Nanomaterials are increasingly being used in new products and devices with a great impact on different fields from sensoristics to biomedicine. Biosynthesis of nanomaterials by microorganisms is recently attracting interest as a new, exciting approach towards the development of ‘greener’ nanomanufacturing compared to traditional chemical and physical approaches. This review provides an insight about microbial biosynthesis of nanomaterials by bacteria, yeast, molds, and microalgae for the manufacturing of sensoristic devices and therapeutic/diagnostic applications. The last ten-year literature was selected, focusing on scientific works where aspects like biosynthesis features, characterization, and applications have been described. The knowledge, challenges, and potentiality of microbial-mediated biosynthesis was also described. Bacteria and microalgae are the main microorganism used for nanobiosynthesis, principally for biomedical applications. Some bacteria and microalgae have showed the ability to synthetize unique nanostructures: bacterial nanocellulose, exopolysaccharides, bacterial nanowires, and biomineralized nanoscale materials (magnetosomes, frustules, and coccoliths). Yeasts and molds are characterized by extracellular synthesis, advantageous for possible reuse of cell cultures and reduced purification processes of nanomaterials. The intrinsic variability of the microbiological systems requires a greater protocols standardization to obtain nanomaterials with increasingly uniform and reproducible chemical-physical characteristics. A deeper knowledge about biosynthetic pathways and the opportunities from genetic engineering are stimulating the research towards a breakthrough development of microbial-based nanosynthesis for the future scaling-up and possible industrial exploitation of these promising ‘nanofactories’.

Food safety plays an important and fundamental role, primarily for human health and certainly for the food industry. In this context, developing efficient, highly sensitive, safe, inexpensive, and fast analytical methods for determining chemical and biological contaminants, such as electrochemical (bio)sensors, is crucial. The development of innovative and high-performance electrochemical (bio)sensors can significantly support food chain monitoring. In this review, we have surveyed and analyzed the latest examples of electrochemical (bio)sensors for the analysis of some common biological contaminants, such as toxins and pathogenic bacteria and chemical contaminants, such as pesticides, and antibiotics.

Recent works have demonstrated that particulate matter (PM) and specific meteorological conditions played an important role in the airborne transmission of the SARS-CoV-1 and MERS-CoV. These studies suggest that these parameters could influence the transmission of SARS-CoV-2. In the present investigation, we sought to investigate the association between air pollution, meteorological data, and the Lombardy region COVID-19 outbreak caused by SARS-CoV-2. We considered the number of detected infected people at the regional and provincial scale from February to March 2020. Air pollution data were collected over the Lombardy region, nominally, sulphur dioxide, ammonia, nitrogen dioxide, nitrogen monoxide, carbon monoxide, ozone, and suspended particulate matter measuring less than 10 μm (PM10) and less than 2.5 μm (PM2.5). Meteorological data have been collected over the same region for temperature, relative humidity, and wind speed. In this work, we evaluated the combined impact of environmental pollutants and climate conditions on the COVID-19 outbreak. The analysis evidenced a positive correlation between spatial distribution of COVID-19 infection cases with high concentrations of suspended particulate matter and a negative relationship with ozone. Moreover, suspended particulate matter concentration peaks in February correlated positively with infection peaks according to the virus incubation period. The obtained results suggested that seasonal weather conditions and concentration of air pollutants seemed to influence COVID-19 epidemics in Lombardy region.

A study on the acute and chronic effects of the herbicide diuron was carried out. The test, basing on a yeast cell probe, investigated the interference with cellular catabolism and possible self-detoxification capacity of Saccharomyces cerevisiae. Aerobic respiration was taken as the toxicological end-point. Percentage interference (%r) with cellular respiration was measured in water by increased dissolved O₂ concentration (ppm) after exposure to different doses. Interference was calculated through the comparison of respiratory activity of exposed and non-exposed cells. Short-term and long-term (6 and 24 h respectively) exposures were also considered. The test for short-term exposure gave positive %r values except that for 10⁻⁶ M (11.11%, 11.76%, 13.33% and 0% for 10⁻¹⁰ M, 10⁻⁸ M, 10⁻⁷ M and 10⁻⁶ M respectively). In the case of long-term exposure the test showed positive %r values, but less effect than short-term exposure until 10⁻⁸ M and much higher at 10⁻⁶ M (7.41%, 8.82%, 11.76% and 6.06% for 10⁻¹⁰ M, 10⁻⁸ M, 10⁻⁷ M and 10⁻⁶ M respectively). The findings of aerobic respiration as toxicological end-point were in agreement with known mechanisms of toxicity and intracellular detoxification for both the doses and exposure times employed.