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Major losses of fresh tomatoes happen during post-harvest storage due to prompt senescence and diseases. The aim of the research was to evaluate the effects of different spectra of LED lights on the post-harvest preservation of ascorbic acid, lycopene, and total soluble solids, the weight and size of tomato fruits, as well as to determine the optimal exposure time and distance of irradiation and extension of shelf-life. Therefore, experiments were carried out in a climate chamber with shelves equipped with three different light spectra: red light-emitting diodes, red–blue–white light-emitting diodes, and ultraviolet-light-emitting diodes. Light treatment had a certain positive effect on the firmness, size, and mass of samples. Thus, tomato fruits (Panekra) exposed to the spectra of LED lights demonstrated a better quality of firmness and mass compared to the control samples (non-preserved) of tomatoes. The treatments with RL significantly improved the concentration of lycopene than FL and UV-LED lights, although the highest concentration of lycopene was observed in the control samples for the first 7 days of the storage. After 21 days, the ascorbic acid content in the red spectrum was found to be much higher than in the other two spectra and control samples, coming in at about 1.8 mg/100 mL compared to 1.0 mg/100 mL for the control samples. Total soluble solids also increased significantly after preservation, rising from 3.9 °Brix in the control samples to roughly 7.3 °Brix in samples preserved using the full spectrum after 21 days. Overall, the results of the study demonstrated that tomato preservation using the investigated techniques induced lycopene concentration, ascorbic acid, and total soluble solids concentrations. The results derived from this study provide highly useful information in the field of post-harvest preservation.

The biological variety of aquatic ecosystems is significantly impacted by the chemical and microbiological composition of water bodies, and there is strong reciprocal feedback between these two factors, especially for reservoirs, which can and do have a significant impact on neighboring ecosystems. Today there is an acute need to identify the most effective and economically feasible methods for cleaning and restoring water bodies. Therefore, the aim of the study was to find strains of microorganisms which are capable of biodegrading such problematic pollutants as insoluble phosphates and excess nitrogenous compounds and at the same time, are capable of suppressing the bacterial composition in reservoir waters. In the course of the research, a number of the most active strains of microorganisms were isolated from lake water samples. Five isolates were obtained from salt water and the isolates were then identified using morphological, and biochemical techniques, as well as the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In addition to the characterization and identification of the isolates, the species-specific levels of phosphate solubilizing, and nitrifying activities were also established. Thus, all isolated strains were studied and characterized, and their influence on the content of minerals such as phosphorus and nitrogen, which are important for living organisms in water, was studied. In summary, the Pseudomonas Extrem-Orientalis isolate was observed to be highly effective in solubilizing phosphates, nitrifying, and had the greatest antagonistic capacity among the investigated isolates. The information gleaned from the study’s findings helps raise more awareness in the field of microbiology and water treatment in general. The findings offer promise for the development of biopreparations with bioremediation capabilities for cleaning polluted water bodies of pollutants from various sources.

The efficiency of microbial inactivation in water is highly dependent on the type of treatment technology used as well as the characteristics of the water to be treated. Wastewater from poultry slaughterhouses carries a significant number of microorganisms posing threats to humans and the environment in general. Therefore, the treatment of poultry slaughterhouse wastewater requires the use of appropriate purification systems with high removal efficiency for microbial agents. In this study, the performance of an integrated treatment plant with electrolysis, ultrafiltration, and ultraviolet radiation as the principal treatment units was investigated in terms of microbial inactivation from poultry slaughterhouse wastewater. In this case, total microbial number, total coliform bacteria, thermo-tolerant coliform bacteria, pathogenic flora, including salmonella coliphages, spores of sulfite-reducing clostridia, Pseudomonas aeruginosa, and Staphylococcus aureus and Enterococcus were studied. Approximately 63.95% to 99.83% of the microbes were removed by the electrochemical treatment unit as well as a 99.86% to 100% removal efficiency was achieved after the combined treatment. However, Pseudomonas aeruginosa was the only microbial agent detected in the final effluent after the combined treatment. The phenomenon suggests that an upgrade to the treatment plant may be required to achieve 100% removal assurance for Pseudomonas aeruginosa.