Paweł Satora

Interaction of dietary compounds, especially polyphenols, with the intestinal microbiota: a review

The intestinal microbiome plays an important role in the metabolism of chemical compounds found within food. Bacterial metabolites are different from those that can be generated by human enzymes because bacterial processes occur under anaerobic conditions and are based mainly on reactions of reduction and/or hydrolysis. In most cases, bacterial metabolism reduces the activity of dietary compounds; however, sometimes a specific product of bacterial transformation exhibits enhanced properties. Studies on the metabolism of polyphenols by the intestinal microbiota are crucial for understanding the role of these compounds and their impact on our health. This review article presents possible pathways of polyphenol metabolism by intestinal bacteria and describes the diet-derived bioactive metabolites produced by gut microbiota, with a particular emphasis on polyphenols and their potential impact on human health. Because the etiology of many diseases is largely correlated with the intestinal microbiome, a balance between the host immune system and the commensal gut microbiota is crucial for maintaining health. Diet-related and age-related changes in the human intestinal microbiome and their consequences are summarized in the paper.

The profile of volatile compounds and polyphenols in wines produced from dessert varieties of apples.

The aim of this study was to determine the influence of apple variety (Šampion, Idared and Gloster) on the polyphenol profile, volatile composition and sensory characteristics of apple wines. Apples were harvested from the orchard in Garlica Murowana (Poland) and the experiments were conducted on a laboratory scale. Statistically significant differences were detected in the chemical composition of the analyzed wines. The highest antioxidant activity was found in Šampion wines, which was associated with a relatively high concentration of chlorogenic acid and procyanidins. These samples also contained high amounts of acetaldehyde, ethyl acetate and methanol. Idared wines showed a similar polyphenol profile, but they had lower antioxidant capacity and were characterized by a high level of butanol and acetic acid. Gloster wines were distinguished from other samples by a lower concentration of polyphenols and higher concentration of fusel alcohols. During sensory evaluation, wines produced from Idared apples scored the highest value for overall quality.

Influence of indigenous yeasts on the fermentation and volatile profile of plum brandies.

The aim of this study was to determine the influence of different yeasts isolated from fresh blue plum fruits (Aureobasidium sp.) and spontaneously fermenting plum musts (Kloeckera apiculata and Saccharomyces cerevisiae), as well as commercial wine and distillery strains, on the fermentation and chemical composition of plum brandies. Gas chromatography methods were used to detect major volatile components. The most rapid fermentation occurred in musts inoculated with S. cerevisiae. However, the highest concentration of ethanol was detected in samples after spontaneous fermentation (8.40% v/v). Plum brandies obtained after distillation contained from 66.3 (K. apiculata) up to 74.3% v/v ethanol (spontaneous fermentation). The samples after spontaneous fermentation were distinguished by a high content of acetoin, ethyl acetate and total esters, accompanied by a low level of methanol and fusel alcohols. Non-Saccharomyces yeasts were responsible for higher concentrations of esters and methanol, while S. cerevisiae strains resulted in increased levels of higher alcohols. It was also found that isolated indigenous strains of S. cerevisiae synthesized relatively low amounts of higher alcohols compared to commercial cultures. Samples obtained using the distillery strain of S. cerevisiae received the highest score (18.2) during sensory analysis and were characterized by a well-harmonised taste and aroma.

Influence of prefermentative treatments and fermentation on the antioxidant and volatile profiles of apple wines.

The aim of this study was to determine the influence of different factors such as fruit processing, pectinolytic enzyme application, strain of yeast (Johannisberg-Riesling, Steinberg), cell immobilization on the alginate, and type of fermentation on the antioxidant profile and volatile composition of apple wines. Champion and Idared apples were used during experiments. The factors used influenced significantly (p < 0.05) antioxidant capacity, polyphenol profile, and volatile composition of apple wines. Pulp fermentation caused formation of higher amounts of ethanol and favorably influenced the antioxidant activity of wines. Procyanidins B2 and C1 as well as epicatechin and catechin prevailed among polyphenols in these samples. Cell immobilization positively affected the ethanol content, but decreased the antioxidant activity, of wines. Volatile composition of wines was mainly influenced by strain of yeast and type of fermentation. Apple wines fermented spontaneously were characterized by more esters and methanol and fewer higher alcohols compared to inoculated samples.

Chaenomeles japonica, Cornus mas, Morus nigra fruits characteristics and their processing potential.

The aim of this study was to determine the suitability of Japanese quince (Chaenomeles japonica), cornelian cherry (Cornus mas) and black mulberry (Morus nigra) fruits as raw materials for processing. All analyzed fruits were characterized by high antioxidant activity and total phenolic content. Fruits of Japanese quince and cornelian cherry had also high acidity. Products such as fruit wines and liquors were prepared from the tested fruits. In respect of soluble solid content and reducing sugars content the obtained wine should be classified as dry wines. All analyzed liquors were characterized by similar alcohol content and the soluble solid content. Moreover, liquors made from Japanese quince and cornelian cherry were characterized by high total acidity and antioxidant capacity. The results of sensory analysis showed high commercial potential of the examined fruits.

Characterisation of Antimicrobial Properties of Extracts of Selected Medicinal Plants

The scope of the experiments included analysis of the antimicrobial activity of ethanolic, methanolic and aqueous extracts against bacterial and fungal cultures and determination of the minimum inhibitory concentration of plant extracts tested microbial growth. Analysis of the antifungal and antibacterial activity was carried out by the disc diffusion method using paper discs. In the experiment 11 species of microorganisms - 8 bacterial and 3 fungal strains were used. The highest antimicrobial activity against the tested strains was demonstrated by black elder (Sambucus nigra L.), black locust (Robinia pseudoacacia L.) and lingonberry (Vaccinium vitis-idaea L.) extracts. The study showed the diverse morphological activity of specific parts of elderberry and quince, which is the effect of different polyphenolic profile of these plants. The yeast Saccharomyces cerevisiae, Escherichia coli, Pseudomonas putida and Bacillus subtilis showed the highest sensitivity to the effect of extracts of the analysed plants. As a positive control three antibiotics - amphotericin B, vancomycin and amoxicillin with clavulanic acid were used.

Strain‐dependent production of selected bioactive compounds by Cyanobacteria belonging to the Arthrospira genus

To investigate the synthesis of selected bioactive compounds in various strains belonging to the Arthrospira genus.

Influence of Selected Saccharomyces and Schizosaccharomyces Strains and Their Mixed Cultures on Chemical Composition of Apple Wines: Yeast strain influence on apple wine quality…

Currently in apple winemaking, pure cultures of Saccharomyces cerevisiae and S. bayanus strains are mainly used. The aim of this study was to determine the influence of Saccharomyces cerevisiae (Johannisberg Riesling - LOCK 105), S. bayanus (DSMZ 3774), S. paradoxus (CBS 7302), and Schizosaccharomyces pombe (DSMZ 70576) applied in pure and mixed cultures on the chemical composition and sensory profile of apple wines. Pasteurized Gloster apple musts with addition of sucrose (up to 22°Blg) were inoculated with specific volume (0.6 g dry weight per liter) of yeast pure or mixed cultures (in a ratio of 1:1, 1:1:1, or 1:1:1:1) and fermented for 28 d at 22 °C. The influence of pure/mixed culture on the chemical composition, volatile profile, and sensory properties of apple wines was determined using high-performance liquid chromatography (HPLC) and gas chromatography (GC) methods. All pure culture of yeasts used for the apple wines production are characterized by good enological profiles. S. bayanus and Sch. pombe are the most distinct to S. cerevisiae. S. bayanus strain increases the level of malic acid and carbonyl compounds in apple wines, whereas Sch. pombe highly deacidifies it and produces the most of glycerol, esters, and acetic acid. The wines obtained with these 2 species gained also, respectively, the best and the worse notes during sensory analysis. Mixed cultures (in most cases) produce greater amounts of ethanol, methanol, and volatile esters compared to pure cultures. The presence of S. bayanus in the mixed culture is beneficial for the quality of apple wines. PRACTICAL APPLICATION Good understanding of the properties of yeasts and the procedures for their selection will make it easier to find strains that could improve the quality of wine. Since wine is formed by the action of a number of species and strains of yeasts, many authors have studied the effect of mixed cultures on the final quality of the product. Most of this research was focused on the effect of the inoculation of Saccharomyces yeast with other species on the aroma of wine. However, there is a little data on the fermentation using simultaneous inoculation of different strains of S. cerevisiae.

The Compounds Responsible for Air Pollution

Air quality in Poland poses a serious threat for boththe society and the environment. According to the WHO research Poland is located on the 14th place as a country most contaminated by particulate matter (PM10). Equally health-threatening substances are ozone, PAH, nitrogen dioxide, sulfur oxide, carbon oxide and heavy metals. Long-lasting exposure to high concentrations of ozone and nitrogen dioxide may lead to many irreversible changes in lungs, pulmonary oedema and even death. The main PAH, which cumulates in the organism is benzopyrene. This substance has been described by the IARC as a the most cancerogenic factor. High concentration of sulfur oxide in the air may cause severe damage of upper respiratory tract, sulfur oxide contributes greatly also to the appearance of acid rain and is an ingredient of a London type smog. Heavy metals polluting the air are one of the most severe health threat for people, due to the ability to cumulate in the organism.

Comparison of the yeast microbiota of different varieties of cool-climate grapes by PCR-RAPD

The yeast microbiota occurring on different varieties of grapes grown in cool-climate is not completely researched. Therefore, its identification is important to research. On the other hand, yeasts occurring in these fruits can be potentially used as starter cultures to obtain particularly demanded features in the production of wine. In addition, rapid methods for yeast identification allow to eliminate the contamination with pathogenic yeasts, which could cause the loss of wine production. The aim of the study was to isolate and identify the yeasts occurring on the surface of the different varieties of white and red grapes, grown in cool-climate of Poland. Also, the aim was to compare the qualitative and quantitative composition of yeasts on the tested grapes. The 84 cultures of yeasts were isolated, that were initially macroscopic and microscopic analyzed and the purity of cultures was rated on the WL medium. Identification of yeasts by PCR-RAPD was carried using the M13 primer. In the PCR-RFLP method ITS1 and ITS4 primers, as well as restriction enzymes HhaI, HinfI, HaeIII , were used. Preliminary identification of yeasts by standard methods produced results very different from the results obtained by molecular methods. Among the isolated microorganisms yeasts were dominating, but bacteria and molds were also present. Using the PCR-RAPD method most strains of yeasts were identified. Yeast microflora of different varieties of white and red grapes was very similar as the same species of yeasts were identified. Yeasts of the genus Saccharomyces were present in all varieties of grapes. The Rhodotorula mucilaginosa , Saccharomyces cerevisiae , Metschnikowia pulcherrima , Rhodotorula minuta , Pichia kluyveri , Hanseniaspora uvarum and Rhodotorula mucilaginosa were identified by PCR-RAPD. 4 of the 33 tested strains of yeasts were identified by PCR-RFLP. By PCR-RAPD only Hanseniaspora uvarum was identified. The quantity and quality of microorganisms living on the surface of grape fruits is very important for the process of winemaking. Yeasts influence the course of alcoholic fermentation, the flavor, aroma, and thus the quality of the produced wine. To a large extent their presence depends on the condition of the surface of the fruit. Many researchers reported significant differences between yeast microflora in grapes of Mediterranean and cool-climate vineyards. As they are expected to affect the final wine properties precise researching of the microflora of cool-climate grapes may lead to the isolation of new species of yeasts and thus the wines with unique characteristics can be obtained.