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1.
Bioprocess Biosyst Eng ; 46(6): 839-850, 2023 Jun.
Article En | MEDLINE | ID: mdl-37004559

Eucheuma denticulatum is a red macroalgae with a high carbohydrate content. The fermentable sugars from E. denticulatum were obtained through sequential thermal acid hydrolysis, enzymatic saccharification, and detoxification. Thermal acid hydrolysis of E. denticulatum was optimized under the condition of 10% (w/v) slurry content and 300 mM HNO3 at 121 â„ƒ for 90 min. The maximum monosaccharide concentration after thermal acid hydrolysis was 31.0 g/L with an efficiency (ETAH) of 44.7%. By further enzymatic hydrolysis of pretreated biomass solution under 20 U/mL Cellic CTec2 at 50 â„ƒ and 160 rpm for 72 h, the maximum monosaccharide concentration reached 79.9 g/L with an efficiency of 66.2% (ES). To remove 5-hydroxymethylfurfural (5-HMF), a fermentation inhibitor, absorption using 2% activated carbon was performed for 2 min. Ethanol fermentation was performed using wild-type and high galactose-adapted strains of Saccharomyces cerevisiae, Kluyveromyces marxianus, and Candida lusitaniae. As a result, galactose-adapted strains showed higher ethanol production than wild-type strains. Especially, the fermentation result by adaptively evolved S. cerevisiae produced the highest ethanol of 37.6 g/L and with YEtOH of 0.48 g/g. Moreover, the transcript level of MIG1 in the galactose-adapted strain was slightly lower than that in the wild-type strain. The application of adaptive evolution of microorganisms was efficient for bioethanol production.


Galactose , Rhodophyta , Saccharomyces cerevisiae , Monosaccharides , Fermentation , Hydrolysis , Ethanol , Biomass
2.
Glob Pediatr Health ; 10: 2333794X231159224, 2023.
Article En | MEDLINE | ID: mdl-36873558

Purpose: The prevalence of autism spectrum disorder in children, who show problems in social development, is increasing rapidly. If children watch media at an early age, they lose the time to interact with their parents and will not be able to play creatively, which can have a negative impact on social development. This study was performed to evaluate the association of media exposure with social developmental delay. Methods: The sample consisted of 96 patients with social developmental delay who visited the developmental disorder clinic from July 2013 to April 2019. The control group included 101 children who visited our developmental clinic with normal developmental screening test results during the same period. The data were collected using self-reported questionnaires with questions regarding media exposure time, content, background media or foreground media, the age of first exposure, and media exposure with or without parents. Results: In regard to media exposure time, 63.5% of the social developmental delay patients were exposed to media for more than 2 hours a day compared to 18.8% of the control group (P < .001, [OR] = 8.12). In the risk factor analysis of media exposure on social development, male gender, media exposure before 2 years of age, exposure for more than 2 hours, and exposure alone without parents were statistically significant. Conclusion: Media exposure was a significant risk factor for social developmental delay.

3.
J Clin Neurol ; 17(3): 354-362, 2021 Jul.
Article En | MEDLINE | ID: mdl-34184442

BACKGROUND AND PURPOSE: Cerebral visual impairment (CVI) is an underdiagnosed condition in children, and its assessment tools have focused on older children. We aimed to develop a parental questionnaire for cerebral visual impairment (PQCVI) for screening CVI in young children. METHODS: The PQCVI comprised 23 questions based on a modified version of Houliston and Dutton's questionnaire for older children. The PQCVI with neurocognitive function tests was applied to 201 child-parent pairs with typically developing children younger than 72 months (age 32.4±20.1 months, mean±standard deviation). The children were classified into six age groups. The normative data, cutoff scores, and internal reliability were assessed and item analysis was performed. We referred to the total score for all questions as the cerebral visual function (CVF) score. RESULTS: The normative data showed that the CVF score and the scores corresponding to ventral-stream and dorsal-stream visual functions plausibly increased with age. The scores rapidly reached 90% of their maximum values up to the age of 36 months, after which they increased slowly. Cronbach's alpha for all questions across all age groups was 0.97, showing excellent consistency. The item difficulty and item discrimination coefficients showed that the questions were generally adequate for this age stage. CONCLUSIONS: The PQCVI items produced reliable responses in children younger than 72 months. The rapid increase in scores before the age of 3 years supports the importance of early identification of CVI. Following additional clinical verification, the PQCVI may be useful for CVI screening.

4.
Bioprocess Biosyst Eng ; 44(10): 2099-2108, 2021 Oct.
Article En | MEDLINE | ID: mdl-34032903

Lactic acid bacteria (Lactobacillus plantarum KCTC 3103) were fermented to produce gamma-aminobutyric acid (GABA). The conditions of the modified synthetic medium were optimized as 5 g/L glucose, 10 g/L yeast extract, 100 g/L rice bran extract, and 1.0 g/L ascorbic acid for GABA production. Single-step fermentation of cell growth and GABA production with a modified synthetic medium was higher than those with an MRS medium. Two-step fermentation was evaluated by separating the cell growth and GABA production under a modified synthetic medium. The cell concentration of 1.65 g dcw/L produced by the modified synthetic medium was higher than that of 1.0 g dcw/L produced by the MRS medium at 36 h from the first step of two-step fermentation. The highest GABA production of L. plantarum KCTC 3103 was 0.67 g/L with monosodium glutamate addition at 60 h in the second step of fermentation. Two-step fermentation with the modified synthetic medium is suitable for GABA production because of its high GABA productivity and favorable cell growth.


Fermentation , Lactobacillus plantarum/metabolism , gamma-Aminobutyric Acid/biosynthesis , Ascorbic Acid/metabolism , Culture Media , Oryza/metabolism , Plant Extracts/metabolism
5.
J Biotechnol ; 333: 1-9, 2021 Jun 10.
Article En | MEDLINE | ID: mdl-33878391

Glucose and galactose are monosaccharides obtained from Gloiopeltis furcata (Red algae). A total monosaccharide yield of 62.3 g/L was obtained from G. furcata using thermal acid hydrolysis and enzymatic saccharification. Activated carbon was used to eliminate hydroxymethylfurfural (HMF) from the hydrolysate. Previously obtained monosaccharides are used for ethanol production by Saccharomyces cerevisiae. S. cerevisiae consumes glucose first, then galactose. The methods for reducing fermentation time and increasing the ethanol yield coefficient using the simultaneous consumption of glucose and galactose have been evaluated. Gal3p and Gal80p of S. cerevisiae act as signal transducers that govern the galactose inducer Gal4p mediated transcriptional activation of the Gal gene family. Gal80p binds to Gal4p for transcription deactivation. Therefore, Gal80p was deleted for Gal4p expression without interruption.


Rhodophyta , Saccharomyces cerevisiae Proteins , Seaweed , Ethanol , Galactose , Genes, Regulator , Repressor Proteins/genetics , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Transcription Factors/genetics
6.
Clin Exp Pediatr ; 64(10): 497-503, 2021 Oct.
Article En | MEDLINE | ID: mdl-33677854

Reading disability (dyslexia) refers to an unexpected difficulty with reading for an individual who has the intelligence to be a much better reader. Dyslexia is most commonly caused by a difficulty in phonological processing (the appreciation of the individual sounds of spoken language), which affects the ability of an individual to speak, read, and spell. In this paper, I describe reading disabilities by focusing on their underlying neurobiological mechanisms. Neurobiological studies using functional brain imaging have uncovered the reading pathways, brain regions involved in reading, and neurobiological abnormalities of dyslexia. The reading pathway is in the order of visual analysis, letter recognition, word recognition, meaning (semantics), phonological processing, and speech production. According to functional neuroimaging studies, the important areas of the brain related to reading include the inferior frontal cortex (Broca's area), the midtemporal lobe region, the inferior parieto-temporal area, and the left occipitotemporal region (visual word form area). Interventions for dyslexia can affect reading ability by causing changes in brain function and structure. An accurate diagnosis and timely specialized intervention are important in children with dyslexia. In cases in which national infant development screening tests have been conducted, as in Korea, if language developmental delay and early predictors of dyslexia are detected, careful observation of the progression to dyslexia and early intervention should be made.

7.
J Microbiol Biotechnol ; 31(3): 456-463, 2021 Mar 28.
Article En | MEDLINE | ID: mdl-33323671

In this study, the culture conditions for Porphyridium cruentum were optimized to obtain the maximum biomass and lipid productions. The eicosapentaenoic acid content was increased by pH optimization. P. cruentum was cultured with modified F/2 medium in 14-L photobioreactors using a two-phase culture system, in which the green (520 nm) and red (625 nm) light-emitting diodes (LEDs) were used during the first and second phases for biomass production and lipid production, respectively. Various parameters, including aeration rate, light intensity, photoperiod, and pH were optimized. The maximum biomass concentration of 0.91 g dcw/l was obtained with an aeration rate of 0.75 vvm, a light intensity of 300 µmol m-2s-1, and a photoperiod of 24:0 h. The maximum lipid production of 51.8% (w/w) was obtained with a light intensity of 400 µmol m-2s-1 and a photoperiod of 18:6 h. Additionally, the eicosapentaenoic acid and unsaturated fatty acid contents reached 30.6% to 56.2% at pH 6.0.


Fatty Acids, Unsaturated/biosynthesis , Lipids/biosynthesis , Photobioreactors , Porphyridium/metabolism , Biomass , Hydrogen-Ion Concentration , Light , Microalgae/growth & development , Microalgae/metabolism , Photoperiod , Porphyridium/growth & development
8.
J Biotechnol ; 326: 40-47, 2021 Jan 20.
Article En | MEDLINE | ID: mdl-33359212

The optimal conditions for high biomass and lipid production from Nannochloris atomus were evaluated. The parameters used in this study were light emitting diode (LED) wavelength mixing ratio, the photoperiod, salinity tolerance, and single and combined stresses. Biomass production was monitored in the first phase using red LED (625 nm), followed by lipid production by green LED (520 nm) in the second phase. The optimal conditions were obtained using a single red LED with light:dark durations of 20:4 h and two days of exposure in combined stresses of 1.06 M NaCl and green LED. Under these conditions, 68.6 % (w/w) lipid content were obtained. Compared to the non-stress control, the lipid content was increased by 31.9 %. Linolenic acid (C18:3) the omega-3 fatty acid was produced up to 52.4 % in 1.06 M NaCl as a single stress.


Chlorophyta , Microalgae , Biomass , Light , Lipids
9.
Appl Biochem Biotechnol ; 193(2): 335-348, 2021 Feb.
Article En | MEDLINE | ID: mdl-32959326

A total 42.68 g/L monosaccharide with 0.10 g/L HMF was obtained from 10% (w/v) Kappaphycus alvarezii with thermal acid hydrolysis using 350 mM HNO3 at 121 °C for 60 min and enzymatic saccharification with a 1:1 mixture of Viscozyme L and Celluclast 1.5 L for 72 h. To enhance the galactose utilization rate, fermentation was performed with overexpression of GAL1 (galactokinase), GAL7 (galactose-1-phosphate uridyltransferase), GAL10 (UDP-glucose-4-epimerase), and PGM2 (phosphoglucomutase 2) in Saccharomyces cerevisiae CEN.PK2 using CCW12 as a strong promoter. Among the strains, the overexpression of PGM2 showed twofold high galactose utilization rate (URgal) and produced ethanol 1.4-fold more than that of the control. Transcriptional analysis revealed the increase of PGM2 transcription level leading to enhance glucose-6-phosphate and fructose-6-phosphate and plays a key role in ensuring a higher glycolytic flux in the PGM2 strain. This finding shows particular importance in biofuel production from seaweed because galactose is one of the major monosaccharides in seaweeds such as K. alvarezii.


Galactose/metabolism , Gene Expression Regulation, Fungal , Plant Extracts/chemistry , Rhodophyta/chemistry , Saccharomyces cerevisiae Proteins/biosynthesis , Saccharomyces cerevisiae/metabolism , Galactose/chemistry
10.
Appl Biochem Biotechnol ; 193(2): 577-588, 2021 Feb.
Article En | MEDLINE | ID: mdl-33043399

This study was aimed at enhancing galactose consumption from the red seaweed Kappaphycus alvarezii. The optimal pretreatment condition of thermal acid hydrolysis was treated with 350 mM HNO3 for 60 min at 121 °C. The enzymatic saccharification with a 1:1 mixture of Celluclast 1.5 L and Viscozyme L showed the maximum yield of glucose; 42-g/L monosaccharide concentration was obtained with the highest yield of pretreatment and enzymatic saccharification (EPS) and the lowest inhibitory compound concentration. The deletion of the GAL80, MIG1, CYC8, or TUP1 gene was performed to improve the galactose consumption rate. The strains with the deletion of the MIG1 gene (mig1Δ) showed higher galactose consumption rate and ethanol yield than other strains. High transcription levels of regulatory genes revealed that the mig1Δ relieved glucose repression. These results show that the mig1Δ enhances galactose consumption rate from K. alvarezii.


Galactose , Gene Deletion , Rhodophyta/chemistry , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae , Galactose/chemistry , Galactose/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism
11.
Appl Biochem Biotechnol ; 193(2): 502-514, 2021 Feb.
Article En | MEDLINE | ID: mdl-33026615

Ethanol was produced by separate hydrolysis and fermentation using Azolla filiculoides as a biomass. Thermal acid hydrolysis and enzymatic saccharification were used as pretreatment methods to produce monosaccharides from Azolla. The optimal content for thermal acid hydrolysis of 14% (w/v) Azolla weed slurry produced 16.7-g/L monosaccharides by using 200 mM H2SO4 at 121 °C for 60 min. Enzymatic saccharification using 16 U/mL Viscozyme produced 61.6 g/L monosaccharide at 48 h. Ethanol productions with ethanol yield coefficients from Azolla weed hydrolysate using Kluyveromyces marxianus, Candida lusitaniae Saccharomyces cerevisiae, and Pichia stipitis were 26.8 g/L (YEtOH = 0.43), 23.2 g/L (YEtOH = 0.37), 18.2 g/L (YEtOH = 0.29), and 13.7 g/L (YEtOH = 0.22), respectively. Saccharomyces cerevisiae produces the lowest yield as it utilized only glucose. Bioethanol from Azolla weed hydrolysate can be successfully produced by using Kluyveromyces marxianus because it consumed the mixture of glucose and xylose completely within 60 h.


Biomass , Candida/growth & development , Ethanol/metabolism , Ferns/chemistry , Kluyveromyces/growth & development , Saccharomyces cerevisiae/growth & development , Saccharomycetales/growth & development
12.
Front Neurol ; 11: 569486, 2020.
Article En | MEDLINE | ID: mdl-33133008

Introduction: Epilepsy and migraines are frequently observed as comorbidities, with the occurrence of one disorder increasing the probability of the other. The aim of our study was to evaluate the EEG characteristics by the type of headache and the implications of EEGs in headache patients, comparing the clinical characteristics and treatments between the headache patients with normal and abnormal EEGs. Methods: We conducted a retrospective analysis reviewing the medical records of 259 patients with headaches who visited the pediatrics departments of five university hospitals and underwent EEGs over a period of 3 years. Based on the data entered, analyses of the following items were conducted: (1) comparison of the EEG abnormalities by the type of headache and the characteristics of the EEG findings and (2) comparison of the clinical characteristics between patients with normal and abnormal EEGs. Results: Of the 259 patients, 31 showed abnormal EEGs, while 228 had normal EEGs. Of the 31 patients with abnormal EEGs, 17 showed epileptiform discharges, and 11 showed rhythmic slowing. The frequency of EEG abnormalities was significantly high in patients with migraines with auras than other types of headache. The Pediatric Migraine Disability Assessment (PedMIDAS) score was significantly higher in the abnormal EEG group compared with the normal EEG group (p = 0.001). Conclusion: The results of this study suggest that the abnormal EEG group had more significant disruptions in their daily lives due to headaches than the normal EEG group and that patients with migraines with aura may need EEGs and they might also have overlapping pathophysiologic mechanisms with epilepsy.

13.
Environ Res ; 189: 109901, 2020 10.
Article En | MEDLINE | ID: mdl-32980001

Early life exposures to lead (Pb) and mercury (Hg) were reported to be associated with various adverse health outcomes. However, limited data was available for urinary Pb and Hg levels in young children and the proportion of children at risk by age, as well as inter- and intra-subject variations of urinary Pb and Hg levels. Therefore, we collected total 491 urine samples from 241 children by urine collection at birth and at intervals of 3 months until 27 months of age for each child (at 10 monitoring time points), measured urinary Pb and Hg levels, and then evaluated the proportion of children at risk by age and the intra-class correlation (ICC) of the urinary Pb and Hg levels. Both the urinary Pb and Hg levels were significantly different according to the monitoring time points (p < 0.0001 for both Pb and Hg). The number of children with Hg level over the Human BioMonitoring (HBM) I (7 µg/L) and II (25 µg/L) in the first urine at birth were 3 (2.2%) and 1 (0.7%), respectively, while the urinary samples at the other time points did not show Hg level over HBM I or HBM II. However, the exceedance rate for urinary Pb based on HBM values was not calculated due to unavailable HBM values. On the other hands, the proportion of the children with Pb and Hg levels over the reference value derived on the 95th percentile of representative samples (RV95) (1.7 µg/L for Canadian Pb and 0.4 µg/L for German Hg) was relatively high, ranging from 20.0% to 100.0% for Pb and from 13.6% to 100.0% for Hg. The ICC of the repeated measurements from birth to 27 months was 0 for Pb and 0.89 for Hg, while the ICC after the exclusion of the first urine at birth was 0.13 for Pb and 0.47 for Hg. Furthermore, the Pb and Hg exposures were consistent among the high-exposure group for Pb and among all population for Hg. Our data showed Korean children were exposed to relatively high levels of Pb and Hg. However, our Pb and Hg levels in children were based on only urine samples without urinary correction and without consideration of the levels in any other bio-samples such as bloods. Therefore, to explore the Pb and Hg exposures using urine samples warrant further investigation with large sample size considering urinary correction and other bio-samples in the future.


Lead , Mercury , Biological Monitoring , Canada , Child , Child, Preschool , Environmental Monitoring , Humans , Mercury/analysis
14.
J Microbiol Biotechnol ; 30(12): 1912-1918, 2020 Dec 28.
Article En | MEDLINE | ID: mdl-32958731

Hyper-thermal (HT) acid hydrolysis of red seaweed Gelidium amansii was performed using 12% (w/v) slurry and an acid mix concentration of 180 mM at 150°C for 10 min. Enzymatic saccharification when using a combination of Celluclast 1.5 L and CTec2 at a dose of 16 U/ml led to the production of 12.0 g/l of reducing sugar with an efficiency of enzymatic saccharification of 13.2%. After the enzymatic saccharification, 2,3-butanediol (2,3-BD) fermentation was carried out using an engineered S. cerevisiae strain. The use of HT acid-hydrolyzed medium with 1.9 g/l of 5-hydroxymethylfurfural showed a reduction in the lag time from 48 to 24 h. The 2,3-BD concentration and yield coefficient at 72 h were 14.8 g/l and 0.30, respectively. Therefore, HT acid hydrolysis and the use of the engineered S. cerevisiae strain can enhance the overall 2,3-BD yields from G. amansii seaweed.


Butylene Glycols/metabolism , Rhodophyta/metabolism , Saccharomyces cerevisiae/metabolism , Seaweed/metabolism , Acids , Carbohydrates , Fermentation , Furaldehyde/analogs & derivatives , Hydrolysis , Metabolic Engineering , Saccharomyces cerevisiae/genetics
15.
Clin Exp Pediatr ; 63(11): 438-446, 2020 11.
Article En | MEDLINE | ID: mdl-32683817

BACKGROUND: Most developmental screening tools in Korea are adopted from foreign tests. To ensure efficient screening of infants and children in Korea, a nationwide screening tool with high reliability and validity is needed. PURPOSE: This study aimed to independently develop, standardize, and validate the Korean Developmental Screening Test for Infants and Children (K-DST) for screening infants and children for neurodevelopmental disorders in Korea. METHODS: The standardization and validation conducted in 2012-2014 of 3,284 subjects (4-71 months of age) resulted in the first edition of the K-DST. The restandardization and revalidation performed in 2015-2016 of 3.06 million attendees of the National Health Screening Program for Infants and Children resulted in the revised K-DST. We analyzed inter-item consistency and test-retest reliability for the reliability analysis. Regarding the validation of K-DST, we examined the construct validity, sensitivity and specificity, receiver operating characteristic curve analysis, and a criterion-related validity analysis. RESULTS: We ultimately selected 8 questions in 6 developmental domains. For most age groups and each domain, internal consistency was 0.73-0.93 and test-retest reliability was 0.77-0.88. The revised K-DST had high discriminatory ability with a sensitivity of 0.833 and specificity of 0.979. The test supported construct validity by distinguishing between normal and neurodevelopmentally delayed groups. The language and cognition domain of the revised K-DST was highly correlated with the K-Bayley Scales of Infant Development-II's Mental Age Quotient (r=0.766, 0.739), while the gross and fine motor domains were highly correlated with Motor Age Quotient (r=0.695, 0.668), respectively. The Verbal Intelligence Quotient of Korean Wechsler Preschool and Primary Scales of Intelligence was highly correlated with the K-DST cognition and language domains (r=0.701, 0.770), as was the performance intelligence quotient with the fine motor domain (r=0.700). CONCLUSION: The K-DST is reliable and valid, suggesting its good potential as an effective screening tool for infants and children with neurodevelopmental disorders in Korea.

16.
Bioresour Technol ; 313: 123684, 2020 Oct.
Article En | MEDLINE | ID: mdl-32562965

Scenedesmus obliquus, a green microalga of the class Chlorophyceae, has been used to produce biofuels. However, limited research has been reported on platform chemicals that use microalgae as biomass to replace fossil sources. This paper reports on the investigation of levulinic acid (LA) production from lipid-extracted S. obliquus with an acid-catalyzed thermochemical conversion using a statistical experimental approach. For the reaction factors, the highest effect on LA yield resulted from catalyst concentration. The optimized LA yield of 45.63 wt% (70.7 mol%) was achieved with 5 wt% lipid-extracted microalgae and reaction factors of 0.85 M HCl as a catalyst at 180 °C for 10 min. Also, the LA yield as a function of the combined severity factor followed a sigmoid curve. High LA yield resulted from combined severity factors greater than 3.4. These results indicate that the production of platform chemicals may be possible using microalgae feedstocks and thermochemical conversion.


Microalgae , Scenedesmus , Biofuels , Biomass , Levulinic Acids , Lipids
17.
Int J Mol Sci ; 21(10)2020 May 24.
Article En | MEDLINE | ID: mdl-32456353

Neonatal ischemic stroke has a higher incidence than childhood stroke. Seizures are the first sign for the need for clinical assessment in neonates, but many questions remain regarding treatments and follow-up modalities. In the absence of a known pathophysiological mechanism, only supportive care is currently provided. Stroke-induced microglia activation and neuroinflammation are believed to play a central role in the pathological progression of neonatal ischemic stroke. We induced a photothrombotic infarction with Rose Bengal in neonatal rats to investigate the effects of pre- and post-treatment with Aspirin (ASA), Clopidogrel (Clop), and Coenzyme Q10 (CoQ10), which are known for their neuroprotective effects in adult stroke. Pre-stroke medication ameliorates cerebral ischemic injury and reduces infarct volume by reducing microglia activation, cellular reactive oxygen species (ROS) production, and cytokine release. Post-stroke administration of ASA, Clop, and CoQ10 increased motor function and reduced the volume of infarction, and the statistical evidence was stronger than that seen in the pre-stroke treatment. In this study, we demonstrated that ASA, Clop, and CoQ10 treatment before and after the stroke reduced the scope of stroke lesions and increased behavioral activity. It suggests that ASA, Clop, and CoQ10 medication could significantly have neuroprotective effects in the neonates who have suffered strokes.


Aspirin/therapeutic use , Clopidogrel/therapeutic use , Inflammation , Stroke/prevention & control , Ubiquinone/analogs & derivatives , Animals , Animals, Newborn , Aspirin/pharmacology , Brain Ischemia , Clopidogrel/pharmacology , Disease Models, Animal , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use , Rats , Rose Bengal/toxicity , Stroke/chemically induced , Ubiquinone/pharmacology , Ubiquinone/therapeutic use
18.
Appl Biochem Biotechnol ; 192(1): 180-195, 2020 Sep.
Article En | MEDLINE | ID: mdl-32338330

Kariba weed (Salvinia molesta) was used as biomass feedstock for ethanol production by separate hydrolysis and fermentation (SHF). Monosaccharides from Kariba weed hydrolysate were produced using thermal acid hydrolysis, sonication, and enzymatic saccharification. The optimal conditions for thermal acid hydrolysis of 12% (w/v) Kariba weed slurry were evaluated as 200 mM HNO3 at 121 °C for 60 min yielding 10.2 g/L monosaccharides. Sonication for 45 min before enzymatic saccharification yielded more monosaccharides to 18.7 g/L. Enzymatic saccharification with 16 U/mL Cellic CTec2 produced 35.4 g/L monosaccharides. Fermentation was performed using Saccharomyces cerevisiae, Kluyveromyces marxianus, or Pichia stipitis with sonicated Kariba weed hydrolysate. The control fermentations were carried out using Kariba weed hydrolysate without sonication. The improvement of ethanol production from sonicated Kariba weed hydrolysate using P. stipitis produced 15.9 g/L ethanol with ethanol yield coefficient YEtOH = 0.45, K. marxianus produced 14.7 g/L ethanol with YEtOH = 0.41. S. cerevisiae produced the lowest yield of 13.2 g/L ethanol with YEtOH = 0.37 as it utilized only glucose not xylose. Sonication of Kariba weed was essential in the ethanol production to enhance the productivity of monosaccharides. P. stipitis was determined as the best yeast species using hydrolysates with the mixture of glucose and xylose to produce ethanol.


Biomass , Ethanol/chemistry , Fermentation , Seaweed/metabolism , Biotechnology , Hydrolysis , Kluyveromyces/metabolism , Lakes/microbiology , Saccharomyces cerevisiae/metabolism , Saccharomycetales/metabolism , Sonication , Uganda , Water Microbiology
19.
J Microbiol Biotechnol ; 30(6): 930-936, 2020 Jan 28.
Article En | MEDLINE | ID: mdl-32238769

The red seaweed Gracilaria verrucosa has been used for the production of bioethanol. Pretreatment for monosaccharide production was carried out with 12% (w/v) G. verrucosa slurry and 500 mM HNO3 at 121°C for 90 min. Enzymatic hydrolysis was performed with a mixture of commercial enzymes (Cellic C-Tec 2 and Celluclast 1.5 L; 16 U/ml) at 50°C and 150 rpm for 48 h. G. verrucosa was composed of 66.9% carbohydrates. In this study, 61.0 g/L monosaccharides were obtained from 120.0 g dw/l G. verrucosa. The fermentation inhibitors such as hydroxymethylfurfural (HMF), levulinic acid, and formic acid were produced during pretreatment. Activated carbon was used to remove HMF. Wildtype and adaptively evolved Saccharomyces cerevisiae, Candida lusitaniae, and Kluyveromyces marxianus were used for fermentation to evaluate ethanol production.


Candida/metabolism , Ethanol/analysis , Gracilaria/metabolism , Kluyveromyces/metabolism , Monosaccharides/biosynthesis , Saccharomyces cerevisiae/metabolism , Fermentation , Galactose/chemistry , Hydrolysis , Seaweed/metabolism
20.
Sci Rep ; 9(1): 15646, 2019 Oct 30.
Article En | MEDLINE | ID: mdl-31666559

This study aimed to investigate whether obesity and metabolic syndrome (MetS) are associated with pulmonary function in Korean children and adolescents. Data from the 2009-2011 Korea National Health and Nutrition Examination Survey which is cross-sectional, nationwide, and representative survey were used. Adjusted regression analysis was performed to evaluate the association of obesity and MetS with lung function in children and adolescents. A total of 763 children and adolescents aged 10-18 years were evaluated. We found no significant difference in FEV1% predicted, FVC% predicted, and FEV1/FVC ratio among the obesity groups. Subjects with MetS showed a significantly lower FEV1 predicted (91.54 ± 0.74% vs 94.64 ± 0.73%, P = 0.004), lower FVC% predicted (91.86 ± 0.63% vs 95.20 ± 0.63%, P < 0.001), and lower FEV1/FVC ratio (76.76 ± 0.43% vs 80.13 ± 0.43%, P < 0.001) than those without MetS. Elevated waist circumference (WC), systolic blood pressure, fasting glucose, and lower high-density lipoprotein cholesterol (HDL-C) were independently associated with lower FEV1/FVC ratio (all P < 0.05, respectively). Among MetS components, increased WC was the most important factor influencing lower FEV1/FVC ratio. In conclusion, lung function in MetS patients was significantly lower, and the MetS component was independently associated.


Lung/physiopathology , Metabolic Syndrome/physiopathology , Adolescent , Child , Cross-Sectional Studies , Female , Forced Expiratory Volume , Health Surveys , Humans , Male , Metabolic Syndrome/complications , Obesity/complications , Republic of Korea , Waist Circumference
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