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Removing contaminants from plant material with minimal damage to plant cells using different chemical solutions represents very important and one of the most critical steps in establishing plant tissue culture in vitro. Our study deals with the optimisation of the protocol for successful surface sterilization of initial explants in two raspberry cultivars, ‘Meeker’ and ‘Willamette’ in two experimental years. The main objective during the first experimental year was to examine the protocols for surface sterilization which included different combinations of disinfectants (mercuric chloride or commercial bleach solution each in combination with 70% ethanol). In the following year, the impact of the two most effective sterilization treatments on the establishment of aseptic cultures over the four-month period (May, June, July, and August) was investigated in both raspberry cultivars. Aseptic cultures were established on Murashige and Skoog medium (MS) containing 2.0 mg/l N6-Benzyladenine (BA), 0.5 mg/l indole-3-butyric acid (IBA) and 0.1 mg/l gibberellic acid (GA3). The highest percentage of explants initiation in ‘Meekerʼ (79.3%) was achieved with surface sterilization in 70% ethanol (1 min) combined with 10% (v/v) commercial bleach solution (20 min), whereas sterilization in 70% ethanol (1 min) followed by HgCl2 (3 min) gave the best results (38.3%) in ‘Willametteʼ. The most optimal month for the establishment of aseptic culture was May for ‘Meeker’, while June was the most suitable month for the ‘Willametteʼ cultivar.

The purpose of this study was to investigate the antibacterial activity of raw donkey milk toward the clinical isolate of Klebsiella pneumoniae at 9, 15 and 38 °C as well as to clarify the role of lysozyme, lactoferrin and calcium content in the antibacterial activity of donkey’s milk. The effects of contamination level and incubation period on this antibacterial activity were also examined. Antibacterial assays were performed by determing the bacterial count in intentionally contaminated (102, 103, 104 cfu/mL) donkey milk samples during 8 and 96 hours. Lab-on-a-chip electrophoresis and atomic absorption spectrometry were used for the determination of lysozyme, lactoferrin and calcium contents in donkey milk, respectively. The donkey milk samples showed varying degrees of antibacterial activity against the tested strain K. pneumoniae. The antibacterial synergism of lysozyme and lactoferrin was proven for this clinical strain as the samples with higher lactoferrin amount showed a stronger antibacterial activity. The correlation between calcium content and antibacterial activity of donkey milk samples was not established. Donkey milk showed stronger antibacterial potential at 15 °C compared to 9 °C, but this was limited by a higher growth rate of K. pneumoniae at 15 °C. The higher level of contamination resulted in a faster consumption of the antibacterial capacity of donkey milk. The artificial neural network model for prediction of K. pneumoniae count gave acurate fit to experimental data, showing a reasonably good (overall r2 for donkey milk was 0.986, with training error 4.67∙10-4, while r2 for nutrient broth was 0.982 and training error was 0.002).

Protein profile, in vitro gastrointestinal digestion and antioxidant potential of two fresh cheese samples obtained by kombucha inoculum and traditional starter culture have been investigated in this study. There is a significant difference in protein profile and bioactive potential between fresh cheese samples. Kombucha fresh cheese contains higher proportion of protein, predominantly the casein fractions (α-casein and β-casein) compared to fresh cheese obtained by traditional culture. After gastrointestinal digestion (with pepsin and pancreatin), significantly higher amount of soluble protein and higher degree of hydrolyses were measured in kombucha fresh cheese sample than sample obtained by traditional culture. During gastrointestinal digestion, for fresh cheese with traditional starter both fractions of casein are degraded more rapidly by pepsin than in kombucha fresh cheese. The hydrolysates of cheese obtained by kombucha inoculum showed higher phenolic content and higher antiradical scavenging abilities than hydrolysates of fresh cheese produced with traditional starter. These results suggest that kombucha inoculum contributes to improvement of product’s bioactive potential.

The aim of this study was to compare the protein and fatty acid fractions of Balkan donkey and human milk in the early lactation stage (40 and 90 day). This study revealed that donkey milk contains αs1-casein (1.38-1.89 g/L) and higher concentration of β-casein (0.1-0.55 g/L) in comparison to human milk. The concentration of α-lactalbumin increased during the lactation phases from 40 to 90 days in both types of milk. Donkey milk contained β-lactoglobulin in low concentrations which decreased to 90th day of lactation. Donkey milk was particularly rich in two whey proteins, lactoferrin and lysozyme, which were found to have molecular weight of approximately 76 kDa and 14.9-15.4 kDa, respectively. The content of lysozyme in donkey milk ranged from 2.39 to 2.97 g/L, while human milk contained 30-50 times lower concentrations of lysozyme in comparison to donkey milk. Thus, donkey milk contained also a higher concentration of lactoferrin (0.012-0.25 g/L) than it was found in the human milk. Lysozyme and lactoferrin content in donkey milk increased during the period from 40th to 90th day of lactation. The percentage of total SFA, MUFA and PUFA was similar in donkey and human milk. The content of essential fatty acids increased during 40-90 days of lactation and was approximately 2.5 times higher in comparison to human milk.

The paper presents an investigation into the influence of fertigation on generative potential parameters and pomological properties of apple fruits.