• Journal of Mechanical Science and Technology
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• v.19 no.10
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• pp.1902-1909
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• 2005

A process for production of ethyl ester for use as biodiesel has been studied. The sodium hydroxide catalyzed transesterification of soybean oil with ethanol was carried out at different molar ratio of alcohol to oil, reaction temperature and catalyst amount for a constant agitation in two hours of reaction time. Central composite design and response surface methodology were used to determine optimum condition for producing biodiesel. It was found that ethanol to oil ratio and catalyst concentration have a positive influence on ester conversion as well as interaction effects between the three factors considered. An empirical model obtained was able to predict conversion as a function of ethanol to oil molar ratio, reaction temperature and catalyst concentration adequately. Optimum condition for soybean ethyl ester production was found to be moderate ethanol to oil ratio (10.5: 1), mild temperature range ($70^{\circ}C$) and high catalyst concentrations ($1.0\%$wt), with corresponding ester conversion of $93.0\%$.

• KSBB Journal
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• v.5 no.4
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• pp.335-339
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• 1990

In order to develop economic processes for ethanol production from starch, a simultaneous saccharification and fermentation(SSF) process using Zymomonas mobilis and amyloglucosidase (AMG) was studied in semibatch modes using cell recycle. The cell recycle was carried out by adopting two different methods; microfiltration and settling. The cell recycle using microfiltration revealed higher productivity(5.4 g/l/h) than that using a settler(4.3 g/l/h). Taking the large-scale ethanol fermentation into account, the semibatch process using microfiltration system appeared most promising among others with respect to ethanol productivity, feasibility of scale-up and simplification of operation.

• KSBB Journal
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• v.4 no.1
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• pp.11-14
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• 1989

A study on the continuous fermentation with cell recycle by a tower fermentor to produce ethanol has been carried out. ethanol fermentation was conducted with flocculating yeast strain, Saccharomyces cerevisiae TS4, to compare the ethanol productivity with conventional continuous process. Employing a 15% glucose feed, a cell density of 50 g/l was obtaind. The ethanol productivity of the cell recycle system was found to be 26.5g EtOH/1-hr, which was nearly 7.5 times higher than the conventional continuous process without cell recycle. A cell recycle ratio of 7 to 8 resulted in the highest ethanol productivity and cell concentration. Thus the cell recycle ratio was found to be a key factor in controlling the production of clarified overflow liquid. An aeration rate above 3.8 $\times$ 10-3 VVM seemed to decrease the ethanol productivity. The continuous fermentation with cell recycle was successfully used in the separation of cells from fermentation broth with enhancement of mixing in the tower fermentor.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.474-478
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• 2006

For the economically feasible production of ethanol, utilization of SFW (saccharified food wastes) as substrate for synchronous saccharification and fermentation (SSF) process was developed in this study. When 200 g of food wastes and 40 mL of enzyme ($amylase activity,\;3.0\;U/m{\ell}$) were reacted, production rate of reducing sugar was $5.84\;g/{\ell}{\cdot}h$, and consumption rate was $-3.88\;g/{\ell}{\cdot}h\;at\;35^{\circ}C$ So suitable condition of SSF was concluded at temperature of $35^{\circ}C$. Also, optimal enzyme concentration of SSF was concluded in $2.0\;U/m{\ell}$, at this condition, the production rate of reducing sugar was $4.80\;g/{\ell}{\cdot}h$ At SSF process, when 50 g of food wastes was supplied in 12 h interval, $64\;g/{\ell}$ of ethanol and 0.45 g-ethanol/g-reducing sugar in yield were obtained in 120 h fermentation. Thus, the technology of high yield of ethanol production using food wastes was confirmed. And semi-continuos SSF system for cutting off cost of enzymatic saccharification was developed in this study.

• Korean Journal of Medicinal Crop Science
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• v.23 no.3
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• pp.231-236
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• 2015

Skin anti-wrinkle activities of the stems and leaves of Abeliophyllum distichum Nakai were evaluated by the extracts obtained from various extraction processes such as using hot water at $100^{\circ}C$, 70% ethanol at $85^{\circ}C$, and 70% ethanol with ultrasonication at $60^{\circ}C$ The ultrasonicated extract showed 95.62% of the highest cell viability in addition of $0.3mg/m{\ell}$ of the extracts into the normal human fibroblast cell, CCD-986sk. For antioxidant activities, the extracts using ultrasonicated extract showed the highest DPPH free radical scavenging as 80.27%, followed by 75.88% and 62.44% for the extracts using ethanol extract and water extract. The ultrasonicated extract also showed the highest elastase inhibition activity as 25.32%, compared to ethanol extract and water extract based method at 22.01% and 12.88%, respectively. MMP-1 production was most effectively decreased down to $2908.1pg/m{\ell}$ with ultrasonicated extract while $6640.8pg/m{\ell}$ with water extract and $3609.3pg/m{\ell}$ with ethanol extract, in addition of $0.3mg/m{\ell}$. Collagen production was increased up to $154.7ng/m{\ell}$ in addition of ultrasonicated extract, and followed by $121.4ng/m{\ell}$ and $31.2ng/m{\ell}$ for ethanol extract and water extract, respectively. These results indicate that the ethanol extract should have skin anti-wrinkling activities and can be improved by the ultrasonication process that high energy input elute more amounts of bioactive substances eluting more amounts of bioactive substances from the high energy input of ultrasonication.

• Mycobiology
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• v.40 no.1
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• pp.35-41
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• 2012

A repeated batch fermentation system was used to produce ethanol using $Saccharomyces$ $cerevisiae$ strain (NCIM 3640) immobilized on sugarcane ($Saccharum$ $officinarum$ L.) pieces. For comparison free cells were also used to produce ethanol by repeated batch fermentation. Scanning electron microscopy evidently showed that cell immobilization resulted in firm adsorption of the yeast cells within subsurface cavities, capillary flow through the vessels of the vascular bundle structure, and attachment of the yeast to the surface of the sugarcane pieces. Repeated batch fermentations using sugarcane supported biocatalyst were successfully carried out for at least ten times without any significant loss in ethanol production from sugarcane juice and molasses. The number of cells attached to the support increased during the fermentation process, and fewer yeast cells leaked into fermentation broth. Ethanol concentrations (about 72.65-76.28 g/L in an average value) and ethanol productivities (about 2.27-2.36 g/L/hr in an average value) were high and stable, and residual sugar concentrations were low in all fermentations (0.9-3.25 g/L) with conversions ranging from 98.03-99.43%, showing efficiency 91.57-95.43 and operational stability of biocatalyst for ethanol fermentation. The results of the work pertaining to the use of sugarcane as immobilized yeast support could be promising for industrial fermentations.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.316-321
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• 2017

Hyperthermal acid hydrolysis pretreatment of Eucheuma denticulatum was carried out using 12% (w/v) seaweed slurry and 90 mM $H_3PO_4$ at $150^{\circ}C$ for 10 min. The use of Candida lusitaniae with adaptive evolution was evaluated for ethanol fermentation. The levels of ethanol production by separate hydrolysis and fermentation (SHF) at 72 h with non-adapted and adapted C. lusitaniae were 10.1 g/l with ethanol yield ($Y_{EtOH}$) of 0.23, and 18.1 g/l with $Y_{EtOH}$ of 0.45, respectively. Adaptive evolution was employed in this study to improve the efficiency of ethanol fermentation. Development of the SHF process could enhance the overall ethanol fermentation yields of the red seaweed E. denticulatum.

• Carbon letters
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• v.17 no.1
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• pp.1-10
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• 2016

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1876-1884
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• 2020

Ethanol often accumulates during the process of wine fermentation, and mitophagy has critical role in ethanol output. However, the relationship between mitophagy and ethanol stress is still unclear. In this study, the expression of ATG11 and ATG32 genes exposed to ethanol stress was accessed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The result indicated that ethanol stress induced expression of the ATG11 and ATG32 genes. The colony sizes and the alcohol yield of atg11 and atg32 were also smaller and lower than those of wild type strain under ethanol whereas the mortality of mutants is higher. Furthermore, compared with wild type, the membrane integrity and the mitochondrial membrane potential of atg11 and atg32 exhibited greater damage following ethanol stress. In addition, a greater proportion of mutant cells were arrested at the G1/G0 cell cycle. There was more aggregation of peroxide hydrogen (H2O2) and superoxide anion (O2•-) in mutants. These changes in H2O2 and O2•- in yeasts were altered by reductants or inhibitors of scavenging enzyme by means of regulating the expression of ATG11 and ATG32 genes. Inhibitors of the mitochondrial electron transport chain (mtETC) also increased production of H2O2 and O2•- by enhancing expression of the ATG11 and ATG32 genes. Further results showed that activator or inhibitor of autophagy also activated or inhibited mitophagy by altering production of H2O2 and O2•. Therefore, ethanol stress induces mitophagy which improves yeast the tolerance to ethanol and the level of mitophagy during ethanol stress is regulated by ROS derived from mtETC.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.95-105
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• 1998

This research was investigated which denitrification of wastewater containing nitrate, using upflow anaerobic sludge blanket process. The upflow anaerobic sludge blanket process is also used for both artifical and industrial wastewater. Main ingredients investigated in the artifical and industrial wastewater experiment were the determination of optimum organism/nitrate ratios, nitrate removal efficiency by various hydrogen donor addition and characteristics of granular sludge and gas production in case of various hydrogen donor addition. From the experimental results the following conclusions were made: In case of adding methanol, ethanol and sodium acetate as hydrogen donor granular sludge was formed 50 days after seeding. Average diameter of granular sludge was 4.0 mm and settling velocity was 37 cm/min. Production rate of gas 3.3 L/d in case of adding methanol as hydrogen donor in wastewater containing 150mg/L nitrate. However adding ethanol and sodium acetate as hydrogen donor, gas production rate were 2.2-2.7L/d respectively. In case of adding methanol as hydrogen donor treatability of artifical wastewater contained 150mg/L as nitrate was about 93%. But in addition of sodium acetate in wastewater contained 40mg.L as nitrate, nitrate removal efficiency was 80%.