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Zinc oxide, manganese dioxide, and silicon dioxide nanoparticles were individually tested for managing the bacterial leaf spot disease complex of beetroot (Beta vulgaris L.) caused by Meloidogyne incognita and Pseudomonas syringae pv. aptata. The combined presence of both pathogens resulted in significant reductions in plant growth and photosynthetic pigments while increasing proline contents more than either pathogen alone. Foliar application of nanoparticles significantly improved plant growth, chlorophyll, carotenoid, and proline levels in infected plants. Among the treatments, zinc oxide nanoparticles had the most pronounced positive effects followed by silicon dioxide and manganese dioxide nanoparticles. Zinc oxide nanoparticles also significantly reduced root galling, nematode population, and disease indices. Principal component analysis highlighted the distinct influence of each nanoparticle on disease management with zinc oxide nanoparticles proving the most effective. [ABSTRACT FROM AUTHOR]

The presence of nitrate and heavy metals in wastewater are common but serious problem throughout the world. Thus, considering their toxicity, in the present study, denitrification-induced carbonate precipitation by Pseudomonas aeruginosa was researched in the simultaneous removal of nitrate and cadmium. Prior to the experimentation, P. aeruginosa was immobilized in bio-composite material (BCM) comprised of varying concentration of bentonite and alginate. The BCM with formulation 3% (m/v) bentonite and 1% (m/v) alginate (BA3) was found to more sustained and controlled release of bacterial cells in the solution, thus was utilized for bioremediation studies. The BCM with formulation BA3 effectively removed nitrate and Cd2+ by 93 and 74% (m/m), when their initial concentrations were 100 and 5 mg/L, respectively, in 24 h. Further, the P. aeruginosa cells inside the BCM were able to produce nitrite reductase and nitrate reductase in the spiked solution. Based on experimental results, denitrification by BCM reduced nitrate, generated alkalinity, and formed bicarbonate ions that, when reacting with Cd2+ ions, formed cadmium carbonate. The research presented in this study is important to know the significance of bio-composite material with denitrifiers in actively producing key enzymes of denitrification leading to simultaneous removal of nitrate and heavy metal from water. [ABSTRACT FROM AUTHOR]

Looking from the mechanical point of view the suspension containing the bacteria may be considered as a system of living active ultrafine particles. Here a model is developed for the interaction of the bacterium in an oblique direction during contact. The model considers an adhesive bacterium moving through a fluid, acting with appropriate specific forces, such as steric, electrostatic double layer and hydrodynamic forces. To understand the influence of the latter hydrodynamic forces on the bacterium, numerical experiments using DEM are carried out with this force and without it. A comparison of these two cases shows the difference in movement. [ABSTRACT FROM AUTHOR]

Increased use of fertilizers under intensive agriculture has the possibility of environmental contamination. The use of microbial inoculants may be effective in sustaining crop productivity, soil health, and supplementing chemical fertilizers. The investigation evaluated responses of arbuscular mycorrhizal (AM) fungi, Glomus mosseae (G) and Acaulospora laevis (A) and the bacterium Pseudomonas fluorescens (Pf) on bell pepper (Capsicum annuum L.) when provided superphosphate at F1 = 60 kg ha−1 (0.45 g/pot), F2 = 120 kg ha−1 (0.90 g/pot), or F3 = 240 kg ha−1 (1.80 g/pot). Plant growth, nutrient content, and yield 120 days after transplanting (DAT) were determined. Plants responded best to F1 followed by F2, while F3 produced inhibitory effects. The highest AM colonization and spore numbers were with G + A+ Pf, resulting in an increase in chlorophyll content, root phosphatase activity, shoot fresh weight, early fruit formation, number of fruit/plant, fruit size, weight, and early ripening. Inoculation with G. mosseae alone increased leaf area, photosynthesis, plant height, root freshness and dry weight. The G+ Pf commonly produced highest shoot fresh weight and fruit nutrient content. The effectiveness of these inoculants on bell pepper growth and yield was highest; 60 and 120 kg ha−1P-fertilizer level when amended with G + A+ Pf. Use of AM or micro-inoculants may reduce fertilizer input and enhance nutrient utilization efficiency, which positively affected qualitative characteristics, nutrient uptake, and resistance to suboptimal conditions, but has few or little effect on quantitative characteristics. More work is needed to determine optimum rates of the materials tested to produce marketable size fruit. [ABSTRACT FROM AUTHOR]

Recent outbreak of the mango bacterial black spot disease has resulted in massive damages to the Ghanaian mango industry. Research was carried out to confirm the etiology of the disease. Diseased mango fruits and leaves were collected from Greater Accra (Asutuare and Dodowa), Eastern (Akuse, Somanya) and Volta (Juapong) regions, and the suspected causal bacterium was isolated. The pathogen was identified as Xanthomonas citri pv mangiferaeindicae based on cultural and morphological characteristics and sequence analysis of the cpn60 gene. The pathogenicity of the bacterial pathogen on mango and cashew was determined and its sensitivity to some selected copper based fungicides available in Ghana was evaluated by the agar diffusion bio-assay. All strains of the pathogen were able to cause disease symptoms on artificially inoculated mango and cashew leaves. The pathogen was highly sensitive to Copper oxychloride, Copper hydroxide and Coprous oxide at very low concentrations. [ABSTRACT FROM AUTHOR]

Introduction: The discoveries of HIV and Helicobacter pylori in the 1980s were landmarks in identification of novel pathogens causing unexplained infectious syndromes using conventional microbiological technologies. In the last few decades, advancement of molecular technologies has provided us with more robust tools to expand our armamentarium in this microbial hunting process. Areas covered: In this article, we give a brief overview of the most important molecular technologies we use for identification of emerging microbes associated with unexplained infectious syndromes, including 16S rRNA and other conserved targets sequencing for bacteria, internal transcribed spacer (ITS) and other target gene sequencing for fungi, polymerase and other gene sequencing for viruses, as well as deep sequencing. Then, we use several representative examples to illustrate how these techniques have been used for the discoveries of a few notable bacterial, fungal and viral pathogens associated with unexplained infectious syndromes in the last 20–30 years. Expert opinion: In the past and present, characterization of emerging pathogens of unexplained infectious disease syndromes has relied on a combination of conventional culture- and phenotype-based technologies and nucleic acid amplification and sequencing. In the next era, we envisage more widespread adoption of next generation technologies that can detect both known and previously undescribed pathogens. [ABSTRACT FROM AUTHOR]

From the deep-sea-derived bacterium Bacillus subterraneus 11593, a new indole alkaloid (1) was isolated along with three known compounds (2‒4). By detailed analysis of its NMR spectroscopic data, and further by the theoretical ECD calculations, the absolute configuration of the new compound was determined to be (R)-N-[2-(3-hydroxy-2-oxoindolin-3-yl)ethyl]acetamide, and named bacilsubteramide A. All four isolates were tested for anti-allergic bioactivities; however, none exhibited positive effect (IC50 > 0.2 mM). Noteworthily, it is the first report on secondary metabolites from the bacterium B. subterraneus. [ABSTRACT FROM AUTHOR]

AgBr–Ag3PO4nanostructures, prepared by an ionic liquid-assisted precipitation method, were used as the effective visible-light driven photocatalytic system for the treatment of wastewaters. The prepared samples were characterised by X-ray diffraction powder (XRD), Diffuse Reflectance Spectroscopy (DRS), Fourier transform infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and nitrogen adsorption–desorption isotherms (BET) methods. The photoactivity of the products was studied by degradation of rhodamine B dye andStaphylococcus aureus(S. aureus) Gram-positive bacteria. The photoreaction kinetics and mechanism over the nanostructures was investigated and according to the results, the kinetic of dye degradation was realised to be pseudo-first order. Moreover, we observed that the bacterial regrowth was at the lowest level after the photocatalytic treatment. The photogenerated electron–holes reacted with the species in the solution and produced the reactive radicals such as OH•, HO2•and O2•‾ which can attack the organic pollutants and pathogenic micro-organisms. The reuse ability tests indicated that the prepared nanostructures had considerable capacity for the photodegradation of the dye after five times of repeated using. [ABSTRACT FROM AUTHOR]

Antarctic biota evolved under the influence of a suite of geological and climatic factors, including geographic isolation of the landmass and continental shelves, extremely low temperatures and seasonality. Current warming trends in the continent and surrounding oceans may trigger substantial shifts in community composition and biodiversity, impacting the dominance of cold-adapted over more generalist species. Until recently, the diversity of microorganisms in cold environments was investigated only in terms of distribution, with little attention to their functional roles in important environmental processes. The ‘omic’ methodologies now offer effective tools to investigate the relationships between biodiversity and ecosystem functioning and to understand the evolutionary principles of adaptation and tolerance/resistance to extreme conditions. In this review we summarise how cold temperatures affect the physiology of microorganisms and focus on the molecular mechanisms of cold adaptation revealed by recent biochemical and genetic studies. [ABSTRACT FROM AUTHOR]

Over the past century, a number of synthetic antimicrobial agents have been discovered and developed, but drug resistance and toxicity are still the major hindrances to gaining successful therapeutic outcomes in many instances. Herbal medicines may represent a safe and useful supplement to existing chemotherapeutic therapies for the management of infectious diseases. Ganoderma has traditionally been used to treat chronic infectious diseases, such as chronic hepatitis and bronchitis in Asia, when it is administered alone or more often in combination with chemotherapeutic agents. Preclinical (in vitro and in vivo animal) studies indicate that Ganoderma exhibits a broad spectrum of antibacterial and antiviral activities, whereas data in human beings are scanty. Polysaccharides or triterpenoids from Ganoderma showed activities against Herpes simple virus, Hepatitis B virus, HIV, and Epstein-Barr virus in vitro or in animal models. Ganoderma species also contain antibacterial constituents inhibiting gram-positive and/or gram-negative bacteria in vitro . However, it is difficult to extrapolate these findings to humans, as most of these preclinical studies were conducted under optimized conditions with the use of high doses of Ganoderma components. A double-blind, randomized, placebo-controlled clinical study indicated that treatment of hepatitis B patients with G. lucidum polysaccharides at 5400 mg/day for 12 weeks resulted in significantly decreased serum HBV DNA and hepatitis B e antigen (HbeAg) levels. The mechanisms for the antimicrobial and antiviral activities of Ganoderma are largely undefined. Currently available data do not support the use of Ganoderma as an antibiotic, but it may play an adjunct role for the management of bacterial and viral infection. Further studies are needed in humans. [ABSTRACT FROM AUTHOR]

Abstract not available. [ABSTRACT FROM AUTHOR]