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1.
BackgroundEthanol concentration (PE), ethanol productivity (QP) and sugar consumption (SC) are important values in industrial ethanol production. In this study, initial sugar and nitrogen (urea) concentrations in sweet sorghum stem juice (SSJ) were optimized for high PE (≥ 10%, v/v), QP, (≥ 2.5 g/L·h) and SC (≥ 90%) by Saccharomyces cerevisiae SSJKKU01. Then, repeated-batch fermentations under normal gravity (NG) and high gravity (HG) conditions were studied.ResultsThe initial sugar at 208 g/L and urea at 2.75 g/L were the optimum values to meet the criteria. At the initial yeast cell concentration of ~ 1 × 108 cells/mL, the PE, QP and SC were 97.06 g/L, 3.24 g/L·h and 95.43%, respectively. Repeated-batch fermentations showed that the ethanol production efficiency of eight successive cycles with and without aeration were not significantly different when the initial sugar of cycles 2 to 8 was under NG conditions (~ 140 g/L). Positive effects of aeration were observed when the initial sugar from cycle 2 was under HG conditions (180–200 g/L). The PE and QP under no aeration were consecutively lower from cycle 1 to cycle 6. Additionally, aeration affected ergosterol formation in yeast cell membrane at high ethanol concentrations, whereas trehalose content under all conditions was not different.ConclusionInitial sugar, sufficient nitrogen and appropriated aeration are necessary for promoting yeast growth and ethanol fermentation. The SSJ was successfully used as an ethanol production medium for a high level of ethanol production. Aeration was not essential for repeated-batch fermentation under NG conditions, but it was beneficial under HG conditions.How to cite: Sriputorn B, Laopaiboon P, Phukoetphim N, et al. Enhancement of ethanol production efficiency in repeated-batch fermentation from sweet sorghum stem juice: Effect of initial sugar, nitrogen and aeration. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.06.001 相似文献
2.
BackgroundOleaginous yeasts can be grown on different carbon sources, including lignocellulosic hydrolysate containing a mixture of glucose and xylose. However, not all yeast strains can utilize both the sugars for lipogenesis. Therefore, in this study, efforts were made to isolate dual sugar-utilizing oleaginous yeasts from different sources.ResultsA total of eleven isolates were obtained, which were screened for their ability to utilize various carbohydrates for lipogenesis. One promising yeast isolate Trichosporon mycotoxinivorans S2 was selected based on its capability to use a mixture of glucose and xylose and produce 44.86 ± 4.03% lipids, as well as its tolerance to fermentation inhibitors. In order to identify an inexpensive source of sugars, nondetoxified paddy straw hydrolysate (saccharified with cellulase), supplemented with 0.05% yeast extract, 0.18% peptone, and 0.04% MgSO4 was used for growth of the yeast, resulting in a yield of 5.17 g L−1 lipids with conversion productivity of 0.06 g L−1 h−1. Optimization of the levels of yeast extract, peptone, and MgSO4 for maximizing lipid production using Box–Behnken design led to an increase in lipid yield by 41.59%. FAME analysis of single cell oil revealed oleic acid (30.84%), palmitic acid (18.28%), and stearic acid (17.64%) as the major fatty acids.ConclusionThe fatty acid profile illustrates the potential of T. mycotoxinivorans S2 to produce single cell oil as a feedstock for biodiesel. Therefore, the present study also indicated the potential of selected yeast to develop a zero-waste process for the complete valorization of paddy straw hydrolysate without detoxification.How to cite: Sagia S, Sharma A, Singh S, et al. Single cell oil production by a novel yeast Trichosporon mycotoxinivorans for complete and ecofriendly valorization of paddy straw. Electronic Journal of Biotechnology 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.009. 相似文献
3.
BackgroundFuels and chemicals from renewable feedstocks have a growing demand, and acetone, butanol and ethanol (ABE) are some relevant examples. These molecules can be produced by the bacterial fermentation process using hydrolysates generated from lignocellulosic biomass as sugarcane bagasse, one of the most abundant sources of lignocellulosic biomass in Brazil. It originates as a residue in mills and distilleries in the production of sugar and ethanol.ResultsIn the present work, two strategies to generate hydrolysates of sugarcane bagasse were adopted. The fermentation of the first hydrolysate by Clostridium acetobutylicum DSM 6228 resulted in final concentrations of butanol, acetone and ethanol of 6.4, 4.5 and 0.6 g/L, respectively. On the other hand, the second hydrolysate presented better results (averages of 9.1, 5.5 and 0.8 g/L, respectively), even without the need for nutrient supplementation, since key elements were already present in the medium. The productivity (QP) and yield (YP/S) of the solvents with second hydrolysate were 0.5 g/L·h-1 and 0.4 g/g, respectively.ConclusionsThe results described herein open new perspectives for the production of important molecules from residual lignocellulosic biomass for the fuel and chemical industries within the context of second-generation biorefinery.How to cite: Gomes AC, Rodrigues MI, Passos DF, et al. Acetone-butanol-ethanol fermentation from sugarcane bagasse hydrolysates: utilization of C5 and C6 sugars. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.ejbt.2019.10.004. 相似文献
4.
BackgroundMicrobial oils produced by diverse microorganisms are being considered as alternative sources of triglycerides for biodiesel production. However, the standalone production of biodiesel from microorganisms is not currently economically feasible. In case of yeasts, the use of low-value nutrient sources in microbial production and the implementation of cost-efficient downstream processes could reduce costs and make microbial lipids competitive with other commodity-type oils in biodiesel production. Industrial biodiesel synthesis from oleaginous seeds is currently based on a multistep process. However, a simple process called in situ transesterification (ISTE), which takes place within the biomass without a previous lipid extraction step, is receiving increasing interest. In this work, the optimal conditions for an ISTE process to obtain biodiesel from previously selected oleaginous yeast (Rhodotorula graminis S1/S2) were defined using the response surface methodology (RSM).ResultsUsing the RSM approach, the optimal conditions for the maximum yield with minimum reaction time included a methanol-to-biomass ratio of 60:1, 0.4 M H2SO4, and incubation at 70°C for 3 h. The optimized in situ process yield was significantly higher (123%) than that obtained with a two-step method in which fatty acids from saponifiable lipids were first extracted and then esterified with methanol. The composition of the fatty acid methyl ester mixture obtained from R. graminis S1/S2 by ISTE met Uruguayan standards for biodiesel.ConclusionThe characteristics achieved by the optimized method make microbial oil a potential alternative for biodiesel production from yeast at an industrial scale.How to cite: Martinez-Silveira A, Villarreal R, Garmendia G, et al. Process conditions for a rapid in situ transesterification for biodiesel production from oleaginous yeasts. Electron J Biotechnol 2018;37. https://doi.org/10.1016/j.ejbt.2018.11.006. 相似文献
5.
BackgroundThis work studied how the exposure to an unusual substrate forced a change in microbial populations during anaerobic fermentation of crude glycerol, a by-product of biodiesel production, with freshwater sediment used as an inoculum.ResultsThe microbial associations almost completely (99.9%) utilized the glycerol contained in crude glycerol 6 g L−1 within four days, releasing gases, organic acids (acetic, butyric) and alcohols (ethanol, n-butanol) under anaerobic conditions. In comparison with control medium without glycerol, adding crude glycerol to the medium increased the amount of ethanol and n-butanol production and it was not significantly affected by incubation temperature (28 °C or 37 °C), nor incubation time (4 or 8 d), but it resulted in reduced amount of butyric acid. Higher volume of gas was produced at 37 °C despite the fact that the overall bacterial count was smaller than the one measured at 20 °C. Main microbial phyla of the inoculum were Actinobacteria, Proteobacteria and Firmicutes. During fermentation, significant changes were observed and Firmicutes, especially Clostridium spp., began to dominate, and the number of Actinobacteria and Gammaproteobacteria decreased accordingly. Concentration of Archaea decreased, especially in medium with crude glycerol. These changes were confirmed both by culturing and culture-independent (concentration of 16S rDNA) methods.ConclusionsCrude glycerol led to the adaptation of freshwater sediment microbial populations to this substrate. Changes of microbial community were a result of a community adaptation to a new source of carbon.How to cite: Paiders M, Nikolajeva V, Makarenkova G, et al. Changes in freshwater sediment microbial populations during fermentation of crude glycerol. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.10.007 相似文献
6.
BackgroundProdigiosin has been demonstrated to be an important candidate in investigating anticancer drugs and in many other applications in recent years. However, industrial production of prodigiosin has not been achieved. In this study, we found a prodigiosin-producing strain, Serratia marcescens FZSF02, and its fermentation strategies were studied to achieve the maximum yield of prodigiosin.ResultsWhen the culture medium consisted of 16.97 g/L of peanut powder, 16.02 g/L of beef extract, and 11.29 mL/L of olive oil, prodigiosin reached a yield of 13.622 ± 236 mg/L after culturing at 26 °C for 72 h. Furthermore, when 10 mL/L olive oil was added to the fermentation broth at the 24th hour of fermentation, the maximum prodigiosin production of 15,420.9 mg/L was obtained, which was 9.3-fold higher than the initial level before medium optimization. More than 60% of the prodigiosin produced with this optimized fermentation strategy was in the form of pigment pellets. To the best of our knowledge, this is the first report on this phenomenon of pigment pellet formation, which made it much easier to extract prodigiosin at low cost. Prodigiosin was then purified and identified by absorption spectroscopy, HPLC, and LCMS. Purified prodigiosin obtained in this study showed anticancer activity in separate experiments on several human cell cultures: A549, K562, HL60, HepG2, and HCT116.ConclusionsThis is a promising strain for producing prodigiosin. The prodigiosin has potential in anticancer medicine studies.How to cite: Lin C, Jia X, Fang Y, et al. Enhanced production of prodigiosin by Serratia marcescens FZSF02 in the form of pigment pellets. Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.04.007 相似文献
7.
BackgroundFermentation process development has been very important for efficient ethanol production. Improvement of ethanol production efficiency from sweet sorghum juice (SSJ) under normal gravity (NG, 160 g/L of sugar), high gravity (HG, 200 and 240 g/L of sugar) and very high gravity (VHG, 280 and 320 g/L of sugar) conditions by nutrient supplementation and alternative feeding regimes (batch and fed-batch systems) was investigated using a highly ethanol-tolerant strain, Saccharomyces cerevisiae NP01.ResultsIn the batch fermentations without yeast extract, HG fermentation at 200 g/L of sugar showed the highest ethanol concentration (PE, 90.0 g/L) and ethanol productivity (QE, 1.25 g/L·h). With yeast extract supplementation (9 g/L), the ethanol production efficiency increased at all sugar concentrations. The highest PE (112.5 g/L) and QE (1.56 g/L·h) were observed with the VHG fermentation at 280 g/L of sugar. In the fed-batch fermentations, two feeding regimes, i.e., stepwise and continuous feedings, were studied at sugar concentrations of 280 g/L. Continuous feeding gave better results with the highest PE and QE of 112.9 g/L and 2.35 g/L·h, respectively, at a feeding time of 9 h and feeding rate of 40 g sugar/h.ConclusionsIn the batch fermentation, nitrogen supplementation resulted in 4 to 32 g/L increases in ethanol production, depending on the initial sugar level in the SSJ. Under the VHG condition, with sufficient nitrogen, the fed-batch fermentation with continuous feeding resulted in a similar PE and increased QP by 51% compared to those in the batch fermentation. 相似文献
8.
BackgroundFoods including probiotics are considered “functional foods.” As an alternative to dairy products, we investigated the behavior of Lactobacillus casei when exposed to low-pH fruit juice. Juices of fruits such as pineapple, raspberry, and orange were assessed. Free and microencapsulated forms of L. casei were compared, and the viability of the probiotic was evaluated under storage at 4°C for 28 d. Microbiological analyses were carried out to ensure a safe and healthy product for consumers who look for foods with probiotics from sources other than dairy.ResultsLow pH affected L. casei survival during storage depending on the type of fruit juice. In the case of pineapple juice, some microcapsules were broken, but microcapsules recovered at the end of the storage period had 100% viability (2.3 × 107 CFU/g spheres). In the case of orange juice, more than 91% viability (5.5 × 106 CFU/g spheres) was found. In raspberry juice, viability decreased rapidly, disappearing at the end of the storage period, which was caused by the absorption of high concentrations of anthocyanin inside microcapsules more than low pH.ConclusionLow pH affected the survival of L. casei under refrigeration; even when they were microencapsulated, acidic conditions impacted their viability. Although pH affects viability, its value is very sensitive and will depend on the type of fruit juice and its composition. Some fruit juices contain compounds used as substrates for Lactobacillus and other compounds with antimicrobial effects.How to cite: Olivares A, Soto C, Caballero E, et al. Survival of microencapsulated Lactobacillus casei (prepared by vibration technology) in fruit juice during cold storage. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.ejbt.2019.10.002. 相似文献
9.
BackgroundBiotechnological processes are part of modern industry as well as stricter environmental requirements. The need to reduce production costs and pollution demands for alternatives that involve the integral use of agro-industrial waste to produce bioactive compounds. The citrus industry generates large amounts of wastes due to the destruction of the fruits by microorganisms and insects together with the large amounts of orange waste generated during the production of juice and for sale fresh. The aim of this study was used orange wastes rich in polyphenolic compounds can be used as source carbon of Aspergillus fumigatus MUM 1603 to generate high added value compounds, for example, ellagic acid and other molecules of polyphenolic origin through submerged fermentation system.ResultsThe orange peel waste had a high concentration of polyphenols, 28% being condensed, 27% ellagitannins, 25% flavonoids and 20% gallotannins. The major polyphenolic compounds were catechin, EA and quercetin. The conditions, using an experimental design of central compounds, that allow the production of the maximum concentration of EA (18.68 mg/g) were found to be: temperature 30°C, inoculum 2 × 107 (spores/g) and orange peel polyphenols 6.2 (g/L).ConclusionThe submerged fermentation process is an effective methodology for the biotransformation of molecules present in orange waste to obtain high value-added as ellagic acid that can be used as powerful antioxidants, antibacterial and other applications.How to cite: Sepúlveda L, Laredo-Alcalá E, Buenrostro-Figueroa JJ, et al. Ellagic acid production using polyphenols from orange peel waste by submerged fermentation. Electron J Biotechnol 2020;43. https://doi.org/10.1016/j.ejbt.2019.11.002. 相似文献
10.
BackgroundThe use of agro-industrial wastes to produce high value-added biomolecules such as biosurfactants is a promising approach for lowering the total costs of production. This study aimed to produce biosurfactants using Rhizopus arrhizus UCP 1607, with crude glycerol (CG) and corn steep liquor (CSL) as substrates. In addition, the biomolecule was characterized, and its efficiency in removing petroderivatives from marine soil was investigated.ResultsA 22 factorial design was applied, and the best condition for producing the biosurfactant was determined in assay 4 (3% CG and 5% CSL). The biosurfactant reduced the surface tension of water from 72 to 28.8 mN/m and produced a yield of 1.74 g/L. The preliminary biochemical characterization showed that the biosurfactant consisted of proteins (38.0%), carbohydrates (35.4%), and lipids (5.5%). The compounds presented an anionic character, nontoxicity, and great stability for all conditions tested. The biomolecule displayed great ability in dispersing hydrophobic substrates in water, thereby resulting in 53.4 cm2 ODA. The best efficiency of the biosurfactant in removing the pollutant diesel oil from marine soil was 79.4%.ConclusionsThis study demonstrated the ability of R. arrhizus UCP1607 to produce a low-cost biosurfactant characterized as a glycoprotein and its potential use in the bioremediation of the hydrophobic diesel oil pollutant in marine soil.How to cite: Pele MA, Ribeaux DR, Vieira ER, et al. Conversion of renewable substrates for biosurfactant production by Rhizopus arrhizus UCP 1607 and enhancing the removal of diesel oil from marine soil. Electron J Biotechnol 2019;38. https://doi.org/10.1016/j.ejbt.2018.12.003. 相似文献
11.
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
12.
BackgroundMicroalgae are aquatic chlorophyll-containing organisms comprising unicellular microscopic forms, and their biomasses are potential sources of bioactive compounds, biofuels and food-based products. However, the neuroprotective effects of microalgal biomass have not been fully explored. In this study, biomass from two Chlorella species was characterized, and their antioxidant, anticholinesterase and anti-amyloidogenic activities were investigated.ResultsGC–MS analysis of the extracts revealed the presence of some phenols, sterols, steroids, fatty acids and terpenes. Ethanol extract of Chlorella sorokiniana (14.21 mg GAE/g) and dichloromethane extract of Chlorella minutissima (20.65 mg QE/g) had the highest total phenol and flavonoid contents, respectively. All the extracts scavenged 2,2-diphenyl-1-picrylhydrazyl, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) and hydroxyl radicals. The highest metal chelating activity of the extracts was observed in the ethanol extracts of C. minutissima (102.60 μg/mL) and C. sorokiniana (107.84 μg/mL). Furthermore, the cholinesterase inhibitory activities of the extracts showed that ethanol extract of C. sorokiniana (13.34 μg/mL) exhibited the highest acetylcholinesterase inhibitory activity, while dichloromethane extract of C. minutissima (11.78 μg/mL) showed the highest butyrylcholinesterase inhibitory activity. Incubation of the β-amyloid protein increased the aggregation of amyloid fibrils after 96 h. However, ethanol extract of C. sorokiniana and C. minutissima inhibited further aggregation of Aβ1–42 and caused disaggregation of matured protein fibrils compared to the control. This study reveals the modulatory effects of C. sorokiniana and C. minutissima extracts on some mediators of Alzheimer's disease and provides insights into their potential benefits as functional food, nutraceutics or therapeutic agent for the management of this neurodegenerative disease.How to cite: Olasehinde T, Odjadjare EC, Mabinya LV, et al. Chlorella sorokiniana and Chlorella minutissima exhibit antioxidant potentials, inhibit cholinesterases and modulate disaggregation of β-amyloid fibrils. Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.03.008 相似文献
13.
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
14.
BackgroundAmmonium stress is a prime limiting phenomenon that occurs during methane formation from poultry manure. It is caused by elevated ammonium nitrogen concentrations that result from substrate decomposition. The amounts of methane formed depend on the activity of methanogenic microbes.ResultsDuring the research reported in this paper, the response of a mesophilic consortium inhabiting a biogas reactor to rising load of poultry manure was investigated. The taxonomic composition of bacterial population was mostly typical, however syntrophic bacteria were not detected. This absence resulted in limitation of succession of some methanogenic microorganisms, especially obligate hydrogenotrophs. The methanogenic activity of the consortium was totally dependent on the activity of Methanosaeta. Inhibition of methanoganesis was noticed at ammonium nitrogen concentration of 3.68 g/L, total cessation occurred at 5.45 g/L. Significant amounts of acetic acid in the fermentation pulp accompanied the inhibition.ConclusionsThe effectiveness of the consortium was totally dependent on the metabolic activity of the acetoclastic Methanoseata genus and lack of SAOB did not allow hydrogenotrophic methanogens to propagate and lead to cessation of biogas production at an elevated ammonium concentration at which acetoclastic methanogens were inhibited.How to cite: Świątek M, Lewicki A, Szymanowska D, et al. The effect of introduction of chicken manure on the biodiversity and performance of an anaerobic digester. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.11.002. 相似文献
15.
BackgroundThe increasing rate of breast cancer globally requires extraordinary efforts to discover new effective sources of chemotherapy with fewer side effects. Glutaminase-free l-asparaginase is a vital chemotherapeutic agent for various tumor malignancies. Microorganisms from extreme sources, such as marine bacteria, might have high l-asparaginase productivity and efficiency with exceptional antitumor action toward breast cancer cell lines.Resultsl-Asparaginase-producing bacteria, Bacillus velezensis isolated from marine sediments, were identified by 16S rRNA sequencing. l-Asparaginase production by immobilized cells was 61.04% higher than that by free cells fermentation. The significant productivity of enzyme occurred at 72 h, pH 6.5, 37°C, 100 rpm. Optimum carbon and nitrogen sources for enzyme production were glucose and NH4Cl, respectively. l-Asparaginase was free from glutaminase activity, which was crucial medically in terms of their severe side effects. The molecular weight of the purified enzyme is 39.7 KDa by SDS-PAGE analysis and was ideally active at pH 7.5 and 37°C. Notwithstanding, the highest stability of the enzyme was found at pH 8.5 and 70°C for 1 h. The enzyme kinetic parameters displayed Vmax at 41.49 μmol/mL/min and a Km of 3.6 × 10−5 M, which serve as a proof of the affinity to its substrate. The anticancer activity of the enzyme against breast adenocarcinoma cell lines demonstrated significant activity toward MDA-MB-231 cells when compared with MCF-7 cells with IC50 values of 12.6 ± 1.2 μg/mL and 17.3 ± 2.8 μg/mL, respectively.ConclusionThis study provides the first potential of glutaminase-free l-asparaginase production from the marine bacterium Bacillus velezensis as a prospect anticancer pharmaceutical agent for two different breast cancer cell lines.How to cite: Mostafa Y, Alrumman S, Alamri S, et al. Enhanced production of glutaminase-free L-asparaginase by marine Bacillus velezensis and cytotoxic activity against breast cancer cell lines. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.ejbt.2019.10.001. 相似文献
16.
BackgroundMethanol can be effectively removed from air by biofiltration. However, formaldehyde is one of the first metabolic intermediates in the consumption of methanol in methylotrophic microorganisms, and it can be released out of the cell constituting a secondary emission.ResultsThe total removal of methanol was achieved up to input loads of 263 g m−3 h−1 and the maximum elimination capacity of the system was obtained at an empty bed residence times of 90 s and reached 330 g m−3 h−1 at an input methanol load of 414 g m−3 h−1 and 80% of removal efficiency. Formaldehyde was detected inside the biofilter when the input methanol load was above 212 g m−3 h−1. Biomass in the filter bed was able to degrade the formaldehyde generated, but with the increase of the methanol input load, the unconsumed formaldehyde was released outside the biofilter. The maximum concentration registered at the output of the system was 3.98 g m−3 when the methanol load was 672 g m−3 h−1 in an empty bed residence times of 60 s.ConclusionsFormaldehyde is produced inside a biofilter when methanol is treated in a biofiltration system inoculated with Pichia pastoris. Biomass present in the reactor is capable of degrading the formaldehyde generated as the concentration of methanol decreases. However, high methanol loads can lead to the generation and release of formaldehyde into the environment.How to cite: Guerrero K, Arancibia A, Cáceres M, et al. Release of formaldehyde during the biofiltration of methanol vapors in a peat biofilter inoculated with Pichia pastoris GS115. Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.04.003. 相似文献
17.
BackgroundSalep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation.ResultThe OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source.ConclusionsBifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.How to cite: Usta-Gorgun B, Yilmaz-Ersan L. Short-chain fatty acid production by the Bifidobacterium species in the presence of salep. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.06.004. 相似文献
18.
BackgroundBioremoval of phenolic compounds using fungi and bacteria has been studied extensively; nevertheless, trinitrophenol bioremediation using modified Oscillatoria cyanobacteria has been barely studied in the literature.ResultsAmong the effective parameters of bioremediation, algal concentration (3.18 g·L−1), trinitrophenol concentration (1301 mg·L−1), and reaction time (3.75 d) were screened by statistical analysis. Oscillatoria cyanobacteria were modified by starch/nZVI and starch/graphene oxide in a bubble column bioreactor, and their bioremoval efficiency was investigated. Modifiers, namely, starch/zero-valent iron and starch/GO, increased trinitrophenol bioremoval efficiency by more than 10% and 12%, respectively, as compared to the use of Oscillatoria cyanobacteria alone.ConclusionsIt was found that starch/nano zero-valent iron and starch/GO could be applied to improve the removal rate of phenolic compounds from the aqueous solution.How to cite: Bavandi R, Emtyazjoo M, Saravi HN, et al. Study of nano-structure zero-valent iron and graphene-oxid capability onbioremoval of trinitrophenol from wastewater in a bubble column bioreactor. Electron J Biotechnol 2019;39. https://doi.org/10.1016/j.ejbt.2019.02.003. 相似文献
19.
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
20.
Biosurfactant produced by Candida utilis UFPEDA1009 with potential application in cookie formulation
BackgroundBiosurfactants are biomolecules that have the potential to be applied in food formulations due to their low toxicity and ability to improve sensory parameters. Considering the ability of yeasts to produce biosurfactants with food-friendly properties, the aim of the present study was to apply a biosurfactant produced by Candida utilis in the formulation of cookies.ResultsThe biosurfactant was obtained with a yield of 24.22 ± 0.23 g/L. The characterization analysis revealed that the structure of a metabolized fatty acid with high oleic acid content (68.63 ± 0.61%), and the thermogravimetric analysis demonstrated good stability at temperatures lower than 200°C, potential for food applications. The biosurfactant also exhibited satisfactory antioxidant activity at concentrations evaluated, without cytotoxic potential for cell strains, L929 and RAW 264.7, according to the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The incorporation of the surfactant into the dough of a standard cookie formulation to replace animal fat was carried out, achieving a softer, spongier product without significantly altering the physical and physicochemical properties or energy value.ConclusionThe thermal stability and antioxidant activity of the biosurfactant produced by C. utilis were verified, besides the positive contribution in the texture analysis of the cookies. Therefore, this biomolecule presents itself as a potential ingredient in flour-based sweet food formulations. How to cite: Ribeiro BG, de Veras BO, Aguiar JS, et al. Biosurfactant produced by Candida utilis UFPEDA1009 with potential application in cookie formulation. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.05.001. 相似文献