Abd El-Fatah Abomohra

Effective bio-pretreatment of sawdust waste with a novel microbial consortium for enhanced biomethanation

Anaerobic digestion (AD) is considered an efficient cost-effective technology for sustainable biogas production from lignocellulosic wastes. A novel lignocellulosic degradation microbial consortium (LCDC) was isolated from rotten sawdust, and further used for sawdust pretreatment prior to AD. Results showed that pretreatment of sawdust for 10days led to significant reduction in cellulose, hemicelluloses, and lignin contents by 37.5%, 39.6%, and 56.7%, respectively, with respect to the control. In addition, the pretreatment enhanced cumulative biogas yield, which reached its maximum value of 312.0Lkg-1VS after 28days of AD (25.6% higher than the corresponding control). Moreover, the maximum significant cumulative methane yield was recorded after 28days of AD of the pretreated sawdust (155.2Lkg-1VS), which represented 72.6% higher than the corresponding control. Significantly higher biomethane yield from sawdust pretreated with LCDC confirms that this process is more economical than the previous reports.

Effect of lipid-free microalgal biomass and waste glycerol on growth and lipid production of Scenedesmus obliquus: Innovative waste recycling for extraordinary lipid production

In the present work, a novel approach of using growth medium with different substitutions of lipid-free algal hydrolysate (LFAH, 0, 5, 10 and 15%) and/or waste glycerol (WG, 0, 5, 10 and 20u202fgu202fL-1) for enhanced biodiesel production from Scenedesmus obliquus was studied. Combination of different concentrations of WG with 15% LFAH showed the maximum significant biomass productivity, which represented 27.4, 30.5 and 28.9% over the control at combined 5, 10 and 20u202fgu202fL-1 WG, respectively. The combinations of different LFAH with 20u202fgu202fL-1 WG showed the maximum significant lipid accumulation, where lipid productivity showed its maximum significant value of 59.66u202fmgu202fL-1u202fd-1 using LFAH15-WG10. In addition, LFAH15-WG10 significantly enhanced total FAMEs yield by 21.2% over the control. Moreover, it reduced polyunsaturated fatty acids (PUFAs) ratio from 52.1% to 47.8% of total FAMEs, and increased monounsaturated fatty acids (MUFAs) ratio from 26.6% to 31.3% of total FAMEs.

Analysis of the Genetic Diversity and Population Structure of Austrian and Belgian Wheat Germplasm within a Regional Context Based on DArT Markers

Analysis of crop genetic diversity and structure provides valuable information needed to broaden the narrow genetic base as well as to enhance the breeding and conservation strategies of crops. In this study, 95 Austrian and Belgian wheat cultivars maintained at the Centre for Genetic Resources (CGN) in the Netherlands were characterised using 1052 diversity array technology (DArT) markers to evaluate their genetic diversity, relationships and population structure. The rarefacted allelic richness recorded in the Austrian and Belgian breeding pools (A25 = 1.396 and 1.341, respectively) indicated that the Austrian germplasm contained a higher genetic diversity than the Belgian pool. The expected heterozygosity (HE) values of the Austrian and Belgian pools were 0.411 and 0.375, respectively. Moreover, the values of the polymorphic information content (PIC) of the Austrian and Belgian pools were 0.337 and 0.298, respectively. Neighbour-joining tree divided each of the Austrian and Belgian germplasm pools into two genetically distinct groups. The structure analyses of the Austrian and Belgian pools were in a complete concordance with their neighbour-joining trees. Furthermore, the 95 cultivars were compared to 618 wheat genotypes from nine European countries based on a total of 141 common DArT markers in order to place the Austrian and Belgian wheat germplasm in a wider European context. The rarefacted allelic richness (A10) varied from 1.224 (Denmark) to 1.397 (Austria). Cluster and principal coordinates (PCoA) analyses divided the wheat genotypes of the nine European countries into two main clusters. The first cluster comprised the Northern and Western European wheat genotypes, whereas the second included the Central European cultivars. The structure analysis of the 618 European wheat genotypes was in a complete concordance with the results of cluster and PCoA analyses. Interestingly, a highly significant difference was recorded between regions (26.53%). In conclusion, this is the first study to reveal the high diversity levels and structure of the uncharacterised Austrian and Belgian wheat germplasm maintained at the CGN as well as place them in a wider European context. The results should help plant breeders to utilise the most promising wheat genotypes of this study in future breeding programmes for enhancing wheat cultivars.

A comparative study on the quality of bio-oil derived from green macroalga Enteromorpha clathrata over metal modified ZSM-5 catalysts

The green macroalga Enteromorpha clathrata was pyrolyzed with or without catalysts at the temperature of 550u202f°C for producing high-quality bio-oil. The ZSM-5 and 1,2,3u202fmmol Mg-Ce/ZSM-5 catalysts were introduced to investigate the yields and components distribution of bio-oil. Increase of bio-oil production was obtained with the use of ZSM-5 and 1,2,3u202fmmol Mg-Ce/ZSM-5 catalysts. The 1u202fmmolu202fMg-Ce/ZSM-5 catalyst exhibited more promising property for promoting the relative content of C5-C7 compounds, and decreasing the relative content of acids in bio-oil. The results suggested that E. clathrata had potential as pyrolysis feedstocks for producing the high-quality bio-oil with large amounts of C5-C7 compounds and low relative content of acids when the 1u202fmmolu202fMg-Ce/ZSM-5 catalyst was used. Furthermore, the physicochemical properties of ZSM-5 and 1u202fmmolu202fMg-Ce/ZSM-5 catalysts were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and temperature-programmed desorption of ammonia.

Potential of macroalgae for biodiesel production: Screening and evaluation studies

Nowadays, biofuel production is a fast expanding industry and is facing a growing dilemma about a feedstock source capable of keeping up with demand. Recently, macroalgae have been attracting a wide attention as a source for biofuel. In the present study, ten macroalgae were collected and screened as biodiesel feedstocks. As a result of their high biomass production and relatively high lipid content, Ulva lactuca, Padina boryana and Ulva intestinalis showed the highest significant lipids and fatty acid methyl esters (FAMEs) areal productivities among the studied species. Saturated fatty acids (SAFs) showed insignificant differences in the selected species, with noticeably significant higher polyunsaturated fatty acids (PUFAs) content in U.xa0lactuca by 4.2 and 3 times, with respect to P.xa0boryana and U.xa0intestinalis, respectively. The recorded increase in PUFAs was attributed to higher content of C16:4n-3, C18:3n-3 and C18:4n-3. By lipid fractionation, P.xa0boryana showed significant higher concentration of neutral lipids (37.7xa0mgxa0g-1 CDW, representing 46.7% of total fatty acids) in comparison to U.xa0lactuca and U.xa0intestinalis, which showed 16% and 17% lower neutral lipid fractions, respectively. In addition, biodiesel characteristics of the studied macroalgae complied with that of international standards. Furthermore, oil-free residual biomass can be readily converted into fermentable sugars or biogas due to its high carbohydrates content, which adds to the economics of macroalgae as biofuel feedstock. In conclusion, the present study confirmed that macroalgae represent an attractive alternative renewable feedstock for biodiesel and other biofuels.

Protoplast fusion and genetic recombination between Ochromonas danica (Chrysophyta) and Haematococcus pluvialis (Chlorophyta)

Abstract: We carried out interphylum protoplast fusion between Ochromonas danica and Haematococcus pluvialis using polyethylene glycol. Different enzyme mixtures were evaluated to prepare the protoplast of H. pluvialis; however, in the absence of a cell wall, O. danica was not treated with lytic enzymes. Maximum lytic activity of 57% was observed using proteinase K for 90 min. The heterofusants were easily identified by pigmentation of the hybrid colonies on BG11 medium. Fatty acid analysis in putative hybrids of O. danica and H. pluvialis confirmed the hybrid origin of these cells. Accordingly, the characteristic fatty acids of O. danica (C16:2 and C24:0) and H. pluvialis (C16:0 and C18:3n-6) were detected in the hybrid algae. These results indicated successful genetic recombination between the two microalgal phyla.

Co-pyrolysis and catalytic co-pyrolysis of Enteromorpha clathrata and rice husk

AbstractCatalytic co-pyrolysis process of Enteromorpha clathrata (EN) and rice husk (HU) was studied in a fixed bed reactor with ZSM-5 and MCM-41 catalysts at 550xa0°C. The yields and product distribution were compared when EN, HU and different mass ratios of EN and HU were pyrolyzed with or without catalysts. Bio-oil products were analyzed by Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry (GC–MS) and bio-char products were analyzed by X-ray photoelectron spectroscopy. Under co-pyrolysis conditions without catalysts, the experimental yield of bio-gas was higher than the theoretical. In contrast, the yield of bio-oil was lower than the theoretical. In the catalytic pyrolysis, ZSM-5 significantly improved the yield of bio-oil and reduced the bio-gas product. However, the effect of MCM-41 on the yield of the pyrolysis products was weaker than that of ZSM-5. In the GC–MS analysis of bio-oil with catalysts, ZSM-5 showed a catalytic effect on the decomposition of hemicellulose and protein. The protein was further cracked, and the relative content of hydrocarbon component also increased. With MCM-41 catalyst, there was significant catalytic effect on lignin and lipid, and the result showed that MCM-41 had a further catalytic influence in the synergetic effect of co-pyrolysis.n

Co-pyrolysis of macroalgae and lignocellulosic biomass: Synergistic effect, optimization studies, modeling, and simulation of effects of co-pyrolysis parameters on yields

Synergistic effect of co-pyrolysis of macroalgae [Enteromorpha prolifera (EP)] and lignocellulosic biomass [rice husk (RH)] in a fixed bed reactor for maximum and enhanced biofuels yield has been investigated. The main and interaction effects of three effective co-pyrolysis parameters (pyrolysis temperature, feedstock blending ratio, and heating rate) were also modeled and simulated to determine the yield rates of bio-oil and bio-char, respectively. Optimization studies were, then, performed to predict the optimal conditions for maximum yields using the central composite circumscribed experimental design in Design Expert® software 8.0.6. Analysis of variance was carried out to determine whether the fit of the multiple regressions is significant for the second-order model. Normal pyrolysis oils from EP, RH, and co-pyrolysis oils obtained from different feedstock blending ratios were examined using the gas chromatography-mass spectrometry to identify their compositions. Some vital properties of oils and bio-chars such as the heating value, water content, elemental compositions, and specific gravity were also determined, which unveiled that synergistic effect exists between EP and RH during co-pyrolysis, and this led to increase in products’ yields and improved co-pyrolysis products’ quality.

Comparative Study of Combustion Properties of Two Seaweeds in a Batch Fluidized Bed

ABSTRACT In the present study, combustion of two seaweeds, Enteromorpha clathrate and Sargassum natans, was carried out in a bench-scale fluidized bed. According to the shrinking core model, combustion of E. clathrate particles resulted in dehydration and release of volatile components first, followed by char combustion. While combustion of S. natans particles resulted in scraps formation due to the rapid release of large amounts of volatiles, followed by expansion and fragmentation. The cross sections of E. clathrate particles and the cokes collected after different combustion durations were analyzed with a scanning electron microscope. Some micro-pores were generated with a rougher surface after being burned for 30 s. When combustion continued for 3 min, a cotton wool-like structure was obtained due to complete release of volatiles. After 4 min of burning, internal surface of the ash particle became cohesive, due to partial melting of ash particles. In addition, the released gases were studied during the combustion process. Results showed that SO2, NOx, and other gases emitted spontaneously as soon as seaweed particles were fed into the fluidized bed, indicating that both pyrolysis and oxidation reactions rapidly take place within the seaweed particles. In general, the heat transfer rate was accelerated by increasing bed temperature and led to an earlier release of volatile components with shortened burnout time. Moreover, increasing air velocity and raising the bed height also enhanced, to some extent, the combustion and shortened the burnout time.

Biorefining of rice straw by sequential fermentation and anaerobic digestion for bioethanol and/or biomethane production: Comparison of structural properties and energy output

Three routes; namely R1 representing direct anaerobic digestion (AD), R2 representing enzymatic hydrolysis followed by fermentation, distillation, then AD, and R3 representing AD of fermentation broth without distillation; of alkali pretreated rice straw were investigated. Results showed that sequential fermentation and AD effectively enhanced fibers degradation with significant changes in the composition. Fermentation through R2 resulted in ethanol yield of 87.4u202fgu202fkg-1 dry straw. Maximum biogas yields of 286.9, 233.3 and 372.4u202fLu202fkg-1u202fVS were recorded by AD for R1, R2 and R3 after reaching the steady state at 36, 24 and 33u202fdays, respectively. However, biogas produced through R3 showed the highest significant biomethane content (79.3%) which represented 15 and 8% higher than that of R1 and R2, respectively. Therefore, the highest bioenergy output and energy conversion efficiency of 10.58u202fGJu202fton-1 and 75.6%, respectively, were obtained through R3 demonstrating the positive effect of fermentation prior to AD.