Because of significant yield losses caused by fungal pathogens, new efficient and environmentally safe methods of pest control are needed, and amphiphilic compounds (biosurfactants) produced by many microbes are considered a good alternative. In the present study, biosurfactants produced by the rhizosphere isolate Bacillus mojavensis P1709 were assessed for their ability to protect postharvest cherry tomatoes from decay and mycotoxin contamination caused by Fusarium oxysporum f. sp. lycopersici. It was demonstrated that the genome of B. mojavensis P1709 contained the fenD and srfAA genes, which are responsible for the synthesis of compounds of the fengycin and surfactin families. APF (acid-precipitated fraction) of B. mojavensis P1709 culture medium at a concentration of 20 g L−1 inhibited pathogen radial growth on agar plates by 93%, and T-2 and HT-2 mycotoxin production by 98%, after 5 days of cultivation. APF also suppressed fungal growth in the in vivo test on cherry tomato fruits by 93% and 25% on the 2nd and 7th days of incubation, respectively. The results obtained demonstrate that biosurfactants produced by B. mojavensis P1709 are an efficient tool for protecting postharvest cherry tomatoes from fungal mold decay and mycotoxin contamination.

The number of registered cases of COVID-19 is increasing in the world, and some countries are reporting a second wave of the pandemic. Accurate and real time information about epidemiological situation is therefore urgently needed for managing decisions in the countries, regions and municipalities which are affected. Massive testing of viral presence in human saliva, a smear from the nose, nasopharynx and / or oropharynx, bronchial lavage water obtained by fibrobronchoscopy (bronchoalveolar lavage), as well as from (endo) tracheal, nasopharyngeal aspirate, sputum, biopsy or autopsy material of the lungs, whole blood, serum or antibodies presence in blood cannot give relevant information about the COVID-19 infection rate in the community since simultaneous testing of the whole community is not technically possible, the information obtained in testing of specific groups is retarded and, in addition, such testing is expensive. The alternative to mass testing of the population is the testing of wastewater that could contain SARS-CoV-2 particles originating from excreta. Such testing has several limitations connected with the particularities of the testing procedure. In the present study, a modified approach for detection of COVID-19 infection rate using wastewater analysis has been developed. The approach includes i) the creation of a calibration curve on the basis of the serial dilution of excreta collected from people who are infected with COVID-19 and ii) the analysis of wastewater samples and their serial dilutions but the approach excludes usage of concentration techniques before wastewater sample analysis as well as usage of external control in RT-PCR reactions for calculation of numbers of viral particles. The minimum infection rate that can be detected using this approach is 0.01%. The approach developed was used to investigate wastewater from eleven sewage inspection chambers in the city of Kazan (Russia). It was demonstrated that the average infection rate of people using these sewers was over 0.4% in July 2020.

One way to increase yields in agriculture using organic alternative methods is the introduction of manure-based composts into the soil. However, the use of such composts carries a risk of soil contamination with antibiotic resistance genes (ARG) from the gut and manure of the livestock. The contamination of the composts with heavy metals or antibiotics can increase this risk, while the addition of porous materials, such as biochar, to the composts has the potential to decrease it. This study is devoted to revealing the fate of ARGs in bedding chicken manure composted with the addition of oxytetracycline (OTC), heavy metals, and chicken manure biochar. It was revealed that the additives did not affect the physicochemical parameters of the compost. The bacterial communities in different composting mixtures had similar structures and dynamics. It was revealed that the shifts of the bacterial compositions of the composting mixtures were mainly determined by the duration of the process. However, some minor differences in the OTU (operational taxonomic unit) levels were observed between the variants. The addition of biochar and metals led to 26.7% and 34.5% decreases, respectively, in the number of tet(A) gene copies, while the addition of oxytetracycline led to a 43.7% increase. The number of copies of the int1 gene increased by 45.9% after the addition of oxytetracycline. The correlation between the abundance levels of different bacterial OTU and ARG contents was estimated, and biochar’s impact on those OTUs was analyzed. It was assumed that some OTUs might be carriers of ARGs (such as Natronobacillus, Luteimonas, and Trichococcus), and their abundance in the presence of the biochar decreased due to competitive exclusion by noncarriers (such as Corynebacterium, Clostridia, and Halorhodospira). The use of biochar in composting can be considered a way to reduce the contamination of the final composts with ARGs.

Chicken manure is a source of biogenic elements and therefore can be used as a nonconventional fertilizer after composting. However, chicken manure can contain different hazardous substances including antibiotic resistant bacteria and corresponding genes of antibiotic resistance that can be transmitted to human and livestock trough soils and plants even after composting. Besides chicken manure composts can contain heavy metals that not only harm soils and yields directly but also stimulate the process of antibiotic resistance genes transfer and therethrough harm soils and plant consumers indirectly. The purpose of the present study was to reveal the potential of the chicken manure biochar, the type of biochar that is not fully studied yet, as a tool to reduce the level of available heavy metals content in the chicken manure composts. For this purpose, chicken manure was composted with straw (control), and with addition of heavy metals mixture (M) as well as with addition of those with 15% chicken manure biochar (BM). Ni, Fe, Cd and Cu were added to the compost mixtures M and BM to reach concentrations of 70, 1500, 130, and 1000 mg/kg, respectively. Composting lasted for 120 days, in all three cases � C, M and BM - the thermophilic stage phase lasted from days 2 to 5, and the temperature values were 44-53 ?�. It was found that chicken manure biochar is an effective way to reduce the content of available forms of Cd, Fe and Ni at the early stages of composting and reduces the concentration of those metals by 47, 17 and 45 % on the first day, respectively.

Composting chicken droppings with the addition of biochar and an antibiotic led to a decrease in the concentration of oxytetracycline on the 28th day and an increase in the amount of the resistant tet(X) gene.