Promising strategies of circular bioeconomy using heavy metal phytoremediated plants - A critical review.

Phytoremediation is an excellent method for removing harmful heavy metals from the environment since it is eco-friendly, uses little energy, and is inexpensive. However, as phytoremediated plants can turn into secondary sources for heavy metals, complete heavy metal removal from phytoremediated plants is necessary. Elimination of toxic heavy metals from phytoremediated plants should be considered with foremost care. This review highlights about important sources of heavy metal contamination, health effects caused by heavy metal contamination and technological breakthroughs of phytoremediation. This review critically emphasis about promising strategies to be engaged for absolute reutilization of heavy metals and spectacular approaches of production of commercially imperative products from phytoremediated plants through circular bioeconomy with key barriers. Thus, phytoremediation combined with circular bioeconomy can create a new platform for the eco-friendly life.

Synthesize and characterization of CaOx crystals against various citrus waste peel extracts: an in vitro study.

Citrus fruits have been consumed by world's population for several centuries. Since it's an edible source possesses various uses in treating many diseases. Among various diseases urolithiasis is one of the major issues globally demands in painless surgical treatment. Calcium Oxalate (CaOx) is found to be the most prevailing constituent of renal calculus in humans which tends to be the categories of the urolithiasis. Citric acid is commonly used in treating to dissolve them in medications. Citrate compound has the ability to bind with calcium stones to relieve oxalates in urine. The objective of the present study is to assess the efficacy of citrate compounds from waste citrate peels describing the inhibition of calcium oxalate (CaOx) crystals. Multistep extraction procedures were performed for the selected citrus peels of Citrus limon, Citrus limetta and Citrus sinensis using different solvents (hexane, aqueous and ethanol) and were tested for its inhibitory actions with different parameters against the synthesized CaOx crystals. The synthetic CaOx crystals were characterized by Microscopy, FTIR, SEM, XRD, and TGA. The structural change in the crystal was observed for inhibition at various stages like nucleation, growth and aggregation when treated with the ethanol extracts of citrus peels. Thus the present investigation concludes that the ethanol extracts of C. sinensis peels highly inhibits at a concentration of 1000 (µg/mL) in 60 min when compared to other solvents. This research would give additional information in preparation of drugs against CaOx urolithiasis in future pharmaceutical development processes.

Process optimization, green chemistry balance and technoeconomic analysis of biodiesel production from castor oil using heterogeneous nanocatalyst.

In the present work, zinc doped calcium oxide was used as a nanocatalyst for biodiesel production from castor oil. The optimal conditions of biodiesel conversion and green chemistry balance were obtained with response surface methodology. Five green chemistry parameters like carbon efficiency, atom economy, reaction mass efficiency, stoichiometric factor and environmental factor were optimized. The sustainable biodiesel yield 84.9% and green chemistry balance 0.902 was achieved at methanol to oil molar ratio 10.5:1, temperature 57 °C, time 70 min, and catalyst concentration 2.15%. The synthesized biodiesel was characterized by GCMS and FTIR, and physic-chemical properties were determined. Based on experimental study annually 20.3 million kg capacity plant was simulated using SuperPro designer. The sensitivity analysis of oil purchase cost and biodiesel selling price on ROI, payback period, IRR and NPV were investigated. The optimization and technoeconomic analysis provided a sustainable platform for commercial based biodiesel production.

Algal biomass as a source for novel oral nano-antimicrobial agent.

In the present study, sulphated polysaccharide Ulvan from Ulva lactuca was used for the synthesis of biogenic Selenium Nanoparticles (SeNPs) conjugate and Mouth rinse was prepared using this conjugate. The synthesis of nanoparticles was confirmed by UV-Visible spectrophotometry and characterized using Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and X-ray diffraction (XRD). TEM showed that the average size of the nanoparticle was 85 nm and spherical in shape. Furthermore, nanoparticle conjugates were evaluated for cell viability using MTT assay 3T3-L1 cell line and at 30 µl/ml showed 34% cell viability. The antimicrobial activity of SeNPs mouth rinse was tested against oral pathogens such as Streptococcus mutans, Staphylococcus aureus, Lactobacillus, and Candida albicans and it was effective against all tested microorganism at the concentration of 100 µl/ml. The present study has shown that Ulvan from algal biomass can be a safe and effective source for the development of oral nano-antimicrobial agents.

Enhanced malic acid production using Aspergillus niger coupled with in situ product recovery.

In the present investigation, recovery of malic acid from the fermentation broth was performed by using in situ reactive extraction method employing different combination of amine and solvent systems. Totally six solvent mixtures were tested for toxicity on Aspergillus niger PJR1. Further, effect of solvent mixture concentration on separation of malic acid was investigated. Solvent system consisting of 2 M of trioctylamine in 1-octanol was found to be non-toxic to A. niger PJR1 and resulted in the maximum partition coefficient of 0.75 when the solvent mixture to liquid ratio of 1:2 used. A. niger PJR1 from crude glycerol using in situ reactive batch fermentation resulted in the maximum malic acid titer of 115.67 ± 3.5 g/L with the productivity of 0.53 g/L.h after 216 h. Further, fed batch extractive fermentation with crude glycerol resulted in malic acid titer of 131.48 ± 3.4 g/L with the productivity of 0.45 g/L.h after 288 h. Thus reactive extraction combined with in situ fermentation could become effective method for enhanced malic acid production.

Bioethanol production from woody stem Prosopis juliflora using thermo tolerant yeast Kluyveromyces marxianus and its kinetics studies.

In the present study, Kluyveromyces marxianus was utilized to study the batch fermentation kinetics of biomass production, substrate utilization and bioethanol production from woody stem Prosopis juliflora. The pre-treated substrate was subjected to Simultaneous Saccharification and Fermentation (SSF) under optimised conditions of pH (4.9), temperature (41 °C), substrate concentration 5% (w/v), inoculum concentration 3% (v/v) and the maximum concentration of bioethanol was found to be 21.45 g/l. The experimental data thus obtained from cell growth, substrate utilization and product formation are employed in the determination of kinetic parameters. Biological models such as Logistic model, Hinshelwood model were used for microbial growth and substrate utilization kinetics respectively. In case of product kinetics, Leudking-Piret plot, Gompertz model and Modified Gompertz model were utilised. Based on these models, kinetic parameters like maximum specific growth rate (µm), saturation constant (Ks), growth associated (α), non-growth associated (ß) and yield coefficients (YX/S, YP/S) were estimated.

Synergism of clay with zinc oxide as nanocatalyst for production of biodiesel from marine Ulva lactuca.

In the present work, Ulva lactuca, a marine macroalgae was used for the production of biodiesel. The ultrasound assisted extraction of oil from autoclaved algal biomass was found effective with maximum yield. The maximum oil was extracted at optimal conditions of 5% moisture content of algal biomass, 0.15 mm size of biomass, 6:1 solvent: solid ratio, at 55 °C in 140 min. The n-hexane with co-solvent methyl tertbutyl ether has shown higher oil when compared to other co-solvents. The extracted oil was transesterified into biodiesel using silica doped with zinc oxide as novel heterogeneous nanocatalyst. The maximum biodiesel yield of 97.43% was obtained at optimized conditions of 800 °C calcination temperature, 8% catalyst concentration, 9:1 methanol to oil ratio, 55 °C reaction temperature and 50 min reaction time. The kinetics of the transesterification reaction was also studied. The Ulva lactuca was found as a potential source for biodiesel production.

Biodiesel production from Calophyllum inophyllum oil using zinc doped calcium oxide (Plaster of Paris) nanocatalyst.

The present study was mainly focused on the production of biodiesel from Calophyllum inophyllum oil. The oil was characterized by GC-MS and stored for biodiesel production. The heterogeneous catalyst was synthesized for effective production of biodiesel. The synthesized catalyst was found to have good activity and stability. The surface and element characterization of zinc doped calcium oxide was characterized by SEM and EDAX. The size of nanocomposite was found to be in the range of 14.3-65.6 nm. The EDAX has confirmed the presence of zinc on the surface of the calcium oxide. The maximum biodiesel yield of 89.0% (v/v) was obtained at 55 °C in 80 min and catalyst concentration of 6% (w/v). The optimized methanol:oil molar ratio was obtained at 9:1 for the production of biodiesel. The produced methyl ester was confirmed by GC-MS analysis.

Process optimization and kinetic analysis of malic acid production from crude glycerol using Aspergillus niger.

In the present work, optimization of crude glycerol fermentation to produce malic acid by using Aspergillus niger was investigated using response surface methodology and artificial neural network. Kinetic investigation of bioconversion of crude glycerol into malic acid using Aspergillus niger was studied using Monod, Mosser, and Haldane-Andrew models. Crude glycerol concentration, initial pH and yeast extract concentration were found to be significant compounds affecting malic acid production by Aspergillus niger. Both dry cell weight and malic acid titre were found decreased with increase in crude glycerol concentration. Haldane-Andrew model gave the best fit for the production of malic acid from crude glycerol with µmax of 0.1542 h-1. The maximum malic acid production obtained under optimum conditions was 92.64 + 1.54 g/L after 192 h from crude glycerol using Aspergillus niger.

Bioethanol production from palm wood using Trichoderma reesei and Kluveromyces marxianus.

In the present work, palm wood was pretreated using hydrothermal technique in conjunction with chemical method for removal of lignin. Pretreated palm wood was subjected to hydrolysis using Trichoderma reesei MTCC 4876. Subsequently bioethanol was produced using palm wood hydrolysate by Kluveromyces marxianus MTCC 1389. RSM was used to identify the non-linear relationship and optimize various process parameters such as parameters such as pH, temperature, agitation rate, substrate concentration and inoculum size for bioethanol production. ANN constructed with 5-2-1 topology was also used to optimize process parameters. The experimental bioethanol yield of 22.90 g/l was obtained at ANN optimum conditions of temperature 45 °C, agitation rate 156 rpm, pH 5, substrate concentration 8% (v/v) and inoculum size 3.2% (v/v).

Synthesis, characterization and synergistic activity of cerium-selenium nanobiocomposite of fungal l-asparaginase against lung cancer.

Cerium selenium nanobiocomposites are novel lung cancer drug as they possess combined anti-cancer property of nanocomposite with l-asparaginase working in synergetic manner. Cerium selenium nanobiocomposites were synthesized using simple co-precipitation method. The size of the nanocomposite was found to be in the range 60-90 nm. Maximum absorption was observed using UV spectrum in the range of 350-490 nm. The nanobiocomposites was characterized using H-NMR and FTIR analysis it was found that secondary alkyl, allylic carbon, monosubstituted alkenes and sp2 hybridized CH bonds of alkenes were involved in binding of cerium and selenium nanoparticles with l-asparaginase for the formation of cerium selenium nanobiocomposite. The spherical shape of the cerium selenium nanobiocomposites were confirmed using SEM. Anticancer activity was checked by performing MTT assay resulting in 70.84% and 48.78% toxicity for maximum concentration of 1000 (µg/ml) and IC50 concentration of 125 (µg/ml) respectively on A549 lung cancer cell line using fluorescent microscopic analysis.

Malic acid production from biodiesel derived crude glycerol using morphologically controlled Aspergillus niger in batch fermentation.

In the present investigation, the effects of crude glycerol concentration, spore inoculum concentration, yeast extract concentration and shaking frequency on seed morphology of Aspergillus niger PJR1 on malic acid production were investigated and dispersed fungal mycelium with higher biomass (20.25 ±â€¯0.91 g/L) was obtained when A. niger PJR1 grow on crude glycerol. Dry cell weight under dispersed fermentation was 21.28% higher than usual pellet fermentation. The optimal crude glycerol, nitrogen source and nitrogen source concentration were found to be 160 g/L, yeast extract and 1.5 g/L, respectively. Batch fermentation in a shake flask culture containing 160 g/L crude glycerol resulted in the yield of malic acid 83.23 ±â€¯1.86 g/L, after 192 h at 25 °C. Results revealed that morphological control of A. niger is an efficient method for increased malic acid production when crude glycerol derived from biodiesel production is used as feedstock.

Ultrasonic assisted green synthesis of Fe and Fe/Zn bimetallic nanoparticles for invitro cytotoxicity study against HeLa cancer cell line.

Nanomaterial synthesis for the biomedical application is the latest improvement in nanotechnology. These nanomaterials can be used as therapeutic agent, drug carrier and also as activating agents. When the nanoparticles are prepared from biological sources, they show better medical competence with fewer side effects. Iron and zinc oxide nanoparticle have been found to exhibit good antimicrobial property; hence this bimetallic nanoparticle can be used for biomedical applications. Therefore the present work focused on synthesis of iron oxide and Fe/Zn bimetallic nano particle by Coriandrum sativum leaf extract as reducing agent using ultrasonic assisted method. The UV-Vis spectroscopy was used to confirm the synthesized nanoparticle. The crystallinity and shape of the particle formed was confirmed by XRD and SEM. The HeLa cell line and normal cell line were used to find the invitro cytotoxic activity of iron oxide and Fe/Zn bimetallic nanoparticle. Fe/Zn bimetallic nanoparticle and Iron oxide nanoparticle showed 61.96% and 54.95% cytotoxicity at 200 µg/ml concentration respectively against HeLa cancer cell line.

Biodiesel production from castor oil using heterogeneous Ni doped ZnO nanocatalyst.

In the present study, castor oil with high free fatty acid was used for biodiesel production using heterogeneous Ni doped ZnO nanocatalyst. Ni doped ZnO nanocomposite calcinated at 800 °C has shown better catalytic activity. Process parameters on heterogeneous catalysis of castor oil into biodiesel were optimized using conventional and Response Surface Methodology (RSM). RSM was found more accurate in estimating the optimum conditions with higher biodiesel yield (95.20%). The optimum conditions for transesterification was found to be oil to methanol molar ratio of 1:8, catalyst loading 11% (w/w), reaction temperature of 55 °C for 60 min of reaction time by response surface method. The reusability studies showed that the nanocatalyst can be reused efficiently for 3 cycles.

Malic acid production by chemically induced Aspergillus niger MTCC 281 mutant from crude glycerol.

In the present investigation, crude glycerol derived from transesterification process was utilized to produce the commercially-valuable malic acid. A combined resistant on methanol and malic acid strain of Aspergillus niger MTCC 281 mutant was generated in solid medium containing methanol (1-5%) and malic acid (40-80 g/L) by the adaptation process for 22 weeks. The ability of induced Aspergillus niger MTCC 281 mutant to utilize crude glycerol and pure glycerol to produce malic acid was studied. The yield of malic acid was increased with 4.45 folds compared with that of parent strain from crude glycerol. The highest concentration of malic acid from crude glycerol by using beneficial mutant was found to be 77.38 ±â€¯0.51 g/L after 192 h at 25 °C. This present study specified that crude glycerol by-product from biodiesel production could be used for producing high amount of malic acid without any pretreatment.

Ultrasound assisted phytosynthesis of iron oxide nanoparticle.

The present work deals with the ultrasound assisted green synthesis of iron oxide nano particle using Coriandrum sativum leaf extract as a reducing agent. The synthesized iron oxide nanoparticle was confirmed by UV spectra. The characterization was done to know more about morphology and size of the particle by SEM analysis which shows spherical particles with size ranging from 20 to 90nm. The antimicrobial activity of the leaf extract and the synthesized nanoparticles was studied against the pathogens Micrococcus luteus, Staphylococcus aureus and Aspergillus niger. The ultrasound assisted iron oxide nanoparticle shows higher scavenging activity and antimicrobial activity compared with iron oxide nanoparticle synthesized by magnetic stirrer and Coriandrum sativum leaf extract.

Glutaraldehyde-Mediated Synthesis of Asparaginase-Bound Maghemite Nanocomposites: Cytotoxicity against Human Colon Adenocarcinoma Cells.

Drugs processed using nanobiotechnology may be more biocompatible, with sustainable and stabilised release or action. L-asparaginase produced from fungi has many advantages for treatment of lymphocytic leukemia with lesser side effect. In the present work, maghemite nanobiocomposites of fungal asparaginase were produced using glutaraldehyde-pretreated colloidal magnetic nanoparticles. Formation of nanobiocomposites was observed using laser light scattering and confirmed by UV-visible spectrophotometry with the absorption peak at 497 nm. The specific asparaginase activity was increased from 320 U/mg with crude asparaginase to 481.5 U/mg. FTIR analysis confirmed that primary amines are the functional groups involved in binding of asparaginase on magnetic nanoparticles. The average size of the produced nanobiocomposite was found in the range of 30 nm to 40 nm using histogram analysis. The magnetic nanobiocomposite of asparaginase synthesised using glutaraldehyde showed 90.75% cytotoxicity against human colon adenocarcinoma cell lines. Hence it can be used as an active anticancer drug with an augmented level of bioavailability.

Microbial abatement of toluene using Aspergillus niger in upflow bioreactor.

Microbial abatement of toluene using Aspergillus niger in coir packed upflow bioreactor was investigated in this study. Toluene degrading microbes were isolated from municipal sewage effluent and identified by 16s rRNA sequencing method. The microbes were cultured in 2% (v/v) toluene input per day, which exhibited 95% removal efficiency with the kinetic correction value (R2) of 0.9024 at the optimum flow rate of about 0.4m3h-1. Various parameters such as effect of flow rate, column height, elimination capacity and EBRT with removal efficiency for 50 day cycle were also optimized. The plug flow model for toluene degradation was properly expressed and the Monod kinetics constant Km and rmax values were determined as 2.25gm-3 and 67.773gm-3h-1 respectively for microbial growth rate.

Biodegradation of toluene vapor in coir based upflow packed bed reactor by Trichoderma asperellum isolate.

In the present study, a new biofiltration system involving a selective microbial strain isolated from aerated municipal sewage water attached with coir as packing material was developed for toluene degradation. The selected fungal isolate was identified as Trichoderma asperellum by 16S ribosomal RNA (16S rRNA) sequencing method, and pylogenetic tree was constructed using BLASTn search. Effect of various factors on growth and toluene degradation by newly isolated T. asperellum was studied in batch studies, and the optimum conditions were found to be pH 7.0, temperature 30 °C, and initial toluene concentration 1.5 (v/v)%. Continuous removal of gaseous toluene was monitored in upflow packed bed reactor (UFPBR) using T. asperellum. Effect of various parameters like column height, flow rate, and the inlet toluene concentration were studied to evaluate the performance of the biofilter. The maximum elimination capacity (257 g m(-3) h(-1)) was obtained with the packing height of 100 cm with the empty bed residence time of 5 min. Under these optimum conditions, the T. asperellum showed better toluene removal efficiency. Kinetic models have been developed for toluene degradation by T. asperellum using macrokinetic approach of the plug flow model incorporated with Monod model.

Performance and cost evaluation of constructed wetland for domestic waste water treatment.

Root zone treatment through constructed wetlands is an engineered method of purifying wastewater. The aim of the present research was to study the potential of wetland plants Phragmites and Typha in treatment of wastewater and to compare the cost of constructed wetlands with that of conventional treatment systems. A pilot wetland unit of size 2x1x0.9 m was constructed in the campus. 3x3 rows of plants were transplanted into the pilot unit and subjected to wastewater from the hostels and other campus buildings. The raw wastewater and treated wastewater were collected periodically and tested for Total nitrogen (TN),Total Phosphorous (TP), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD). It was observed that this pilot unit reduced the concentrations of TN, TP, BOD and COD by 76, 73, 83 and 86%, respectively, on an average. Root zone system achieved standards for tertiary treatment with low operating costs, low maintenance costs, enhance the landscape, provide a natural habitat for birds, and did not emit any odour.