Nanomaterials (NMs) tailored via conventional physicochemical routes play havoc with the environment that has led to the evolution of competent green routes for the actualization of a circular ...economy on an industrial-scale. Algae belonging to the class Cyanophyceae, Chlorophyceae, Phaeophyceae and Rhodophyceae have been harnessed as nano-machineries through intracellular and extracellular synthesis of gold (Au), silver (Ag) and several other metallic nanoparticles. Algae are an appealing platform for the production of diverse NMs, primarily due to the presence of bioactive compounds such as pigments and antioxidants in their cell extracts that act as biocompatible reductants. Chlorella spp. and Sargassum spp. have been extensively explored for the synthesis of nanoparticles having antimicrobial properties, which can potentially substitute conventional antibiotics. Characterization of nanoparticles (NPs) synthesised from algae has been done using advanced spectroscopic, diffractographic and microscopic techniques such as UV-Vis FT-IR, DLS, XPS, XRD, SEM, TEM, AFM, HR-TEM, and EDAX. The present paper reviews the information available on algae-mediated biosynthesis of various NPs, their characterization and applications in different domains.
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•Comprehensive review on algae mediated biosynthesis of metallic nanoparticles (NPs).•Mechanism of synthesis of NPs from micro and macroalgae and their characterization.•Chorella spp and Sargassum spp have been extensively explored to fabricate diverse NPs such as Au-NPs, Ag-NPs and ZnO-NPs.•Characterization of NPs synthesised from algae is done using different advanced techniques.•Application of metallic NPs in different domains such as antimicrobial and antifouling agents.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A microwave-alkali-acid pre-treatment method for rice straw was proposed.•SEM, XRD, FT-IR and 13C CP/MAS NMR analyses supported the pre-treatment efficiency.•A Taguchi orthogonal array design was ...used for optimal ethanol production via SSF.•An ethanol yield of 0.38g/g was achieved using a lab-scale bioreactor.
Microwave-alkali-acid pre-treated rice straw was found most suitable feedstock for ethanol production via simultaneous saccharification and fermentation (SSF). Native rice straw had 42.54% cellulose, 24.51% hemicelluloses, and 9.16% lignin. Upon microwave-alkali-acid pre-treatment, cellulose content was increased to 60.07%, whereas hemicelluloses and lignin was decreased to 14.90% and 4.52%, respectively in solid fraction of the biomass. Physico-chemical characteristics of native and pre-treated rice straw were examined using SEM, XRD, TGA, FT-IR and solid state 13C CP/MAS NMR spectroscopy. SEM of pre-treated rice straw revealed distorted surface morphology and XRD analysis showed an increase (8.97%) in the crystallinity index (CrI) as compared to native biomass. Ethanol production was optimized for microwave-alkali-acid pre-treated rice straw using Taguchi orthogonal array design. An excellent correlation between predicted (18.74g/L) and experimental values (18.9g/L) for ethanol production was observed under optimized SSF conditions: substrate loading, 11% (w/v); enzyme concentration, 0.5% (v/v); inoculum size, 8% (v/v); pH, 4.5 at 30°C after 24h. A ∼1.3-fold gain in ethanol concentration (25.2g/L) was obtained which corresponded to a yield of 0.38g/g using a lab-scale bioreactor on scaling up the shake-flask SSF under optimal conditions.
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GEOZS, IJS, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Conventional treatment technologies for removal of heavy metals from aqueous solution ...are not economical and generate huge quantity of toxic chemical sludge. Biosorption of heavy metals by metabolically inactive non-living biomass of microbial or plant origin is an innovative and alternative technology for removal of these pollutants from aqueous solution. Due to unique chemical composition biomass sequesters metal ions by forming metal complexes from solution and obviates the necessity to maintain special growth-supporting conditions. Biomass of
Aspergillus niger,
Penicillium chrysogenum,
Rhizopus nigricans,
Ascophyllum nodosum,
Sargassum natans,
Chlorella fusca,
Oscillatoria anguistissima,
Bacillus firmus and
Streptomyces sp. have highest metal adsorption capacities ranging from 5 to 641
mg
g
−1 mainly for Pb, Zn, Cd, Cr, Cu and Ni. Biomass generated as a by-product of fermentative processes offers great potential for adopting an economical metal-recovery system. The purpose of this paper is to review the available information on various attributes of utilization of microbial and plant derived biomass and explores the possibility of exploiting them for heavy metal remediation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The purpose of designing this book is to discuss and analyze security protocols available for communication. Objective is to discuss protocols across all layers of TCP/IP stack and also to discuss ...protocols independent to the stack. Authors will be aiming to identify the best set of security protocols for the similar applications and will also be identifying the drawbacks of existing protocols. The authors will be also suggesting new protocols if any.
Butachlor is a chloroacetamide pre-emergence herbicide, with a half-life of 1.6 to 29 days. It is a suspected carcinogen, genotoxin, neurotoxin and persists in the environment having toxic effect on ...living systems. Butachlor degrading bacterial strain A16 was isolated from coal tar contaminated soil, which showed 99.38% similarity with
Bacillus altitudinis
41KF2b
T
as revealed by 16S rRNA analysis.
B. altitudinis
strain A16 utilised butachlor as a sole source of carbon and degraded 90% of 50 mg L
−1
butachlor in 5 days at a rate constant and half-life (
t
1/2
) of 0.02 h
−1
and 34.65 h, respectively, following the first-order reaction kinetics. Five metabolites (
N
-(butoxymethyl)-
N
-(2-chloroethyl)-2,6-diethylaniline, (
N
-(butoxymethyl)-2-chloro-
N
-(2-ethylphenyl) acetamide,
N
-(butoxymethyl)-2,6-diethyl-
N
-propylaniline, 2-chloro-
N
-(2,6-diethylphenyl) acetamide and 2,6-diethylaniline) were produced during the breakdown of butachlor by
B. altitudinis
A16 as identified by GC–MS analysis, which are further mineralized to carbon dioxide and water. A metabolic pathway is proposed and compared with other bacteria. The findings have immense beneficial application since such microbes can be used on large scale for faster soil bioremediation and minimizing negative impact of pesticide butachlor on health and environment.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Lactic acid (LA) production from sugar mixture derived from lignocellulosic rice straw employing co- culture system of thermotolerant and inhibitor tolerant
Bacillus licheniformis
DGB and
Bacillus ...sonorenesis
DGS15 was carried out. In minimal media, both the strains of
Bacillus
DGB and DGS15 worked together by efficiently utilising glucose and xylose respectively. Response Surface Methodology (RSM) was used for optimisation of pretreatment of rice straw to achieve maximum yield of 50.852 g/L total reducing sugar (TRS) from 100 gm of rice straw biomass. Pretreatment of rice straw resulted in its delignification, as confirmed by FTIR spectroscopy, since the peak at 1668 cm
−1
disappeared due to removal of lignin and scanning electron microscopy (SEM) revealed disruption in structural and morphological features. Crystallinity index (
CrI)
of treated rice straw increased by 15.54% in comparison to native biomass. DGB and DGS15 individually yielded 0.64 g/g and 0.82 g/g lactic acid respectively, where as their co-cultivation led to effective utilisation of both glucose and xylose within 15 h (70%) and complete utilisation in 48 h, producing 49.75 g/L LA with a yield of 0.98 g/g and productivity of 1.036 g/L/h, and resulting in reduction in fermentation time. Separate hydrolysis of rice straw and co-fermentation (SHCF) of hydrolysates by
Bacillus
spp. enhanced the production of lactic acid, can circumvent challenges in biorefining of lignocellulosic biomass.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Copper is known for its bactericidal properties since ancient time. Development of copper nanoparticle (CNP) based antimicrobial products has generated interest in studying their toxicological ...properties. In this article, we have investigated the ROS (reactive oxygen species)–induced cytotoxicity of colloidal CNPs on MCF-7 human breast cancer cells. To understand the dependence of nanoparticle’s anticancer potential on their per batch yield, three identical sets of CNPs with similar physical properties with hydrodynamic size (11–14 nm) were prepared by chemical reduction method with per batch yield of 0.2 g, 0.3 g, and 0.4 g. Dose-dependent toxicity of as-synthesized (i.e., without any post preparation treatment) CNPs was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) colorimetric assay for CNP concentrations of 0.001–100 μg/mL. Strong dose-dependent toxicity was observed in all CNPs batches, which was because of the mitochondrial damage in MCF-7. Cytotoxicity in MCF-7 exposed to CNPs was observed due to rupture of cell membrane and shrinkage as well as oxidative stress induced by reactive oxygen species (ROS). IC
50
values of CNPs were independent of per batch yield of CNPs. This confirms that increase in CNPs yield from 0.2 to 0.4 g has no negative correlation with their cytotoxic response. The ability to scale up the nanoparticle yield with strong dose-dependent cytotoxicity makes CNPs potential candidate for the development of anticancer drugs.
Graphical Abstract
An electrochemical mixed aptamer-antibody sandwich assay based on the aptamer-induced HCR amplification strategy was fabricated for the highly sensitive detection of MUC16. The mixed aptamer-antibody sandwich assay showed acceptable performance of detection range, detection limit, reproducibility, and selectivity.
Insecticides are extensively applied in crop production and sometimes at higher concentration than their recommended doses, which has become an environmental hazard. Sustainable agricultural ...practices highlight minimal application of insecticides at low concentration. Use of controlled release formulations (CRFs) of pesticides in which active compound is associated with inert materials has emerged as an appealing alternative. In this study, nanospheres of insecticide cartap hydrochloride were developed using chitosan (CS) in the presence of tripolyphosphate (TPP) as crosslinker with the help of ionic gelation method, for the delivery of cartap hydrochloride. The nanoformulations were characterized by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectra. The FESEM images revealed that the size of chitosan tripolyphosphate (CS-TPP) nanospheres (nps) was in range of 117.01–185.27 nm, whereas cartap hydrochloride entrapped chitosan tripolyphosphate (C-CS-TPP) nanospheres had a size of 163.50–276.74 nm. FTIR results confirmed loading of cartap hydrochloride into chitosan tripolyphosphate nanospheres. The nanospheres showed encapsulation efficiency of 86.1% and were stable for 30 days at ambient temperature. In vitro release kinetics of insecticide from nanospheres followed a non Fickian diffusion mechanism. These nanospheres can act as slow-release formulation for the delivery of insecticide to the target organisms over a period of time, which is effective as well as environmentally safe.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Release of metallic nanoparticles in soil poses a serious threat to the ecosystem as they can affect the soil properties and impose toxicity on soil microbes that are involved in the biogeochemical ...cycling. In this work, in vitro ecotoxicity of as‐synthesised copper nanoparticles (CuNPs) on Bacillus subtilis (MTCC No. 441) and Pseudomonas fluorescens (MTCC No. 1749), which are commonly present in soil was investigated. Three sets of colloidal CuNPs with identical physical properties were synthesised by chemical reduction method with per batch yield of 0.2, 0.3 and 0.4 gm. Toxicity of CuNPs against these soil bacteria was investigated by MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), cytoplasmic leakage and ROS (reactive oxygen species) assay. MIC of CuNPs were in the range of 35–60 µg/ml and 35–55 µg/ml for B. subtilis and P. fluorescens respectively, while their MBC ranged from 40–70 µg/ml and 40–60 µg/ml respectively. MIC and MBC tests reveal that Gram‐negative P. fluorescens was more sensitive to CuNPs as compared to Gram positive B. subtilis mainly due to the differences in their cell wall structure and composition. CuNPs with smaller hydrodynamic size (11.34 nm) were highly toxic as revealed by MIC, MBC tests, cytoplasmic leakage and ROS assays, which may be due to the higher active surface area of CuNPs and greater membrane penetration. Leakage of cytoplasmic components and generation of extra‐cellular oxidative stress by reactive oxygen species (ROS) causes cell death. The present study realizes in gauging the negative impact of inadvertent release of nanoparticles in the environment, however, in situ experiments to know its overall impact on soil health and soil microflora can help in finding solution to combat ecotoxicity of nanoparticles.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Metal nanoparticles with plasmonic properties have gained significant attention due to their unique physical, chemical and antimicrobial properties. Among different metal nanoparticles, copper ...nanoparticles (CNPs) are especially important because of their antimicrobial activities against multidrug resistant strains. Synthesis of stable CNPs in feasible amounts remains a challenge due to the poor chemical stability of CNPs against oxidation. In this article, CNPs were synthesized with moderate yield (191.2 ± 9.5 µg/mL) by a chemical reduction method. The effects of various factors (type of copper precursor, temperature and reaction time) on the plasmonic properties, hydrodynamic size and the yield values were studied by UV-visible spectroscopy, photon correlation spectroscopy and inductively coupled plasma atomic emission spectroscopy. The CNPs synthesized by the optimized procedure (CuCl
2
as copper precursor, reaction time of 5 min and reaction temperature of 80°C) possess small hydrodynamic size (38 ± 0.52 nm) and stable plasmon resonance (571.5 ± 10 nm). These CNPs may find potential applications in development of cost-effective antimicrobial agents against multi-drug resistant strains.
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