Effect of microfibers induced toxicity in marine sedentary polychaete Hydroides elegans: Insight from embryogenesis axis

Presence of surgical face masks in the environment are more than ever before after the COVID-19 pandemic, and it poses a newer threat to aquatic habitats around the world due to microfibers (MFs) and other contaminants that get discharged when these masks deteriorate. The mechanism behind the developmental toxicity of MFs, especially released from surgical masks, on the early life stages of aquatic organisms are not well understood. Toxicity test were developed to examine the effects of MFs released from surgical facemask upon deterioration using the early gametes and early life stages of marine sedentary polychaete Hydroides elegans. For MFs release, cut pieces of face masks were allowed to degrade in seawater for different time points (1 day, 30 days and 120 days) after which the fibers were obtained for further toxicity studies. The gametes of H. elegans were exposed to the MFs (length < 20 μm) separately for 20 min at a concentration of 50 MFs/ml before fertilization. In addition, we also analyzed the experimental samples for heavy metals and organic substances released from face masks. Our findings demonstrated that gametes exposed to MFs affected the percentage of successful development, considerably slowed down the mitotic cell division and significantly postponed the time of larval hatching and also produced an adverse effect during embryogenesis. When the sperm were exposed fertilization rate was decreased drastically, whereas when the eggs were exposed to MFs fertilization was not inhibited but a delay in early embryonic development observed. In addition the release of heavy metals and other volatile organics from the degrading face masks could also contribute to overall toxicity of these materials in environment. Our study thus shows that inappropriately discarded face masks and MFs and other pollutants released from such face masks could pose long-term hazard to coastal ecosystems.

Deciphering Microalgal Diversity of Peculiar Lentic Ecosystem in Chennai, South India: A Way Towards Sustainability

Microalgae are quickly gaining attention among the researchers in various aspects such as biofuel applications, biogas, biomass production, waste water treatment, carbon fixation, animal feed ingredients, pigment production, and pharmaceutical products. One of the approaches to choose microalgae for biotechnological applications is to investigate their diversity and abundance in all possible wet environments. Samples were collected from three sampling sites for the period of 1 year (October 2021-September 2022) in Vadapalani temple tank at Chennai. Physicochemical parameters in current investigation were estimated according to APHA, 2017. Qualitative and quantitative analyses of phytoplankton were done throughout the study period. One-way ANOVA (Analyses of Variance) and Karl Pearson's correlation coefficient were estimated using SPSS (V.26.0). A total of 11 diversity indices were estimated using PAST (V 4.0). A total of 52 algal species were identified, prevailed over by Chlorophyceae (15 species), followed by Zygnematophyceae, Bacillariophyceae, Cyanophyceae, and Trebouxiophyceae. Chlorophyceae quantitatively structured the major category. The maximum and minimum values of density were observed during the season of summer (287 Cells/L) and monsoon (80 Cells/L), respectively. Chlorophyceae showed dominance with a density of 168 cells/L. The maximum and minimum densities of Chlorophyceae were recorded in the summer season (55 cells/L) and monsoon season (24 cells/L), respectively. Shannon's index (H') attained its zenith in February and April month of 2022 (3.60). This study further ignites the researchers to phycoprospect various temple water to address the nature of microalgae occurrence and for biotechnological purposes.

An Intensive Study on Algal Diversity in the Ancient Man-Made Aquatic Ecosystem of Tiruvallur, South India: Exploration for Sustainable Development

Eco-friendly and beneficial nature algae make it prominent in our earth as well as for human life. In recent decades, microalgal applications is sought in varied fields from the remediation of wastes to the production of pharmaceutical products. Still, more extensive research on bioprospecting should to conducted to get the genus-specific or species-specific applications of microalgae with high efficiency. This inquiry was carried out (October 2021 to September 2022) for the effectual understanding of microalgal composition structure along with seasonal physicochemical variations in the age-old holy tank at Tiruvallur, southeast India. This inquiry also acts as the source data and makes the bioprospecting process easier. It also ignites the researchers to address the microalgae seasonal composition structure of peculiar wet environments. A total of 41 microalgae species were recorded, in which six major algal groups were in order of, Chlorophyceae > Bacillariophyceae > Cyanophyceae > Euglenophyceae > Zygnematophyceae > Trebouxiophyceae. Mean seasonal abundance was highest in the summer season (351 cells/L) and lowest in the monsoon (113 cells/L). One-way ANOVA showed seasonal variations of physicochemical parameters, in which the majority of them attained their peak during summer. Mean values of water temperature, pH, salinity, total dissolved solids, total solids, electrical conductivity, chemical oxygen demand, total hardness, total alkalinity, ammonia, nitrite-nitrogen, and nitrate-nitrogen for the summer were 31.43 °C, 8.53, 0.56 ppt, 383 mg/L, 525 mg/L, 0.85 mS/cm, 46.27 mg/L, 300 ppm, 251.67 ppm, 1.51 mg/L, 0.62 mg/L, and 0.70 mg/L, respectively. Karl Pearson's correlation revealed a most significant relationship between water quality factors and algal density. The Shannon's diversity index (2.78-3.39) indicated moderately rich microalgal diversity in the study area. Palmer's pollution index stated that the temple tank was organically polluted all over the study period except November.

A novel encapsulation of 16 polycyclic aromatic hydrocarbons in petroleum sludge with palm oil fuel ash binder; an optimization study and sensitivity analysis using machine learning application

Palm oil fuel ash (POFA) has limited use as a fertilizer, while contribute effectively to the environmental contamination and health risks. Petroleum sludge poses a serious effect on the ecological environment and human health. The present work aimed to present a novel encapsulation process with POFA binder for treating petroleum sludge. Among 16 polycyclic aromatic hydrocarbons, four compounds were selected for the optimization of encapsulation process due to their high risk as carcinogenic substrates. Percentage PS (10-50%) and curing days (7-28 days) factors were used in the optimization process. The leaching test of PAHs was assessed using a GC-MS. The best operating parameters to minimize PAHs leaching from solidified cubes with OPC and10% POFA were recorded with 10% PS and after 28 days, at which PAH leaching was 4.255 and 0.388 ppm with R² is 0.90%. Sensitivity analysis of the actual and predicted results for both the control and the test (OPC and 10% POFA) revealed that the actual results of the 10% POFA experiments have a high consistency with the predicted data (R² 0.9881) while R² in the cement experiments was 0.8009. These differences were explained based on the responses of PAH leaching toward percentage of PS and days of cure. In the OPC encapsulation process, the main role was belonged to PS% (94.22%), while with 10% POFA, PS% contributed by 32.36 and cure day contributed by 66.91%.

Evaluating Biofilm Inhibitory Potential in Fish Pathogen, Aeromonas hydrophila by Agricultural Waste Extracts and Assessment of Aerolysin Inhibitors Using In Silico Approach

Aeromonas hydrophila, an opportunistic bacteria, causes several devastating diseases in humans and animals, particularly aquatic species. Antibiotics have been constrained by the rise of antibiotic resistance caused by drug overuse. Therefore, new strategies are required to prevent appropriate antibiotic inability from antibiotic-resistant strains. Aerolysin is essential for A. hydrophila pathogenesis and has been proposed as a potential target for inventing drugs with anti-virulence properties. It is a unique method of disease prevention in fish to block the quorum-sensing mechanism of A. hydrophila. In SEM analysis, the crude solvent extracts of both groundnut shells and black gram pods exhibited a reduction of aerolysin formation and biofilm matrix formation by blocking the QS in A. hydrophila. Morphological changes were identified in the extracts treated bacterial cells. Furthermore, in previous studies, 34 ligands were identified with potential antibacterial metabolites from agricultural wastes, groundnut shells, and black gram pods using a literature survey. Twelve potent metabolites showed interactions between aerolysin and metabolites during molecular docking analysis, in that H-Pyran-4-one-2,3 dihydro-3,5 dihydroxy-6-methyl (-5.3 kcal/mol) and 2-Hexyldecanoic acid (-5.2 kcal/mol) showed promising results with potential hydrogen bond interactions with aerolysin. These metabolites showed a better binding affinity with aerolysin for 100 ns in molecular simulation dynamics. These findings point to a novel strategy for developing drugs using metabolites from agricultural wastes that may be feasible pharmacological solutions for treating A. hydrophila infections for the betterment of aquaculture.

A review on biodegradable polylactic acid (PLA) production from fermentative food waste - Its applications and degradation

Due to its low carbon footprint and environmental friendliness, polylactic acid (PLA) is one of the most widely produced bioplastics in the world. Manufacturing attempts to partially replace petrochemical plastics with PLA are growing year over year. Although this polymer is typically used in high-end applications, its use will increase only if it can be produced at the lowest cost. As a result, food wastes rich in carbohydrates can be used as the primary raw material for the production of PLA. Lactic acid (LA) is typically produced through biological fermentation, but a suitable downstream separation process with low production costs and high product purity is also essential. The global PLA market has been steadily expanding with the increased demand, and PLA has now become the most widely used biopolymer across a range of industries, including packaging, agriculture, and transportation. Therefore, the necessity for an efficient manufacturing method with reduced production costs and a vital separation method is paramount. The primary goal of this study is to examine the various methods of lactic acid synthesis, together with their characteristics and the metabolic processes involved in producing lactic acid from food waste. In addition, the synthesis of PLA, possible difficulties in its biodegradation, and its application in diverse industries have also been discussed.

A comprehensive review on polylactic acid (PLA) - Synthesis, processing and application in food packaging

Plastics play an essential role in food packaging; their primary function is to preserve the nature of the food, ensure adequate shelf life and ensure food safety. Plastics are being produced on a global scale in excess of 320 million tonnes annually, with demand rising to reflect the material in wide range of applications. Nowadays, the packaging industry is a significant consumer of synthetic plastic made from fossil fuels. Petrochemical-based plastics are regarded as the preferred material for packaging. Nonetheless, using these plastics in large quantities results in a long-standing environment. Environmental pollution and the depletion of fossil fuels have prompted researchers and manufacturers to develop eco-friendly biodegradable polymers to replace petrochemical-based polymers. As a result, the production of eco-friendly food packaging material has sparked increased interest as a viable alternative to petrochemical-based polymers. Polylactic acid (PLA) is one of the compostable thermoplastic biopolymers that is biodegradable and renewable in nature. High-molecular-weight PLA can be used to produce fibres, flexible, non-wovens, hard and durable materials (100,000 Da or even higher).The chapter focuses on food packaging techniques, food industry waste, biopolymers, their classification, PLA synthesis, the importance of PLA properties for food packaging, and technologies used to process PLA in food packaging.

Microplastic contamination in commercial fish species in southern coastal region of India

Due to its potential impact on food safety and human health, commercial species that have been contaminated with microplastics (MPs) are drawing more attention on a global scale. This study investigated the possibility of MPs contamination in different marine fish species with substantial commercial value that was captured off the south coast of India, from Adyar and Ennore regions. Over the course of six months, from October 2019 to March 2020, 220 fish were examined. It was discovered that the gills and guts had accumulated more numbers of MPs (1115 MPs) of which 68% were fibres and fragments. The commercial fish samples contained an average of 3.2-7.6 MPs per fish. Greater MPs pollution is seen in the Ennore regions. The prevalence of MPs was observed in carnivorous and planktivorous fish collected from both the sites. Fish guts contained the most MPs, according to the data. Pelagic fish accounted for the least amount of MPs, followed by mid- and demersal fish. Four different types of polymers were also identified in the present study: polyethylene, polypropylene, polystyrene, and polyamide. These results clearly showed the degree of microplastic contamination in fish tissues from the south Indian coastal regions of Adyar and Ennore. These results we hope will create a baseline data for MPs contamination in commercial fish species. The presence of MPs in the fish could have detrimental effects both on the environment and human health and thus comprehensive steps are required to prevent plastic pollution of the environment in south India's coastal region.

Photosynthetic microbial fuel cells for methanol treatment using graphene electrodes

Photosynthetic microbial fuel cells (pMFC) represent a promising approach for treating methanol (CH₃OH) wastewater. However, their use is constrained by a lack of knowledge on the extracellular electron transfer capabilities of photosynthetic methylotrophs, especially when coupled with metal electrodes. This study assessed the CH₃OH oxidation capabilities of Rhodobacter sphaeroides 2.4.1 in two-compartment pMFCs. A 3D nickel (Ni) foam modified with plasma-grown graphene (Gr) was used as an anode, nitrate mineral salts media (NMS) supplemented with 0.1% CH₃OH as anolyte, carbon brush as cathode, and 50 mM ferricyanide as catholyte. Two simultaneous pMFCs that used bare Ni foam and carbon felt served as controls. The Ni/Gr electrode registered a two-fold lower charge transfer resistance (0.005 kΩ cm²) and correspondingly 16-fold higher power density (141 mW/m²) compared to controls. The underlying reasons for the enhanced performance of R. sphaeroides at the graphene interface were discerned. The real-time polymerase chain reaction (PCR) analysis revealed the upregulation of cytochrome c oxidase, aa3 type, subunit I gene, and Flp pilus assembly protein genes in the sessile cells compared to their planktonic counterparts. The key EET pathways used for sustaining CH₃OH oxidation were discussed.

The role of plant-associated rhizobacteria in plant growth, biocontrol and abiotic stress management

The rhizosphere is the region around the plant roots where maximum microbial activities occur. In the rhizosphere, microorganisms' beneficial and harmful activities affect plant growth and development. The mutualistic rhizospheric bacteria which improve plant growth and health are known as plant growth-promoting rhizobacteria (PGPR). They are very important due to their ability to help the plant in diverse ways. PGPR such as Pseudomonas, Bacillus, Azospirillum, Azotobacter, Arthrobacter, Achromobacter, Micrococcus, Enterobacter, Rhizobium, Agrobacterium, Pantoea and Serratia are now very well known. Rhizomicrobiome plays critical roles in nutrient acquisition and assimilation, improved soil texture, secreting and modulating extracellular molecules such as hormones, secondary metabolites, antibiotics and various signal compounds, all leading to the enhancement of plant growth and development. The microbes and compounds they secrete constitute valuable biostimulants and play pivotal roles in modulating plant stress responses. In this review, we highlight the rhizobacteria diversity and cutting-edge findings focusing on the role of a PGPR in plant growth and development. We also discussed the role of PGPR in resisting the adverse effects arising from various abiotic (drought, salinity, heat, heavy metals) stresses.

Unraveling the role of plant-associated rhizobacteria in plant growth, biocontrol, and abiotic stress management

The rhizosphere is the region around the plant roots where maximum microbial activities occur. In the rhizosphere, microorganisms' beneficial and harmful activities affect plant growth and development. The mutualistic rhizospheric bacteria which improve plant growth and health are known as plant growth-promoting rhizobacteria (PGPR). They are very important due to their ability to help the plant in diverse ways. PGPR such as Pseudomonas, Bacillus, Azospirillum, Azotobacter, Arthrobacter, Achromobacter, Micrococcus, Enterobacter, Rhizobium, Agrobacterium, Pantoea, and Serratia are now very well known. Rhizomicrobiome plays critical roles in nutrient acquisition and assimilation, improved soil texture, secreting, and modulating extracellular molecules such as hormones, secondary metabolites, antibiotics, and various signal compounds, all leading to the enhancement of plant growth and development. The microbes and compounds they secrete constitute valuable biostimulants and play pivotal roles in modulating plant stress responses. In this review, we highlight the rhizobacteria diversity and cutting-edge findings focusing on the role of a PGPR in plant growth and development. We also discussed the role of PGPR in resisting the adverse effects arising from various abiotic (drought, salinity, heat, heavy metals) stresses.

Remediation techniques for uranium removal from polluted environment - Review on methods, mechanism and toxicology

Uranium, a radionuclide, is a predominant element utilized for speciality requirements in industrial applications, as fuels and catalyst. The radioactive properties and chemical toxicity of uranium causes a major threat to the ecosystem. The hazards associated with Uranium pollution includes the cancer in bones, liver, and lungs. The toxicological properties of Uranium are discussed in detail. Although there are many methods to eliminate those hazards, this research work is aimed to describe the application of bioremediation methods. Bioremediation methods involve elimination of the hazards of uranium, by transforming into low oxidation form using natural microbes and plants. This study deeply elucidates the methods as bioleaching, biosorption, bioreduction and phytoremediation. Bioleaching process involves bio-oxidation of tetravalent uranium when it gets in contact with acidophilic metal bacterial complex to obtain leach liquor. In biosorption, chitin/chitosan derived sorbents act as chelators and binds with uranium by electrostatic attraction. Bio reduction employs a bacterial transformation into enzymes which immobilize and reduce uranium. Phytoremediation includes phytoextraction and phytotranslocation of uranium through xylems from soil to roots and shoots of plants. The highest uranium removal and uptake reported using the different methods are listed as follows: bioleaching (100% uranium recovery), biosorption (167 g kg^-1 uranium uptake), bioreduction (98.9% uranium recovery), and phytoremediation (49,639 mg kg^-1 uranium uptake). Among all the techniques mentioned above, bioleaching has been proved to be the most efficient for uranium remediation.

Detoxification of coir pith through refined vermicomposting engaging Eudrilus eugeniae

Hazardous coir industrial waste, coir pith has been subjected to 50 days vermicomposting with Eudrilus eugeniae by amending nitrogenous legume plant, Gliricidia sepium together with cattle dung in different combinations, after 21 days precomposting using Pleurotus sajor-caju spawn. An increase in electrical conductivity, total NPK and calcium, and a decrease in organic matter, total organic carbon, C/N ratio, C/P ratio and total phenolic content in the final vermicompost were observed. Dehydrogenase, urease and cellulase activity peaked up to 30 days of vermicomposting and then declined. The phytotoxicity studies with Brassica juncea, C/N ratio and enzyme activities confirmed the stability and maturity of vermicompost. The results also demonstrated that the 2:3:1 ratio (coir pith + Gliricidia sepium + cow dung) is a suitable effective combination for nutrient-rich (N: 2.43%; P: 0.92%; K: 2.09%) vermicompost production. The total phenolic contents declined during the vermicomposting with a lower final content of 21.26 mg/g GAE in 2:3:1 combination of substrates from the initial level (105.56 mg/g GAE). Besides, the concentration of total phenol contents inversely related to the germination index of Brassica juncea (r = -0.761), indicating that the phenolic content could also play an important role in phytotoxicity. Growth and fecundity of Eudrilus eugeniae in 2:3:1 combination revealed the acceptability and rapid decomposition of coir pith substrate into vermifertilizer.

Artificial intelligence (AI) applications in adsorption of heavy metals using modified biochar

The process of removal of heavy metals is important due to their toxic effects on living organisms and undesirable anthropogenic effects. Conventional methods possess many irreconcilable disadvantages pertaining to cost and efficiency. As a result, the usage of biochar, which is produced as a by-product of biomass pyrolysis, has gained sizable traction in recent times for the removal of heavy metals. This review elucidates some widely recognized harmful heavy metals and their removal using biochar. It also highlights and compares the variety of feedstock available for preparation of biochar, pyrolysis variables involved and efficiency of biochar. Various adsorption kinetics and isotherms are also discussed along with the process of desorption to recycle biochar for reuse as adsorbent. Furthermore, this review elucidates the advancements in remediation of heavy metals using biochar by emphasizing the importance and advantages in the usage of machine learning (ML) and artificial intelligence (AI) for the optimization of adsorption variables and biochar feedstock properties. The usage of AI and ML is cost and time-effective and allows an interdisciplinary approach to remove heavy metals by biochar.

A crucial review on polycyclic aromatic Hydrocarbons - Environmental occurrence and strategies for microbial degradation

Over the last century, contamination of polycyclic aromatic hydrocarbons (PAHs) has risen tremendously due to the intensified industrial activities like petrochemical, pharmaceutical, insecticides and fertilizers applications. PAHs are a group of organic pollutants with adverse effects on both humans and the environment. These PAHs are widely distributed in various ecosystems including air, soil, marine water and sediments. Degradation of PAHs generally occurs through processes like photolysis, adsorption, volatilization, chemical degradation and microbial degradation. Microbial degradation of PAHs is done by the utilization of diverse microorganisms like algae, bacteria, fungi which are readily compatible with biodegrading/bio transforming PAHs into H₂O, CO₂ under aerobic, or CH₄ under anaerobic environment. The rate of PAHs degradation using microbes is mainly governed by various cultivation conditions like temperature, pH, nutrients availability, microbial population, chemical nature of PAHs, oxygen and degree of acclimation. Several microbial species including Selenastrum capricornutum, Ralstonia basilensis, Acinetobacter haemolyticus, Pseudomonas migulae, Sphingomonas yanoikuyae and Chlorella sorokiniana are known to degrade PAHs via biosorption and enzyme-mediated degradation. Numerous bacterial mediated PAHs degradation methods are studied globally. Among them, PAHs degradation by bacterial species like Pseudomonas fluorescence, Pseudomonas aeruginosa, Rhodococcus spp., Paenibacillus spp., Mycobacterium spp., and Haemophilus spp., by various degradation modes like biosurfactant, bioaugmentation, biostimulation and biofilms mediated are also investigated. In contrarily, PAHs degradation by fungal species such as Pleurotus ostreatus, Polyporus sulphureus, Fusarium oxysporum occurs using the activity of its ligninolytic enzymes such as lignin peroxidase, laccase, and manganese peroxidase. The present review highlighted on the PAHs degradation activity by the algal, fungal, bacterial species and also focused on their mode of degradation.

Screening of anti-inflammatory phytocompounds from Crateva adansonii leaf extracts and its validation by in silico modeling

Anti-inflammatory phytocompounds from Crateva adansonii DC leaf extracts were identified by GCMS analysis and its anti-inflammatory potential was evaluated by in silico molecular docking study against inflammatory molecular targets. Three different (Aqueous, Methanol and Petroleum ether) dried leaf extracts of Crateva adansonii were obtained from soxhlet extraction method. Preliminary phytoconstituents analysis of three different leaf extracts of C. adansonii confirmed the presence of various major classes of bioactive phytoconstituents such as polyphenols (tannins and flavonoids), steroids, alkaloid, coumarin, carbohydrate and terpenoids. Among three leaf extracts, methanolic leaf extract possess highest total phenolic content of 77 ± 1.65 µg gallic acid equivalent (GAE)/g of dry weight of leaf extract, subsequently methanolic leaf extract also shows maximal in vitro antioxidant activity (DPPH scavenging activity) of 71.22 ± 1.32% among three different leaf extracts. GC-MS analysis of petroleum ether leaf extract revealed the presence of nine phytocompounds representing 95.43% peak area percentage, among nine identified phytocompounds three phytocompounds of C. adansonii possess anti-inflammatory property namely phytol, 1-Hexyl-2-Nitrohexane and 2-Isopropyl-5-Methylcyclohexyl 3-(1-(4-Chlorophenyl)-3-Oxobutyl)-Coumarin-4-Yl Carbonate were chosen for in silico molecular docking study against four inflammatory receptor targets (COX-2, TNFα, IL-1β and IL-6) and they shows less binding energy with highest docking score ranging from -15.9500 to 5.0869. The present study substantially indicated and proven that anti-inflammatory potential of phytocompounds from C. adansonii leaf extracts which can be exploited for commercial designing of novel anti-inflammatory drug to treat various inflammatory disorders.

Biomimetic synthesis of silver nanoparticles using flower extract of Bauhinia purpurea and its antibacterial activity against clinical pathogens

In the present study, we have reported an eco-friendly, rapid, and simple method for the synthesis of silver nanoparticles (AgNPs) using Bauhinia purpurea flower extract as non-toxic bioreducing agent. The formation of AgNPs was confirmed by UV-visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The synthesized AgNPs were spherical in shape with an average size of 20 nm. Furthermore, the antibacterial activities of the synthesized AgNPs (2-10 mM) against clinical pathogens, Klebsiella sp. and Staphylococcus sp., were evaluated under in vitro conditions.

Biosynthesis of silver nanoparticles from Spirulina microalgae and its antibacterial activity

The present work focuses on a low-cost, simple, and green synthesis of silver nanoparticles (AgNPs) by mixing AgNO₃ solution with the extract of Spirulina platensis (SP) without any chemical reducing and/or capping agents. The green synthesis of AgNPs was confirmed by the color change from colorless to yellowish brown. The biosynthesis of AgNPs was further confirmed by UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), biological transmission electron microscopy (Bio-TEM), and energy dispersive X-ray analysis (EDX). The UV-vis spectroscopy results showed the surface plasmon resonance (SPR) of AgNPs around 450 nm. Bio-TEM analysis revealed that the Ag nanoparticles were well dispersed with average range of 5-50 nm. XRD results indicated that the green synthetic process produced face-centered cubic structure of AgNPs. FT-IR spectroscopy analysis showed that the bioactive molecules from the SP extract believed to be the responsible for the reduction of Ag ions. Furthermore, the synthesized AgNPs were evaluated against pathogens such as Staphylococcus sp. and Klebsiella sp. The AgNPs (1-4 mM) extensively reduced the growth rate of the pathogens.

Optimization of protease production from surface-modified coffee pulp waste and corncobs using Bacillus sp. by SSF

The aim of the study was to identify new sources of substrate from agro-industrial waste for protease production using Bacillus sp., a local bacteria isolated from an agro-waste dumping site. The strain was identified as Bacillus sp. BT MASC 3 by 16S rRNA sequence followed by phylogenic analysis. Response surface methodology-based Box-Behnken design (BBD) was used to optimize the variables such as pH, incubation time, coffee pulp waste (CPW) and corncob (CC) substrate concentration. The BBD design showed a reasonable adjustment of the quadratic model with the experimental data. Statistics-based contour and 3-D plots were generated to evaluate the changes in the response surface and understand the relationship between the culture conditions and the enzyme yield. The maximum yield of protease production (920 U/mL) was achieved after 60 h of incubation with 3.0 g/L of CPW and 2.0 g/L of CC at pH 8 and temperature 37 °C in this study. The molecular mass of the purified enzyme was 46 kDa. The highest activity was obtained at 50 °C and pH 9 for the purified enzymes.

Piper betle-mediated synthesis, characterization, antibacterial and rat splenocyte cytotoxic effects of copper oxide nanoparticles

The study reports a simple, inexpensive, and eco-friendly synthesis of copper oxide nanoparticles (CuONPs) using Piper betle leaf extract. Formation of CuONPs was confirmed by UV-visible spectroscopy at 280 nm. Transmission electron microscopy (TEM) images showed that the CuONPs were spherical, with an average size of 50-100 nm. The scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS) peak was observed approximately at 1 and 8 keV. The X-ray diffraction (XRD) studies indicated that the particles were crystalline in nature. CuONPs effectively inhibited the growth of phytopathogens Ralstonia solanacearum and Xanthomonas axonopodis. The cytotoxic effect of the synthesized CuONPs was analyzed using rat splenocytes. The cell viability was decreased to 94% at 300 μg/mL.