Development and deployment of biosensors for the rapid detection of the 2019 novel severe acute respiratory syndrome—coronavirus 2 (SARS-CoV-2) are of utmost importance and urgency during this recent outbreak of coronavirus pneumonia (COVID-19) caused by SARS-CoV-2 infection, which spread rapidly around the world. Cases now confirmed in February 2022 indicate that more than 170 countries worldwide are affected. Recent evidence indicates over 430 million confirmed cases with over 5.92 million deaths scattered across the globe, with the United States having more than 78 million confirmed cases and over 920,000 deaths. The US now has many more cases than in China where coronavirus cases were first reported in late December 2019. During the initial outbreak in China, many leaders did not anticipate it could reach the whole world, spreading to many countries and posing severe threats to global health. The objective of this review is to summarize the origin of COVID-19, its biological nature, comparison with other coronaviruses, symptoms, prevention, treatment, potential, available methods for SARS-CoV-2 detection, and post-COVID-19 symptoms.

This study examines the effect of biochar as an agricultural soil supplement on soil quality indicators, specifically enzyme activity in Missouri regions. While the benefits of biochar on soil bulk density, soil organic carbon, and infiltration have been established, its effect on soil enzyme activity has remained underexplored in this region. A three-year field investigation was conducted with six treatments (compost, biochar, compost + biochar, biochar + compost tea, fescue, and control) to evaluate the effects on enzymes such as β-glucosidase (BG), acid and alkaline phosphatases (ACP-ALP), arylsulfatase (ARS), dehydrogenases (DG), arylamidase (AMD), cellulase (CLS), and urease (URS). Furthermore, soil pH, organic matter (OM), and cation exchange capacity (CEC) were determined. The results showed that compost and biochar treatments considerably increased soil enzyme activity compared to other treatments, with nitrogen application further increasing enzyme activity. Soil pH, OM, and CEC were all important determinants in determining enzyme activity, with BG demonstrating strong positive associations with ACP and AMD (99.5%). This study shows that compost and biochar amendments significantly improve soil physicochemical and biological properties, thereby enhancing soil health and assisting farmers’ sustainable soil management practices.

Regenerative practices such as rotational grazing and silvopasture are increasingly important in organic livestock production systems, where forage productivity and quality depend on soil health and long-term nutrient availability. Biologically active or labile soil organic matter (SOM) is a critical nutrient pool for plants and the soil food web. However, the impact of different regenerative practices on microbial communities and soil health indicators linked to the labile SOM pool remains underexplored in organic systems. A field study was conducted after 11+ years of organic management across four regenerative systems: cover crop–based annual cropping, rotationally grazed pasture, hayed pasture, and silvopasture with restored native prairie served as reference (“soil health target”). Labile SOM indicators included soil organic carbon (SOC), total nitrogen (TN), permanganate oxidizable carbon (POXC), potentially mineralizable nitrogen (PMN), phospholipid fatty acid (PLFA) profiles, and enzyme activities were analyzed. Treatment effects were evaluated using an effect size approach, and microbial community structure was assessed using non-metric multidimensional analysis (NMDS) with Bray–Curtis dissimilarity. Although no statistically significant differences were observed (p > 0.05), effect size analysis revealed meaningful patterns. Hayed pasture approached restored prairie levels in SOC, PMN, and TN. Grazed pasture had the lowest enzyme activities, while the cover crop system tended toward increased POXC. Restored prairie supported distinctive bacterial community structure. Eleven-years of organic management did not lead systems to converge toward restored prairie conditions, though hayed pasture demonstrated favorable trends. Further research is warranted to elucidate mechanisms driving enhanced SOC, PMN, and TN in hayed pasture. Graphical Abstract

Improved rapid and sensitive biosensors for detecting foodborne pathogens in the environment are urgently needed to curtail disease outbreaks. This study aims to develop and optimize a fast and sensitive biosensor for detecting Escherichia coli O157 using an advanced Förster Resonance Energy Transfer (FRET) technology. Building on recent FRET technological advancements, we intend to measure the degree of interaction between primary antibodies labeled with fluorescein isothiocyanate (FITC) and secondary antibodies labeled with tetramethyl rhodamine isothiocyanate (TRITC) in a sandwich format. This study assesses the detection of E. coli O157:H7 at various pH levels in contaminated lettuce juice. A detection range of 10² to 10⁴ CFU/mL after a 4-h pre-enrichment at 37 °C enabled sensitive quantification. In this FRET-based method, FITC-IgG was used as the donor and TRITC-IgY as the acceptor. Samples were stimulated at 350 nm, and emissions were measured from 500 to 680 nm, capturing a wide range of fluorescence signals. FRET microscopic fluorescence imaging was used to determine how pH affects the concentration of live E. coli O157:H7. The results showed that pH change has a considerable impact on detection. The approach illustrates FRET’s effectiveness in identifying live pathogens under diverse settings, indicating its underlying relevance in pathogen identification. • FITC-labeled primary antibodies and TRITC-labeled secondary antibodies were used in a sandwich arrangement to optimize a Förster Resonance Energy Transfer (FRET) biosensor for the detection of E. coli O157:H7. • A detection range of 10² to 10⁴ CFU/mL was achieved by pre-enriching the samples for four hours at 37 °C. Emissions from 500 to 680 nm were recorded after exciting the samples at 350 nm to measure fluorescence signals. The LOD and LOQ were found to be 168 CFU/mL and 510 CFU/mL, respectively. • E. coli O157:H7 detection in contaminated lettuce juice at varying pH levels was examined using FRET microscopic fluorescence imaging, which demonstrated a notable influence of pH on pathogen identification.

The magnitude of bacterial transport through runoff into surface water or infiltration into groundwater is influenced by the adsorption processes in soil. The objective of this study was to evaluate fluorescent‐labeled Escherichia coli (E. coli) adsorption by soil under agroforestry buffer (AB), grass buffer (GB), and row crop (RC) management. Adsorption experiments were conducted by inoculating three masses (0.5, 1, and 10 g) of each treatment (AB, GB, and RC) with E. coli O157:H7‐GFP with concentration ranges of 10⁵–10⁸ colony‐forming units (cfu) ml⁻¹. Adsorption data were evaluated using Langmuir, Freundlich, and Temkin adsorption isotherm models. The Freundlich isotherm model described the observed data well for all treatments using the 10‐g soil mass, with the R² values closer to unity in all treatments. The Freundlich K_f parameter, an indicator of adsorption capacity, was higher for the AB treatment (9.93 cfu ml⁻¹) compared with the GB and RC treatments (2.32 and 1.27 cfu ml⁻¹, respectively). The multiple pairwise comparisons test (Tukey test) of the Freundlich 1/n_f parameter demonstrated a significant difference (p < .05) between the AB treatment and the RC and GB treatments. Similarly, the K_f values were significantly (p = .05) higher for the 10‐g mass under the same test conditions, but no significant differences were observed in the 0.5‐ and 1‐g masses. This study demonstrated that AB has a higher E. coli adsorption capacity and the potential for mitigating the effects of E. coli O157:H7 transport to surface or groundwater through the soil ecosystem.