum officinale on the specific growth rate, lag phase duration and the amount of yeasts biomass of Candida sphaerica F-II-7a, Candida famata A-II-4b, C. famata M-I-1a oraz Yarrowia lipolytica P-II-6b, Y. lipolytica A-101 was studied . The effect of spices addition was studied during the yeast propagation in Bioscreen C at the temperature of 28⁰C. A stimulating effect on the growth of tested strains was observed. An important diminution of lag phase, of the time to reach maximal growth rate and the increase of μ_max were noted in the presence of 0,1 and 1% spices extracts, specially for C. sphaerica and C. famata.

Abstract: Flours obtained from four species of legumes plants were undergone hydrolysis process. In study five proteases were used, different in optimal conditions of work and substrate specificity. In foothold about degree of hydrolysis function of optimal ratio enzyme: substrate in reaction mix and time of hydrolysis were set. The vulnerability of protein on enzyme impact was conditioned by plant species and kind of enzyme, only in bromelaine and bacterial protease case influence of E/S ratio and time of hydrolysis was visible. Flours all investigated plants the most effective were hydrolyzed by pepsin and trypsin. Proteins Grapis pea in contrary to Piast were more vulnerable on digestion with bacterial protease and pepsin. Bacterial protease was significantly more active against flours obtained from vetch and lentil than two strain of pea.

Bacillus subtilis B3 strain during growth in a synthetic medium with feather keratin synthesize extracellular proteases exhibiting keratinolytic activity. These extracellular enzymes take part in biodegradation of keratin, which results in the rise of concentration of peptides, free amino acids and thiol groups. Complete liquification of chicken feathers was observed within 5-7 days of bacterial culture. The tested strain in disadvantageous conditions formed a biofilm. The composition of biofilm’s exopolymeric matrix depends mainly on medium ingredients and contains 1,3-9,2 mg% of proteins and 1-5 mg% of polysaccharides. In a medium containing feather keratin as a hardly accessible source of carbon and nitrogen, the strain B.subtilis B3 formed biofilm composed of polysaccharides and proteins in 84% and 16%, respectively.

The aim of this work was to determine the stability of crude and pure preparations of Carnobacterium divergens AS7 bacteriocin (divercin) during long-term storage at 4 and 20 ⁰C. The influence of freezing and freeze drying on divercin activity and stability during storage were also studied. Divercin antilisterial activity was decreased during storage. The highest bacteriocin stability was obtained at 4 ⁰C in crude preparations, while the lowest activities was observed during storage pure divercin at 20 ⁰C. Freezing and freeze drying had negative effect on divercin activity in purified preparations, but the activity of crude preparations of divercin was stable during these processes. Pure divercin was also sensitive to multiple freezing. Divercin stability during long-term storage was increased after freezing and freeze drying. Antilisterial activity of divercin crude preparations were remained stable during storage at -20 ⁰C for 6 months. The same stability had also freeze dried crude preparations storaged at 4 ⁰C. Activity of pure divercin after freezing and freeze drying were decreased during storage, but divercin was more stable in freeze dried products than in frozen poducts. The divercin activity in freeze dried crude preparations increased during storage at 20 ⁰C.

The aim of the work was to determine the ability of Yarrowia lipolytica yeast strains: JII1a, JII1c and PII6a, isolated from blue veined cheese Rokpol and selected previously as potential cheese co-starters, to produce biogenic amines in milk. All investigated yeast strains were proven to be able to grow in milk and degrade milk proteins. All those yeast strains showed the ability to produce biogenic amines, but the concentration of those compounds was strain dependent. Strains: JII1c and PII6a produced significantly more biogenic amines than strain JII1a. Those two strains caused also more intensive degradation of milk proteins. These observations led to conclusion that higher concentration of biogenic amines was generated in milk of advanced proteolysis.

Seven yeast strains isolated from Polish blue cheese Rokpol: Candida famata MI1a, C. intermedia BI2a, C. kefyr PII1b, C. sphaerica FII7a, Geotrichum penicillatum EII6a, Saccharomyces kluyveri BII3a i Yarrowia lipolytica PII6a, were used to aseptically inoculate model cheeses at the level 10⁵ c.f.u.×g^-1 of cheese. During one week incubation period their growth as well as protein and lipid degradation processes were analysed. The highest number of yeast in cheese was observed within strain Y. lipolytica, which also appeared to cause the most advanced proteolytic and lipolytic changes.

A Gremmeniella abietina strain, a Scots pine pathogenic fungus, was used to investigate its ability to reduce five selected acetophenones, aromatic prochiral ketones. In all cases enantiospecificity of the process was recorded, and the enantiospecificity, calculated as the enantiomeric excess, as well as resulting secondary alcohol yield, depended on the reaction time and the structure of a given substrate.