| 1. |
- Diez, Cristina M., et al.
(författare)
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Influence of novel lignocellulosic residues in a biobed biopurification system on the degradation of pesticides applied in repeatedly high doses
- 2013
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 16:6
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Tidskriftsartikel (refereegranskat)abstract
- Background: The biobed is a simple biopurification system used to prevent the point-source pesticide contamination that occurs at farm level. The typical composition of the biomixture used in this system is soil, peat and straw in volumetric proportions of 1:1:2. The principal component is straw due to its positive effects on biological activity and thus pesticide degradation. However, access to straw can be limited in some regions, so it must be replaced by other more readily available lignocellulosic residues. Results: Therefore, two alternate lignocellulosic materials (barley husks and pine sawdust) were evaluated as partial substitutes for straw. The degradation of a repeatedly applied mixture of six pesticides by these alternates was assessed. The microbial respiration and fluorescein diacetate (FDA) hydrolysis activity were also assessed. The results showed that the highest degradation efficiency was found in mixtures containing straw and barley husks. Each biomixtures tested achieved a high degradation (50 to 90%) of all the pesticides used except iprodione. Repeated applications of pesticides resulted in a slowing of the degradation rate of all pesticide types in all biomixtures. FDA activity and microbial respiration were higher in the biomixtures containing barley husks and straw compared to the mixture with pine sawdust, a result consistent with the pesticide degradations observed. Conclusions: This paper demonstrates that the straw in the traditional biomixture can be partially replaced by other lignocellulosic materials to efficiently degrade a mixture of pesticides, even when the pesticides are added in successive applications and high concentrations.
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| 2. |
- Eberhard, Thomas H
(författare)
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High density process to cultivate Lactobacillus plantarum biomass using wheat stillage and sugar beet molasses
- 2011
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Conclusions: The use of a fermentation medium consisting of distillery wastewater and molasses to obtain value-added products (such as LAB biomass and lactic acid) is a possible step for classical ethanol production to move towards a biorefinery model production in which all by and waste products are utilized to increase produced values and reduce waste production. This enables a cost-effective utilization of the problematic wastewater from ethanol and sugar production.
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| 3. |
- El-Gamal, Rehab, et al.
(författare)
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The use of chitosan in protecting wooden artifacts from damage by mold fungi
- 2016
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 24, s. 70-78
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMany buildings in Egypt e.g. museums, mosques and churches, do not possess controlled environments for minimizing the risks of damage of wooden artifacts due to the growth of fungi. Fungal damage usually appears as change in wood color, appearance of stains, and sometimes deformation of wooden surfaces. In this study we focused on the effect that some fungi exert on the properties of wooden artifacts and evaluated the effectiveness of different concentrations of chitosan on their protection against damage by mold fungi.ResultsSamples were collected from different monuments and environments, and fungi growing on them were isolated and identified. The isolated Penicillium chrysogenum, Aspergillus flavus and A. niger strains were used for the infestation of new pitch pine samples. The results revealed that the lightness of samples infected with any of the tested fungi decreased with increasing incubation times. XRD analysis showed that the crystallinity of incubated samples treated individually with the different concentrations of chitosan was lower than the crystallinity of infected samples. The crystallinity index measured by the first and the second method decreased after the first and second months but increased after the third and fourth months. This may due to the reducing of amorphous part by enzymes or acids produced by fungi in wooden samples.ConclusionsThe growth of fungi on the treated wood samples decreased with increasing the concentration of chitosan. Hence, it was demonstrated that chitosan prevented fungal growth, and its use could be recommended for the protection of archaeological wooden artifacts.
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| 4. |
- Matsakas, Leonidas, et al.
(författare)
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Effect of synthetic and natural media on lipid production from Fusarium oxysporum
- 2017
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier. - 0717-3458. ; 30, s. 95-102
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundDependence on fossil resources, for the production of fuels and energy, has resulted in environmental and financial problems, which require our immediate action in order to reverse the situation. Use of renewable sources for the production of fuels and energy is an important alternative with biodiesel remains as one of the promising options. Aim of this work is to evaluate the fungus Fusarium oxysporum for its potentials to accumulate microbial lipids when grown on synthetic media and saccharified sweet sorghum stalks.ResultsThe effect of different carbon sources, nitrogen sources and C/N ratio on the lipid production was initially examined, which resulted in a lipid concentration of 4.4 g/L, with lipid content of 42.6% w/w. Sweet sorghum stalks were able to support growth and lipid production of the fungus, both as carbon source and as nitrogen source. It was also shown that saccharification of the dried stalks is an important step to increase lipid production. Removal of the remaining stalk solids enabled the lipid production during cultivation in increased initial solids of up to 16 w/w. This resulted in a lipid production of 3.81 g/L.ConclusionsIt was demonstrated that F. oxysporum can be used as an efficient oleaginous microorganism, with sweet sorghum serving as an excellent raw material for the cultivation of the fungus. The lipids obtained during this work were also found to have a fatty acid profile with good potentials to be used for biodiesel production.
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| 5. |
- Matsakas, Leonidas, et al.
(författare)
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Green conversion of municipal solid wastes into fuels and chemicals
- 2017
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 26
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Forskningsöversikt (refereegranskat)abstract
- Presently, the society is facing a serious challenge for the effective management of the increasing amount of produced municipal solid wastes. The accumulated waste has caused a series of environmental problems such as uncontrolled release of greenhouse gases. Moreover, the increasing amount of wastes has resulted in a shortage of areas available for waste disposal, resulting in a nonsustainable waste management. These problems led to serious public concerns, which in turn resulted in political actions aiming to reduce the amount of wastes reaching the environment. These actions aim to promote sustainable waste management solutions. The main objective of these policies is to promote the recycling of municipal solid waste and the conversion of waste to energy and valuable chemicals. These conversions can be performed using either biological (e.g., anaerobic digestion) or thermochemical processes (e.g., pyrolysis). Research efforts during the last years have been fruitful, and many publications demonstrated the effective conversation of municipal solid waste to energy and chemicals. These processes are discussed in the current review article together with the change of the waste policy that was implemented in the EU during the last years.
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| 6. |
- Mohamadi, Marzieh, 1988, et al.
(författare)
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Improvement of ethanol production from birch and spruce pretreated with 1-H-3-methylmorpholinium chloride
- 2019
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 41, s. 95-99
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Tidskriftsartikel (refereegranskat)abstract
- Background : Pretreatment is the critically important step for the production of ethanol from lignocelluloses. In this study, hardwood birch (Betula pendula) and softwood spruce (Norway spruce) woods were pretreated with a newly synthesized morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]), followed by enzymatic hydrolysis and fermentation to ethanol. Results : [HMMorph][Cl] was synthesized using inexpensive raw materials, i.e., hydrochloric acid and N-methyl morpholine, following a simple process. The influence of pretreatment time (2, 3, 5, and 8 h) and temperature (120 and 140°C) in terms of hydrolysis efficiency was investigated. Glucose yields from enzymatic hydrolysis were improved from 13.7% to 45.7% and 12.9% to 51.8% after pretreatment of birch and spruce woods, respectively, under optimum pretreatment conditions (i.e., at 140°C for 3 h) as compared to those from pristine woods. Moreover, the yields of ethanol production from birch and spruce were increased to 34.8% and 44.2%, respectively, while the yields were negligible for untreated woods. Conclusions : This study demonstrated the ability of [HMMorph][Cl] as an inexpensive agent to pretreat both softwood and hardwood.
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| 7. |
- Mshandete, Anthony Manoni, et al.
(författare)
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Performance of biofilm carriers in anaerobic digestion of sisal leaf waste leachate
- 2008
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Three methanogenic biofilm bioreactors were studied to evaluate the performance of three types of carriers. The carrier material were consisted of sisal fibre waste, pumice stone and porous glass beads, and the bioprocess evaluated was the methanogenesis anaerobic digestion of sisal leaf waste leachate. Process performance was investigated by increasing the organic loading rate (OLR) step-wise. The best results were obtained from the bioreactor packed with sisal fibre waste. It had the highest chemical oxygen demand ( COD) removal efficiencies in the range of 80-93% at OLRs in the range of 2.4-25 g COD L(-1)d(-1). The degradation pattern of volatile fatty acids (VFAs) showed that the degradation of propionate was limiting at higher OLRs. The stable pH and higher partial alkalinity (PA) of the outflow illustrated that packed-bed bioreactors have a good ability to withstand the variations in load and volatile fatty acid concentrations that can occur in a two-stage anaerobic process. In conclusion, sisal fibre waste was shown to be a novel promising biofilm carrier and would work very well in methanogenic biofilm bioreactors treating sisal leaf tissue waste leachate. Furthermore both sisal wastes are available in the neighbourhood of sisal industries, which makes anaerobic digestion scale up at sisal factory level feasible and cost-effective.
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| 8. |
- Ortiz Rios, Rodomiro Octavio
(författare)
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Plant prebiotics and human health: Biotechnology to breed prebiotic-rich nutritious food crops
- 2014
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 17, s. 238–245-
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Forskningsöversikt (refereegranskat)abstract
- Microbiota in the gut play essential roles in human health. Prebiotics are non-digestible complex carbohydrates that are fermented in the colon, yielding energy and short chain fatty acids, and selectively promote the growth of Bifidobacteria and Lactobacillae in the gastro-intestinal tract. Fructans and inulin are the best-characterized plant prebiotics. Many vegetable, root and tuber crops as well as some fruit crops are the best-known sources of prebiotic carbohydrates, while the prebiotic-rich grain crops include barley, chickpea, lentil, lupin, and wheat. Some prebiotic-rich crop germplasm have been reported in barley, chickpea, lentil, wheat, yacon, and Jerusalem artichoke. A few major quantitative trait loci and gene-based markers associated with high fructan are known in wheat. More targeted search in genebanks using reduced subsets (representing diversity in germplasm) is needed to identify accessions with prebiotic carbohydrates. Transgenic maize, potato and sugarcane with high fructan, with no adverse effects on plant development, have been bred, which suggests that it is feasible to introduce fructan biosynthesis pathways in crops to produce health-imparting prebiotics. Developing prebiotic-rich and super nutritious crops will alleviate the widespread malnutrition and promote human health. A paradigm shift in breeding program is needed to achieve this goal and to ensure that newly-bred crop cultivars are nutritious, safe and health promoting. (C) 2014 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V. All rights reserved.
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| 9. |
- Westman, Johan, 1983, et al.
(författare)
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Inhibitor tolerance and flocculation of a yeast strain suitable for second generation bioethanol production
- 2012
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Robust second generation bioethanol processes require microorganisms able to ferment inhibitory lignocellullosic hydrolysates. In this study, the inhibitor tolerance and flocculation characteristics of Saccharomyces cerevisiae CCUG53310 were evaluated in comparison with S. cerevisiae CBS8066. Results: The flocculating strain CCUG53310 could rapidly ferment all hexoses in dilute acid spruce hydrolysate, while CBS8066 was strongly inhibited in this medium. In synthetic inhibitory media, CCUG53310 was more tolerant to carboxylic acids and furan aldehydes, but more sensitive than CBS8066 to phenolic compounds. Despite the higher tolerance, the increase in expression of the YAP1, ATR1 and FLR1 genes, known to confer resistance to lignocellulose-derived inhibitors, was generally smaller in CCUG53310 than in CBS8066 in inhibitory media. The flocculation of CCUG53310 was linked to the expression of FLO8, FLO10 and one or more of FLO1, FLO5 or FLO9. Flocculation depended on cell wall proteins and Ca2+ ions, but was almost unaffected by other compounds and pH values typical for lignocellulosic media. Conclusions: S. cerevisiae CCUG53310 can be characterised as being very robust, with great potential for industrial fermentation of lignocellulosic hydrolysates relatively low in phenolic inhibitors.
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| 10. |
- Wünschiers, Roebbe, et al.
(författare)
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Experimental and bioinformatic approaches for analyzing and visualizing cyanobacterial nitrogen and hydrogen metabolism
- 2007
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Ingår i: Electronic Journal of Biotechnology. - : Elsevier BV. - 0717-3458. ; 10:4, s. 549-562
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Tidskriftsartikel (refereegranskat)abstract
- Many cyanobacteria are capable of utilizing light energy for nitrogen fixation. As a byproduct of this nitrogenase mediated catalysis, hydrogen gas is produced. Several approaches to increase hydrogen prodn. from cyanobacteria exist. Usually, these approaches are non-targeted. Here we exemplify how DNA-microarray based gene-expression anal. and bioinformatic visualization techniques can be used to analyze nitrogen and hydrogen metab. from the filamentous, heterocyst forming cyanobacterium Nostoc PCC 7120. We analyzed the expression of 1249 genes from major metabolic categories under nitrogen fixing and non-nitrogen fixing growth. Of the selected genes, 494 show a more than 2-fold expression difference in the two conditions analyzed. Under nitrogen-fixing conditions 465 genes, mainly involved in energy metab., photosynthesis, respiration and nitrogen-fixation, were found to be stronger expressed, whereas only 29 genes showed a stronger expression under non-nitrogen fixing conditions. To help understanding probe hybridization, all expression data were correlated with potential target secondary structures and probe GC-content. For the first time the expression of high light-induced stress proteins (HLIP-family) is shown to be linked to the nitrogen availability.
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