Pyrimidine analogues, essential nitrogen-containing heterocycles, play vital roles in nucleic acid architecture and cellular metabolism, with growing applications in aquatic animal health. This review synthesizes current knowledge on their pharmacological potential, focusing on the freshwater catfish Heteropneustes fossilis. An analysis of peer-reviewed literature revealed pyrimidine derivatives’ broad-spectrum bioactivities, including anticancer and antimicrobial properties. Notably, recent investigations demonstrate that waterborne exposure to the synthetic analogue 4,6-dimethyl-2-hydroxypyrimidine hydrochloride (4,6-DHP) (10 pg/mL) has been reported to improve physiological resilience in H. fossilis. Observed benefits include enhanced oxygen transport capacity, reduced markers of immune-stress, and elevated tissue energy reserves. Crucially, this derivative has been shown to provide neuroprotection by reducing oxidative stress and effectively remediating hypoxia-induced brain alterations; furthermore, short-term observations suggest a rapid clearance, though long-term bioaccumulation studies remain necessary. Despite these robust systemic benefits, a significant knowledge gap persists regarding reproductive endocrinology. While the compound’s stress-mitigating and metabolic-enhancing profile may contribute to positive modulation of the Brain-Pituitary-Gonad axis, direct evidence concerning hormonal regulation (GnRH, LH, steroids) and gametogenesis remains absent. Because reproductive regulation in teleosts is highly complex and sensitive to both direct endocrine signalling and indirect metabolic factors, this lack of direct gonadal data represents a critical limitation. Therefore, rigorous experimental validation is required to definitively confirm any reproductive efficacy. Future research must prioritize dose-dependent investigations into reproductive outcomes, including fecundity and larval viability, and evaluate interactions with induced breeding protocols. Addressing these gaps could help develop sustainable aquaculture methods by using pyrimidine analogues that do not accumulate in the body and act on multiple biological processes. This review highlights the need to connect mechanistic understanding with practical reproductive studies to improve aquaculture productivity.

Securing critical raw materials for net-zero energy systems and green technologies, has become a global priority. This urgency is fuelled by increasing demand, dwindling natural reserves, and rising geopolitical instabilities. Urban waste streams, often rich in metal concentrations than natural ores, are emerging as viable alternative for metal recovery. Bioleaching, a natural process utilising microorganism to mobilise metals from solid mineral matrices, has become increasingly popular as a sustainable and economically attractive alternative to conventional mining of minerals, particularly for low-grade ores and waste-derived feedstocks. The attractiveness of bioleaching lies in low environmental impact and high efficiency, even at low metal concentrations. This review explores different metal-bearing secondary materials containing critical, precious, and rare earth elements (REEs) as potential feedstocks for bioleaching. It traces the evolution of bioleaching from natural ore processing to its growing utility in urban waste valorisation within a circular economy framework. It compares bioleaching process in natural ores versus urban waste, while showcasing recent advancements toward commercial implementation. The review also identifies existing challenges and proposes strategies for improvement. Finally, it articulates bioleaching's potential for integration into a circular economy model, emphasising its role in enabling sustainable metal recovery and achieving carbon neutrality goals.

The present study investigated and optimized biogenic cyanide (bio-CN) production by using mine indigenous bacterial strains with the aim of extracting precious metals from Upper Group Two (UG-2) platinum group metals (PGM) ore. Among all the bacterial strains tested, under optimized conditions, Pseudomonas brassicacearum produced the highest bio-CN (14.1 ± 1 mg/L) and was therefore used in subsequent experiments. The study examined glycine consumption during cyanogenesis, as well as the stability and speciation of bio-CN. The findings confirmed that while glycine was consumed during cyanogenesis, the produced bio-CN was not stable and decreased over time, transforming into different cyanide species. The dose–response analysis for P. brassicacearum showed EC50 of 1785 g/L and 107.9 g/L against untreated and pre-treated PGM concentrate, respectively, suggesting higher toxicity for the latter. Two-step bioleaching of the pre-treated PGM concentrate showed extractions of 75.7, 18.7, 9.4, and 0.3

The recovery of metals from waste material has been on the increase in the past few years due to a number of reasons such as supporting the diversification of metal supply resources. In addition, the alternative use of the waste material for metal recovery can add to the main production line, boosting production throughput and profitability thus, allowing companies to sustain their activities during times of low commodity prices. While there has been a lot of research and interest in the recovery of precious metals such as platinum group metals (PGMs), Au, and Ag from solid waste material, there has been limited focus on the recovery of these value metals from wastewater. This is mostly related to challenges associated with finding cost-effective technologies that can recover these metals from solutions of low metal concentrations. In recent years, bio-based technologies have, however, become established as potential alternatives to traditional techniques in the treatment of wastewater due to their ability to recover metals from solutions of low concentrations. While wastewater might be characterized by some significant value metal content, it also contains other components that have potential economic value if recovered or converted to by-products. Such an approach may not only provide an opportunity for extraction of metal resources from wastewater but also contributes toward the circular economy. This chapter presents insights into precious metal recovery from wastewater using bio-based technologies, compares such an approach to the traditional techniques, explores the recovery of other value-added products and finally considers some of the challenges associated with the large-scale application of the bio-based technologies.

The ongoing global transition towards the development of greener technologies, along with a focus on reducing carbon emissions and environmental footprints, has prompted the mining industry to pursue greener alternatives. Bioleaching is a cost-effective and environmentally friendly technology that can be an appropriate alternative. At present, bio-oxidation of metals from ores is successfully practiced in industries; however, there is currently no bio-based process for the extraction of precious metals. Therefore, we aimed to develop a complete biological process for bioprocessing UG-2 PGM ores. The first part of the study involved bio-pretreatment to remove base metals from ores, followed by cyanogenic bioleaching of the pre-treated material. Microorganisms indigenous to a South African platinum mine were isolated and screened for their ability to produce biogenic cyanide. Four bacterial strains, namely Pseudomonas aeruginosa, Pseudomonas stutzeri, Pseudomonas brassicacearum, and Bacillus sp., exhibited significant bio-CN-producing capability. Among these strains, under optimized conditions, P. brassicacearum demonstrated the highest bio-CN production (14 ± 1 mg/L) at 18 hours of growth. Compared to one-step bioleaching, two-step bioleaching yielded higher mobilization of metals. Additionally, the two-step bioleaching approach was found to give higher precious metal recoveries from pre-treated material as opposed to untreated material. Amongst all bacterial strains, P. brassicacearum showed the highest metal extractions, i.e. 75.69, 18.69, 9.38, and 0.28

Titanium dioxide nanoparticles (TiO2 NPs) have become a focal point of research due to their widespread daily use and diverse synthesis methods, including physical, chemical, and environmentally sustainable approaches. These nanoparticles possess unique attributes such as size, shape, and surface functionality, making them particularly intriguing for applications in the biomedical field. The continuous exploration of TiO2 NPs is driven by the quest to enhance their multifunctionality, aiming to create next-generation products with superior performance. Recent research efforts have specifically focused on understanding the anatase and rutile phases of TiO2 NPs and evaluating their potential in various domains, including photocatalytic processes, antibacterial properties, antioxidant effects, and nanohybrid applications. The hypothesis guiding this research is that by exploring different synthesis methods, particularly chemical and environmentally friendly approaches, and incorporating doping and co-doping techniques, the properties of TiO2 NPs can be significantly improved for diverse applications. The study employs a comprehensive approach, investigating the effects of nanoparticle size, shape, dose, and exposure time on performance. The synthesis methods considered encompass both conventional chemical processes and environmentally friendly alternatives, with a focus on how doping and co-doping can enhance the properties of TiO2 NPs. The research unveils valuable insights into the distinct phases of TiO2 NPs and their potential across various applications. It sheds light on the improved properties achieved through doping and co-doping, showcasing advancements in photocatalytic processes, antibacterial efficacy, antioxidant capabilities, and nanohybrid applications. The study concludes by emphasizing regulatory aspects and offering suggestions for product enhancement. It provides recommendations for the reliable application of TiO2 NPs, addressing a comprehensive spectrum of critical aspects in TiO2 NP research and application. Overall, this research contributes to the evolving landscape of TiO2 NP utilization, offering valuable insights for the development of innovative and high-performance products.

The discovery of antibiotics has fully changed medicinal therapy. However, with the increased therapeutic use of antibiotics, bacteria continued to develop mechanisms to resist these drugs. Today, antibiotics are being prescribed to a range of patients from the common cold to cancer. Antibiotics are poorly metabolized in the body, about 70–80

The escalating issue of drug-resistant Plasmodium falciparum strains poses a significant challenge to malaria treatment. This research paper presents a comprehensive analysis of the Structure-Activity Relationship (SAR) of innovative compounds designed to combat drug-resistant malaria. Through systematic examination of the chemical structures and their biological activity, we aim to identify potential drug candidates that can effectively address this global health concern. Our study contributes to the ongoing efforts in antimalarial drug development, offering insights into the design of novel compounds that may prove instrumental in countering drug resistance among Plasmodium falciparum strains and improving the efficacy of malaria treatment strategies. Keywords: Plasmodium falciparum, Antimalarial Compounds, Drug Resistance, Chemical Structure Analysis, Novel Compounds

The global demand for raw materials in technology, combined with environmental regulations and growing social awareness about the negative impacts of traditional metal extraction processes, has led to a shift towards green technology. Green technology has been defined as the use of science and technology to create less harmful products that protect the environment. Since biogenic cyanide (bio-CN) is naturally produced by microorganisms and is biodegradable, its use in precious metals (PMs) recovery from metal-bearing resources can be considered a viable and green alternative to chemical cyanidation. Several microorganisms are known to produce bio-CN, however, only a few such as Chromobacterium violaceum (C. violaceum), Pseudomonas fluorescence (P. fluorescence), Bacillus megaterium (B. megaterium), Pseudomonas aeruginosa (P. aeruginosa), Pseudomonas chlororaphis (P. chlororaphis) have been quantified. The present review summarizes research on cyanogenic microorganisms known to produce bio-CN, the mechanism and metabolic pathways involved in bio-CN production, and the genetics of cyanide production. This paper also discusses the factors influencing bio-CN production and the methods used for its quantification. The application of bio-CN in leaching PMs i.e., gold (Au), palladium (Pd), platinum (Pt), and rhodium (Rh) from primary and secondary resources, pre-treatment approaches used, and the mechanism of residual bio-CN detoxification are systematically and comprehensively reviewed and provided. Further, the review provides essential insights into challenges faced during bio-CN production and its application in PMs leaching and offers insight into new ways of thinking to move the process towards commercialization.

Malaria, a deadly disease caused by the Plasmodium falciparum parasite, poses a global health crisis with limited treatment options due to drug resistance. In the quest for new antimalarial drugs, computational molecular docking has emerged as a pivotal approach. This study delves into the application of computational docking techniques to identify potential drug candidates targeting critical proteins within the parasite. Leveraging genetic and structural data, we scrutinize key Plasmodium falciparum proteins involved in essential biological processes. The evaluation of various computational methodologies, including molecular dynamics simulations and scoring functions, aids in the identification of promising compounds. Additionally, we highlight recent advances in machine learning and artificial intelligence for more efficient virtual screening. The results of these studies provide a promising pool of candidate compounds, accelerating the development of novel antimalarial drugs to combat this persistent global health threat. Keywords: Computational Molecular Docking, Plasmodium falciparum, Molecular Dynamics, Protein- Ligand Interactions, Protein Structure.

Antimicrobial resistance (AMR) is the potential of the microorganisms to resist the impacts of medicine/drugs that once could positively treat the microbial infection. The resistant microorganisms are hard to treat, may require elevated antimicrobial doses or alternative medications. Resistance arises through several mechanisms including natural resistance, by one species acquiring resistance from another or genetic mutation. All types of microorganisms including fungus, viruses, bacteria and protozoa can develop resistance. The increasing resistance among microbes is a major concern among medical microbiologists and other researchers related to the field. This chapter covers the AMR development among microbes including possible mechanisms, biochemical and molecular cascades.

Up to two-thirds of the world population is at risk of deficiency in one or more fundamental mineral elements. In order to overcome deficiency disorder of mineral nutrients, a biofortification approach in crops is an absolute requirement to eliminate hidden hunger. Hence the goal of crop biofortification is shifting from food security to nutritional security. In this context, ionomics becomes essential to recognize potential gene(s) responsible for the uptake, transport, and storage of ions in plants. Ionomics is one of the major pillars for the study of structural and functional genomics. It includes the estimation of elemental composition of an organism and changes in its composition in relation to physiological, formative, environmental, and genetic variables. The whole ionomic profiling of the plant is done by various analytical tools fruitfully used to measure elemental composition. Among the best are atomic absorption spectrometry, ion beam analysis, ICP-OES, X-ray crystallography, inductively coupled plasma–mass spectrometry, and neutron activation analysis. These tools gave complete profiles of the ions present in the plants. These data are stored in a database called PiiMS (Purdue Ionomics Information Management System). The vast amount of data available in the database helps the forward and reverse genetic approach for studying the structural and functional genomics of particular organisms. It renders the functional analysis of genes and gene networks that directly or indirectly influence the complete ionome. This chapter discusses the study of ionome with special reference to different types of ionic interaction, quantifications, and gene identification.

Radon gas is the prime contributor to natural radiation and poses a significant human health risk. Radon is the second leading cause of cancer after smoking. The estimation of the level of naturally occurring gases become important for determining radiation risk and has been the subject of interest of researchers worldwide. In the present study, the survey of radon, thoron, and their daughter’s product concentration has been carried out in the dwelling situated nearby selected sugar mills of Uttar Pradesh and Uttarakhand state of India by using a pin-hole dosimeter and direct radon/thoron progeny sensor with LR-115 Solid State Nuclear Track Detector (SSNTDs). The results show that the average value of radon and thoron concentration varied from 28.37 Bqm-3 to 43.02 Bqm-3, and 17.67 Bqm-3 to 25.04 Bqm-3 respectively. The average value of radon and thoron progeny concentration varied from 6.71 Bqm-3 to 14.16 Bqm-3, and 0.70 Bqm-3 to 1.41 Bqm-3 respectively.

In the present study, native bacterial strains isolated from abandoned gold mine and Chromobacterium violaceum (MTCC-2656) were applied for bioleaching of metals from waste printed circuit boards (WPCBs). Toxicity assessment and dose–response analysis of WPCBs showed EC50 values of 128.9, 98.7, and 90.8 g/L for Bacillus sp. SAG3, Bacillus megaterium SAG1 and Lysinibacillus sphaericus SAG2, respectively, whereas, for C. violaceum EC50 was 83.70 g/L. This indicates the viable operation range and technological feasibility of metals bioleaching from WPCBs using mine isolates. The influencing factors such as pH, pulp density, temperature, and precursor molecule (glycine) were optimized by one-factor at a time method (OFAT). The maximum metal recovery occurred at an initial pH of 9.0, a pulp density of 10 g/L, a temperature of 30 °C and a glycine concentration of 5 g/L, except for L. sphaericus which showed optimum activity at initial pH of 8.0. Under optimal conditions the metals recovery of Cu and Au from WPCBs were recorded as 87.5 ± 8% and 73.6 ± 3% for C. violaceum and 72.7 ± 5% and 66.6 ± 6% for B. megaterium, respectively. Kinetic modeling results showed that the data was best described by first order reaction kinetics, where the rate of metal solubilization from WPCBs depended upon microbial lixiviant production. This is the first report on bioleaching of metals from e-waste using bacterial isolates from the gold mine of Solan, HP. Our study demonstrated the potential of bioleaching for resource recovery from WPCBs dust, aimed to be disposed at landfills, and its effectiveness in extraction of elements those are at high supply risk and demand.

Proteases are ubiquitous enzymes, having significant physiological roles in both synthesis and degradation. The use of microbial proteases in food fermentation is an age-old process, which is today being successfully employed in other industries with the advent of ‘omics’ era and innovations in genetic and protein engineering approaches. Proteases have found application in industries besides food, like leather, textiles, detergent, waste management, agriculture, animal husbandry, cosmetics, and pharmaceutics. With the rising demands and applications, researchers are exploring various approaches to discover, redesign, or artificially synthesize enzymes with better applicability in the industrial processes. These enzymes offer a sustainable and environmentally safer option, besides possessing economic and commercial value. Various bacterial and fungal proteases are already holding a commercially pivotal role in the industry. The current review summarizes the characteristics and types of proteases, microbial source, their current and prospective applications in various industries, and future challenges. Promoting these biocatalysts will prove significant in betterment of the modern world.

Two-step bioleaching was applied using a cyanogenic bacterium Pseudomonas balearica SAE1 to recover gold (Au) and silver (Ag) from the computer printed circuit boards (CPCBs) via central composite design of a response surface methodology (CCD-RSM). To enhance Au and Ag recovery, factors like pH level, pulp density, temperature and glycine concentration were optimized and their interactions were studied. CCD-RSM optimization resulted in 73.9 and 41.6% dissolution of Au and Ag, respectively, at initial pH 8.6, pulp density 5 g/L, temperature 31.2 °C, and glycine concentration 6.8 g/L, respectively. Two quadratic models were proposed by RSM which can be utilized as an efficient tool to predict Au and Ag recovery through bioleaching. The experimental results are in line with the predicted results, indicating reliability of RSM model in enhancing the Au and Ag recovery from CPCBs. The increased bioleaching yield of Au and Ag from discarded CPCBs has its importance in industrial e-waste recycling and safe disposal.

Indigenous bacterial strain Pseudomonas balearica SAE1, tolerant to e-waste toxicity was isolated from an e-waste recycling facility Exigo Recycling Pvt. Ltd., India. Toxicity tolerance of bacterial strain was analyzed using crushed (particle size ≤150 µm) waste computer printed circuit boards (PCBs)/liter (L) of culture medium. The EC50 value for SAE1 was 325.7 g/L of the e-waste pulp density. Two-step bioleaching was then applied to achieve the dissolution of gold (Au) and silver (Ag) from the e-waste. To maximize precious metal dissolution, factors including pulp density, glycine concentration, pH level, and temperature were optimized. The optimization resulted in 68.5 and 33.8% of Au and Ag dissolution, respectively, at a pH of 9.0, a pulp density of 10 g/L, a temperature of 30 °C, and a glycine concentration of 5 g/L. This is the first study of Au and Ag bioleaching using indigenous e-waste bacteria and its analysis to determine e-waste toxicity tolerance.