Indian Journal of Microbiology最新文献

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.

Multidrug resistance (MDR) in bacteria poses a serious global health threat, compromising the effectiveness of antibiotics. MDR causes approximately 700,000 deaths annually, with MDR tuberculosis alone claiming 230,000 lives. While bacteria inherently possess intrinsic resistance, acquired resistance stands out as the primary culprit in MDR development. Acquired resistance mechanisms mediated by the bacterial cell wall, nucleic acids, and proteins play a pivotal role in the genesis of MDR. Bacteria can modify their cell wall structure, produce resistant enzymes, exhibit mutations in antibiotic-targeted genes, and acquire resistant genes through horizontal gene transfer. Bacteria can produce proteins that act as enzymes, chemically modifying or directly degrading the antibiotic molecules, leading to the loss of their functionality. Apart from these mechanisms, biofilms also play a pivotal role in MDR expansion. Despite the development of several antibiotics since the discovery of penicillin, continuous structural and molecular modifications in bacteria render these antibiotics ineffective against MDR. The most recent approaches such as clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (CRISPR-Cas), nanotechnology, a combination of CRISPR-Cas, and nanoparticles, show promise in treating MDR. Thus, this review delves deep into the molecular mechanisms of MDR, emphasizing the limitations of current antibiotics due to bacterial evolution and highlighting current strategies in the fight against MDR bacteria. This will drive comprehensive research to uncover additional resistance mechanisms and develop innovative strategies to combat resistant bacteria effectively.

Nutrient-limited soils from growing global contamination with polycyclic aromatic hydrocarbons (PAHs) and the massive organic waste generation from agro-based and food industries have raised more demand for exploring and recycling the latter as sustainable, cost-effective, and green nutrient-rich sources for soil amendment. To further enhanced the potentials of these substrates in soil, immobilisation or biological pre-treatment techniques using fungi are employed. The white-rot fungi- basidiomycetes, are the most widely researched and efficient organisms to perform these functions because of their high lignin-degrading ability for organic materials, such as corn cob, straws, spent brewery grains, sugarcane bagasse, etc. This review addresses the importance of organic amendment to enhance the biodegradation efficiency of PAH from contaminated soils and it also highlights various biological techniques for improving PAH biodegradation using organic waste materials and white-rot basidiomycetes. This review will also show a better understanding of the concepts of fungal immobilisation and pre-treatment for PAH degradation in soil and show their insights as feasible and optimise techniques for developing remedial strategies for contaminated soils.

Lung cancer is responsible for highest mortality rates among both men and women globally. There is a need of effective and safe treatment modality that specifically targets cancer cells and doesn’t not harm healthy cells. Procyanidolic oligomers (PCOs) is a natural antioxidant found in grape seed, acts as medicament for the treatment of various disease which are linked with oxidative stress specifically cancer. The aim of the current study was to synthesize highly stable gliadin encapsulated PCOs nanoformulation (PCO-NF). The PCOs nanoformulation (PCO-NF) showed spherical morphology (17.18–76.56 nm) with an average particle size 49.37 ± 22.17 nm diameter in electron microscopy and stable zeta potential i.e. − 23.1 mV and low polydispersity index i.e. 0.246 in dynamic light scattering (DLS). The therapeutic efficacy of PCO-NF has been evaluated through antioxidative, anticancer as well as antimicrobial studies. Antioxidant potency was assessed using DPPH scavenging assay and it was observed that IC₅₀ of PCO-NF (9.02 µg/ml) was even lower than that of Vitamin C (10.22 µg/ml) as well as pure PCOs. The MTT assay was performed for the comparative anticancer activity of pure PCOs and PCO-NF against SK-MES-1 lung cancer cell line. It was found that PCO-NF significantly inhibited the lung cancer cells at all tested concentration. Moreover at 125 µg/ml concentration the PCO-NF showed 31.54% cell viability which was even lesser than the standard anticancer drug. The antimicrobial efficacy of PCO-NF was assessed against gram-positive and gram-negative bacteria. An augmented antimicrobial, antioxidant and anticancer potential was observed due to nanoencapsulation of PCOs.