Neurospora sp. Mediated Synthesis of Naringenin for the Production of Bioactive Nanomaterials.

The application of Neurospora sp., a fungus that commonly thrives on complex agricultural and plant wastes, has proven successful in utilizing citrus peel waste as a source of naringin. A UV-Vis spectrophotometric method proved the biotransformation of naringin, with an absorption maximum (λmax) observed at 310 nm for the biotransformed product, naringenin (NAR). Further verification of the conversion of naringin was provided through thin layer chromatography (TLC). The Neurospora crassa mediated biotransformation of naringin to NAR was utilized for the rapid (within 5 min) synthesis of silver (Ag) and gold (Au) nanoconjugates using sunlight to accelerate the reaction. The synthesized NAR-nano Ag and NAR-nano Au conjugates exhibited monodispersed spherical and spherical as well as polygonal shaped particles, respectively. Both of the nanoconjugates showed average particle sizes of less than 90 nm from TEM analysis. The NAR-Ag and NAR-Au nanoconjugates displayed potential enhancement of the antimicrobial activities, including antibacterial and nematicidal properties over either standalone NAR or Ag or Au NPs. This study reveals the potential of naringinase-producing Neurospora sp. for transforming naringin into NAR. Additionally, the resulting NAR-Ag and NAR-Au nanoconjugates showed promise as sustainable antibiotics and biochemical nematicides.

Effect of Polyethylene Glycol and Activated Carbon Macroparticles on Thermal Conductivity of Paraffin Wax for Thermal Storage Applications.

Low thermal conductivity is the major obstacle for the wide range utilization of phase change materials (PCMs), especially organic PCMs, for most practical applications in thermal engineering. This study investigates the potential of enhancing the charging and discharging rates of organic PCM (RT44HC) by introducing polyethylene glycol (PEG) and activated carbon macroparticles (ACMPs). Different concentrations of PEG and ACMPs ranging from 0.3 wt% to 2 wt% were tested separately. The optimized concentrations found were used as dual reinforcements to attain the highest possible thermal conductivity. The specimens were tested for a complete charging-discharging cycle using an improvised thermal apparatus. Use of ACMP alone resulted in a minimal reduction in complete charging-discharging time due to the settlement of ACMPs at the bottom after 2-3 heating-cooling cycles. However, the addition of PEG with ACMPs exhibited a reduction in charging-discharging time due to the formation of a stable dispersion. PEG served as a stabilizing agent for ACMPs. The lowest charging-discharging time of 180 min was exhibited by specimens containing 1 wt% PEG and 0.5 wt% ACMPs which is 25% lower compared to bare PCM.

Selective production of furfural from the dehydration of xylose using Zn doped CuO catalyst.

Furfural is a versatile biomass-derived platform compound used for the synthesis of several strategic chemicals. The sonochemically synthesized Zn doped CuO nanoparticles (NPs) were used for the production of furfural. The catalytic activity of the Zn doped CuO NPs was examined, as a model, during the dehydration reaction of xylose to furfural. In addition to that, we have also compared the catalytic activity of the Zn doped CuO NP with ZnO NPs, ZnO bulk, CuO NPs, CuO bulk, etc. This nanoscale catalyst (Zn doped CuO NP) has a large surface area, which enhances its catalytic activity and enables it to completely convert the xylose to furfural at 150 °C within 12 h without any trace of by-products, as confirmed by HPLC, 13C NMR and 1H NMR. HPLC analysis demonstrated that the yield of furfural is up to 86 mol %, compared to the 45 mol % obtained with ZnO NPs, ZnO bulk, CuO NPs, CuO bulk, etc. as catalysts.

Continuous flow through a microwave oven for the large-scale production of biodiesel from waste cooking oil.

This report presents a method for producing large quantities of biodiesel from waste cooking oil (WCO). Preliminary studies on optimization of the WCO transesterification process in a continuous-flow microwave reactor are carried out using commercial SrO as a catalyst. The SrO catalyst can be separated and reused for five reaction cycles without loss in activity. Challenges like mass flow and pressure drop constraints need to be surmounted. SrO nanoparticles deposited on millimeter-sized (3-6mm) silica beads (41wt% SrO/SiO2) are prepared and evaluated as a substitute for the SrO catalyst. A WCO conversion value to biodiesel as high as 99.2wt% was achieved with the reactor packed with 15g of 41wt% SrO/SiO2 catalyst in 8.2min with 820mL of feed. Excellent performance of the fixed-bed catalyst without loss in activity for a lifetime of 24.6min converting a feed of 2.46L to FAME was observed.

Bioethanol production from Ficus religiosa leaves using microwave irradiation.

A microwave assisted feasible process for the production of bioethanol from Ficus religiosa leaves was developed. Under the process conditions (8 min. microwave irradiation, 1 M HCl), 10.1 wt% glucose yield was obtained from the leaves. Microwave based hydrolysis process yielded higher glucose content (10.1 wt%) compared to the conventional hydrothermal process (4.1 wt%). Upon fermentation of the hydrolysate using Baker's yeast, 3 wt% (dry wt. basis) of bioethanol was produced.

Solar-Energy Driven Simultaneous Saccharification and Fermentation of Starch to Bioethanol for Fuel-Cell Applications.

A solar reactor was designed to perform the conversion of starch to ethanol in a single step. An aqueous starch solution (5 wt %) was fed into the reactor bed charged with Baker's yeast (Saccharomyces cerevisiae) and amylase, resulting in approximately 2.5 wt % ethanol collected daily (ca. 25 mL day(-1) ). A significant amount of ethanol (38 g) was collected over 63 days, corresponding to 84 % of the theoretical yield. The production of ethanol without additional energy input highlights the significance of this new process. The ethanol produced was also demonstrated as a potential fuel for direct ethanol fuel cells. Additionally, the secondary metabolite glycerol was fully reduced to a value-added product 1,3-propanediol, which is the first example of a fungal strain (Baker's yeast) converting glycerol in situ to 1,3-propanediol.

Assessment of holocellulose for the production of bioethanol by conserving Pinus radiata cones as renewable feedstock.

Renewable and green energy sources are much sought. Bioethanol is an environmentally friendly transportation fuel. Pine cones from Pinus radiata were shown to be a potential feedstock for the production of bioethanol. Alkaline (NaOH) pretreatment was carried out to delignify the lignocellulosic material and generate holocellulose (72 wt. % yield). The pretreated biomass was hydrolysed using HCl as catalyst under microwave irradiation and hydrothermal conditions. Microwave irradiation was found to be better than the hydrothermal process. Microwave irradiation accelerated the hydrolysis of biomass (42 wt. % conversion) with the reaction conditions being 3 M HCl and 5 min of irradiation time. Interestingly, even the xylose, which is the major component of the hydrolyzate was found to be metabolized to ethanol using Baker's yeast (Saccharomyces cerevisiae) under the experimental conditions. 5.7 g of ethanol could be produced from 100 g of raw pine cones.