Microbial induced carbonate precipitation for remediation of heavy metals, ions and radioactive elements: A comprehensive exploration of prospective applications in water and soil treatment.

Improper disposal practices have caused environmental disruptions, possessing by heavy metal ions and radioactive elements in water and soil, where the innovative and sustainable remediation strategies are significantly imperative in last few decades. Microbially induced carbonate precipitation (MICP) has emerged as a pioneering technology for remediating contaminated soil and water. Generally, MICP employs urease-producing microorganisms to decompose urea (NH2CONH2) into ammonium (NH4+and carbon dioxide (CO2), thereby increasing pH levels and inducing carbonate precipitation (CO32-), and effectively removing remove contaminants. Nonetheless, the intricate mechanism underlying heavy metal mineralization poses a significant challenge, constraining its application in contaminants engineering, particularly in the context of prolonged heavy metal leaching over time and its efficacy in adverse environmental conditions. This review provides a comprehensive idea of recent development of MICP and its application in environmental engineering, examining metabolic pathways, mineral precipitation mechanisms, and environmental factors as well as providing future perspectives for commercial utilization. The use of ureolytic bacteria in MICP demonstrates cost-efficiency, environmental compatibility, and successful pollutant abatement over tradition bioremediation techniques, and bio-synthesis of nanoparticles. limitations such as large-scale application, elevated Ca2+levels in groundwater, and gradual contaminant release need to be overcome. The possible future research directions for MICP technology, emphasizing its potential in conventional remediation, CO2 sequestration, bio-material synthesis, and its role in reducing environmental impact for long-term economic benefits.

Trade-offs between reducing complex terminology and producing accurate interpretations from environmental DNA: Comment on "Environmental DNA: What's behind the term?" by Pawlowski et al., (2020).

In a recent paper, "Environmental DNA: What's behind the term? Clarifying the terminology and recommendations for its future use in biomonitoring," Pawlowski et al. argue that the term eDNA should be used to refer to the pool of DNA isolated from environmental samples, as opposed to only extra-organismal DNA from macro-organisms. We agree with this view. However, we are concerned that their proposed two-level terminology specifying sampling environment and targeted taxa is overly simplistic and might hinder rather than improve clear communication about environmental DNA and its use in biomonitoring. This terminology is based on categories that are often difficult to assign and uninformative, and it overlooks a fundamental distinction within eDNA: the type of DNA (organismal or extra-organismal) from which ecological interpretations are derived.

The Interaction of Amines with Gold Nanoparticles.

Understanding the interactions between amines and the surface of gold nanoparticles is important because of their role in the stabilization of the nanosystems, in the formation of the protein corona, and in the preparation of semisynthetic nanozymes. By using fluorescence spectroscopy, electrochemistry, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and molecular simulation, a detailed picture of these interactions is obtained. Herein, it is shown that amines interact with surface Au(0) atoms of the nanoparticles with their lone electron pair with a strength linearly correlating with their basicity corrected for steric hindrance. The kinetics of binding depends on the position of the gold atoms (flat surfaces or edges) while the mode of binding involves a single Au(0) with nitrogen sitting on top of it. A small fraction of surface Au(I) atoms, still present, is reduced by the amines yielding a much stronger Au(0)-RN.+ (RN. , after the loss of a proton) interaction. In this case, the mode of binding involves two Au(0) atoms with a bridging nitrogen placed between them. Stable Au nanoparticles, as those required for robust semisynthetic nanozymes preparation, are better obtained when the protein is involved (at least in part) in the reduction of the gold ions.

The unseen invaders: Tracking phylogeographic dynamics and genetic diversity of cryptic Pomacea canaliculata and P. maculata (Golden apple snails) across Taiwan.

The cryptic invasion of golden apple snails (Pomacea canaliculata and P. maculata) in Taiwan has caused significant ecological and economical damage over the last few decades, however, their management remains difficult due to inadequate taxonomic identification, complex phylogeny, and limited population genetic information. We aim to understand the current distribution, putative population of origin, genetic diversity, and potential path of cryptic invasion of Pomacea canaliculata and P. maculata across Taiwan to aid in improved mitigation approaches. The present investigation conducted a nationwide survey with 254 samples collected from 41 locations in 14 counties or cities across Taiwan. We identified P. canaliculata and P. maculata based on mitochondrial COI and compared their genetic diversity across Taiwan, as well as other introduced and native countries (based on publicly available COI data) to understand the possible paths of invasion to Taiwan. Based on mitochondrial COI barcoding, sympatric and heterogeneous distributions of invasive P. canaliculata and P. maculata were noted. Our haplotype analysis and mismatch distribution results suggested multiple introductions of P. canaliculata in Taiwan was likely originated directly from Argentina, whereas P. maculata was probably introduced from a single, or a few, introduction event(s) from Argentina and Brazil. Our population genetic data further demonstrated a higher haplotype and genetic diversity for P. canaliculata and P. maculata in Taiwan compared to other introduced regions. Based on our current understanding, the establishment of P. canaliculata and P. maculata is alarming and widespread beyond geopolitical borders, requiring a concerted and expedited national and international invasive species mitigation program.

Transformative and sustainable insights of agricultural waste-based adsorbents for water defluoridation: Biosorption dynamics, economic viability, and spent adsorbent management.

With the progression of civilization, the harmony within nature has been disrupted, giving rise to various ecocidal activities that are evident in every spheres of the earth. These activities have had a profound and far-reaching impact on global health. One significant example of this is the presence of fluoride in groundwater exceeding acceptable limits, resulting in the widespread occurrence of "Fluorosis" worldwide. It is imperative to mitigate the concentration of fluoride in drinking water to meet safety standards. While various defluoridation techniques exist, they often have drawbacks. Biosorption, being a simple, affordable and eco-friendly method, has gained preference for defluoridation. However, its limited commercialization underscores the pressing need for further research in this domain. This comprehensive review article offers a thorough examination of the defluoridation potential of agro-based adsorbents, encompassing their specific chemical compositions and preparation methods. The review presents an in-depth discussion of the factors influencing fluoride biosorption and conducts a detailed exploration of adsorption isotherm and adsorption kinetic models to gain a comprehensive understanding of the nature of the adsorption process. Furthermore, it evaluates the commercial viability through an assessment of regeneration potential and a cost analysis of these agro-adsorbents, with the aim of facilitating the scalability of the defluoridation process. The elucidation of the adsorption mechanism and recommendations for overcoming challenges in large-scale implementation offer a comprehensive outlook on this eco-friendly and sustainable approach to fluoride removal. In summary, this review article equips readers with a lucid understanding of agro-adsorbents, elucidates their ideal conditions for improved performance, offers a more profound insight into the fluoride biosorption mechanism, and introduces the concept of effective spent adsorbent management.

The role of bacterial exopolysaccharides (EPS) in the synthesis of antimicrobial silver nanomaterials: A state-of-the-art review.

The emergence of multi-drug resistant (MDR) pathogens poses a significant global health concern due to the failure of conventional medical treatment. As a result, the development of several metallic (Ag, Au, Zn, Ti, etc.) nanoparticles, has gained prominence as an alternative to conventional antimicrobial therapies. Among these, green-synthesized silver nanoparticles (AgNPs) have gained significant attention due to their notable efficiency and broad spectrum of antimicrobial activity. Bacterial exopolysaccharides (EPS) have recently emerged as a promising biological substrate for the green synthesis of AgNPs. EPS possess polyanionic functional groups (hydroxyl, carboxylic, sulfate, and phosphate) that effectively reduce and stabilize AgNPs. EPS-mediated AgNPs exhibit a wide range of antimicrobial activity against various pathogenic microbes, including Gram-positive and Gram-negative bacteria, as well as fungi. The extraction and purification of bacterial EPS play a vital role in obtaining high-quality and -quantity EPS for industrial applications. This study focuses on the comprehensive methodology of EPS extraction and purification, encompassing screening, fermentation optimization, pretreatment, protein elimination, precipitation, and purification. The review specifically highlights the utilization of bacterial EPS-mediated AgNPs, covering EPS extraction, the synthesis mechanism of green EPS-mediated AgNPs, their characterization, and their potential applications as antimicrobial agents against pathogens. These EPS-mediated AgNPs offer numerous advantages, including biocompatibility, biodegradability, non-toxicity, and eco-friendliness, making them a promising alternative to traditional antimicrobials and opening new avenues in nanotechnology-based approaches to combat microbial infections.

Insight interactions of engineered nanoparticles with aquatic higher plants for phytoaccumulation, phytotoxicity, and phytoremediation applications: A review.

With the growing age of human civilization, industrialization has paced up equally which is followed by the innovation of newer concepts of science and technology. One such example is the invention of engineered nanoparticles and their flagrant use in widespread applications. While ENPs serve their intended purposes, they also disrupt the ecological balance by contaminating pristine aquatic ecosystems. This review encompasses a comprehensive discussion about the potent toxicity of ENPs on aquatic ecosystems, with a particular focus on their impact on aquatic higher plants. The discussion extends to elucidating the fate of ENPs upon release into aquatic environments, covering aspects ranging from morphological and physiological effects to molecular-level phytotoxicity. Furthermore, this level of toxicity has been correlated with the determination of competent plants for the phytoremediation process towards the mitigation of this ecological stress. However, this review further illustrates the path of future research which is yet to be explored. Determination of the genotoxicity level of aquatic higher plants could explain the entire process comprehensively. Moreover, to make it suitable to be used in natural ecosystems phytoremediation potential of co-existing plant species along with the presence of different ENPs need to be evaluated. This literature will undoubtedly offer readers a comprehensive understanding of the stress induced by the irresponsible release of engineered nanoparticles (ENP) into aquatic environments, along with insights into the resilience characteristics of these pristine ecosystems.

Heavy metals distribution and ecological risk assessment including arsenic resistant PGPR in tidal mangrove ecosystem.

Heavy metals (HM) are the major proximate drivers of pollution in the mangrove ecosystem. Therefore, ecological risk (ER) due to HM distribution/concentration in core-sediment of Puzi mangrove region (Taiwan) was examined with tidal influence (TI) along with indigenous rhizospheric bacteria (IRB). The HM concentration was observed higher at active-tidal-sediment compared to partially-active-sediment. Geo-accumulation index (Igeo) and contamination factor (CF) indicated the tidal-sediment was highly contaminated with arsenic (As) and moderately contaminated with Lead (Pb) and Zinc (Zn). However, the pollution loading index (PLI) and degree of contamination (Cd) exhibited 'no pollution' and 'low-moderate degree of contamination', in the studied region respectively. The isolated IRB (Priestia megaterium, Bacillus safenis, Bacillus aerius, Bacillus subtilis, Bacillus velenzenesis, Bacillus lichenoformis, Kocuria palustris, Enterobacter hormaechei, Pseudomonus fulva, and Paenibacillus favisporus; accession number OM979069-OM979078) exhibited the arsenic resistant behavior with plant-growth-promoting characters (IAA, NH3, and P-solubilization), which can be used in mangrove reforestation and bioremediation of HM.

How the Environment Encourages the Natural Formation of Hydrated V2O5.

Herein, we report the microscopic and spectroscopic signatures of the hydrated V2O5 phase, prepared from the α-V2O5 powder, which was kept in deionized water inside an airtight glass container for approximately 2.5 years. The experimental results show an evolution of the V4+ component in V 2p3/2 core energy level spectra, and a peak corresponding to σ-OH- bond appeared in the valence band spectra in the hydrated V2O5 powder sample due to the water intercalation. Vanadium metal oxide particles were found to be self-nucleated into micro/nanorods after a long period of exposure to an extremely humid environment. The distinct features in the spectra obtained with high-resolution transmission electron microscopy, micro-Raman scattering, and X-ray photoelectron spectroscopy confirmed the presence of structural water molecules for the first time in the long-aged naturally hydrated V2O5 phase.

New aspects of lipopeptide-incorporated nanoparticle synthesis and recent advancements in biomedical and environmental sciences: a review.

The toxicity of metal nanoparticles has introduced promising research in the current scenario since an enormous number of people have been potentially facing this problem in the world. The extensive attention on green nanoparticle synthesis has been focussed on as a vital step in bio-nanotechnology to improve biocompatibility, biodegradability, eco-friendliness, and huge potential utilization in various environmental and clinical assessments. Inherent influence on the study of green nanoparticles plays a key role to synthesize the controlled and surface-influenced molecule by altering the physical, chemical, and biological assets with the provision of various precursors, templating/co-templating agents, and supporting solvents. However, in this article, the dominant characteristics of several kinds of lipopeptide biosurfactants are discussed to execute a critical study of factors affecting synthesis procedure and applications. The recent approaches of metal, metal oxide, and composite nanomaterial synthesis have been deliberated as well as the elucidation of the reaction mechanism. Furthermore, this approach shows remarkable boosts in the production of nanoparticles with the very less employed harsh and hazardous processes as compared to chemical or physical method-based nanoparticle synthesis. This study also shows that the advances in strain selection for green nanoparticle production could be a worthwhile and strong economical approach in futuristic medical science research.

Environmental DNA analysis as an emerging non-destructive method for plant biodiversity monitoring: a review.

Environmental DNA (eDNA) analysis has recently transformed and modernized biodiversity monitoring. The accurate detection, and to some extent quantification, of organisms (individuals/populations/communities) in environmental samples is galvanizing eDNA as a successful cost and time-efficient biomonitoring technique. Currently, eDNA's application to plants remains more limited in implementation and scope compared to animals and microorganisms. This review evaluates the development of eDNA-based methods for (vascular) plants, comparing its performance and power of detection with that of traditional methods, to critically evaluate and advise best-practices needed to innovate plant biomonitoring. Recent advancements, standardization and field applications of eDNA-based methods have provided enough scope to utilize it in conservation biology for numerous organisms. Despite our review demonstrating only 13% of all eDNA studies focus on plant taxa to date, eDNA has considerable environmental DNA has considerable potential for plants, where successful detection of invasive, endangered and rare species, and community-level interpretations have provided proof-of-concept. Monitoring methods using eDNA were found to be equal or more effective than traditional methods; however, species detection increased when both methods were coupled. Additionally, eDNA methods were found to be effective in studying species interactions, community dynamics and even effects of anthropogenic pressure. Currently, elimination of potential obstacles (e.g. lack of relevant DNA reference libraries for plants) and the development of user-friendly protocols would greatly contribute to comprehensive eDNA-based plant monitoring programs. This is particularly needed in the data-depauperate tropics and for some plant groups (e.g., Bryophytes and Pteridophytes). We further advocate to coupling traditional methods with eDNA approaches, as the former is often cheaper and methodologically more straightforward, while the latter offers non-destructive approaches with increased discrimination ability. Furthermore, to make a global platform for eDNA, governmental and academic-industrial collaborations are essential to make eDNA surveys a broadly adopted and implemented, rapid, cost-effective and non-invasive plant monitoring approach.

Atomically resolved 3D structural reconstruction of small quantum dots.

Semiconducting quantum dots (QDs) have potential applications in light-emitting diodes, single-photon sources and quantum computing due to shape-dependent (opto) electronic properties. Atomic resolution 3D-structure determination is important in understanding growth kinetics and improving device performance. 3D-reconstruction of large QDs was reported using characterization techniques like atomic force microscopy, atom probe tomography and tilt series electron tomography, but, still, atomic resolution tomography of QDs, especially those sized below 10 nm, is a challenge. Inline-3D-holography is an emerging and promising technique to perform atomic resolution tomography at low electron doses. In the present study, atomically resolved 3D structures of QDs were reconstructed using inline-3D-holography, implemented on InN QDs (<10 nm) grown on a Si substrate. The residual amorphous glue distorts the exit surface geometry; hence an error correction method was proposed. This is the first experimental evidence of pre-pyramid shaped 3D structure of QDs sized below 10 nm that supports theoretical predictions.

Atomically resolved tomographic reconstruction of nanoparticles from single projection: Influence of amorphous carbon support.

Nanoparticles have a wide range of applications due to their unique geometry and arrangement of atoms. For a precise structure-property correlation, information regarding atomically resolved 3D structures of nanoparticles is utmost beneficial. Though modern aberration-corrected transmission electron microscopes can resolve atoms with the sub-angstrom resolution, an atomic-scale 3D reconstruction of a nanoparticle using Scanning Transmission Electron Microscopy (STEM) based tomographic method faces hurdles due to high electron irradiation damage and "missing-wedge". Instead, inline 3D holography based tomographic reconstructions from single projection registered at low electron doses is more suitable for defining atomic positions at nanostructures. Nanoparticles are generally supported on amorphous carbon film for Transmission Electron Microscopy (TEM) experiments. However, neglecting the influence of carbon film on the tomographic reconstruction of the nanoparticle may lead to ambiguity. To address this issue, the effect of amorphous carbon support was quantitatively studied using simulations and experiments and it was revealed that increasing thickness and/or density of carbon support increases distortion in tomograms.

Reinforcement of Environmental DNA Based Methods (Sensu Stricto) in Biodiversity Monitoring and Conservation: A Review.

Recently developed non-invasive environmental DNA-based (eDNA) techniques have enlightened modern conservation biology, propelling the monitoring/management of natural populations to a more effective and efficient approach, compared to traditional surveys. However, due to rapid-expansion of eDNA, confusion in terminology and collection/analytical pipelines can potentially jeopardize research progression, methodological standardization, and practitioner adoption in several ways. Present investigation reflects the developmental progress of eDNA (sensu stricto) including highlighting the successful case studies in conservation management. The eDNA technique is successfully relevant in several areas of conservation research (invasive/conserve species detection) with a high accuracy and authentication, which gradually upgrading modern conservation approaches. The eDNA technique related bioinformatics (e.g., taxon-specific-primers MiFish, MiBird, etc.), sample-dependent methodology, and advancement of sequencing technology (e.g., oxford-nanopore-sequencing) are helping in research progress. The investigation shows that the eDNA technique is applicable largely in (i) early detection of invasive species, (ii) species detection for conservation, (iii) community level biodiversity monitoring, (iv) ecosystem health monitoring, (v) study on trophic interactions, etc. Thus, the eDNA technique with a high accuracy and authentication can be applicable alone or coupled with traditional surveys in conservation biology. However, a comprehensive eDNA-based monitoring program (ecosystem modeling and function) is essential on a global scale for future management decisions.

A novel BMSN (biologically synthesized mesoporous silica nanoparticles) material: synthesis using a bacteria-mediated biosurfactant and characterization.

Mesoporous materials (MMs) have recently been applied as advanced nanomaterials in different fields (separation, catalysis, adsorption etc.). Synthesis of MMs by chemical surfactants is not ecofriendly. This study focused on the biological synthesis of a MM by sol-gel method, using a Bacillus subtilis BBK006-mediated surfactant (template) and a precursor (TEOS). The biologically synthesized mesoporous silica nanoparticles (BMSN) were formed at calcination temperatures of 450-600 °C. The BMSN comprise Si and O elements with specific weights of 56.09% and 42.13% respectively, where the atomic% was detected to be 41.79% and 55.10%, respectively. The phase identity of the synthesized particles (61-300 nm uniform spherical shape; surface area: 8.2616 m2 g-1; pore diameter at 550 °C: 14.8516 nm) was confirmed with wide-angle XRD (10°-81°). A typical type IV isotherm was exhibited (BET curves) following IUPAC nomenclature and confirmed the mesoporous nature. The green-synthesized biosurfactant-mediated BMSN is an environmentally promising material to apply in biomedical science (e.g., antimicrobial activity, drug delivery, CMC, anticancer activity) and oil spill management.

Probing Nanoscale Phase Separation at Atomic Resolution within ß-Type Ti-Mn Alloy: A Potential Candidate for Biomedical Implants.

Biocompatible ß-type Ti alloys with high ultimate tensile strength (UTS) and yield strength are potential candidates for certain orthopedic and cardiovascular implants. Aiming for these applications, Ti alloy with 14 wt % Mn (Ti-14 Mn) as ß-stabilizer was processed through thermomechanical treatment along with solutionizing and quenching, followed by 95% cold rolling, which resulted in ultrahigh UTS and yield strength. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolimbromide assay with different cell lines suggests efficient cell growth on alloy surface without compromising biocompatibility. Cell adhesion and spreading assay show that cells are not only able to attach to the alloy surface but also able to spread and grow with normal morphology, which projects this material as a potential candidate for biomedical application. Previous studies on binary ß-type Ti alloy systems treated with the above-mentioned processing route confirm the presence of nanoscale phase separation, which enhances its mechanical properties. To discover the same phenomena in the alloy of the present study, bright-field and high-resolution transmission electron microscopy (HRTEM) imaging experiments were performed and nanoscale contrast-modulated lamella regions were observed. Geometrical phase analysis on complex-valued exit wave, reconstructed using focal series HRTEM images, demonstrates that the lamella is a result of d-spacing modulation. Ab initio calculation indicates that d-spacing modulation with the same crystal structure occurs due to composition modulation and was proved by scanning transmission electron microscopy imaging coupled with quantitative energy-dispersive X-ray spectroscopy. Correlating contrast, strain, and composition modulation confirms nanoscale phase separation, which is the first report of this phenomenon in Ti-Mn alloy system.

Outstanding Prevalence of Methicillin Resistant Staphylococcus aureus in Neonatal Omphalitis.

INTRODUCTION: Omphalitis is the infection of the umbilical cord stump, which can lead to septicaemia and significant neonatal morbidity and mortality. Very little data is available on the aetiology of neonatal omphalitis in India. AIM: To identify the causative agents of omphalitis in neonates and determine the antimicrobial susceptibility patterns of the isolates. MATERIALS AND METHODS: A prospective study was conducted at ESI-PGIMSR and ESIC Medical College, Joka, a tertiary care teaching hospital in Eastern India for a period of four months (from 1st January 2016 to 30th April 2016). Neonates were screened for omphalitis on the basis of presence of pus and redness for inclusion. Clinical examination, Gram stain and culture of umbilical discharge, identification of organisms by biochemical tests and VITEK 2 Compact (bioMereiux Inc., France) was done. Antimicrobial susceptibility by Kirby Bauer disc diffusion method and E-strip agar diffusion method (for vancomycin and teicoplanin) were performed and interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines version 2015. RESULTS: A total of 623 neonates were screened, among whom 21 (3.37%) were positive for our screening criteria for omphalitis. Cultures from the exudates of those cases yielded growth of Staphylococcus aureus in 19 (90.47%) samples, all of which were found to be methicillin resistant Staphylococcus aureus (MRSA). Resistance to erythromycin was seen among 36.82% isolates and inducible clindamycin resistance was seen among 31.57% isolates of Staphylococcus aureus. CONCLUSION: MRSA can be the most common cause of omphalitis. However, this finding needs to be evaluated in larger prospective studies.