• Journal of Microbiology and Biotechnology
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• 제7권2호
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• pp.127-131
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• 1997

Alkaline phosphatase (APase) was found to be inducible in Anabaena sp. strain CA Growth was less than control in presence of most amino acids except glycine and serine, but most amino acids enhanced APase activity. Highest APase activity was recorded in tyrosine supplemented culture followed by hydroxyproline, cystein, valine and glutamic acid. Threonine supplemented material showed lowest APase level (1.8 nmol/mg protein/min). Lactose, glucose, sodium pyruvate and succinate stimulated growth but not APase activity. APase activity was high in the presence of sucrose, mellibiose, mannitol, arabinose, maltose and sorbose, even though the growth in these supplements was less than in control. Organic phosphate sources supported good growth of the organism. Best growth occurred in presence of inorganic phosphate, adenosine diphosphate, fructose 1,6-diphosphate or ribulose 1,5-diphosphate, followed by other phosphorus sources tested. APase activity in presence of any of the organic phosphate sources was 3 to 5 fold low as compared to phosphate limited culture. Also, there was no APase activity in cultures grown on inorganic phosphate. These data indicate that most amino acids and a few carbohydrates (sucrose, mellibiose, arabinose and sorbose) are suitable for APase production. Lactose, glucose, pyruvate or succinate may be used as a carbon source during photoheterotrophic growth of the cyanobacterium. Glycine and serine are preferred nitrogen sources for its growth. Phosphate repressible APase activity has been found in Anabaena sp. strain CA.

• 한국수산과학회지
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• 제43권6호
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• pp.573-580
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• 2010

The study investigated the effect of diets supplemented with different levels (0 and 2.5%) of yuza (Citrus junos Sieb ex Tanaka) on the nutritional characteristics of eels (Auguilla japonica). Fish ($9.8{\pm}1.3g$) was fed to apparent satiation twice daily for 8 months. There were no significant differences in proximate composition among the treatment groups, except for the ash and carbohydrate contents (P<0.05). The vitamin C content of eel muscle in the yuza-added group was two-times higher than in non-added groups (P<0.05). Among eight organic acids in eel muscle, lactic acid was predominant, followed by citric acid, oxalic acid, malic acid, and acetic acid. Eels fed a 2.5% yuza diet had the highest lactic acid content in all groups. Six sugars were found in all groups and glucose was the major sugar. Glucose and maltose were the dominant sugars in the yuza-added group. The abundant fatty acids in the yuza-added group were C18:1 n-9, C16:0, and C16:1 n-7, which comprised over 80% of the total fatty acids. The major amino acids in samples were glutamic acid, aspartic acid, lysine, and leucine. There were few differences in the free amino acid compositions among the groups. However, histidine was the predominant amino acid and constituted over 53% of the total free amino acids.

• 한국식생활문화학회지
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• 제31권5호
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• pp.489-497
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• 2016

Kunrak, a type of Korea traditional cheese, is made using Tarak, a yogurt produced with makgeolli as the fermentation source. Kunrak is produced by removing whey from Tarak, followed by drying process for safe storage and consumption over a longer period. In this study, we produced kunrak based on the method described in "Imwonsibyukji". Prepared Kunrak was ripening for 96 hours at 20, 30, and $40^{\circ}C$. In order to study characteristics of Kunrak, physiochemical properties (pH, acidity, water contents) and contents of metabolites (organic acids, sugars, amino acids, and fatty acids) were analyzed. During ripening, water contents decreased. The main organic acids in Kunrak were citric acid and lactic acid, and the main free sugar was lactose. Main amino acids were glutamate and phenylalanine, and main fatty acid was saturated capric acid. At later ripening, all metabolites increased immediately after preparation. The sensory evaluation score of overall preference was highest for Kunrak, which was ripening at $40^{\circ}C$ for 96 hours. This study was aimed to assay metabolites of Kunrak under various ripening conditions. The results provide basic data to produce conditions for standardized manufacturing of Kunrak.

• 한국식품과학회지
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• 제29권5호
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• pp.913-918
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• 1997

전통식 고추장의 품질 개선과 담금방법을 표준화하기 위하여 담금원료를 달리한 고추장을 90일간 숙성시키면서 맛성분의 변화를 조사하였다. 고추장의 유리당은 maltose와 glucose가 대부분이었고 엿기름 첨가구에서 많았다. 유기산은 succinic acid와 citric acid가 다량 함유되었고 다음으로 formic acid이었으며, succinic acid는 숙성 중 감소하였으나 citric acid는 증가하였고, 자색고구마와 구기자 첨가 고추장에서 많았다. 고추장 중의 유리아미노산은 glutamic acid, serine, aspartic acid, alanine, lysine이 다량 함유되었고 cysteine, methionine, histidine은 소량 함유되었다. 숙성중 유리아미노산은 증가하였고 glutamic acid, aspartic acid, histidine이 다른 아미노산에 비하여 숙성중 많이 증가하였으며 자색고구마 첨가 고추장에서 높았다. 핵산성분은 담금초 cytidine-5-monophosphate가 대부분을 차지하나 90일 숙성후에는 hypoxanthine이 대부분을 차지하였고 자색고구마와 구기자 첨가 고추장에서 많았다.

• 유기물자원화
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• 제6권1호
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• pp.13-20
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• 1998

고농도 유기폐수인 양돈 폐수에 광합성 미생물(Rhodospirillum rubrum N-1)을 접종하고 여기에 공기를 160 mL/min 주입함으로써 양돈분뇨의 악취제거 효과를 조사하였다. 7일 동안 1일 간격으로 이화학적 변화를 검토하였다. 검토 결과 Biochemical Oxygen Demand (BOD) 20,000ppm인 양돈폐수의 경우 호기적 조건과, Rhodospirillum rubrum N-1 접종한 경우 volatile fatty acids(VFAs)의 제거율이 87.0%였으며, BOD제거율 54.6%, $PO_4-P$는 54.5%의 감소를 보였고, PH, $NH_3$ 등은 증가하는 경향을 나타내었다. T-N, T-P, $NO_3-N$, $NO_2-N$, $H_2S-N$, mercaptane 등은 별다른 증감율을 보이지 않고 일정하게 나타났다.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.1-8
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• 2017

The production of high-value chemicals from natural resources as an alternative for petroleum-based products is currently expanding in parallel with biorefinery. The use of lignocellulosic biomass as raw material is promising to achieve economic and environmental sustainability. Filamentous fungi, particularly Aspergillus species, are already used industrially to produce organic acid as well as many enzymes. The production of lignocellulose-degrading enzymes opens the possibility for direct fungal fermentation towards organic acids such as itaconic acid (IA) and fumaric acid (FA). These acids have wide-range applications and potentially addressable markets as platform chemicals. However, current technologies for the production of these compounds are mostly based on submerged fermentation. This work showed the capacity of two Aspergillus species (A. terreus and A. oryzae) to yield both acids by solid-state fermentation and simultaneous saccharification and fermentation. FA was optimally produced at by A. oryzae in simultaneous saccharification and fermentation (0.54 mg/g wheat bran). The yield of 0.11 mg IA/g biomass by A. oryzae is the highest reported in the literature for simultaneous solid-state fermentation without sugar supplements.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.171-171
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• 1998

The metabolic behavior of Debaryomyces hansenii was investigated in terms of substrate utilization and by product formation under different cultural conditions. Debaryomyces hansenii exhibited best growth and most tolerant of increased NaCl, sucrose and potassium sorbate at their optimum pH (5.0). A combination of two or more environmental stresses had stronger inhibitory effects on their growth kinetics, utilization of carbohydrate substrates and the production of organic acids, volatile compounds and other metabolites. Significant amounts of glycerol (0.35-4.4 g/L) and arabitol (0.08-9.8 g/L) were produced by D. hansenii. The main organic acids produced were citric (0.6-1.4 g/L), acetic (0.3-2.8 g/L), fumaric (0.2-1.0 g/L) and malic acids (1.1-1.7 g/L). A range of other compounds such as ethyl acetate, n-propanol, isoamyl alcohol, 2-phenylethanol and acetoin were also produced. The concentration of these compounds varied with the cultural conditions. Such compounds would have specific impacts on food quality in which D. hansenii is found.

• Journal of Ginseng Research
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• 제20권3호
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• pp.307-317
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• 1996

This study was undertaken to examine the effects of fresh ginseng addition on the chemical and sensory properties of dongchimi juice fermented under various conditions. The contents of free sugars in dongchimi juice during fermentation increased at the initial stage, but decreased at the palatable stage and then increased again thereafter. Free sugars were higher in dongchlml juice with 4% of ginseng addition than with Soye ginseng and without ginseng addition. Analyses of organic acid contents showed that all three groups contained relatively high amounts of citric, lactic and malic acids. It was also found that, as fermentation progressed, the amounts of tactic and acetic acids in- creased, while that of malic acid decreased at the palatable stage and increased again thereafter. Total saponins were highest in dongchimi juice fermented at 4$^{\circ}C$ with 4% of ginseng addition and panax atrlol ginsenosldes were found more than panaxadiol ginsenosides in dongchimi juice The results of sensory evaluation revealed that dongchimi juice prepared with the addition of $4^{\circ}C$ and 4% ginseng was lower in sour taste and moldy off flavor than the control, thus scoring high In total acceptability. Dongchimi juice with 4% of ginseng addition was best in most sensory characteristics.

• 한국식품영양학회지
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• 제32권5호
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• pp.442-453
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• 2019

The purpose of this study was to compare differences in the main food components between Korean and imported quinoa from Peru, the U.S., and Thailand. Proximate composition of Korean quinoa showed highest crude protein and crude ash, while Korean quinoa had lowest moisture. Total amino acid content was higher in Korean quinoa than in imported quinoa. Fatty acid content was highest in quinoa cultivated in the U.S. and Wonju. Quinoa cultivated in Wonju was rich in palmitic acid, lignoceric acid, linoleic acid, eicosadienoic acid, erucic acid, and nervonic acid. Mineral content was higher in Korean quinoa than in imported quinoa. Quinoa cultivated in Wonju showed highest contents of P, Mg, Zn, while quinoa cultivated in Hongcheon showed the highest content of Na. Citric acid was found the major organic acid in quinoa. Citric acid content was highest in quinoa imported from the U.S. and lowest in quinoa cultivated in Hongcheon. Among free sugar, raffinose and glucose contents were highest in quinoa cultivated in Hongcheon, The results of this study show Korean quinoa has high contents of protein, amino acids, fatty acids, minerals and free sugar, offering essential amino acids in an excellent balance.

• Ocean and Polar Research
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• 제45권3호
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• pp.113-123
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• 2023

Humic substances are refractory organic compounds that are relatively low in biological activity but known to stimulate phytoplankton growth in estuarine and marine environments. The effect of humic substances on phytoplankton growth was investigated in the seawater zone of the Yeongsan River estuary where an episodic anthropogenic freshwater is discharged, affecting its water properties directly. Water samples and data of water properties were collected at three stations (Sts. A-C) along the channel of the seawater zone in February, May, August and November, 2009. The collected water samples were incubated after humic acids (HA) were added in mesocosm experiments. Phytoplankton (chlorophyll-a) were fractionated into net- (> 20 ㎛) and nano-size (< 20 ㎛) to examine the response of phytoplankton according to size. Their response to HA treatment was assessed by repeated measures analysis of variance (RM-ANOVA). The experiments showed that phytoplankton biomass (chlorophyll-a) significantly increased after HA were added at the stations near the sea dike. Especially, nano-sized chlorophyll-a concentrations increased significantly throughout the seasons. This indicates that understanding the behavior of refractory organic matters such as humic substances is required to better manage altered estuarine ecosystems including the Yeongsan River estuary which are affected by episodic discharge of freshwater from sea dikes.