Antioxidant and antimicrobial properties of an extract rich in proteins obtained from Trametes versicolor.

Introduction: Bioactive proteins and peptides generated from fruit, vegetables, meat or fish have great potential as functional food or substitutes for antibiotics. In recent years it has also been demonstrated that the fungus kingdom could be a source of these compounds. The study investigated the bioactivity of an extract of the lignicolous fungus Trametes versicolor and its hydrolysate. Material and Methods: The fungus was collected in a mixed forest in October, extracted and hydrolysed. To inspect the protein and peptide profiles before and after hydrolysis, matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometric analysis was performed. To evaluate the antioxidant properties of the preparations, 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+) radical scavenging assays were used. The activity of the fungus extract and hydrolysate against Aeromonas veronii, Bacillus cereus, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella Typhimurium, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus uberis was determined by the minimum inhibitory concentration and minimum bactericidal concentration values. Results: The extract and its hydrolysate showed almost 100% ABTS•+ and DPPH• radical scavenging with a low half maximal inhibitory concentration. The water extract and hydrolysate of T. versicolor exhibited antimicrobial activity against two S. aureus strains, E. coli, P. aeruginosa and Salmonella Typhimurium. Conclusion: These results provide compelling evidence that the analysed fungus extract and its hydrolysate hold promise with their antibacterial and antioxidant properties.

Detection of immunoreactive proteins of Escherichia coli, Streptococcus uberis, and Streptococcus agalactiae isolated from cows with diagnosed mastitis.

Introduction: Mastitis is a widespread mammary gland disease of dairy cows that causes severe economic losses to dairy farms. Mastitis can be caused by bacteria, fungi, and algae. The most common species isolated from infected milk are, among others, Streptococcus spp., and Escherichia coli. The aim of our study was protein detection based on both in silico and in vitro methods, which allowed the identification of immunoreactive proteins representative of the following species: Streptococcus uberis, Streptococcus agalactiae, and Escherichia coli. Methods: The study group included 22 milk samples and 13 serum samples obtained from cows with diagnosed mastitis, whereas the control group constituted 12 milk samples and 12 serum samples isolated from healthy animals. Detection of immunoreactive proteins was done by immunoblotting, while amino acid sequences from investigated proteins were determined by MALDI-TOF. Then, bioinformatic analyses were performed on detected species specific proteins in order to investigate their immunoreactivity. Results: As a result, we identified 13 proteins: 3 (molybdenum cofactor biosynthesis protein B, aldehyde reductase YahK, outer membrane protein A) for E. coli, 4 (elongation factor Tu, tRNA uridine 5-carboxymethylaminomethyl modification enzyme MnmG, GTPase Obg, glyceraldehyde-3-phosphate dehydrogenase) for S. uberis, and 6 (aspartate carbamoyltransferase, elongation factor Tu, 60 kDa chaperonin, elongation factor G, galactose-6-phosphate isomerase subunit LacA, adenosine deaminase) for S. agalactiae, which demonstrated immunoreactivity to antibodies present in serum from cows with diagnosed mastitis. Discussion: Due to the confirmed immunoreactivity, specificity and localization in the bacterial cell, these proteins can be considered considered potential targets in innovative rapid immunodiagnostic assays for bovine mastitis, however due to the limited number of examined samples, further examination is needed.