An increase in the number of reports of legionellosis in the European Union and the European Economic Area have been recorded in recent years. The increase in cases is significant: from 6947 reports in 2015 to 11,298 in 2019. This is alarming as genus Legionella, which comprises a large group of bacteria inhabiting various aquatic systems, poses a serious threat to human health and life, since more than 20 species can cause legionellosis, with L. pneumophila being responsible for the majority of cases. The ability to colonize diverse ecosystems makes the eradication of these microorganisms difficult. A detailed understanding of the Legionella habitat may be helpful in the effective control of this pathogen. This paper provides an overview of Legionella environments in Europe: natural (lakes, groundwater, rivers, compost, soil) and anthropogenic (fountains, air humidifiers, water supply systems), and the role of Legionella spp. in nosocomial infections, which are potentially fatal for children, the elderly and immunocompromised patients. Graphical abstract
Defining the biological and physicochemical parameters in soil under illegally dumping sites provides information on the real threat and the direction of changes in the soil environment. The aim of the study was to investigate the effect of uncontrolled dump sites which differed in the composition of the waste deposited on the development of selected groups of soil microorganisms and the activity of redox enzymes and selected physicochemical soil parameters. Additionally, it was verified whether the biological and physicochemical parameters differ in soil depending on the depth (0–20 and 20–40 cm). The research covered three waste landfill sites (W1, W2, W3), the arable field (A) found in the zone of the effect of the dumping site as well as the control point (C). The microbiological analyses show that most amylolytic microorganisms (87.0 × 105 cfu), celullolytic (46.4 × 105 cfu), proteolytic (148.6 × 105 cfu) and bacteria in total (123.2 × 105 cfu) were isolated from the surface later of control soil (C), and definitely least—from the area of dumping sites W1 and W2. The waste accumulated in W1 and W2 led to the soil depletion in organic matter, inhibited the development of microorganisms and their enzymatic activity. The soil under landfill site W3 showed the highest values recorded for physicochemical properties, the count of Actinobacteria, as well as the activity of dehydrogenases and catalase. The concentration of heavy metals in soil under landfill site W3 was even tenfold higher than the values recorded at the other measurement points, which must have been due to the effect of the type of the waste dumped in landfill site W3, where biodegradable waste of organic origin dominated. Disturbing the biological control and unfavourable changes in the microbiocenotic composition were mostly revealed in soil at landfill site W1.
Tillage is an agrotechnical practice that strongly affects the soil environment. Its effect on soil properties depends on the system and, more specifically, on the degree of soil inversion and loosening. Strip-till is a non-inversive method that loosens only narrow soil strips. In strip-till one-pass (ST-OP) technology, tillage is combined with a simultaneous application of fertilizers and seed sowing. In a static multi-year field experiment, the soil properties after application of ST-OP for 8 years were compared to those of soil under conventional tillage with the use of a moldboard plough to a depth of 20 cm (CT), and equally deep loosened and mixed reduced tillage (RT). A field experiment of these three treatments was performed since 2012 in sandy loam soil, Luvisol. A total of 44 features were examined that described the physical, chemical, biological, and biochemical soil properties in the 0–20 cm layer, and penetration resistance (PR), bulk density (BD), and soil moisture (SM) in the 25–30 cm layer. The influence of the ST-OP technology on the yield of crops was also determined. Multivariate analysis shows that the ST-OP method, in terms of affecting the soil properties, differs considerably from RT and CT treatments. The soil after the ST-OP method contained two- to four-fold more earthworms (En), with a mass (Em) 2- to 5-fold higher, than those in the soil following RT and CT, respectively. In the ST-OP soil the content of available phosphorus (Pa) and available potassium (Ka); the total count of bacteria (Bt), cellulolytic microorganisms (Bc), and fungi (Ff); and the activity of phosphatases (AlP, AcP) were significantly higher. Compared with CT, the content of total organic carbon (Ct) and its content in the fractions of organic matter were also higher, with the exception of humins (CH). The yields of winter rapeseed and winter wheat using the ST-OP technology were marginally higher compared with those using the CT and RT technology.
The present research aimed to assess the influence of illegal dumping on changes in the content of phosphorus and its relationship with selected chemical properties. Soil was sampled from two horizons: 0–20 and 20–40 cm. Samples from points W1, W2 and W3 (waste 1, 2 and 3) were collected directly from under illegally deposited landfill sites that differed in the morphological composition. At a distance of 30 m from landfill W3 there were agricultural lands where maize was cultivated (arable soil, AS). The control point (C) was located far from the waste landfill sites determined and beyond the range of their effect. In soil the following were determined: total organic carbon, phosphorus (total, organic, mineral, available, active), the microbiological activity, the content of heavy metals and the activity of alkaline and acid phosphatase. The study concluded that the composition of treatments W1 and W2 had a more negative impact on the soils than landfill site W3. The results show that the changes depended on the type of the waste deposited. In AS and landfills W3 there was observed a high P availability and count of bacteria. The results have shown that an addition of organic residues to soil has a variety of effects on microbial and phosphatase activities. The lowest resistance (RS) for alkaline and acid phosphatases was found in soil from the area of dumping sites W1 and W2; the highest RS was determined in AS. Statistical analyses of simple correlations showed clearly that microbiological populations were also particularly implicated in the activity of phosphomonoesterases.
Compared to conventional agriculture, organic farming is believed to provide a higher nutritional and health value in its products due to the elimination of harmful contaminants (pesticides, nitrates, heavy metals, etc.). Numerous studies have been conducted to show how the production system affects the quality of food in terms of the content of bioactive compounds. The aim of this study was to compare the content of some bioactive compounds (vitamin C, β-carotene, Ca content) and lactic acid bacteria (LAB) number and their bacteriocinogenic activity in organic and conventional fermented food. Although the results do not provide an unambiguous conclusion regarding the superiority of one production system over the other, the LAB number in organic pickled carrot juice, sauerkraut, yogurt, and kefir was higher than in their conventional counterparts. Their bacteriocinogenic potential against selected pathogens was also higher in most organic products. Organic vegetables contained significantly more vitamin C, and the calcium content in the organic yogurt was higher compared to the conventional version of the product. Relatively similar concentrations of ß-carotene for both production systems were found in carrot juice, while in organic pickled beet juice, there was five-fold less ß-carotene than in conventional juice.