Indian Journal of Microbiology最新文献

The emergence of the COVID-19 pandemic has pointed out the urgent need for rapid and accurate diagnostic tools to detect the SARS-CoV-2 virus. Nanotechnology-based biosensors have emerged as a promising solution due to their high sensitivity, specificity, and speed in detecting biological molecules. This article focuses on the advancements in using nanotechnology for the development of modern biosensors tailored for the detection of the SARS-CoV-2 virus. Various nanomaterials, such as quantum dots, metallic nanoparticles, and nanowires, have been harnessed to enhance the performance of biosensors, offering improved detection limits and specificity. Besides this, innovative detection platforms, such as field-effect transistors, surface plasmon resonance, and electrochemical sensors, have revolutionized the landscape of SARS-CoV-2 diagnostics. These nanotechnology-based biosensors demonstrate the potential for point-of-care testing, enabling rapid and on-site detection with minimal sample preparation. The scalability, cost-effectiveness, and portability of these biosensors make them suitable for mass screening efforts in various healthcare settings, including hospitals, clinics, and community centers. The development of reliable biosensors for SARS-CoV-2 detection aligns with global efforts to curb the spread of the virus through early identification and containment strategies.

Mangroves are distinguished as a unique ecotone, characterized by their specialized habitat and extreme environmental conditions, including high salinity, tidal fluctuations, elevated temperatures, low oxygen levels, and waterlogging. While these stressors impose numerous challenges on mangroves, the plants have evolved adaptive mechanisms to cope with such harsh conditions. Crucially, the root-associated microbial community, particularly plant growth-promoting bacteria (PGPB), plays an essential role in aiding mangrove plants to withstand these adverse conditions, highlighting the symbiotic relationship vital for mangrove resilience. The study aims to explore the root-associated PGPB in mangrove ecosystems, focusing on their roles and potential biotechnological applications. It has been found that these diverse PGPB, isolated from mangroves, exhibited plant growth-promoting properties, including nitrogen fixation, solubilization of phosphorus and potassium, and the production of beneficial compounds such as phytohormones, exopolysaccharides, and volatile organic compounds. These traits of PGPB contribute not only to plant growth and development but also to resilience against various stresses, especially salinity. They aid in maintaining nutrient and ionic balance, modulating hormonal levels, providing osmoprotection, mitigating oxidative stress, and enhancing resistance to pathogens within the mangrove ecosystem. Moreover, the study highlights the promising biotechnological applications of these microbes in promoting sustainable agricultural practices in saline environments, enhancing environmental remediation efforts, and supporting mangrove reforestation initiatives. In conclusion, leveraging the symbiotic relationships between mangrove plants and their root-associated PGPB offers innovative, sustainable solutions to contemporary environmental challenges, paving the way for enhanced ecosystem resilience and productivity.

The urgent need for innovative solutions to global environmental challenges has driven the convergence of biology and nanotechnology, resulting in the emergence of bionanotechnology as a transformative force. This comprehensive review paper explores the fundamental principles, applications, benefits, and potential risks associated with harnessing bionanotechnology to advance environmental sustainability. Beginning with an elucidation of the fundamental concepts underlying bionanotechnology, this paper establishes the synergy between biological systems and nanomaterials. The unique properties of nanomaterials, coupled with the adaptability of biological processes, form the foundation for a diverse array of real-world applications. Focusing on applications, the paper highlights how bionanotechnology addresses critical environmental issues. It showcases case studies that exemplify its impact on water purification, air quality improvement, waste management, renewable energy production, and more. These case studies underscore the tangible benefits and efficacy of bionanotechnology in tackling complex challenges. However, as the potential of bionanotechnology is harnessed, it is crucial to navigate potential ecological risks. The paper emphasizes the importance of ecotoxicological considerations, discussing how nanomaterials interact with ecosystems and organisms. Ethical and responsible development of bionanotechnology, informed by these considerations, ensures that its benefits are maximized while minimizing potential harm. In conclusion, this review paper underscores bionanotechnology’s potential to revolutionize environmental sustainability. By fusing the power of nanomaterials and biology, bionanotechnology offers a holistic approach to address pressing global challenges. While celebrating its transformative promise, the paper emphasizes the need for a balanced approach that safeguards environmental health. As society looks towards a more sustainable future, bionanotechnology stands as a pivotal paradigm for shaping an environmentally conscious world.

In the present study, hydrothermally prepared, one-dimensional gadolinium oxide (Gd₂O₃) nanorods were utilized to modify the gold electrode (AuE) for the fabrication of Gd₂O₃/AuE sensor. The nanorod-modified electrode was employed for the sensitive and selective detection of nitrobenzene. The material serves as a highly active electrode material due to its many active sites, high electrocatalytic efficiency, and fast kinetics lead to superior sensing capabilities. The successful synthesis of Gd₂O₃ nanorod was confirmed using different characterization techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), and electron mapping. After fabrication, the shape and phase of NRs did not change. The electrocatalytic performance of Gd₂O₃/AuE sensor against nitrobenzene was investigated through cyclic voltammetric (CV), amperometry, and EIS. As a result, the modified electrode exhibits a low detection limit of 0.0091 µM, a wide linear response of 0.01 to 3 µM, with an excellent sensitivity of 3.09 µA µM⁻¹ cm⁻². In addition, the modified electrode provides an excellent selectivity toward nitrobenzene detection in the presence of various interfering compounds. The fabricated electrode displayed notable storage stability, repeatability, and reproducibility. It has the potential to create an excellent environmental monitoring platform.

Graphical Abstract

Graphical representation of reduction of Nitrobenzene by GdO NRs.

Study of gut microbiome is an emerging area in modern research with over one trillion population is known to inhabit the gut of organisms. The gut microbiome constitutes bacteria, viruses, protozoa and fungi and their collective genetic material present in the gastrointestinal tract. It is an essential part of a species’ ecology and influenced by the diet and phylogeny of the host. Most studies on the significance of gut microbiota and its association with physiology were done in humans than animals, and even fewer in elephants. Here in this study, we ventured to study the diversity of faecal bacteria of elephants of various age groups and musth. Bacteriological analysis of faecal samples from elephants of various age groups and musth were done and a total viable count was determined. Bacterial colonies obtained from elephant faecal samples of various age groups and musth were identified employing 16S rDNA sequencing. Here we evolved a PCR based strategy to amplify partial gene which encodes 16S rRNA was sequenced and the sequence obtained was analyzed by NCBI BLAST to identify these bacterial strains. Stenotrophomonas maltophilia, Lactococcus lactis and Staphylococcus arlettae were the major species of bacteria identified from the samples of captive elephants, of which, Stenotrophomonas maltophilia is an opportunistic pathogen that dominates in all the age groups. Lactococcus lactis is the major bacteria in the fecal samples of four years old elephant (Juvenile) and found to constitute nearly 68%. Fecal samples collected from 25 years old constitute Stenotrophomonas maltophilia as the major bacteria (73%) followed by Lactococcus lactis while 45 years old showed the higher occurrence of Staphylococcus arlettae followed by Lactococcus lactis. Elephant of the very old age group (84 years) showed high diversity in the fecal bacteria with Stenotrophomonas maltophilia dominating in this group (72%). Elephant in musth, a condition characterized by the high level of testosterone, temporal secretion and high gastric acidity was shown the dominance of acidophilic Stenotrophomonas maltophilia in the gut while alkalophilic Lactococcus lactis which was prevalent in other groups was not detected in musth condition.

Copper nanoparticles embedded in polystyrene (PS) nanocomposite foils were prepared via the solution casting method to study their optical characteristics and antimicrobial activities. Structural and surface morphology of the prepared nanocomposite foils were carried out by FTIR and FESEM. UV–vis spectra reveal that the nanocomposite foils are optically transparent in the visible region, with a strong absorbance peak at ~ 264 nm. Optical parameters such as optical band gap (E_g), refractive index (n), extinction coefficient (k), and dielectric constants (ε₁, ε₂, tanδ) were calculated using UV–vis spectroscopy. The Single Oscillator Wemple DiDomenico model was employed to determine the dispersion energy characteristics (E₀, E_d), optical moments (M_-1, M_-3), and dispersion of refractive index (n₀). The nonlinear index of refraction (n₂) and third-order optical nonlinear susceptibility (χ³) were calculated using Miller’s expression. In-vitro antimicrobial activity was tested against Gram-negative bacterial species isolated from a hospital wastewater treatment plant, showing multiple drug resistance activity. The study revealed that PS/Cu nanocomposite foils exhibit promising results as optical limiters with significant antibacterial activity.

Waste water pollution is one of the most prominent concerns across the globe due to its severe impact on human health and environment which affects the ecosystem directly. Therefore, for sustainable and consistence environment, waste water treatment is the primary and mandatory agenda of agencies involve worldwide to rectify this issue. Additionally, among various sustainable trail based strategies for waste water treatment, biochar catalyst utilization is very potential and impactful whereas, use of nanoform of biochar which is also known as nanobiochar is more impactful in waste water pollution remediation. Therefore, the present review represents the sustainable fabrication of nanobiochar from organic waste biomass and process strategy for its reduction from bulk form to nano form using different sustainability procedures. Type and mode of action of different biomass, types, fabrication, methods and functional properties along with their functional efficacy have been highlighted and discussed in the review. Existing challenges and sustainable possibilities to overcome them have also discussed as future prospects for sustainable and promising application of nanobiochar as potential sensor foreco-friendly remediation of waste water pollution.

Graphical Abstract

The figure present general overview to fabricate nanobiochar from waste biomass biomass for environmental application

Proteases represent 60% of the enzyme market and around 66% of the proteases are derived from the microbial sources. In the present study, protease enzyme was produced from bacterial isolate Ochrobactrum anthropi KTP9 under submerged fermentation having 17.43 IU/mL activity and 3.626 mg/ml of protein content. Ammonium sulphate precipitation increased the specific activity from 4.80 to 22.45 IU/ ml with 4.67 purification fold. Free protease has optimum pH 8.0, temperature 35 °C and found stable upto 28 days on storage at 4 °C. The immobilization yield and immobilization efficiency were found as 40.54% and 89.72%, respectively. Upon immobilization, shift in temperature (35 to 45 °C) and pH optima (8.0 to 10.0) was observed as compared to free protease. The immobilized protease was found to retain 50% residual activity upto 35 days of storage at 4 °C. Immobilization enzyme can be reused upto 6 cycles with 50% residual activity. The immobilized protease showed 76% protein hydrolysis in 120 min as compare to free KTP9 protease.

The increased demand of energy across the globe has led us to rely on biofuels which are nowadays presenting an ideal contender to meet energy requirements in ultimate sustainable manner. Nowadays lignocellulosic biomass (LCB) is a promising source for energy production and also for maintaining sustainable environment. Lignocellulolytic enzymes are dynamically used to develop an environmental friendly and economic biological technique for degradation of LCB leading to secretion of different value added products. There is scarce availability of microbial strains which secretes all types of enzymes required for the complete hydrolysis of LCB. Thus, the formulation of effective and economic enzyme cocktail for LCB hydrolysis is major research platforms within biorefinery. In this study thermophiles were isolated from hot springs of Western Himalayan Range (Manikaran, Manali and Kasol, Himachal Pradesh) using CMC agar media at 55 °C, pH 7.0 under shaking (180 rpm). Out of total 23 isolated thermophilic bacterial strains, 5 bacterial strains (NIBE9, NIBE 10, NIBE 11, NIBE 13 and NIBE 23) displayed an ability to utilize cellulose and hemicellulose. The enzyme activity and specific activity was calculated with reference to standard curve of DNS and BSA for protein. Potent extracellular and cell bound cellulase activity was detected. The 16S rRNA analysis revealed that strain NIBE 9, NIBE 11, NIBE 13 and NIBE 23 showed 99.86%, 100%, 99.86% and 99.93% similarity with Bacillus licheniformis. The isolate NIBE 10 showed 100% similarity with Bacillus smithi. Evolutionary distances and clustering were based on the neighbor joining and maximum-likelihood method.