• 한국식품조리과학회지
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• 제6권4호통권13호
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• pp.59-68
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• 1990

Juices prepared from carrots, apples, and mandarin oranges were fermented with Leuconostoc mesenteroides or along with Saccharomyces cerevisiae. The pH of the fermented juices was not found significantly different between the mixed and single-cultured groups. The juices containing 0.5% NaCl had lower pH than the groups without 0.5% NaCl. The final pH of the single-cultured gruops was the highest among the sample groups. However, reducing sugar content of the mixed-cultured groups was lower than that of the single-cultured groups. The viable cells of the mixed-cutured groups were remarkably increased until 3 days of storage, and after 6 days they were gradually decreased. The results of the sensory evaluation demonstrated acidic, salty and alcoholic flavors were significantly different among the groups. The single-cultured group without salt was significantly more acidic than the non-pasteurized control group. The mixed-cultured group with salt was significantly more alcoholic than the group without salt and control groups. The non-pasteurized control group was significantly more homogeneous than the mixed-cultured groups and single-cultured group with salt. Preference ranking test showed that flavor and overall acceptability of the fermented juices was significantly different among the groups. Flavor of the single-cultured group without salt was found significantly better than those of the groups with salt. With the respect of overall acceptability, the single-cultured group without salt was significantly more acceptable than the non-pasteurized control group and the mixed-cultured group with salt.

• 한국식품영양과학회지
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• 제45권2호
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• pp.298-305
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• 2016

발효과정(양파 알코올 발효 및 양파 초산 발효) 중의 정미성분을 분석하였다. 유기산의 분석 결과 양파 착즙액(유기산 함량 1,180.8 mg/100 g)에서 malic acid(50.1%)와 citric acid(26.9%)가 대부분의 함량을 차지하였다. 양파 알코올 발효액(유기산 함량 2,008.8 mg/100 g)은 malic acid(28.1%), acetic acid(20.8%), lactic acid(20.1%), citric acid(13.3%) 및 succinic acid(12.0%) 순으로 높은 함량을 차지하였다. 양파 초산 발효액의 총유기산 함량은 4,612.0 mg/100 g으로 양파 착즙액이나 알코올 발효액에 비해 각각 약 3.9배와 2.3배 증가하였으나 acetic acid 이외 유기산의 함량은 감소하였다. 비단백태 질소화합물은 양파 착즙액(총비단백태 질소 함량 $9,803.1{\mu}g/100g$)에 비하여 알코올 발효 후 4.23배($41,526.8{\mu}g/100g$)로 증가하였고, 특히 urea(81.43%)가 두드러지는 증가를 보였다. 양파 초산 발효액은 $2,658.9g/100g$으로 초산균의 생육과 관련하여 소비가 이루어진 것으로 사료된다. 양파 착즙액에 검출된 유리당(포도당, 과당, 자당)은 발효과정 중 과당을 제외하고는 검출되지 않았다.

• 한국식품저장유통학회지
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• 제24권3호
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• pp.472-482
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• 2017

본 연구는 국산 캠벨얼리 와인의 주질 개선과 기능성 향상을 위해 캠벨얼리 뿐만 아니라 안토시아닌과 폴리페놀 성분이 풍부하여 항산화능이 우수하다고 알려진 아로니아를 이용하여 상업용 효모인 S. cerevisiae Fermivin과 향미증진능을 지닌 P. anomala JK04를 각각 단독 또는 5:5(v/v)의 비율로 혼합발효한 후 블렌딩하는 실험을 진행하였다. 최적 블렌딩 비율을 정하기 위하여 예비실험으로 캠벨얼리 와인에 아로니아 와인을 각각 5, 10, 20%(v/v) 첨가하여 항산화능과 관능검사를 실시하였으며, 실험 결과를 바탕으로 캠벨얼리 와인과 아로니아 와인의 블렌딩 비율을 9:1(v/v)로 설정하였다. P. anomala JK04로 단독발효한 캠벨얼리 와인은 낮은 알코올 함량으로 인해 블렌딩에서 제외하였고, 나머지는 발효에 이용된 균주에 따라 블렌딩하였다. 블렌딩와인의 기능성을 평가하기 위하여 총 안토시아닌 함량, DPPH 라디칼 소거능, 총 페놀성 화합물 함량 분석을 진행하였으며, 모든 블렌딩와인에서 대조구인 S. cerevisiae로 단독발효한 캠벨얼리보다 높은 수치를 나타내었다. 블렌딩와인의 유리당 분석 결과에서는 P. anomala JK04로 단독발효한 아로니아 와인을 첨가한 시험구(A,D)에서 glucose와 fructose 같은 잔당이 남아있는 것을 확인하였으며, 유기산 분석 결과에서는 상기 두 시험구에서 특히 malic acid 함량이 높게 측정되었다. 블렌딩와인의 외관적 품질을 검사하기 위해 색도, 휘발성 향기성분, 관능검사가 수행되었으며, P. anomala JK04를 사용 여부에 따라 A, B, C와 D, E, F 순으로 hue와 intensity 값이 증가하는 경향을 나타내었다. 또한 Hunter's color value에서는 아로니아 와인의 첨가가 와인의 a value와 b value를 증가시키는 경향을 나타내었다. 휘발성 향기성분분석에서는 P. anomala JK04의 사용이 와인에 부정적인 성분인 aldehyde와 acid 함량이 소폭 증가시키긴 하였지만, 중요한 향기성분은 ester 화합물의 함량이 큰 폭으로 증가하는 것을 확인하였다. 관능검사 결과에서는 P. anomala JK04로 단독발효한 아로니아 와인을 사용한 시험구(A,D)에서 색, 맛, 신맛, 전반적인 기호도에서 다른 시험구보다 높은 점수를 받았으며, 향기 항목에서는 모든 블렌딩와인이 대조구보다 높은 점수를 받았다. 본 연구에서는 캠벨얼리 와인에 아로니아 와인을 블렌딩하여 기능성을 증가시켰으며, S. cerevisiae Fermivin과 P. anomala JK04를 혼합발효하여 향기성분의 증가 및 관능적 품질이 향상됨을 확인하였다.

• BMB Reports
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• 제42권4호
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• pp.227-231
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• 2009

The eukaryotic genome forms a chromatin structure that contains repeating nucleosome structures. Nucleosome packaging is regulated by chromatin remodeling factors such as histone chaperones. The Saccharomyces cerevisiae H3/H4 histone chaperones, CAF-1 and Asf1, regulate DNA replication and chromatin assembly. CAF-1 function is largely restricted to non-transcriptional processes in heterochromatin, whereas Asf1 regulates transcription together with another H3/H4 chaperone, HIR. This study examined the role of the yeast H3/H4 histone chaperones, Asf1, HIR, and CAF-1 in chromatin dynamics during transcription. Unexpectedly, CAF-1 was recruited to the actively transcribed region in a similar way to HIR and Asf1. In addition, the three histone chaperones genetically interacted with Set2-dependent H3 K36 methylation. Similar to histone chaperones, Set2 was required for tolerance to excess histone H3 but not to excess H2A, suggesting that CAF-1, Asf1, HIR, and Set2 function in a related pathway and target chromatin during transcription.

• 신재생에너지
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• 제7권3호
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• pp.6-16
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• 2011

In order to study the utilization of seaweeds as an alternative renewable feedstock for bioethanol production, their properties of hydrolysis and fermentation were investigated. The seaweeds were well hydrolyzed with diluted sulfuric acid. The weight loss of seaweeds reached 75-90%, but only 12-51% of them was converted into reducing sugars after the acid-hydrolysis at $130^{\circ}C$ for 4-6h. The yield of reducing sugars increased with increasing the hydrolysis time up to 4h and then decreased thereafter. In contrast, the ethanol yield from the hydrolysates increased with hydrolysis time except for green seaweeds maximizing at 4h. Optimal fermentation time by Saccharomyces cerevisiae (ATCC 24858) varied with seaweeds; 48h for green seaweeds, 96h for brown and red seaweeds. The ethanol yield from the hydrolysate reached 138${\pm}$37mg/g-dry for green seaweeds, 258${\pm}$29mg/g-dry for brown seaweeds, and 343${\pm}$53mg/g-dry for red seaweeds, which correspond to approximately 1.5-4.0 times more than the theoretical yield from total reducing sugars in the hydrolysates. The results obtained indicate clearly that the non-reducing sugars or oligosaccharides dissolved in the hydrolysate played an important role in producing bioethanol. Considering the productivity and production cost of each seaweed, brown seaweeds such as Laminaria japonica and Undaria pinnatifida seem to be a promissing feedstock for bioethanol production.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1259-1266
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• 2016

Bioethanol was produced from Kappaphycus alvarezii seaweed biomass using separate hydrolysis and fermentation (SHF). Pretreatment was evaluated for 60 min at 121℃ using 12% (w/v) biomass slurry with 364 mM H₂SO₄. Enzymatic saccharification was then carried out at 45℃ for 48 h using Celluclast 1.5 L. Ethanol fermentation with 12% (w/v) K. alvarezii hydrolyzate was performed using the yeasts Saccharomyces cerevisiae KCTC1126, Kluyveromyces marxianus KCTC7150, and Candida lusitaniae ATCC42720 with or without prior adaptation to high concentrations of galactose. When non-adapted S. cerevisiae, K. marxianus, and C. lusitaniae were used, 11.5 g/l, 6.7 g/l, and 6.0 g/l of ethanol were produced, respectively. When adapted S. cerevisiae, K. marxianus, and C. lusitaniae were used, 15.8 g/l, 11.6 g/l, and 13.4 g/l of ethanol were obtained, respectively. The highest ethanol concentration was 15.8 g/l, with Y_EtOH = 0.43 and Y_T% = 84.3%, which was obtained using adapted S. cerevisiae.

• 한국미생물·생명공학회지
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• 제18권3호
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• pp.322-325
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• 1990

During transportation and preservation of Takju, alcohol fermentation has continued to produce $C0_2$ from residual sugar and frequently spoiled owing to bacterial contaminants wich produce organic acids. The authors could preserve Takju for more than 50 days at room temperature by pasteurization without any changes of quality. For the optimal condition of pasteurization, fresh Takju was heated at various temperatures and times. D-Value of the Saccharomyces sp. which isolated from Takju collected at seoul area was 19 see at $55^{\circ}C$. Non-spore forming bacterial contaminants, most of which known to cause acid-spoilage, were decreased when heated at $55^{\circ}C$ for 5 min. The optimal pasteurization condition of Takju was at $55^{\circ}C$ for 10 min. Spore forming bacterial contaminants, considered to be EuciiLw sp., were not sterilized after pasteurized at the optimal condition. However, the spore-forming bacteria could not increase any more and also not cause increment of acidity during preservation even at room temperature for 50 days. Reducing sugar was increased during storage of Takju after pasteurization. This suggests that the residual glucoamylase in Takju is still active after pasteurizsation and keep sweet taste.

• 한국가금학회지
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• 제22권4호
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• pp.203-211
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• 1995

In order to investigate the effect of feeding live yeast on growth performance, nutrients utilization, tibia mineral deposit and intestinal microorganism changes, a growth assay was conducted with 360 broiler chicks. Treatments were four levels of yeast as 0, 0.025, 0.05 and 0.1% in 1.83% tricalcium phosphate and two levels of yeast as 0 and 0.05% in 1.15% tricalcium phosphate. The crude protein content of live yeast was 45%, and 97% of it was in the pure protein form, with 46.6% of essential amino acids and 53.4% of non-essential amino acids. Growth performance was tended to increase by feeding the yeast but there was no significant difference(P>.05). The protein digestibility was increased as the feeding level of yeast increased. However, digestibilities of fat, fiber, calcium and phosphorus were not affected by the yeast. Ash and calcium content of tibia were increased as the level of yeast increased. Total number of E. coli in small intestine was significantly decreased(P<.05) in chicks fed yeast. Total number of Lactobaci1lus was significantly increased by the yeast feeding. The changes of microorganism in cecum had the same trend with the changes of microorganism in small intestine.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.320-328
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• 2021

High GABA-enriched yeast extract, for various nutritionally and pharmaceutically important functional foods, was prepared using a novel isolate of Debaryomyces hansenii JBCC541. Under optimized conditions, GABA conversion rates are significantly enhanced up to 7.55 g/l by D. hansenii JBCC541, increasing their synthesis yield 40 times. The total amino acid content of the prepared yeast extract was 10733.86 mg/l (257.36 mg/g), consisting of alanine, lysine, glutamine, leucine, and valine as the primary amino acids. The GABA content was significantly enhanced up to 6790 mg/l (162.80 mg/g) in the presence of glutamic acid, with approximately 10-fold higher GABA production. Flavor amino acids were also highly enhanced, indicating that the prepared yeast extract might be useful for preparing various functional and sensuous foods. Our results were promising as a GABA-enriched yeast extract preparation tool ensuring a suitable food material level with the potential for functionally enhanced food industrial applications.

• Journal of Microbiology and Biotechnology
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• 제32권8호
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• pp.1054-1063
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• 2022

Trehalose is a non-conventional sugar with potent applications in the food, healthcare and biopharma industries. In this study, trehalose was synthesized from maltose using whole-cell Pseudomonas monteilii TBRC 1196 producing trehalose synthase (TreS) as the biocatalyst. The reaction condition was optimized using 1% Triton X-100 permeabilized cells. According to our central composite design (CCD) experiment, the optimal process was achieved at 35℃ and pH 8.0 for 24 h, resulting in the maximum trehalose yield of 51.60 g/g after 12 h using an initial cell loading of 94 g/l. Scale-up production in a lab-scale bioreactor led to the final trehalose concentration of 51.91 g/l with a yield of 51.60 g/g and productivity of 4.37 g/l/h together with 8.24 g/l glucose as a byproduct. A one-pot process integrating trehalose production and byproduct bioremoval showed 53.35% trehalose yield from 107.4 g/l after 15 h by permeabilized P. moteilii cells. The residual maltose and glucose were subsequently removed by Saccharomyces cerevisiae TBRC 12153, resulting in trehalose recovery of 99.23% with 24.85 g/l ethanol obtained as a co-product. The present work provides an integrated alternative process for trehalose production from maltose syrup in bio-industry.