Indian Journal of Microbiology最新文献

Adenoviruses are important water borne pathogens. This viral candidate imposes major public health concerns with clinical manifestations including gastroenteritis, eye infections, and respiratory infections. Adenoviruses are found to be prevalent in rivers, pool waters, drinking water, and coastal waters. Adenoviruses are listed as contamination candidates for drinking water because of their survival characteristics during water treatment technologies. Therefore, it is important to monitor raw and treated water routinely for the presence of adenoviruses. PCR based molecular methods are considered most suitable for monitoring adenoviruses in environmental samples. Choosing the correct type of PCR depends on specific methods of approach and the type of viral assay. The present review summarizes the process of monitoring adenoviruses in water and wastewater through different PCR methods and their recent advancements. The review also covers a brief overview of PCR inhibitors.

In the present study, an economical and commercially viable process has been standardized using a novel strategy of recycling the mediator and reusing the enzyme for multiple cycles of denim bleaching. Bacillus cabrialesii SJ2 produced an extracellular laccase active/ stable in a wide range of temperature (40-70 °C) and pH (6-9). The enzyme yield was significantly enhanced with a 154-fold increase (2216.5 IUml^-1) under the optimized conditions. The enzyme efficiently degraded indigo carmine within 30 and 45 min at 50 °C/8.5 pH with and without a laccase-mediator, respectively. Enzyme was able to bleach denim without any mediator; however, effective bleaching was achieved in the presence of ABTS as a mediator. To make the process economical, the cost of the reaction was reduced by recycling the mediator and adding a reduced dose of enzyme for multiple bleaching cycles. In recycling studies, the same bleaching effect on fabric was maintained for up to eight cycles with the same mediator in the reaction mixture (500 µM ABTS) and the addition of reduced doses of the enzyme (10 IU in the first cycle and 5 IU in subsequent cycles). The mechanical properties of the enzymatically bleached fabric, elongation (7.6 mm), tensile strength (1105 N) and color fastness were comparable to those of the unbleached fabric and superior to the chemically bleached samples. This study represents the first report of standardizing a process by recycling the mediator and the enzyme for denim biobleaching, making it an economically viable and a practical alternative for industrial application.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-024-01418-z.

Tenuazonic acid (TeA) is a mycotoxin usually produced by Alternaria species. Its toxicological potency is considered to be the highest among all Alternaria-mycotoxins. The present study for the first time reports Paradendryphiella arenariae isolated from tomato (Lycopersicon esculentum) as a source of TeA mycotoxin, thus adding a new genus to the array of TeA-producing fungi. The study involves optimizing culture conditions for maximum TeA production, and employing analytical techniques to characterize the compound. Thin-layer chromatography and high-pressure liquid chromatography (HPLC) were employed for the isolation and characterization of the mycotoxin produced by P. arenariae. Structural elucidation was achieved using Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. Quantitative determination of TeA was conducted using HPLC with a standard TeA reference. The presence of TeA was further confirmed through electronspray ionization-mass spectrometry and high-resolution liquid chromatography-mass spectrometry. In cytotoxicity assays, the isolated TeA exhibited significant toxicity to murine splenocytes, with an IC₅₀ of 25 µg/mL. This study highlights the need for vigilance regarding TeA contamination in food products. The identification of P. arenariae as a new source of TeA underscores the importance of expanding monitoring efforts to include diverse fungal species. Ensuring food safety through stringent regulations and routine testing is essential to mitigate health risks associated with TeA exposure.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-025-01494-9.

The biotic stress induced by phytopathogens causes a significant loss to several crops in terms of yield and quality. Biotic stress may disrupt phenotypic characteristics and alter metabolic pathways in plants. Sustainable approaches like the employment of rhizobacteria control phytopathogens and diseases thereof through production of antimicrobial compounds and boosting plant defense systems. Rhizobacteria protect plants through mechanisms such as competition for food and niche to pathogens, production of antibiotics, induced systemic resistance and stimulation of antioxidant enzymes in plants helping them to mitigate pathogen-induced oxidative stress. This review concisely presents ample studies on the role of rhizobacteria in controlling phytopathogens including their mechanism of action, pathogenesis responsive metabolic pathways and regulatory genes. There are commercially available biocontrol agents for a variety of crops and more need to be developed based on host specificity and agro climatic conditions. This review further highlights the approaches for rhizobacterial formulation development and employment methods followed by future prospects to reduce the dependence on agrochemicals to ensure food security and quality using an eco-friendly sustainable approach. Encapsulated formulation of bacteria with nanomaterial is an innovative technological approach for enhanced efficacy and controlled delivery of active chemicals leading to suppression of plant disease severity more effectively versus bare bacteria to achieve improved plant health and food security.

The continuous rising volume of solid waste and depletion of conventional energy reserves are important global challenges which humanity faces in twenty-first century. Food waste (FW) constitutes major (organic) fraction of solid waste in the developing nations. Therefore, the segregation of food waste and its utilization for the generation of biogas through anaerobic digestion (AD) could provide a viable solution for the global challenges. Therefore, the present review article explores the possibility of sustainable biotransformation of FW into biogas production via AD process. The present article also describes various parameters including operational parameters (pH, temperature), prominent feed stocks, their properties, effective pretreatment impact on the anaerobic digestion of food waste (FW). Additionally, the bioprocess parameters which can improve the possibility of productivity of biogas at pilot scale level has been explored and discussed. Moreover, the most critical and influencing bioprocess parameters which can affect the pilot scale productivity at economical and commercial have been attempted to explored in detail and this is the novelty of this work which impacted adoption of commercial frequency of biogas as potential bioenergy option using FW for sustainable management.

Graphical abstract: Sustainable production advantages of biogas production using food waste feedstock and disadvantages of food waste release in the environment.

In the present study, plant mediated green synthesis approach was used for palladium nanoparticle synthesis from Punica granatum peels. The properties of bio-synthesized Palladium nanoparticles (PdNPs) were characterized using UV-Vis and FTIR spectroscopy, SEM, HRTEM and XRD. The HRTEM, SAED and XRD analysis showed that the crystalline monodispersed non-uniformly spherical nanoparticles were within a size range below 27 nm. Energy dispersive spectra (EDS) confirmed the elemental composition and FTIR analysis suggested the role of water-soluble polyols present in the P. granatum extract in mediating the synthesis of PdNPs. The PdNPs were evaluated for biomedical properties including in vitro antimicrobial, antioxidant activities along with both in vitro and in vivo anti-cancer properties. The study showed efficacy and MIC of the crude P. granatum peel extract and PdNPs as antimicrobial agents against S. aureus and C. albicans. In vitro anti-oxidant assay demonstrated enhanced scavenging activity of PdNPs. In vitro anticancer activity of PdNPs against A549 and MCF7 cells showed reduced viability of 43% and 32% respectively. The in vivo study validates its bioactivity claim. This is the first report on palladium nanoparticles with Punica granatum as promising antimicrobial and anticancer agents.

Fungal infections represent a worldwide risk to the health of animals, humans, and wildlife. Among the pathogenic fungal strains, Aspergillus flavus plays a key role in the onset of invasive aspergillosis (IA). Over a while, pathogenic fungi develop resistance to all licensed systemic antifungal drugs. The resistance development in fungal pathogens is attributed to the improper usage of drugs and the inference of the pathogen's cellular mechanisms. This concern could be resolved by the use of antifungal metabolites. Antifungal metabolites derived from Aspergillus giganteus are of profound interest in recent times due to their therapeutic potential. This particular antifungal protein (AFP) holds substantial promise in breaking the virulence mechanism in pathogenic fungi. In light of these circumstances, the study examined how AFP from A. giganteus affects A. flavus, the pathogen responsible for aspergillosis. The co-culturing technique firmly drew the potential of antifungal metabolites to counteract the effects of fungal agonists. A reduction of approximately 91% in the growth of pathogenic A. flavus treated with culture filtrates of antagonist fungi confirms the antagonistic effect of the culture filtrate metabolites on A. flavus viability and indicates that these metabolites are extracellular. The presence of shrunken and damaged spores in the SEM images of A. flavus treated with culture filtrates is evident in supporting its impact on the cellular membrane of the pathogenic bacteria. The MIC and MFC of culture filtrates were found to be 125 μg/ml and 250 μg/ml. Furthermore, the free radical scavenging activity of antifungal metabolites emphasizes its significant antioxidant potential. Finally, the findings of cytotoxicity studies confirmed the druggability of antifungal metabolites of A. giganteus. Thus, the study strongly endorses the antagonistic potential of AFP against A. flavus, suggesting that this metabolite could be developed into a novel treatment for invasive aspergillosis caused by A. flavus.

Microbial bio-refineries offer a sustainable alternative to traditional petrochemical methods for organic acid production by harnessing the metabolic capabilities of microorganisms to convert renewable feed-stocks into valuable products. This review aims to provide an overview of recent advancements in metabolic engineering techniques that have significantly enhanced the efficiency and productivity of microbial organic acid production. The review discusses key strategies, including pathway engineering, strain optimization, and process optimization, that have contributed to the development of these bio-refineries. Furthermore, it highlights the potential of microbial bio-refineries for sustainable bio-based manufacturing, emphasizing their role in reducing reliance on fossil fuels and promoting a circular economy. This review will serve as a valuable resource for researchers and industry professionals seeking to advance the development of sustainable and economically viable microbial biorefineries for the production of organic acids.

Nitrification oxidizes ammonia in soil into nitrate, leading to significant nitrogen losses, and reducing nitrogen use efficiency (NUE) in agricultural systems. Majority of applied nitrogen fertilizers contribute to environmental issues resulting from nitrification, denitrification, volatilization, leaching, etc., while only 30-50% are absorbed by crops. Nitrification inhibitors (NIs) are compounds designed to slow the conversion of ammonia to nitrate, improving NUE thereby reducing nitrogen loss and mitigating environmental pollution. Chemical NIs, though widely used, pose environmental and health concerns due to their toxicity and persistence. In contrast, biological nitrification inhibitors (BNIs), derived from plant exudates, offer a more sustainable and eco-friendly alternative, effectively inhibiting nitrification without harmful side effects. Advancements in BNIs and their mode of action present promising opportunities for enhancing sustainable farming practices and reducing the environmental impact of nitrogen fertilizers. This review examines the mechanisms of action, effectiveness, and environmental benefits of chemical and biological NIs, highlighting their potential to improve agricultural productivity, reduce nitrogen pollution, and promote greener agriculture.

One of the most significant problems of the twenty-first century is the appearance and rapid evolution of multiple drug-resistant (MDR) bacterial strains. The emergence of resistance towards available drugs poses a growing threat to global public health. Unfortunately, developing new antibiotics is a tedious and difficult challenge, urging the research community to strive for unusual clinical targets with a different mode of action. The antivirulence strategy disarms pathogenic bacteria and attacks the virulence factors. Type III secretion system (T3SS) facilitates virulence in many pathogenic gram-negative bacteria. T3SS is considered an effective needle-syringe mechanism associated with humans, plants, and animal hosts to inject effectors inside the cytosol of host cells. This review focuses on T3SS, its assembly, and visualization, along with presently developed small molecules, peptides, and antibodies to inhibit the complex. Evaluation of the effectiveness of compounds is in progress on animal models, and promising studies are being conducted to develop antibodies and vaccines that target T3SS. Reports published till now specify that T3SS inhibitors can evolve into innovative antibacterial therapy, bringing about a revolution in the pharmaceutical world. Apart from this, to get a better understanding of the mechanism at the molecular level, the functioning of T3SS in Salmonella is also discussed.