Neodymium (Nd)-substituted cobalt ferrite nanoparticles (NPs), i.e., CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs, were synthesized by the sonochemical method. The compositional characterization was done by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Antistaphylococcal activity was found to be enhanced, i.e., survival rate was 50%, 45%, 40%, and 30% with the increase in the ratio of Nd (0.0 ≤ x ≤ 0.2), whereas anticandidal activity was found efficient, i.e., 9%, 20%, 22%, and 40% survival rate at all the four ratios. The morphogenesis studies indicated that the synthesized metal−ligand, improves the antimicrobial capacity by binding them strongly to the microbial walls. To the best of our knowledge, this is the first report which demonstrates the series of CoNdxFe2−xO4 (0.0 ≤ x ≤ 0.2) NPs being active towards Staphylococcus aureus and Candida albicans and encourages its potential candidature for pharmaceuti... [more]

In order to overcome process instability and buffer deficiency in the anaerobic digestion of mono food waste (FW), chemically enhanced primary sludge (CEPS) was selected as a co-substrate for FW treatment. In this study, batch tests were conducted to study the effects of CEPS/FW ratios on anaerobic co-digestion (coAD) performances. Both soluble chemical oxygen demand (SCOD) and protease activity were decreased, with the CEPS/FW mass ratio increasing from 0:5 to 5:0. However, it was also found that the accumulation of volatile fatty acids (VFAs) was eliminated by increasing the CEPS/FW ratio, and that corresponding VFAs concentrations decreased from 13,872.97 to 1789.98 mg chemical oxygen demand per L (mg COD/L). In addition, the maximum value of cumulative biogas yield (446.39 mL per g volatile solids removal (mL/g VSsremoval)) was observed at a CEPS/FW ratio of 4:1, and that the tendency of coenzyme F420 activity was similar to biogas production. The mechanism analysis indicated that... [more]

Anaerobic digestion (AD) is an established process for integrating waste management with renewable energy and nutrient recovery. Much of the research in this field focuses on the utilisation of new substrates, yet their effects on operational aspects such as fluid behaviour and power requirement for mixing are commonly overlooked, despite their importance for process optimisation. This study analysed rheological characteristics of samples from 21 laboratory-scale continuous stirred-tank biogas reactors (CSTBRs) digesting a range of substrates, in order to evaluate substrate effect on mixing efficiency and power demand through computational fluid dynamics (CFD). The results show that substrate and process parameters, such as solids content and organic loading, all have a significant effect on CSTBR fluid rheology. The correlation levels between rheological and process parameters were different across substrates, while no specific fluid behaviour patterns could be associated with substra... [more]

The ethnobotanical survey of Euclea divinorum Hiern (Ebenaceae) was conducted on Soqotra Island, Yemen. The root bark is used to treat mouth, dental, dermal and blood diseases in the traditional medicine of the island. The study is the first report about the effect of the plant root barks against six human pathogenic fungi. The non-polar dichloromethane extract of Euclea divinorum root bark showed stronger antifungal activities compared to polar direct and sequential methanolic extracts. These extracts showed significant broad antifungal activity against Absidia corymbifera, Aspergillus fumigatus, Candida krusei, Microsporum gypseum, Mucor sp. and Trichophyton mentagrophytes compared to the standard antibiotic drug nystatin. Thin-layer chromatography (TLC) revealed the presence of the naphthoquinones in the extracts. The results showed an extraction process to separate most antifungal naphthoquinones from the root bark by using non-polar solvent dichloromethane, while flavonoids remain... [more]

Bioleaching is an environment-friendly and low-investment process for the extraction of metals from flotation concentrate. Surfactants such as collectors and frothers are widely used in the flotation process. These chemical reagents may have inhibitory effects on the activity of microorganisms through a bioleaching process; however, there is no report indicating influences of reagents on the activity of microorganisms in the mixed culture which is mostly used in the industry. In this investigation, influences of typical flotation frothers (methyl isobutyl carbinol and pine oil) in different concentrations (0.01, 0.10, and 1.00 g/L) were examined on activates of bacteria in the mesophilic mixed culture (Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, and Acidithiobacillus thiooxidans). For comparison purposes, experiments were repeated by pure cultures of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans in the same conditions. Results indicated that increasing... [more]

Two-stage solid-state fermentation strategy was exploited and systematically optimized to enhance Bacillus subtilis growth and sporulation for increasing effective cell number in B. subtilis microbial ecological agents. The first stage focused on improving cell growth followed by the second stage aiming to enhance both cell growth and sporulation. The optimal fermentation condition was that temperature changed from 37 °C to 47 °C at a fermentation time of 48 h and Mn2+ content in medium was 4.9 mg MnSO4/g dry medium. Solid medium properties were improved by the optimal two-stage fermentation. HPLC results demonstrated that glucose utilization was facilitated and low-field nuclear magnetic resonance (LF-NMR) results showed that more active sites in medium for microbial cells were generated during the optimal two-stage fermentation. Moreover, microbial growth and sporulation were enhanced simultaneously during the second stage of fermentation through delaying microbial decline phase and... [more]

Processing biodiesel from non-edible sources of feedstock seems to be thriving in recent years. It also has also gathered more attention than in the past, mainly because the biodiesel product is renewable and emits lower pollution compared to fossil fuels. Researchers have started their work on various kinds of biodiesel product, especially from a non-edible feedstock. Non-edible feedstocks such as Ceiba pentandra show great potential in the production of biodiesel, especially in the Southeast Asia region because the plants seem to be abundant in that region. Ceiba pentandra, also known as the Kapok tree, produces hundreds of pods with a length of 15 cm (5.9 in) and diameter 2−5 cm (1−2 in). The pods consist of seeds and fluff in the surrounding areas inside the pod, which itself contains yellowish fibre, a mixture of cellulose and lignin. The seeds of Ceiba pentandra can be used as feedstock for biodiesel production. The study for Ceiba pentandra will involve techno-economic, as well... [more]

In this work, gold nanostar (AuNPs) and gold nanodendrites were synthesized by one-pot and environmentally friendly approach in the presence of gelatin. Influence of gelatin concentrations and reaction conditions on the growth of branched (AuNPs) were investigated further. Interestingly, the conversion of morphology between dendritic and branched nanostructure can be attained by changing the pH value of gelatin solution. The role of gelatin as a protecting agent through the electrostatic and steric interaction was also revealed. Branched nanoparticles were characterized by surface plasmon resonance spectroscopy (SPR), transmission electron microscopy (TEM), XRD, dynamic light scattering (DLS) and zeta-potential. The chemical interaction of gelatin with branched gold nanoparticles was analyzed by Fourier transform infrared spectroscopy (FT-IT) technique. Ultraviolet visible spectroscopy results indicated the formation of branched gold nanoparticles with the maximum surface plasmon reson... [more]

Ginkgo biloba leaves are well known for their high content of nutrients and bioactive substances. However, unpleasant smell and a small number of ginkgolic acids greatly reduce the utilization of the leaves. In this work, solid-state fermentation of G. biloba leaves using Eurotium cristatum was studied by investigation of the nutrient changes and its feasibility as a functional feed. E. cristatum could grow on pure G. biloba leaves and the addition of excipients could significantly improve the growth of E. cristatum. The optimal medium was with 10% (w/w) of whole G. biloba seeds and the optimized water content, pH, inoculum size and fermentation time were 45% (w/w), 4.5, 4.76 × 107 CFU/100 g wet medium, and eight days, respectively. Under the optimal conditions, the spore number increased by about 40 times. The content of flavonoids was greatly increased by 118.6%, and the protein and polyprenyl acetates (PPAs) were increased by 64.9% and 10.6%, respectively. The ginkgolic acids, ligni... [more]

Nowadays, increased interest among the scientific community to explore the Calophyllum inophyllum as alternative fuels for diesel engines is observed. This research is about using mixed Calophyllum inophyllum-palm oil biodiesel production and evaluation that biodiesel in a diesel engine. The Calophyllum inophyllum−palm oil methyl ester (CPME) is processed using the following procedure: (1) the crude Calophyllum inophyllum and palm oils are mixed at the same ratio of 50:50 volume %, (2) degumming, (3) acid-catalysed esterification, (4) purification, and (5) alkaline-catalysed transesterification. The results are indeed encouraging which satisfy the international standards, CPME shows the high heating value (37.9 MJ/kg) but lower kinematic viscosity (4.50 mm2/s) due to change the fatty acid methyl ester (FAME) composition compared to Calophyllum inophyllum methyl ester (CIME). The average results show that the blended fuels have higher Brake Specific Fuel Consumption (BSFC) and NOx emiss... [more]

Abandoned oil palm trunk (OPT) is among the most abundant left-over biomass in Malaysia and is allowed to decompose naturally in the field. However, the recycling of OPT is less considered although OPT is a bioresource that has a high potential for conversion into value-added products. In this study, waste OPT was rapidly converted by hydrolysis using subcritical water (sub-CW). This work is the first attempt to explore the utilization of waste OPT based on the differences in moisture, cellulose and hemicellulose contents in the top and bottom segments, and from various ages of the waste OPT. 21- and 35-year-old OPTs were divided into top and bottom sections. The OPTs was subjected to sub-CW at a heating rate of 3.8 °C/s at various temperatures and times. The 21-year-old OPT was superior to the 35-year-old OPT for conversion into sugar and organic acid. The yield of the total sugar was between 0.41 and 0.77 kg/kg-OPT in the bottom and top sections. The excellent correlation between the... [more]

Batch tests were carried out to study the effect of simultaneous addition of ethylenediaminetetraacetic acid and Ni2+ (EDTA-Ni) on anaerobic digestion (AD) performances of kitchen wastes (KWs). The results indicated that the cumulative biogas yield and methane content were enhanced to 563.82 mL/gVS and 63.7% by adding EDTA-Ni, respectively, which were almost 1.15 and 1.07-fold of that in the R2 with Ni2+ addition alone. At the same time, an obvious decrease of propionic acid was observed after EDTA-Ni addition. The speciation analysis of Ni showed that the percentages of water-soluble and exchangeable Ni were increased to 38.8% and 36.3% due to EDTA-Ni addition, respectively. Also, the high-throughput sequencing analysis revealed that the EDTA-Ni promoted the growth and metabolism of Methanosarcina and Methanobacterium, which might be the major reason for propionic acid degradation and methane production.

Biomass materials have become a research focus for humankind, due to the decreasing availability of fossil fuels and the increasing release of greenhouse gas. In this work, we prepared biodegradable composites with waste cassava residues and polybutylene succinate (PBS) by modifying cassava residues using 4,4’-methylene diisocyanate phenyl ester (MDI) and tested their properties. The effects of MDI modification on the structure, mechanical properties, water absorption, microstructure, and thermal stability of the composites were studied via Fourier transform infrared spectroscopy, contact angle measurement, mechanical property testing, water absorption analysis, scanning electron microscopy, and thermogravimetric analysis, respectively. The results showed that the tensile strength and flexural strength of the material increased by 72% and 20.89%, respectively, when the MDI-modified cassava residue content was 30%. When 10% MDI-modified cassava residues were added, the tensile strength... [more]

The current study was aimed to observe the influence of pulsed electric field (PEF) on the extraction of bioactive components; antioxidant activity and physicochemical properties of date palm fruit extract (DPFE) as compared to the extract untreated by PEF. The fruit was treated with PEF (frequency: 10 Hz, time: 100 µs, pulses number: 30, electric field strength (EFS): 1, 2, and 3 kV/cm. The results show that PEF has a positive impact on the total content of carotenoids, anthocyanins, flavonoids, and phenolics by increasing the EFS. DPFE treated with PEF exhibit a strong antioxidant activity as compared to untreated extract, while electrical conductivity, pH values, and titratable acidity were not affected by PEF. The results indicate a notable increase in the volatile components in DPFE treated with PEF at 3 kV/cm. Thus, PEF treatment can assist the ethanolic extraction of DPFE to improve the bioactivity and antioxidative activity. These findings suggest that PEF can be a more suitabl... [more]

The current study investigates the effect of hydrothermal pretreatment (HTP) on acidification of source-separated organics (SSO) in terms of volatile fatty acids (VFAs) production and solubilization. Temperature and retention time for HTP of SSO ranged from 150 to 240 °C and 5 to 30 min, respectively. The soluble substance after hydrothermal pretreatment initially increased, reaching its peak at 210 °C and then declined gradually. The highest overall chemical oxygen demand (COD) solubilization of 63% was observed at “210 °C-20 min” compared to 17% for raw SSO. The highest VFAs yield of 1536 mg VFAs/g VSS added was observed at “210 °C-20 min” compared to 768 mg VFAs/g VSS for raw SSO. Intensification of hydrothermal pretreatment temperature beyond 210 °C resulted in the mineralization of the organics and adversely affected the process.

Eutrophication is an inevitable phenomenon, and it has recently become an unabated threat. As a positive, the thriving microalgal biomass in eutrophic water is conventionally perceived to be loaded with myriad valuable biochemical compounds. Therefore, a sugarcane-bagasse-based adsorbent was proposed in this study to harvest the microalgal biomass for producing biodiesel. By activating the sugarcane-bagasse-based adsorbent with 1.5 M of H2SO4, a highest adsorption capacity of 108.9 ± 0.3 mg/g was attained. This was fundamentally due to the surface potential of the 1.5 M H2SO4 acid-modified sugarcane-bagasse-based adsorbent possessing the lowest surface positivity value as calculated from its point of zero charge. The adsorption capacity was then improved to 192.9 ± 0.1 mg/g by stepwise optimizing the adsorbent size to 6.7−8.0 mm, adsorption medium pH to 2−4, and adsorbent dosage to 0.4 g per 100 mL of adsorption medium. This resulted in 91.5% microalgae removal efficiency. Excellent-qu... [more]

There is a significant interest in valorizing swine manure that is produced in enormous quantities. Therefore, considering the high moisture content in swine manure, the objective of this research was to convert manure slurry into hydrochars via hydrothermal carbonization and analyze the yields, pH, energy contents, and thermal and oxidation kinetic parameters. Experiments were performed in triplicate in 250 mL kettle reactors lined with polypropylene at 180 °C, 200 °C, 240 °C, 220 °C, and 260 °C for 24 h. Analyses of the results indicated that the process temperature affected the hydrochar yields, with yield generally decreasing with increasing temperature, but it had little effect on the composition of the hydrochar. The hydrochars were found to have higher volatile contents and H/C and O/C ratios and about 85% of the energy compared to coal. However, the presence of high fraction (35−38%) of ash in hydrochars is a serious concern and needs to be addressed before the complete utiliza... [more]

Despite that diclofenac has been embodied to the European watch list of priority substances of concern, studies on diclofenac biodegradation are limited and the diversity of diclofenac-degrading microbiota remains unknown. In this work, an immobilized cell biofilter was constructed and operated to evaluate its effectiveness to depurate high strength diclofenac wastewater and to identify the diclofenac-degrading community accommodated in activated sludge by employing high-throughput sequencing techniques. After a two-month adaptation period, biofilter removal efficiencies reached values as high as 97.63 ± 0.62%, whereas utilization of diclofenac in the immobilized cell biofilter led to a drastic pH decrease. Based on Illumina sequencing, the major bacterial taxa identified in the immobilized cell biofilter were members of the species Granulicella pectinivorans and Rhodanobacter terrae, followed by members of the species Castellaniella denitrificans, Parvibaculum lavamentivorans, Bordete... [more]

The study attempts the optimization of the total flavonoid content (TFC) and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) antioxidant activity of the white radish (Raphanus sativus L.) root ethanolic extract (WRE) with regard to several parameters including ethanol concentration, the ratio of solvent/material, temperature and extraction time. Then antifungal analysis of WRE was performed against four fungal species including Aspergillus flavus NBRC 33021, Aspergillus niger NBRC 4066, Aspergillus clavatus NBRC 33020, and Fusarium solani NBRC 31094. At the WRE concentration of 75 mg/mL, diameters of inhibition zone were 9.11 ± 1.5, 19.55 ± 1.68, 17.72 ± 0.25, and 17.50 ± 0.73 mm respectively against the four examined species. Minimum fungal concentration (MFC) values of WRE against the four species were 30, 10, 20 and 30 mg/mL respectively. Evaluation of the sponge cake added with white radish root extract suggested that shelf-life of the sponge cake is 8 weeks in a... [more]

Butterfly pea (Clitoria ternatea L.) is a traditional medicinal and edible herb, whose health-promoting benefits have been attributed to its phenolic constituents. In this study, the effects of enzymatic hydrolysis on total phenolic content (TPC) and total flavonoid content (TFC), antioxidant (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP)) and antibacterial activities of raw and roasted (200 °C, 10−20 min) butterfly pea seeds were investigated. Roasting reduced the yield of seed aqueous extracts, but it increased the TPC and FRAP values, hence the reducing ability, of the extracts. Bromelain hydrolysis enhanced the TPC and TFC of the roasted seeds up to 2- and 18-fold higher, respectively. Trypsin hydrolysis drastically increased the TPC, but not TFC, of roasted seeds; trypsin-hydrolyzed, 20 min roasted sample had the highest TPC (54.07 μg gallic acid equivalent (GAE)/mg... [more]

Improving water quality is a relevant environmental aspect, and using constructed wetlands (CWs) is a sustainable option for this; both porous material filled cells and plants that collectively remove contaminants must be readily available and inexpensive. This study evaluated CWs and their functionality by comparing two ornamental plants (Spathiphyllum wallisii and Hedychium coronarium) planted in experimental mesocosm units filled with layers of porous river rock, tepezil, and soil, or in mesocosms with layers of porous river rock, and tepezil, without the presence of soil. The findings during the experiments (180 days), showed that the removal of pollutants (chemical oxygen demand (COD), total solids suspended (TSS), nitrogen as ammonium (N-NH4), as nitrate (N-NO3), and phosphate (P-PO4) was 20−50% higher in mesocosms with vegetation that in the absence of this, and those mesocosms with the soil layer between 33−45% favored removal of P-PO4. Differences regarding of vegetation remov... [more]

Artemisia species are used as folk medicines in several countries. This work was aimed to shed more light on the effect of methanol, water, ethyl acetate extracts, and essential oil (EO) of A. santonicum on selected enzymes (cholinesterase, tyrosinase α-amylase, and α-glucosidase) as well of their antioxidant and pharmacological effects. The chemical profile of the essential oil was determined using gas chromatography coupled to mass spectrometry (GC-MS) analysis, while the extracts were chemically characterized by high performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Forty-nine constituents were identified and camphor (36.6%), 1,8-cineole (10.2%), α-thujone (10.1%), borneol (4.5%), and β-thujone (3.6%) were the major components. Overall, 45, 74, and 67 components were identified from the ethyl acetate, methanol, and water extracts, respectively. The EO and extracts showed significant antioxidant properties, in a cell-free model; particularly, methanol and wate... [more]

Poor aqueous solubility limits the therapeutic efficacy of many marketed and investigational drugs. Synthesis of new drugs with improved solubility is challenging due to time constraint and expenses involved. Therefore, finding the solubility enhancers for existing drugs is an attractive and profitable strategy. In this study, PEGylated oleic acid (OA-mPEG5000), a conjugate of oleic acid and mPEG5000 was synthesized and evaluated as a solubilizer for furosemide. OA-mPEG5000 was evaluated as a nanocarrier for furosemide by formulating polymersomes. Solubility of furosemide in milli-Q water and aqueous OA-mPEG5000 solution was determined using shake flask method. At 37 °C, the solubility of furosemide in OA-mPEG5000 (1% w/w) and milli-Q water was 3404.7 ± 254.6 µg/mL and 1020.2 ± 40.9 µg/mL, respectively. Results showed there was a 3.34-fold increase in solubility of furosemide in OA-mPEG5000 compared to water at 37 °C. At 25 °C, there was a 3.31-fold increase in solubilization of furose... [more]

The impact of thermo−ultrasound (TU) on the quality of fresh wheat plantlets juice is described in this study. Fresh wheat plantlets juice was treated with TU using ultrasound (US) bath cleaner with different treatment variables, including power (70%, 420 W), frequency (40 kHz), processing time (20 and 40 min) and temperature (30, 45 and 60 °C) for the determination of free amino acids, minerals, microbial loads and bioactive compounds. The treatments have non-significant effects in ºBrix, pH, and titratable acidity while a significant increase in non-enzymatic browning, viscosity, and cloud value. The TU treatment at 30 °C for 20 and 40 min has achieved the highest value of total phenolics, flavonoids, total antioxidant capacity, 2, 2-diphenyl-1-picrylhydrazyl (DPPH), carotenoids, anthocyanin contents, chlorophyll (a + b), minerals and free amino acids than other treatments as well as untreated sample. A lightly visible variation in the color was observed among all treatments. TU trea... [more]

This research aimed to optimize the total polyphenol content (TPC) extracted from soybean sprout powder under different experimental parameters, including ethanol concentration (60−100% v/v), extraction temperature (40−80 °C), extraction time (15−150 min), material:solvent ratio (1:4−1:10 g/mL), the number extraction cycles (1, 2 and 3 times), the age of sprout (0−7 days), and the used part of the sprout (cotyledon, hypocotyl, or radicle). The obtained results were used in response surface methodology, in combination with a central composite design, to model the total polyphenol content (TPC) with respect to three variables, including ethanol concentration, extraction temperature, and material:solvent ratio. The experimental conditions for optimal recovery of TPC consisted of ethanol concentration of 88% (v/v), extraction temperature of 59 °C, material:solvent ratio of 1:6.5 g/mL, extraction time of 60 min, and 2 cycles of maceration. In addition, for maximal TPC, the sprout should und... [more]