Appl. Biosci., Volume 2, Issue 3 (September 2023) – 11 articles

Bacterial contamination of water and food sources is still a major source of diseases. Early detection of potential pathogens is key to prevent their spreading and severe health risks. Here, we describe a fast, low-cost detection assay based on horseradish peroxidase (HRP) conjugated to streptavidin for the direct identification of bacteria. Streptavidin can bind to bacterial cells due to its high affinity for biotin, a natural component of microbial cell surfaces. Upon binding to bacteria, the HRP converts a chromogenic substrate, resulting in a visible color change. In the present study, we evaluated different detection platforms regarding their compatibility with the detection principle. To reduce background signals and increase the sensitivity of HRP-based assays, the binding of HRP to surfaces and biomolecules was intensively investigated. The final assay successfully detected the most relevant bacterial strains in drinking water, such as Escherichia coli, Klebsiella pneumonia, and Enterobacter cloacae. Full article

Dermatoses are essentially caused by infection or free radical aggression, immunoallergic disorders, or can be secondary to general diseases. Management of dermatoses by modern medicine is complex and costly, and the development of alternative treatments is urgent. Opilia amentacea Roxb. is a woody climber plant traditionally used in Burkina Faso for treatment of bad skin diseases. This study was carried out to evaluate the antimicrobial and antioxidant activities of extracts of O. amentacea and to characterize potent fractions. The antimicrobial activity was determined using the disc diffusion and microdilution methods, while antioxidant activity was assessed using the 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) assays. The content of the plant extracts in polyphenols and flavonoids was also studied. The results revealed several secondary metabolites in the leaves, stems and root bark extracts of the plant, including sterols, triterpenes, and flavonoids and tannins, and a generally high total polyphenol and total flavonoid content. Dichloromethane fractions of leaves (FDFe) and stem barks (FDET) exhibited the best antioxidant activity and were the most active on Gram-positive bacilli. Hexane leaves (FHFe) and hexane root bark (FHER) fractions exhibited the best antifungal activity against Candida tropicalis. High correlation (R² = 0.932) was found between the total flavonoid content of extracts and ferric-reducing antioxidant power. In view of these results, the present study describes O. amentacea as a potential source of antibacterial, antifungal and antioxidant agents and justifies the traditional uses of the plant as an anti-dermatosis plant. Full article

The interest in under-utilized crops as a functional food for animals and humans has been increasing recently with advancing research and the need for crop improvement. Canadian forage crops including alfalfa (Medicago sativa L.) and fenugreek (Trigonella foenum-graecum L.) are marketed in various forms due to their traditionally known health benefits. Sainfoin (Onobrychis viciifolia Scop.) is another forage crop with potential health benefits containing beneficial nutraceuticals. In this study, we assessed selected bioactive phenolic compounds and fatty acids in seeds and seedlings of Canadian-grown alfalfa, sainfoin, and fenugreek. Various phenolic compounds were detected in all three forage crop seeds and seedlings. In general, Sainfoin seeds were high in phenolic compounds relative to that of alfalfa and fenugreek. Chlorogenic acid, epigallo catechin, and gallic acid were at high concentrations at 56.6, 86.8, and 64.7 µg.g⁻¹, respectively, compared to other phenolic compounds in sainfoin seeds. The fatty acids content (%) was significantly affected by the seedling stage and crop type. Some of the bioactive compounds present in seeds were not detected in seedling stages. The comparative bioactive phenolic compounds and fatty acid assessments of these forage legumes could potentially be used as biomarkers for the selection and development of favorable cultivars for animal and human nutrition. In addition, these crops could be used for isolating these bioactive compounds, and thus increasing their agri-food value. Full article

Deregulated transcription is a well-known characteristic of cancer cells, with differentially expressed genes being a common feature of several cancers. Often, deregulated transcription is a consequence of alterations in transcription factors (TFs), which play a crucial role in gene expression and can act as tumour suppressors or proto-oncogenes. In eukaryotic organisms, transcription is carried out by three distinct RNA polymerase complexes: Pol I, Pol II, and Pol III. Pol II, specifically, is responsible for transcribing messenger RNA (mRNA), the protein coding part of the genome, as well as long non-coding RNAs (lncRNAs). While there is considerable research on the impact of specific deregulated transcription factors in cancer development, there is a lack of studies focusing on defects within the RNA polymerase complexes and their subunits. This review aims to shed light in particular on the Pol II complex and highlight the deregulation of its subunits that have a significant impact on tumour development, prognosis, and survival. By providing a comprehensive overview of our current understanding of Pol II subunits in cancer, this review emphasizes the importance of further research in this area. It suggests that exploring these subunits’ deregulations could lead to the identification of valuable biomarkers and potential therapeutic targets, making it a topic of collective interest. Full article

Rapid and accurate pathogen identification is crucial in effectively combating infectious diseases. However, the current diagnostic tools for bacterial infections predominantly rely on century-old culture-based methods. Furthermore, recent research highlights the significance of host–microbe interactions within the host microbiota in influencing the outcome of infection episodes. As our understanding of science and medicine advances, there is a pressing need for innovative diagnostic methods that can identify pathogens and also rapidly and accurately profile the microbiome landscape in human samples. In clinical settings, such diagnostic tools will become a powerful predictive instrument in directing the diagnosis and prognosis of infectious diseases by providing comprehensive insights into the patient’s microbiota. Here, we explore the potential of long-read sequencing in profiling the microbiome landscape from various human samples in terms of speed and accuracy. Using nanopore sequencers, we generate native DNA sequences from saliva and stool samples rapidly, from which each long-read is basecalled in real-time to provide downstream analyses such as taxonomic classification and antimicrobial resistance through the built-in software (<12 h). Subsequently, we utilize the nanopore sequence data for in-depth analysis of each microbial species in terms of host–microbe interaction types and deep learning-based classification of unidentified reads. We find that the nanopore sequence data encompass complex information regarding the microbiome composition of the host and its microbial communities, and also shed light on the unexplored human mobilome including bacteriophages. In this study, we use two different systems of long-read sequencing to give insights into human microbiome samples in the ‘slow’ and ‘fast’ modes, which raises additional inquiries regarding the precision of this novel technology and the feasibility of extracting native DNA sequences from other human microbiomes. Full article

As schools go digital, the use of tablet computers is increasing. Concerns are raised that the extensive use of tablets and the associated bent-over posture may negatively affect the individual’s health. In order to analyse the possible effects of prolonged tablet use on physical health, a detailed analysis of the posture during tablet use is needed so that appropriate preventive measures can be taken to prevent degenerative changes. Therefore, the aim of this study was to measure and report the posture of 56 students while working with a tablet computer and compare it with an upright posture. Sagittal and frontal images were used for measurements of the subjects’ postures while seated, using the tablet, and in a neutral sitting position looking straight ahead. The body position during tablet use was recorded in two different user configurations: tablet flat on the table and tablet in individual freely chosen user configuration. After appropriate annotation of the data, the following parameters were evaluated in different planes. The craniovertebral angle (CVA), head tilt angle (HTA), and forward shoulder angle (FSA) are measurements that describe the extent to which the head bends forward and downward and how the shoulders are aligned in the sagittal plane. On the other hand, the head shoulder angle (HSA), lateral head tilt angle (LHTA), and trunk flexion angle (TFA) are angles measured in the frontal plane, which indicate the degree of head tilt and trunk bending to the right or left side. The measurement results clearly showed that the use of a tablet had a pronounced effect on the positions and rotations of the participants’ head, neck, and shoulders. This was evident through strong deviations observed in the angles measured between the sitting straight posture and the postures while using the tablet. For example, depending on the body posture class, the mean CVA values were 45.76° for straight sitting posture, 28.25° for holding the tablet individually posture, and 26.04° for the posture adopted while using a tablet placed flat on the table. Full article

Two-P-domain K⁺ (K2p) channels are responsible for maintaining the resting membrane potential. K2p channels have varied expression in healthy tissue, but they also change in cancerous or diseased states. The correlation and causation as regards the alteration of K2p channel expression are still being investigated. The compound doxapram seems to block K2p channels and depolarize cells. Using Drosophila, the increased expression of the ORK1 K2p channel in cardiac and skeletal muscle was investigated. The heart rate in larval Drosophila is very sensitive to pH, and since doxapram blocks a subset of the K2p channels that are known to be acid-sensitive, it was postulated that doxapram would affect heart rate. A pH change from 7.1 to 6.5 increased the rate, while that from 7.1 to 7.5 decreased the rate. An amount of 0.1 mM of doxapram had no effect, but 0.5 of mM depressed Drosophila heart rates within five minutes. Exposure to 5 mM of doxapram immediately decreased the rate. Lipopolysaccharides (LPSs) from Gram-negative bacteria acutely increased the rate. LPSs activate K2p channels in the skeletal muscle of larvae and are blocked by doxapram. LPSs slightly reduce depression in the rate induced by doxapram. The overexpression of K2p channels in the heart and skeletal muscle depressed the heart rate and heightened pH sensitivity. At larval neuromuscular junctions, the overexpression in skeletal muscle increases the frequency of spontaneous quantal events and produces a more negative resting membrane potential. Full article

The build-up of lipofuscin—an age-associated biomarker referred to as hyperfluorescence—is considered a precursor in the progression of geographic atrophy (GA). Prior studies have attempted to classify hyperfluorescent regions to explain varying rates of GA progression. In this study, digital image processing and unsupervised learning were used to (1) completely automate the extraction of hyperfluorescent regions from images, and (2) evaluate prospective patterns and groupings of hyperfluorescent areas associated with varying levels of GA progression. Patterns were determined by clustering methods, such as k-Means, and performance was evaluated using metrics such as the Silhouette Coefficient (SC), the Davies–Bouldin Index (DBI), and the Calinski–Harabasz Index (CHI). Automated extraction of hyperfluorescent regions was carried out using pseudocoloring techniques. The approach revealed three distinct types of hyperfluorescence based on color intensity changes: early-stage hyperfluorescence, intermediate-stage hyperfluorescence, and late-stage hyperfluorescence, with the early and late stages having three additional subclassifications that could explain varying levels of GA progression. The performance metrics for early-stage hyperfluorescence were SC = 0.597, DBI = 0.915, and CHI = 186.989. For late-stage hyperfluorescence, SC = 0.593, DBI = 1.013, and CHI = 217.325. No meaningful subclusters were identified for the intermediate-stage hyperfluorescence, possibly because it is a transitional phase of hyperfluorescence progression. Full article

Medicago sativa (2n = 4x = 32) and M. arborea (2n = 4x = 32) were thought to be reproductively isolated until hybrids (Alborea) were produced by sexual reproduction for the first time in 2003 in Wisconsin. The hybrids were asymmetric, at or near 2n = 4x = 32, and with a predominance of the alfalfa genome. Only M. sativa seed parents with reproductive abnormalities, including unreduced eggs, have produced hybrids; where M. arborea has been used as the seed parent, no hybrids have resulted. Pedigree selection within derivatives of the two original M. sativa seed parents (MB and M8) has been successful in increasing the frequency of hybrids produced. While Alborea individuals more closely resemble M. sativa, a number of M. arborea-specific traits have been observed across different hybrid individuals. These include single-coil flat pods, large seeds, yellow flowers, indeterminate growth, a minimal crown, lodging, frost resistance, and anthracnose resistance. These M. arborea traits have the potential to restructure alfalfa to increase its versatility and utilisation. There is emerging evidence from North and South America and Australia that some Alborea selections have the capacity to complement adapted alfalfa cultivars for yield. Work is continuing to introgress M. arborea traits of value into alfalfa. Full article

Red wine grapes have an important impact on the economy of many regions, both for wine quality and for their richness in phenolic compounds, which have many health benefits. Climate has been changing substantially in the last years, which affects greatly grape polyphenolic composition and wine quality. In this review, we will unveil the importance of climate in grape development, both physically and chemically, the different methodologies used to evaluate grape quality, the interesting new approaches using NIR spectroscopy, and the functional properties of grapes and red wine, due to their high phenolic content. Climate has an impact in the development of phenolic compounds in grapes, namely in the anthocyanins biosynthesis. The phenolic chemical composition changes during maturation, therefore, it is essential to keep on track the accumulation of these key compounds. This information is crucial to help producers choose the best harvest date since specific compounds like polyphenols are responsible for the color, taste, and mouthfeel of wines, which directly affects wine quality. The usage of different methodologies to assess quality parameters in grapes and wine, can be used to provide essential information to create the chemical profile of each variety to develop calibration methods. NIR spectroscopy seems to be a reliable method to be used in vineyards during grape maturation to provide real time information on quality parameters to producers since many reliable calibration models have been developed over time. Full article

The metabolic diversity of soil microbiota embodies diverse functional capabilities that support ecosystem resilience, driving essential biogeochemical processes and facilitating the optimization of sustainable agricultural systems. Integrating cover crops into agricultural systems cultivates a diverse array of metabolic activities among soil microbes, synergistically enhancing ecosystem services and bolstering soil health for sustainable and productive farming practices. In an effort to gain deeper insights and expand our knowledge, we conducted a study examining the effects of cover crops and fertilizer sources, thereby shedding light on their combined impacts on the metabolic activity dynamics of soil microbial communities. In this investigation, we employed a split-plot design with two factors: (a) cover crop with three solo cover crop species—Cereal rye (Secale cereale), wheat (Triticum aestivum), hairy vetch (Vicia villosa), and one mixture of mustard (Brassica rapa) and cereal rye (Secale cereale) (CC-mix), (b) Fertilizer source includes poultry litter, chemical fertilizer, and no-fertilizer treatments. We assessed the metabolic potential of soil microbiota by using carbon substrates utilizing Biolog EcoPlates. The findings revealed that the plots with CC-mix treatment exhibited greater metabolic diversity compared to the other treatments, while among the fertilizer sources, poultry litter demonstrated higher metabolic activity. Furthermore, both treatment factors predominantly metabolized carbohydrates and polymers compared to other carbon substrate categories. The principal component analysis accounted for 46.4% of the variance, collectively represented by PC1 and PC2, emphasizing the substantial contributions of carbohydrates, amino acids, and carboxylic acids to the observed metabolic diversity. Canonical correspondence analysis revealed that pH had positively correlated with microbial functional diversity, whereas total carbon (TC), total nitrogen (TN), and water-stable aggregates (WSA) showed a negative correlation. In conclusion, cover cropping and type of fertilizer source had a notable impact on soil microbial functional diversity, with the cover crop mixture exhibiting a more pronounced influence than the individual cover crop treatments. Full article