고산도 생성 초산균의 분리 및 발효특성

백창호,백성열,이세희,강지은,최한석,김재현,여수환,Baek, Chang-ho,Baek, Seong-yeol,Lee, Se Hee,Kang, Ji-Eun,Choi, Han-Seok,Kim, Jae-Hyun,Yeo, Soo-Hwan 한국미생물·생명공학회 2015 한국미생물·생명공학회지 Vol.43 No.2

본 연구에서는 정치 배양법으로 고농도의 초산을 생산할 수 있고 에탄올 내성이 우수한 균주를 확보하고자 농가형 발효식초에서 초산균을 분리 및 선발하였고, 이들 초산균의 형태적 특징을 조사한 바, 분리균 CV1은 그람 음성으로 운동성이 없는 간균으로 나타났다. 분리균의 chemotaxonomy를 분석한 결과, meso-DAP이며, 대표 퀴논은 Q₁₀이고, G+C mol 함량은 61.0 mol %로 나타났으며 16S rDNA 유전자의 염기서열을 분석한 결과, Gluconacetobacter saccharivorans로 동정되어 Glu. saccharivorans CV1로 명명하였다. CV1 초산균의 최적 성장조건은 30℃, pH 3.0 이상으로 판단되었고 에탄올 농도에 따른 초산 생성능은 10% 에탄올 농도에서 9.3%, 9% 에탄올 농도에서는 8.4% 적정산도를 나타내어 고농도 에탄올 조건에서도 높은 산 생성능을 나타내는 우수한 균주로 판단되었다. Ten types of farm-made brewing vinegars were collected and four high acetic acid-producing strains (CV1, CV3, CV5, and CV6) were isolated. Among them strain CV1, exhibiting highly alcohol-resistant and acetic acid-producing properties, was selected and its taxonomic properties were investigated by phenotypic (particularly chemotaxonomic) characterization and phylogenetic inference based on 16S rRNA gene sequence analysis. On SM broth agar, cells of strain CV1 were gram-stainingnegative and formed pale white colonies with smooth to rough surfaces. Strain CV1 produced acetate from ethanol and was resistant to up to 8% (v/v) ethanol in LM broth. Strain CV1 had a G+C content of 61.0 mol%, contained meso-DAP as the cell wall amino acid, and possessed Q-10 as the major ubiquinone. A comparison of 16S rRNA gene sequences showed that strain CV1 was most closely related to Gluconacetobacter saccharivorans (≥99.0% identity). In liquid media, the optimum growth conditions for acetic acid production were 30℃ and pH >3.0 and strain CV1 produced 9.3% and 8.4% acetic acids from 10% and 9% alcohol concentrations, respectively.

시판 감식초에서 분리한 고산도 초산균의 균학적 특성

백창호,정다희,김주연,최지호,백성열,최한석,박혜영,정석태,권중호,정용진,김재현,여수환 동아시아식생활학회 2013 동아시아식생활학회 학술발표대회논문집 Vol.2013 No.4

탁주용 곰팡이 고체종국 제조 및 품질 특성

백창호,백성열,문지영,최한석,강지은,정석태,여수환 한국식품저장유통학회 2016 한국식품저장유통학회지 Vol.23 No.6

In this study, we investigated the effect of fermentation conditions on the amylolytic and proteolytic activities of Aspergillus luchuensis strain 74-5 and Aspergillus oryzae strain 75-2, which are used in the preparation of the starter culture, for Takju (Korean traditional rice wine). The starter culture was optimized using different conditions, such as inoculum size, inoculation temperature, and incubation time. The enzyme activities under each condition were measured. In the A. luchuensis strain 74-5 starter culture, the α-amylase and glucoamylase activities increased, however the activity of acidic protease decreased as the diluent to starter culture ratio increased. In the A. oryzae 75-2 starter culture, all enzyme activities were maintained at a higher level even at 5% inoculation ratio. Higher enzyme activities were observed in the middle range of inoculation temperature (35, 40℃), than in the lower range (20, 30℃). Enzyme activity in the starter culture varied with incubation time, however it was the highest at 144 and 120 hr, respectively, for A. luchuensis strain 74-5 and A. oryzae strain 75-2. The spore count of the starter culture was approximately 2×107 during fermentation, out of which contamination by aerobic bacteria was about 3×103. The results suggested that the starter culture of each strain could be used as an inoculum for fermentation. However, we needs to conduct further research for the selection of suitable diluting agents as well as drying methods to reduce the contamination by aerobic bacteria, while retaining the enzyme activity.

토착 누룩곰팡이로 만든 쌀누룩의 품질 특성

백창호,김주연,정다희,백성열,최지호,최한석,박혜영,정석태,김재현,여수환 동아시아식생활학회 2013 동아시아식생활학회 학술발표대회논문집 Vol.2013 No.4

전통정치배양에 의한 농가형 현미식초의 품질특성

백창호 ( Chang Ho Ba다 ),정다희 ( Da Hee Jeong ),백성열 ( Seong Yeol Ba다 ),최지호 ( Ji Ho Choi ),박혜영 ( Hye Young Park ),최한석 ( Han Seok Choi ),정석태 ( Seok Tae Jeong ),김재현 ( Jae Hyun Kim ),정용진 ( Yong Jin Jeong ),권중호 한국식품저장유통학회(구 한국농산물저장유통학회) 2013 한국식품저장유통학회지 Vol.20 No.4

본 연구에서는 전통 항아리를 이용하여 발효온도 및 여과 방법을 달리한 현미식초를 제조하여 이들의 품질특성을 조사하였다. 초산발효에 사용하는 발효제와 온도에 따라 적정산도는 발효 4~5주에 가장 높았으며, 강제여과가 전총여과방식보다 산도가 더 높게 나타났다. pH는 모든 구간에서 발효가 진행됨에 따라감소하였고, 당도는 각각의 발효액 모두 초산 생성이 원활할 때는 발효초기와 비슷하게 유지되었지만, 발효액이 과산화 되었을 때는 당도가 낮아졌다. 유기산 함량은 발효온도와 여과방식에는 큰 차이는 없지만 다양한 발효제에 따라 발효 초기에 8종(oxalic, citric, malic, tartaric, succinic, lactic, acctic 및 formic acid 등)이 검출되었고, 발효가 진행되면서 acetic acid가 많이 생성되었다. 총 유리아미노산 함량은 초산 함량이 증가할수록 유지되거나 감소의 폭이 적었으며, 초산함량이 감소하는 발효 6주에 총 아미노산 함량도 급격히 가소하는 것으로 나타났다. 항아리에서 초산발효가 진행됨에 다라 초산함량이 증가할 때 우리 아니노산 함량은 감소하였다. 따라서 본 연구에서는 발효온도 및 여과방식을 달리함에 따라 유기산 및 유리 아니노산 함량의 차이가 큰 것으로 판단되며, 초산발효액의 경우, 향후 숙성과정에서 유기산 및 유리 아니노산의 변화가 있을 것으로 예상되므로 장기 숙성에 따른 초산 발효액의 품질변화에 대한 연구가 요구된다. We investigated the quality characteristics of brewing brown rice vinegar through a traditional static fermentation process. Accordingly, we decided to compare the physicochemical characteristics of brewing vinegar at different temperatures and filtration methods. In four to five weeks` time, the acetic acid fermentation exhibited the highest titratable acidity and then it eventually decreased The titratable acidity was affected by the filtration method It was revealed that the titratable acidity was higher in the forced filtration than the traditional filtration method. Various organic acids were detected in order to initiaLize the fermentation stage and as the fermentation progressed, only the acetic acid could be detected. The total free amino acid content was higher at a temperaiure of 30℃ than at 20℃ Moreover, the free amino acid content was depencenr on the acetate content during the acetic fermentation Process. The main bioactive substance of the γ-aminobutyric acid content was more man twice at a fermentation temperature of 30t: compared to die fermentation temperature of 20t:. Furthermore, the total amino acid and essential amino acid content at a temperature of 30 t was excellent. The quality of the brown rice vinegar via forced filtration method at a temperature of 30 t was the most excellent. Based on these results, the fermentation temperature and the use of nuruks (fermenting agent) affected the quality of the brown rice vinegar, and an appropriate method to consider its purpose is required.

발효조건을 달리하여 제조한 현미 막걸리의 품질특성

백창호 ( Chang Ho Baek ),최지호 ( Ji Ho Choi ),최한석 ( Han Seok Choi ),정석태 ( Seok Tae Jeong ),김재현 ( Jae Hyun Kim ),정용진 ( Yong Jin Jeong ),여수환 ( Soo Hwan Yeo ) 한국미생물생명공학회(구 한국산업미생물학회) 2013 한국미생물·생명공학회지 Vol.41 No.2

본 연구는 발효조건을 달리한 현미 막걸리의 술덧성분 변화를 조사하였다. 서로 다른 발효제와 발효온도에 따른 알코올의 차이는 30oC 발효가 20oC보다 알코올 도수가 평균 2% 정도 높은 것으로 나타났다. 당화력 차이는 발효 초기부터 20oC보다 30oC 발효액의 당도가 높게 나타난 것으로 보아 알코올 도수에도 영향을 미치며, pH는 발효 4일까지는 서서히 감소하였고 그 이후, 변화의 폭은 크지 않았다. 적정산도는 발효가 끝날 때까지 지속적으로 증가하였으며, 20oC AK 의 적정산도가 가장 높게(0.57%) 나타났고, 30oC 발효 술덧에서는 0.66%로 산패 가능성은 없었다. 색도 중 L 값과 a 값은 발효초기의 모든 술덧에 비해 발효 종료시점에 조금 낮아지며, b 값은 발효가 진행됨에 따라 꾸준히 상승하였다. 발효 술덧의 유기산은 총 9종이 검출되었으며,그 중 citric acid 함량이 가장 높게 나타났다. Lactic acid는 오히려 20oC 발효술덧에서 더 많이 검출된 것으로 보아 발효온도에 따라 생성된 유기산이 차이가 있었다. 유리아미노산 함량은 발효제 종류 및 발효온도에 따라 크게 차이가 있었고, 유리아미노산은 20oC보다 30oC 발효 술덧에 많이 있었다. 이상의 결과를 살펴보면, 30oC에서 제조한 현미 막걸리가 더욱 우수한 품질을 가지며, 누룩 종류 및 발효온도에 따라서 현미 막걸리의 주질이 결정된다. 향후, 농가형 흑초 제조에 적합한 현미막걸리의 술덧 제조가 가장 중요하다고 여겨진다. In this study we investigated the possibility of preparing brewed brown rice makgeolli, a traditional Korean rice wine, under diverse conditions. For this purpose the physicochemical characteristics of makgeolli brewed at different temperatures, utilizing a variety of nuruks, the traditional Korean fermentation agent, were studied. The alcohol content was seen to be highest when brewing occurred at 30oC, with the nuruk TN producing 16.2%. At 20oCTN produced 14.1% alcohol content. The alcohol content was therefore higher, by about 2%, for 30oC fermentations than 20oC fermentations. Similarly, saccharifying activity was influenced by temperature and sugar content, with a higher activity seen at 30oC than at 20oC. As the fermentations progressed acidification petered out, with titratable acidity being 0.50-0.67% in all end samples. On the Hunter L, a, b scale; the a value decreased slightly, while the b value increased steadily during the fermentation process. Measurements of total organic acids were highest at 30oC, with the nuruk AK, at about 550 mg%. The content of citric acid was the highest at 30oC, being 230-310 mg% in all samples. However, more lactic acid was detected at 20oC than at 30oC. Total free amino acid was highest at 30oC, with TN at 8,605 μg/ml, AK at 6,083 μg/ml, and RJ at 2,381 μg/ml. Total free amino acid and essential amino acid was shown to be higher at 30oC than at 20oC. The bioactive substance γ-aminobutyric acid was also higher at 30oC, with TN at 223 μg/ml. From all of these results, we surmise that brown rice makgeolli manufacturing conditions are optimal at 30oC fermentation temperatures and using the nuruk TN for brewing vinegar. In addition, the nuruk used clearly affects the quality of brown rice makgeolli and an appropriate method to determine the best nuruk for various purposes should be pursued.

반응표면 분석에 의한 사과 주스의 Patulin 감소 조건 모니터링

백창호 ( Chang Ho Baek ),박난영 ( Nan Young Park ),정용진 ( Yong Jin Jeong ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2010 한국식품저장유통학회지 Vol.17 No.1

발효제 비율에 따른 현미식초의 품질특성

백창호 ( Chang Ho Baek ),최지호 ( Ji Ho Choi ),최한석 ( Han Seok Choi ),정석태 ( Seok Tae Jeong ),이수원 ( Su Won Lee ),권중호 ( Joong Ho Kwon ),우승미 ( Seung Mi Woo ),정용진 ( Yong Jin Jeong ),여수환 ( Soo Hwan Yeo ) 한국식품저장유통학회(구 한국농산물저장유통학회) 2011 한국식품저장유통학회지 Vol.18 No.6

Brown rice vinegar was made from brown rice mash with different brewing starter addition rates in static culture, and its quality characteristics were investigated. As a result, the amounts of alcohol produced in the fermentation process were shown to be 9.1, 8.8, 8.6 and 8.5% in the Nuruk 75 : crude enzyme 25 (B), Nuruk 50 : crude enzyme 50 (C), Nuruk 25 : crude enzyme 75 (D) and Nuruk 0 : crude enzyme 100 (E), respectively. The higher the percentage of crude enzyme added was, the lower the alcohol content that was produced. Nuruk 100 : crude enzyme 0 (A) was appeared to contain the lowest alcohol content (7.7%). In addition, the titratable acidity in all the groups was about 0.7%. The final titratable acidity (BV) of brown rice vinegar made with static culture was the highest (approximately 5.2%). The initial pH appeared to be between 3.6~4.0 and steadily decreased as the fermentation progressed, and the pH was almost unchanged after 15 day fermentation. The examination of the changes in the organic acids showed that the acetic acid content was similar in all the groups, and that the single starter added (AV, EV) group had much more other organic acids than the mixed starters added (BV, CV, DV) group. From these results, the mixed starters (Nuruk and crude enzyme) added group appeared to be superior to the single starter added in terms of alcohol production ability and vinegar quality. As the future aging process, however, is expected to change the flavor components and sensory characteristics, studies on various quality factors of vinegar are needed.

쌀 품종과 누룩 배합비율에 따른 탁주의 품질 특성

임소연,여수환,백창호,백성열,박혜영,최한석,최지호,정석태,신우창,박희동 한국식품저장유통학회 2014 한국식품저장유통학회지 Vol.21 No.6

유용 양조용 효모를 선정하기 위해, 효모의 알코올 생성능을 조사한 결과, Y268 효모가 알코올 생성능이 가장 높았으며 그 중, 0.3% 접종한 효모를 최종 선정하여 사용하였다. 2종류의 양조용 곰팡이(A. luchuensis 34-1, Lich. ramose CN042)와 2종류의 쌀 품종(추청미, 한아름)으로 제조한 4종류 쌀누룩의 특성을 분석한 결과, 쌀 품종에 관계없이 A. luchuensis 34-1 균주의 이화학적 특성이 우수하였고, 균주별 및 쌀 품종별로 제조된 4종류 누룩의 유기산과 유리아미노산을 분석한 결과에서 주요 유기산은 citric acid와 malic acid로 분석되었다. 유리 아미노산은 각각 25~28개로 구성되어 있으며, 균주별과 쌀 품종별에 따라 차이를 보였다. 균주별로 제조한 쌀누룩의 배합비율을 달리하여 4가지 조합(A. luchuensis 34-1: Lich. ramose CN042=1:0, 0:1, 1:1, 1:3)과 2종류 쌀 품종으로 빚은 탁주의 발효기간에 따른 특성을 분석한 결과, 누룩의 배합비율과 쌀 품종에 따라 이화학적 특성 차이를 보였고, 알코올 함량은 발효 6일째 16%로 가장 높았다. 제조한 탁주의 유기산과 유리 아미노산 분석 결과, 전체 7종류 이상의 유기산이 검출되었으며, 주요 유리 아미노산은 arginine, citrulline이었고, 누룩의 배합비율과 쌀 품종에 따라 차이가 있었다. 탁주의 관능특성을 비교한 결과, 전반적인 기호도는A. luchuensis 34-1 누룩의 함량이 높을수록 높은 기호도를 보였고, 누룩 배합비율별로 비교했을 때는 쌀 품종에 관계없이 1:1 비율로 제조한 탁주가, 쌀 품종별로 비교했을 때는 한아름으로 제조한 탁주의 선호도가 더 우수한 것으로 나타났다.

Sequence of Thyroxine - Binding Globulin Gene in a Korean Family with Complete TBG Deficiency

위세찬,최의열,백창호,장연복 한국유전학회 1996 Genes & Genomics Vol.18 No.3

Genomic DNAs from an 11 year-old boy with suspected complete thyroxine-binding globulin deficiency(TBG-CD) and a normal individual were subjected to polymerase chain reactions and sequenced. The entire coding region and exon/intron boundary of TBG gene from a normal individual showed no base change in exons as reported. However, sequence of the TBG gene from the suspected individual revealed a single nucleotide deletion at codon 352 in exon 4. The mutation was further confirmed by allele-specific amplification of genomic DNAs from the affected hemizygous boy, a hemizygous normal male, and the heterozygous boy's mother with primers containing 3' end nucleotide missing in TBG-CD or normal sequence. Several distinct mutations in the coding regions of the TBG gene have been shown to be associated with TBG-CD. The Korean type identified in this study was found to be the same mutation type of TBG-CD in Japanese. In addition, we identified 3 more base changes in introns both in normal and TBG-CD subjects.