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1.
BackgroundFructose and single cell protein are important products for the food market. Abundant amounts of low-grade dates worldwide are annually wasted. In this study, highly concentrated fructose syrups and single cell protein were obtained through selective fermentation of date extracts by Saccharomyces cerevisiae.ResultsThe effect of air flow (0.1, 0.5, 0.75, 1, 1.25 and 1.5 vvm) and pH (4.5, 4.8, 5, 5.3 and 5.6) was investigated. Higher air flow led to lower fructose yield. The optimum cell mass production of 10 g/L was achieved at air flow of 1.25 vvm with the fructose yield of 91%. Similar cell mass production was obtained in the range pH of 5.0–5.6, while less cell mass was obtained at pH less than 5. Controlling the pH at 4.5, 5.0 and 5.3 failed to improve the production of cell mass which were 5.6, 5.9 and 5.4 g/L respectively; however, better fructose yield was obtained.ConclusionsExtension of the modified Gompertz enabled excellent predictions of the cell mass, fructose production and fructose fraction. The proposed model was also successfully validated against data from literatures. Thus, the model will be useful for wide application of biological processes.How to cite: Putra MD, Abasaeed AE, Al-Zahrani SM. Prospective production of fructose and single cell protein from date palm waste. Electron J Biotechnol 2020;48. https://doi.org/10.1016/j.ejbt.2020.09.007. 相似文献
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BackgroundJuglone is a naphthoquinone currently obtained by chemical synthesis with biological activities including antitumor activity. Additionally, juglone is present in the green husk of walnut, which suggests evaluating the effect of GH extracts on carcinogenic cell lines.ResultsWalnut green husk ethanolic extract was obtained as 169.1 mg juglone/100 g Green Husk and antioxidant activity (ORAC) of 44,920 μmol Trolox Equivalent/100 g DW Green Husk. At 1 μM juglone in HL-60 cell culture, green husk extract showed an antiproliferative effect, but pure juglone did not; under these conditions, normal fibroblast cells were not affected. A dose-dependent effect on mitochondrial membrane potential loss was observed. Apoptosis of HL-60 was detected at 10 μM juglone. Despite high ORAC values, neither purified juglone nor the extract showed protective effects on HL-60 cells under oxidative conditions.ConclusionsGreen husk extract generates an antiproliferative effect in HL-60 cells, which is related to an induction of the early stages of apoptosis and a loss of mitochondrial membrane potential. The normal cells were not affected when juglone is present at concentrations of 1 μM, while at higher concentrations, there is loss of viability of both cancerous and healthy cells.How to cite: Soto-Maldonado C, Vergara-Castro M, Jara-Quezada J, et al. Polyphenolic extracts of walnut (Juglans regia) green husk containing juglone inhibit the growth of HL-60 cells and induce apoptosis. Electron J Biotechnol 2019;39. https://doi.org/10.1016/j.ejbt.2019.02.001. 相似文献
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BackgroundA key challenge for manufacturers of pro-health food containing active probiotic microorganisms is to develop a product with attractive sensory features along with maintenance of declared number of microorganisms during storage and transfer by alimentary tract.ResultsThe highest concentration of polyphenols was observed in snacks without an additive of probiotics as well as those with an additive of L. rhamnosus and B. animalis bacteria and concentration of these compounds increased by 9.5% during six months of storage. None of the products distinguished itself in the sensorial assessment although each was assessed positively. The number of microorganisms was stable and comparatively high during six months of storage at a room temperature and in cooling conditions (108 cfu/g). In the digestion model, an influence of aggressive digestion conditions was examined in the alimentary tract on the number of microorganisms, which allowed to arrange strains from the most resistant (S. boulardii) to the most sensitive (B. breve). It must be noted that currently on the market there is no available snack containing probiotic yeast as well as there is no literature data on works on such formulation of food.ConclusionsIn the newly developed snack made of chocolate, in which sugar has been replaced with maltitol, a raw material was added in the form of raspberry, prebiotic in the form of inulin and a strain of probiotic bacteria, including the unprecedented so far S. boulardii, which stands a high chance to occupy a good place on the market of functional food.How to cite: Cielecka-Piontek J, Dziedziński M, Szczepaniak O, et al. Survival of commercial probiotic strains and their effect on dark chocolate synbiotic snack with raspberry content during the storage and after simulated digestion. Electron J Biotechnol 2020;48. https://doi.org/10.1016/j.ejbt.2020.09.005. 相似文献
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Caffeic acid (CA; 3,4-dihydroxycinnamic acid) is an aromatic compound obtained by the phenylpropanoid pathway. This natural product has antioxidant, antitumor, antiviral, and anti-inflammatory activities. It is also a precursor of CA phenethyl ester (CAPE), a compound with potential as an antidiabetic and liver-protective agent. CA can be found at low concentrations in plant tissues, and hence, its purification is difficult and expensive. Knowledge regarding the pathways, enzymes, and genes involved in CA biosynthesis has paved the way for enabling the design and construction of microbial strains with the capacity of synthesizing this metabolite. In this review, metabolic engineering strategies for the generation of Escherichia coli strains for the biotechnological production of CA are presented and discussed.How to cite: Hernández-Chávez G, Martinez A, Gosset G. Metabolic engineering strategies for caffeic acid production in Escherichia coli. Electron J Biotechnol 2019;38. https://doi.org/10.1016/j.ejbt.2018.12.004. 相似文献
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BackgroundAgkistrodon acutus, a traditional Chinese medicine, clinically used in the treatment of rheumatism, tumor, and cardiovascular and cerebrovascular diseases. Due to the unique medicinal value and the difficulty of artificial breeding of Agkistrodon acutus, the supply of Agkistrodon acutus on the market exceeds the demand, and a large number of its adulterants are found on the market. In this study, the cytb gene sequences of Agkistrodon acutus and 9 snakes were compared and analyzed, specific primers were designed, and specific PCR methods were established to detect Agkistrodon acutus medicinal samples on the market.ResultsThis method was successfully applied to distinguish the snake from other adulterated species, and tested 18 Agkistrodon acutus samples randomly purchased from six cities. Twelve samples were counterfeit and six were genuine. The standard reference material of Agkistrodon acutus was cloned by molecular cloning and sequencing, and the gene sequence difference with other species was significant. It shows that the region could be used as the fingerprint region of the target species.ConclusionsThe proposed method can be used as a species-specific marker and can be highly distinguished from other adulterated snake species, which is helpful to effectively avoid the problem of false sale of Agkistrodon acutus.How to cite: Yingnuo L, Yanshuang W, Mingcheng Li, et al. Development of a species-specific PCR assay for authentication of Agkistrodon acutus based on mitochondrial cytochrome b gene. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.07.005 相似文献
6.
BackgroundLiquid wax esters are widely used in cosmetic as well as pharmaceutical and other industries. The demand of organic and natural products is increasing nowadays. Coconut oil contains benefit fatty acids and has been mainly used for oil-based and moisturizer products. Liquid wax esters from coconut oil and unsaturated fatty alcohol can be synthesized by enzymatic reaction; and it is interesting for using as an alternative natural ingredient in these industries.ResultsOptimal condition for coconut oil based wax ester synthesis by immobilized lipase EQ3 was 10 U of enzyme, temperature at 30°C and molar ratio of coconut oil to oleyl alcohol at 1:3 (mol/mol) (0.33X) dissolved in isooctane for 12 h, while for Lipozyme RM IM optimal condition was 10 U of enzyme, temperature at 45°C and oil/alcohol molar ratio at 1:3 (0.33X) dissolved in isooctane for 3 h. Percentage of wax esters synthesized by both lipases reached more than 88%. Both immobilized lipases catalyzed high yield of wax esters within the 2nd batch; after that, the immobilized lipases showed reduced activity and synthesized < 60% of wax esters from the 3rd to 5th batch. The main composition of wax esters was ~ 48% oleyl laurate with 10% degradation at ~ 250°C.ConclusionsThe liquid wax ester synthesis by commercial Lipozyme RM IM had higher effect than immobilized lipase EQ3, but both catalysts were stable within 2 batches in the optimum condition. The characteristic properties of wax esters showed potential for use as components in cosmetics and skin care products.How to citeUngcharoenwiwat P, H-Kittikun A. Enzymatic synthesis of coconut oil based wax esters by immobilized lipase EQ3 and commercial lipozyme RMIM. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.06.005 相似文献
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Chloroplast biotechnology has emerged as a promissory platform for the development of modified plants to express products aimed mainly at the pharmaceutical, agricultural, and energy industries. This technology’s high value is due to its high capacity for the mass production of proteins. Moreover, the interest in chloroplasts has increased because of the possibility of expressing multiple genes in a single transformation event without the risk of epigenetic effects. Although this technology solves several problems caused by nuclear genetic engineering, such as turning plants into safe bio-factories, some issues must still be addressed in relation to the optimization of regulatory regions for efficient gene expression, cereal transformation, gene expression in non-green tissues, and low transformation efficiency. In this article, we provide information on the transformation of plastids and discuss the most recent achievements in chloroplast bioengineering and its impact on the biopharmaceutical and agricultural industries; we also discuss new tools that can be used to solve current challenges for their successful establishment in recalcitrant crops such as monocots.How to cite: Quintín Rascón-Cruz Q, González-Barriga CD, Iglesias-Figueroa BF, et al. Plastid transformation: Advances and challenges for its implementation in agricultural crops. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.03.005 相似文献
8.
Since more than twenty years ago, some species of bacteria and fungi have been used to produce protein biomass or single-cell protein (SCP), with inexpensive feedstock and wastes being used as their sources of carbon and energy. The role of SCP as a safe food and feed is being highlighted more because of the worldwide protein scarcity. Even though SCP has been successfully commercialized in the UK for decades, study of optimal fermentation conditions, various potential substrates, and a broad range of microorganisms is still being pursued by many researchers. In this article, commonly used methods for the production of SCP and different fermentation systems are briefly reviewed, with submerged fermentation being highlighted as a more commonly used method. Emphasis is given to the effect of influencing factors on the biomass yield and productivity in an effort to provide a comprehensive review for researchers in related fields of interest.How to cite: Reihani SFS, Khosravi-Darani K. Influencing factors on single cell protein production by submerged fermentation: A review. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.11.005. 相似文献
9.
BackgroundThis paper presents micro- and nano-fabrication techniques for leachable realgar using the extremophilic bacterium Acidithiobacillus ferrooxidans (A. ferrooxidans) DLC-5.ResultsRealgar nanoparticles of size ranging from 120 nm to 200 nm were successfully prepared using the high-energy ball mill instrument. A. ferrooxidans DLC-5 was then used to bioleach the particles. The arsenic concentration in the bioleaching system was found to be increased significantly when compared with that in the sterile control. Furthermore, in the comparison with the bioleaching of raw realgar, nanoparticles could achieve the same effect with only one fifth of the consumption.ConclusionEmphasis was placed on improving the dissolvability of arsenic because of the great potential of leachable realgar drug delivery in both laboratory and industrial settings.How to cite: Xu R, Song P, Wang J, et al. Bioleaching of realgar nanoparticles using the extremophilic bacterium Acidithiobacillus ferrooxidans DLC. Electron J Biotechnol 2019;38. https://doi.org/10.1016/j.ejbt.2019.01.001. 相似文献
10.
BackgroundPlant tissue cultures have the potential to reprogram the development of microspores from normal gametophytic to sporophytic pathway resulting in the formation of androgenic embryos. The efficiency of this process depends on the genotype, media composition and external conditions. However, this process frequently results in the regeneration of albino instead of green plants. Successful regeneration of green plants is affected by the concentration of copper sulfate (CuSO4) and silver nitrate (AgNO3) and the length of induction step. In this study, we aimed at concurrent optimization of these three factors in barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), and triticale (x Triticosecale spp. Wittmack ex A. Camus 1927) using the Taguchi method. We evaluated uniform donor plants under varying experimental conditions of in vitro anther culture using the Taguchi approach, and verified the optimized conditions.ResultsOptimization of the regeneration conditions resulted in an increase in the number of green regenerants compared with the control. Statistic Taguchi method for optimization of the in vitro tissue culture plant regeneration via anther cultures allowed reduction of the number of experimental designs from 27 needed if full factorial analysis is used to 9. With the increase in the number of green regenerants, the number of spontaneous doubled haploids decreased. Moreover, in barley and triticale, the number of albino regenerants was reduced.ConclusionThe statistic Taguchi approach could be successfully used for various factors (here components of induction media, time of incubation on induction media) at a one time, that may impact on cereals anther cultures to improve the regeneration efficiency.How to cite: Orłowska R, Pachota KA, Machczyńska J, et al. Improvement of anther cultures conditions using the Taguchi method in three cereal crops. Electron J Biotechnol 2020;43. https://doi.org/10.1016/j.ejbt.2019.11.001. 相似文献
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BackgroundPyruvic acid (PA), a vital α-oxocarboxylic acid, plays an important role in energy and carbon metabolism. The oleaginous yeast Yarrowia lipolytica (Y. lipolytica) has considerable potential for the production of PA. An increased NaCl concentration reportedly increases the biomass and PA yield of Y. lipolytica.ResultsTo increase the yield of PA, the NaCl-tolerant Y. lipolytica A4 mutant was produced using the atmospheric and room temperature plasma method of mutation. The A4 mutant showed growth on medium containing 160 g/L NaCl. The PA yield of the A4 mutant reached 97.2 g/L at 120 h (0.795 g/g glycerol) in a 20-L fermenter with glycerol as the sole carbon source, which was 28.9% higher than that of the parental strain.ConclusionThe PA yield from Y. lipolytica can be improved by increasing its NaCl tolerance.How to cite: Yuan W, Lin X, Zhong S, et al. Enhanced pyruvic acid yield in an osmotic stress-resistant mutant of Yarrowia lipolytica. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.002. 相似文献
13.
BackgroundChia seeds are gaining increasing interest among food producers and consumers because of their prohealth properties.ResultsThe aim of this work was to evaluate the potential of chia seeds to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The highest inhibitory activity against AChE and BChE was observed for colored seed ethanol extracts. A positive correlation was found between the presence of quercetin and isoquercetin as well as protocatechuic, hydroxybenzoic, and coumaric acids and the activity of extracts as AChE and BChE inhibitors. It has also been shown that grain fragmentation affects the increase in the activity of seeds against cholinesterases (ChE). Furthermore, seeds have been shown to be a source of substances that inhibit microbial growth.ConclusionsIt was found that the chia seed extracts are rich in polyphenols and inhibit the activity of ChEs; therefore, their use can be considered in further research in the field of treatment and prevention of neurodegenerative diseases.How to cite: Kobus-Cisowska J, Szymanowska D, Maciejewska P, et al. In vitro screening for acetylcholinesterase and butyrylcholinoesterase inhibition and antimicrobial activity of chia seeds (Salvia hispanica). Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.002 相似文献
14.
BackgroundThe main objective of this study was to isolate fungi associated with Anthopleura xanthogrammica and measure their antimicrobial and enzymatic activities. A total of 93 fungal strains associated with A. xanthogrammica were isolated in this study, of which 32 isolates were identified using both morphological characteristics and internal transcribed spacer (ITS) sequence analysis. The antibacterial activities of 32 fungal isolates were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Edwardsiella tarda, Vibrio harveyi, Fusarium oxysporum, and Pyricularia oryzae by agar diffusion assay. Extracellular hydrolytic enzyme activities of the fungal isolates were determined by agar diffusion assays. Enzyme activities were detected from clear halo size.ResultsThe isolated fungi belonged to 18 genera within 7 taxonomic orders of 1 phylum. The genera Aspergillaceae were the most diverse and common. The antimicrobial activities of 32 isolates were evaluated, and 19 (59.4%) of fungi isolate displayed unique antimicrobial activities. All fungal strains displayed at least one enzyme activity. The most common enzyme activities in the fungi isolates were amylase and protease, while the least common were pectinase and xylanase.ConclusionsThis is first report on the sea anemone-derived fungi with antimicrobial and enzyme activities. Results indicated that sea anemone is a hot spot of fungal diversity and a rich resource of bioactive natural products.How to cite: Liu S, Ahmed S, Zhang C, et al. Diversity and antimicrobial activity of culturable fungi associated with sea anemone Anthopleura xanthogrammica. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.003 相似文献
15.
Azotobacter vinelandii is a gram-negative soil bacterium that produces two biopolymers of biotechnological interest, alginate and poly(3-hydroxybutyrate), and it has been widely studied because of its capability to fix nitrogen even in the presence of oxygen. This bacterium is characterized by its high respiration rates, which are almost 10-fold higher than those of Escherichia coli and are a disadvantage for fermentation processes. On the other hand, several works have demonstrated that adequate control of the oxygen supply in A. vinelandii cultivations determines the yields and physicochemical characteristics of alginate and poly(3-hydroxybutyrate).Here, we summarize a review of the characteristics of A. vinelandii related to its respiration systems, as well as some of the most important findings on the oxygen consumption rates as a function of the cultivation parameters and biopolymer production.How to cite: Castillo T, García A, Padilla-Córdova C, et al. Respiration in Azotobacter vinelandii and its relationship with the synthesis of biopolymers. Electron J Biotechnol 2020;48. https://doi.org/10.1016/j.ejbt.2020.08.001 相似文献
16.
BackgroundWheat is one of the most important crops cultivated all over the world. New high-yielding cultivars that are more resistant to fungal diseases have been permanently developed. The present study aimed at the possibility of accelerating the process of breeding new cultivars, resistant to eyespot, by using doubled haploids (DH) system supported by marker-assisted selection.ResultsTwo highly resistant breeding lines (KBP 0916 and KBH 4942/05) carrying Pch1 gene were crossed with the elite wheat genotypes. Hybrid plants of early generations were analyzed using endopeptidase EpD1 and two SSR markers linked to the Pch1 locus. Selected homozygous and heterozygous genotypes for the Pch1-linked EpD1b allele were used to produce haploid plants. Molecular analyses were performed on haploids to identify plants possessing Pch1 gene. Chromosome doubling was performed only on haploid plants with Pch1 gene. Finally, 65 DH lines carrying eyespot resistance gene Pch1 and 30 lines without this gene were chosen for the eyespot resistance phenotyping in a field experiment.ConclusionsResults of the experiment confirmed higher resistance to eyespot of the genotypes with Pch1 in comparison to those without this gene. This indicates the efficiency of selection at the haploid level.How to cite: Wiśniewska H, Majka M, Kwiatek M, et al. Production of wheat doubled haploids resistant to eyespot supported by marker-assisted selection. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.003 相似文献
17.
BackgroundVibrio species display variable and plastic fitness strategies to survive and interact with multiple hosts, including marine aquaculture species that are severely affected by pathogenic Vibrios. The culturable Vibrio sp. strain ArtGut-C1, the focus of this study, provides new evidence of such phenotypic plasticity as it accumulates polyhydroxybutyrate (PHB), a biodegradable polymer with anti-pathogen activity, particularly in the marine larviculture phase. The strain was isolated from the gut of laboratory-reared Artemia individuals, the live diet and PHB carrier used in larviculture. Its main phenotypic properties, taxonomic status and genomic properties are reported based on the whole-genome sequencing.ResultsVibrio sp. ArtGut-C1 yielded 72.6% PHB of cells’ dry weight at 25°C. The genomic average nucleotide identity (ANI) shows it is closely related to V. diabolicus (ANI: 88.6%). Its genome contains 5,236,997-bp with 44.8% GC content, 3,710 protein-coding sequences, 96 RNA, 9 PHB genes functionally related to PHB metabolic pathways, and several genes linked to competing and colonizing abilities.ConclusionsThis culturable PHB-accumulating Vibrio strain shows high genomic and phenotypic variability. It may be used as a natural pathogen biocontrol in the marine hatchery and as a potential cell factory for PHB production.How to cite: Yévenes M, Quiroz M, Maruyama F, et al. Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea). Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.10.003 相似文献
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BackgroundFermentation strategies for bioethanol production that use flocculating Saccharomyces cerevisiae yeast need to account for the mechanism by which inhibitory compounds, generated in the hydrolysis of lignocellulosic materials, are tolerated and detoxified by a yeast floc.ResultsDiffusion coefficients and first-order kinetic bioconversion rate coefficients were measured for three fermentation inhibitory compounds (furfural, hydroxymethylfurfural, and vanillin) in self-aggregated flocs of S. cerevisiae NRRL Y-265. Thièle-type moduli and internal effectiveness factors were obtained by simulating a simple steady-state spherical floc model.ConclusionsThe obtained values for the Thiéle moduli and internal effectiveness factors showed that the bioconversion rate of the inhibitory compounds is the dominant phenomenon over mass transfer inside the flocs.How to cite: Landaeta R, Acevedo F, Aroca G. Effective diffusion coefficients and bioconversion rates of inhibitory compounds in flocs of Saccharomyces cerevisiae. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.rjbt.2019.08.001 相似文献
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BackgroundMathematical modeling is useful in the analysis, prediction, and optimization of an enzymatic process. Unlike the conventional modeling methods, Monte Carlo method has special advantages in providing representations of the molecule’s spatial distribution. However, thus far, Monte Carlo modeling of enzymatic system is namely based on unimolecular basis, not suitable for practical applications. In this research, Monte Carlo modeling is performed for enzymatic hydrolysis of lactose for the purpose of real-time applications.ResultsThe enzyme hydrolysis of lactose, which is conformed to Michaelis–Menten kinetics, is modeled using the Monte Carlo modeling method, and the simulation results prove that the model predicts the reaction kinetics very well.ConclusionsMonte Carlo modeling method can be used to model enzymatic reactions in a simple way for real-time applications.How to cite: Gao L, Guo Q, Lin H, et al. Modeling of lactose enzymatic hydrolysis using Monte Carlo method. Electron J Biotechnol 2019;41.https://doi.org/10.1016/j.ejbt.2019.04.010 相似文献