Green synthesis, characterization, and application of metal oxide nanoparticles for mercury removal from aqueous solution.

In this work, a novel surface-modified, green-based wheat straw-supported magnetite nanoparticles (Fe3O4-NPs) were synthesized via the green synthesis method, and the adsorption of mercury (Hg(II)) ion from aqueous solutions was methodically investigated. The synthesized wheat straw-supported magnetite (Fe3O4-WSS) NPs were characterized using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and scanning electron microscopic (SEM) methods. FT-IR and TGA confirmed that the surface of Fe3O4-NPs was functionalized well. The XRD analysis revealed the existence of magnetite in the synthesized wheat straw-supported Fe3O4-NPs of 19.83 nm average crystalline size. SEM analysis showed Fe3O4-NPs were almost spherical, with an average particle size of 22.48 nm. Adsorption studies were carried out to investigate the adsorption of Hg(II) ions onto Fe3O4-WSS NPs and the effect of various adsorption parameters such as pH, time, adsorbent dosage, and Hg(II) ion concentration. The optimum adsorption conditions were obtained: pH of 6, contact time of 45 min, adsorbate of 40 mg/L, and adsorbent of 1 g. A maximum of 98.04% Hg(II) ion removal efficiency was obtained at these optimum conditions. FT-IR analysis also indicated that surface functional groups such as C = C,-OH, and C-C of the newly produced Fe3O4-NPs led to the more efficient removal of Hg(II) from aqueous solution. The synthesized nano-adsorbent showed an excellent adsorption capability of 101.01 mg/g. Hg(II) ions adsorption onto Fe3O4-WSS NPs fitted well with the Langmuir adsorption isotherm model. Therefore, these reasonable findings reveal that Fe3O4-WSS NPs are an efficient and promising adsorbent for Hg(II) removal from aqueous water environments.

Development of mixed starter culture for the fermentation of Ethiopian honey wine, Tej.

Ethiopian honey wine is one of the country's most popular spontaneously fermented traditional alcoholic beverages. However, the final product of this natural fermentation system is frequently of poor and inconsistent quality. Furthermore, it makes the process difficult to predict, control, and correct. Thus, the main aim of this study was to develop a direct fermentation system for Ethiopian honey wine, Tej. After isolating fermentative microbial strains from Tej samples, they were subjected to intensive screening to fit to its purpose. Later, phenotypic and genotypic characterization, and inoculation of isolates to honey-must were performed sequentially. Finally, microbial interaction and physicochemical analysis, including volatile compounds profiling, were done for the inoculated samples. The identified isolates were strains of Saccharomycetaceae and Lactobacillaceae families. These strains showed a good ability to tolerate osmotic stress and a lower pH environment. Tej sample produced by mixed culture inoculation of Saccharomyces and Lactobacillus species showed similar physicochemical, volatile compounds, and sensory attributes values with that of the control sample. Thus, a mixture of Saccharomyces and Lactobacillus strains could be used as a starter culture to produce Ethiopian honey, Tej, without scarifying of its major quality attributes.

Microbiome dataset of spontaneously fermented Ethiopian honey wine, Tej.

This dataset contains raw and analyzed microbial data for the samples of spontaneously fermented Ethiopian honey wine, Tej, collected from three locations of Ethiopia. It was generated using culture independent amplicon sequencing technique. To gain a better understanding of microbial community variance and similarity across Tej samples from the same and different locations, the raw sequenced data obtained from the Illumina Miseq sequencer was subjected to a bioinformatics analysis. Lower diversity and richness of both bacterial and fungal communities were observed for all of the Tej samples. Besides, samples collected from Debre Markos area showed a significant discriminating tax for both bacterial and fungal communities. In nutshell, this amplicon sequencing dataset provides a useful collection of data for modernizing this spontaneous fermentation into a directed inoculated fermentation. Detail discussion on microbiome of Tej samples is given in [1].

Physicochemical properties, antioxidant activities and microbial communities of Ethiopian honey wine, Tej.

Ethiopian honey wine, Tej, is spontaneously fermented traditional alcoholic beverage, usually made from honey and "gesho" (Rhamnus prinoides). Till now, limited amount of information is available on the characterization of Tej. Thus, the aim of this paper is to reveal the microbiological diversity and physicochemical properties of Tej samples collected from different areas of Ethiopia. High-throughput sequencing, electrochemical and chromatographic techniques, and spectrophotometric methods were used to achieve these objectives. Although there was a statistical difference in the exact values of physicochemical properties between the collected Tej samples, the pH and titratable acidity values of the samples ranged from 2.8 to 3.8 and from 1.81 to 8.65 g/L, respectively. Similarly, the alcohol and sugar contents of the samples were in the range of 6.36-11.34 g/100 mL and from 0.37 to 31.6 g/L, respectively. Moreover, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS) values of the samples were in the range of 37.9-81.0% and 27.4-73.1%, respectively. Furthermore, microbial community structure was predominated by a few fermentative microorganisms. Specifically, the bacterial community structure was dominated by the genera of Lactobacillus (53.15%) and Zymomonas (38.41%). Whereas, the fungal community structure was exclusively dominated by genus of Saccharomyces (99.66%). Additionally, Lactobacillus, Zymomonas and Saccharomyces were the detected core microbiome for the collected Tej samples. Both bacterial and fungal communities had shown no statistically significant differences in alpha diversity analysis based on the area of sample collection. However, the bacterial communities had a statically significant difference in Unweighted Unifrac beta diversity analysis. Generally, the observed shared physicochemical characteristic features and the dominance by certain group of microorganisms might be seen as a boon for the development of direct fermentation system to this traditional alcoholic beverage.

Synthesis of lignin-carbohydrate complex-based catalyst from Eragrostis tef straw and its catalytic performance in xylose dehydration to furfural.

A new catalyst was successfully prepared by functionalization of the lignin-carbohydrate complex structure in the Eragrostis tef straw via simultaneous carbonization and sulfonation. The physical and chemical properties of the surface of the synthesized catalyst were checked by FTIR and XRD. The FTIR results indicate the prepared catalyst exhibited functional groups such as -SO3H, -COOH, and -OH. The synthesis conditions like the temperature and time of carbonization and sulfonation showed significant effect the amount of the strong acid doped into the carbonized lignin-carbohydrate matrix. The newly prepared catalyst was checked for dehydration of xylose to furfural and revealed of course that it has the potential. The maximum yield of furfural 62.4% was achieved and the catalyst showed excellent reusability for 5 runs without significant loss of catalystic activity. The use of catalysts prepared from Eragrostis tef straw is a green strategy for converting xylose to furfural, as these catalysts are solving the problems associated with the use of mineral acid catalysts.

Cereal- and Fruit-Based Ethiopian Traditional Fermented Alcoholic Beverages.

Traditional fermented alcoholic beverages are drinks produced locally using indigenous knowledge, and consumed near the vicinity of production. In Ethiopia, preparation and consumption of cereal- and fruit-based traditional fermented alcoholic beverages is very common. Tella, Borde, Shamita, Korefe, Cheka, Tej, Ogol, Booka, and Keribo are among the popular alcoholic beverages in the country. These beverages have equal market share with commercially produced alcoholic beverages. Fermentation of Ethiopian alcoholic beverages is spontaneous, natural and uncontrolled. Consequently, achieving consistent quality in the final product is the major challenge. Yeasts and lactic acid bacteria are the predominate microorganisms encountered during the fermentation of these traditional alcoholic beverages. In this paper, we undertake a review in order to elucidate the physicochemical properties, indigenous processing methods, nutritional values, functional properties, fermenting microorganisms and fermentation microbial dynamics of Ethiopian traditional alcoholic beverages. Further research will be needed in order to move these traditional beverages into large-scale production.