In our study we developed the edible chitosan and alginate coatings with turmeric or oregano additives. The objective of the research was to evaluate the dose-dependent cytotoxicity of films. In cell line studies on HepG2 and BJ cells, they were shown to be non-cytotoxic materials (IC50% was not reached). For HepG2 increase in cell proliferation was observed for 3, 4, and 7 mg/mL of OS3 (124,79±9,21; 162,4±10,46; 165,37±18,44) after 72 h. In BJ cells, no significant decrease in proliferation was noted after 24- and 48-hour exposure to OS0 and OS1 (1-7 mg/ml). The addition of oregano (1% v/v) resulted in films with higher elongation at break and 40% higher tensile strength compared to the base (OS0) film. Use of additives significantly increased the thermal stability of the complexes (by an average of 10 °C). Coatings were tested on tofu and had proven potent antimicrobial properties.

In the current study, we screened a collection of coagulase-negative staphylococci (CoNS) isolates for orthologues of staphylococcal enterotoxins (SEs) involved in S. aureus-related staphylococcal food poisoning (SFP). The amplicons corresponding to SEs were detected in S. chromogenes, S. epidermidis, S. haemolyticus, S. borealis, S. pasteuri, S. saprophyticus, S. vitulinus, S. warneri, and S. xylosus. All amplicons were sequenced and identified as parts of known S. aureus or S. epidermidis SE genes. Quantitative real-time PCR allowed determining the relative copy number of each SE amplicon. A significant portion of the amplicons of the sea, seb, sec, and seh genes occurred at low copy numbers. Only the amplicons of the sec gene identified in three isolates of S. epidermidis displayed relative copy numbers comparable to sec in the reference enterotoxigenic S. aureus and S. epidermidis strains. Consecutive passages in microbiological media of selected CoNS isolates carrying low copy numbers of sea, seb, sec, and seh genes resulted in a decrease of gene copy number. S. epidermidis isolates harbored a high copy number of sec, which remained stable over the passages. We demonstrated that enterotoxin genes may occur at highly variable copy numbers in CoNS. However, we could identify enterotoxin genes only in whole-genome sequences of CoNS carrying them in a stable form at high copy numbers. Only those enterotoxins were expressed at the protein level. Our results indicate that PCR-based detection of enterotoxin genes in CoNS should always require an additional control, like analysis of their presence in the bacterial genome. We also demonstrate S. epidermidis as a CoNS species harboring SE genes in a stable form at a specific chromosome site and expressing them as a protein.

Diatomite is a source of biologically available silicon but in feed industry its insecticide and anti-caking properties have been also widely recognized. The aim of the study was to evaluate the effect of dietary diatomite-bentonite mixture (DBM) supplementation on the quantitative and qualitative composition of the bacterial microbiome of the broiler chicken gut. The trial was carried out on 960 Ross 308 broiler chickens divided into 2 experimental groups throughout the entire rearing period lasting 6 weeks. The birds were fed complete granulated diets without (group C) or with DBM (group E) in an amount of 1% from the 11 day of life. Two nutritionally balanced diets were used, tailored to the age of the broilers: a grower diet (from day 11 to 34) and a finisher diet (from day 35 to 42 of life). Diatomite used in a mixture with bentonite significantly altered the microbiome. Restricting the description to species that comprise a minimum of 1% of all analyzed sequences, 36 species in group E (with diatomite) and 30 species in group C (without diatomite) were selected. Several bacteria species were identified in intestinal contents of chickens for the first time. Thirteen species occurred only in group E: Agathobaculum butyriciproducens, Anaerobutyricum hallii, Anaerobutyricum soehngenii, Blautia producta ATCC 27,340 = DSM 2950, Gordonibacter pamelaeae 7-10-1-b, Helicobacter pullorum NCTC 12,824, Lactobacillus crispatus, L. helveticus DSM 20,075 = CGMCC 1.1877, Mucispirillum schaedleri, Phascolarctobacterium faecium, Phocaeicola coprocola DSM 17,136, P. massiliensis, and Ruthenibacterium lactatiformans. The findings highlight the intricate and potentially consequential relationship between diet, specifically diatomite-bentonite mixture supplementation, and gut microbiota composition.

The aim of study was to compare the biochemical properties affecting the nutritional quality, safety, and aroma of dry-cured products manufactured from valuable meat of rare native pig breeds: Pulawska (Pul) and Zlotnicka Spotted (ZS). The count of lactic acid bacteria (4.4 log cfu/g) and the release of palmitic (23.1% and 25.9%), oleic (44.1% and 42.2%), and linoleic acids (8.3% and 7.8%), as well as arginine (30.0 and 44.3 mg/kg), histidine (25.8 and 20.6 mg/kg), and lysine (26.8–22.9 mg/kg), shaped the final pH (5.3 and 5.4) in Pul and ZS products during the 4 week maturing, respectively. Lastly, Pul and ZS meat differed in the proportion of decanoic, lauric, stearic, arachidic, and conjugated linoleic acids. The high content of putrescine (23.7 mg/kg), cadaverine (54.3 mg/kg), and tyramine (57.2 mg/kg), as well as a twofold greater share of histamine (163.2 mg/kg) and tryptamine (9.1 mg/kg), indicated a more advanced decarboxylation of ZS meat. Volatile compounds differentiating Pul and ZS meat were primarily hexanal, 3-hydroxybutan-2-one, phenylacetalaldehyde, 2,3-dimethyl-2-cyclopenten-1-one, 2-cyclopenten-1-one, and 3-methyl- and 2-cyclopenten-1-one. Most marked volatile compounds were obtained as a result of microbial activity (acetic acid, 3-methylbutan-1-ol, ethanol, acetone, and 3-hydroxybutan-2-one), advanced lipid oxidation, and decomposition of secondary oxidation products (hexanal, phenylacetaldehyde, and 2-cyclopenten-1-one).

The aim of the study was to evaluate the effect of different levels of dietary hybrid rye on eggs laid by Isa Brown laying hens and their quality, such as physical parameters, nutritional value (basic chemical composition, cholesterol content, fatty acid profile) as well as safety (microbiological purity). A total of 72 Isa Brown hens aged 26 weeks were allocated to 3 groups fed with 0%, 15% and 25% levels of hybrid rye in their diet up to week 50. At week 50, 72 eggs per group were collected for analysis. The 25% rye level had no significant effect on most of the examined physical parameters; however, a tendency to heavier eggs in this group was noted. An increased rye level resulted in lighter yolks with a lowered share of redness and yellowness compared to those obtained from hens fed a control diet. The administration of 25% of rye in the diet influenced the basic chemical composition of the yolks by increasing the water content and reducing the fat content, but with no significant effect on the contents of ash, chlorides and cholesterol. The sum of saturated fatty acids in yolks decreased along with the increase in dietary rye level while the sum of mono- and polyunsaturated fatty acids increased. Moreover, a lowered ratio of ω-6: ω-3 fatty acids was found with dietary rye level increases.