반추위내 서식하는 혼합곰팡이와 박테리아에 의한 Linoleic Acid 가수소화반응과 Stearic Acid 생산에 관한 연구

남인식,Nam, In-Sik 한국미생물학회 2007 미생물학회지 Vol.43 No.2

홀스타인 건유우의 반추위에서 분리한 혼합 곰팡이에 첨가한 linoleic acid가 biohydrogenation 과정 중 생산되는 지방산의 농도와 종류를 측정하고, 최종 산물로 생산되는 지방산이 trans-11 vaccenic acid인지 stearic acid인지 조사하기 위하여 본 연구를 수행하였으며 결과는 다음과 같다. 반추위 혼합 박테리아 배양구에 linoleic acid 용액을 첨가한 결과, 배양 90분 이내에 100%의 linoleic acid가 stearic acid로 biohydrogenation되었다. 반면에 linoleic acid 용액을 반추위 혼합 곰팡이에 첨가한 결과 24시간 이내에 모든linoleic acid는 conjugated linoleic acid (cis-9, trans-11)와 trans-11 vaccenic acid로 biohydrogenation되었다. Linoleic acid가 함유된 혼합곰팡이 처리구는 배양시간이 증가할수록 stearic acid의 농도도 소량 증가하는 경향을 보였다. 또한 linoleic acid가 함유되지 않은 혼합곰팡이 대조구에서도 배양시간이 증가할수록 stearic acid 농도가 처리구와 비슷하게 증가하는 경향을 나타내었다. 그러나 혼합 박테리아의 linoleic acid 첨가구에서는 배양시간이 증가할수록 stearic acid의 농도가 급격하게 증가하는 것을 조사되어 반추위 혼합곰팡이의 stearic acid생산은 linoleic acid의 biohydrogenation과 무관하게 생산되는 것으로 조사되었다. 따라서 반추위 혼합 곰팡이에 의한 linoleic acid biohydrogenation의 최종 산물은 trans-11 vaccenic acid로 판단되며, 혼합 박테리아는 stearic acid로 나타났다. The objective of this study was to confirm biohydrogenation of linoleic acid and stearic acid production by mixed men fungi and bacteria. In mixed fungal biohydrogenation study, when linoleic acid solution was added to fungal culture (after 24 hr pre-incubation), all linoleic acids were converted to trans-11 vaccenic acid via cis-9, trans-11 conjugated linoleic acid production within 24 hr period of incubation. All linoleic acid solution was hydrogenated to trans-11 vaccenic acid within 24 hr incubation and this was continued until the end of incubation (48 hr). Both treatments (added linoleic acid solution or the same amount of solution without containing linoleic acid into fungal cultures) produced the similar amount of stearic acid. In contrast, 100% of linoleic acid solution was hydrogenated to stearic acid in mixed bacterial culture. It is concluded that the end product of mixed fungal biohydrogenation of linoleic acid is trans-11 vaccenic acid whereas mixed bacteria produced stearic acid as an end product of their biohydrogenation.

Quality characteristics of soy yogurt produced using proteases and mixed microbial consortia

Park, Mi-Jung,Lee, Sook-Young 한국응용생명화학회 2015 Applied Biological Chemistry (Appl Biol Chem) Vol.58 No.5

In this study, we examined the quality characteristics of soy yogurts produced using two proteases($Flavourzyme^{(R)}$ and $Neutrase^{(R)}$) and the mixed microbial consortia of Lactobacillus bulgaricus and Streptococcus thermophilus (two-mixed) and Lactobacillus acidophilus, Bifidobacterium lactis, and S. thermophilus (three-mixed). The viscosity was the highest in the untreated yogurt. Among the proteolyzed samples, those treated with $Flavourzyme^{(R)}$ for 20 min showed the highest viscosity, whereas the samples treated with $Neutrase^{(R)}$ for 30 min and cultured with three-mixed microbial consortia showed the lowest viscosity. The numbers of viable bacteria in the $Flavourzyme^{(R)}$-treated samples were slightly greater than those in the $Neutrase^{(R)}$-treated samples. The number of viable bacteria increased as hydrolysis time increased.The organic acid content was higher in the three-mixed group than in the two-mixed group, and it was higher in the $Flavourzyme^{(R)}$-treated samples than in the $Neutrase^{(R)}$-treated samples.Among the $Flavourzyme^{(R)}$-treated samples, the three-mixed group showed higher total free amino acid content than the two-mixed group. In contrast, among the $Neutrase^{(R)}$-treated samples, those cultured with both mixed microbial consortia produced the similar amounts of free amino acids. The above results showed that proteolytic treatment promoted the growth of lactic acid-producing bacteria. Soy yogurts produced using $Flavourzyme^{(R)}$ and three-mixed microbial consortia were thought to be more desirable because ofmore organic acids and free amino acids than those produced using $Neutrase^{(R)}$ and two-mixed microbial consortia.

Gluconacetobacter sp. gel_SEA623-2를 이용한 Bacterial Cellulose 생산에 초산농도 및 유산균 혼합배양이 미치는 영향

김경민,김지현,양경월,Kim, Kyung min,Kim, Jihyeon,Yang, Kyong Wol 한국미생물학회 2014 미생물학회지 Vol.50 No.3

In this study, Gluconacetobacter sp. gel_SEA623-2 isolated from citrus that produces bacterial cellulose was used to examine the effect of initial concentration of acetic acid and mixed culture inoculated with Lactobacillus plantarum KCCM 80077 on productivity of bacterial cellulose. In mixed culture added with 0.5% acetic acid, the viable cell count increased from $2.4{\times}10^6CFU/ml$ to $1.1{\times}10^7CFU/ml$ after 14 days of culture, and total acidity was about 0.3% higher than single culture added with 0.5% acetic acid, which implies that additional lactic acid was produced by L. plantarum KCCM 80077. In single culture, although bacterial cellulose productivity was higher when the initial concentrations of acetic acid were 0.0% and 0.5%, than when it was 1.0%, there was no significant difference. However, in mixed culture, adding 0.5% acetic acid resulted in dry weight of $37.83{\pm}6.81g/L$ and thickness of $10.33{\pm}0.58mm$, showing a significant difference from that of single culture added with 1% acetic acid, $28.40{\pm}1.23g/L$ and $7.50{\pm}0.50mm$ (P<0.05). 본 연구에서는 bacterial cellulose를 생산하는 감귤에서 분리된 Gluconacetobacter sp. gel_SEA623-2를 이용하여 초기 초산농도 및 Lactobacillus plantarum KCCM 80077 유산균을 접종한 mixed culture가 bacterial cellulose 생산성에 미치는 영향을 알아보았다. 0.5%의 초산을 첨가한 mixed culture의 경우 초기 생균수가 $2.4{\times}10^6CFU/ml$에서 14일 동안 배양한 이후에 $1.1{\times}10^7CFU/ml$까지 증가하였고 total acidity가 0.5%의 초산을 첨가한 single culture와 비교하여 0.3% 가량 높게 측정되어 유산균에 의해 추가적으로 젖산이 생성된 것으로 판단된다. Single culture에서는 초기 초산농도가 0.0 및 0.5%일 때 1.0% 농도와 비교하여 상대적으로 높은 bacterial cellulose 생산성을 나타내기는 하였으나 유의적인 차이는 보이지 못하였다. 하지만 mixed culture에서는 0.5%의 초산을 첨가하였을 때 $37.83{\pm}6.81g/L$의 dry weight과 $10.33{\pm}0.58mm$의 thickness를 나타냄으로써 1%의 초산을 첨가한 single culture의 $28.40{\pm}1.23g/L$와 $7.50{\pm}0.50mm$의 생산량과 비교하여 유의적인 차이를 나타내었다(P<0.05).

Preparation of Cellulose Nanocrystals via a Mild Mixed Acid Hydrolysis with High Yield and High Thermal Stability

Zhufan Zou,Xianghao Yang,Hongxiang Xie,Hongyan Lan,Yang Cheng,Jiahui Shen,Youngsoo Bae,Chuanling Si 강원대학교 산림과학연구소 2018 강원대학교 산림과학연구소 학술대회 Vol.2018 No.09

Cellulose nanocrystals (CNCs) are mainly produced by traditional mineral acid hydrolysis, such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, etc., which usually causes some problems such as corrosion of equipment, inability of acid recovery, large amounts of water usage, and over-degradation of cellulose. In this work, a green and sustainable approach for the preparation of CNCs was developed by using a mixed acid hydrolysis of oxalic acid and sulfuric acid. The acid ratio, reaction temperature, and reaction time were investigated in detail. It was discovered that a high yield up to 85 % was achieved by this mixed acid with a ratio of 5:1:4 for sulfuric acid: oxalic acid: H2O respectively at 95 oC for 2 h. Results showed that the resultant CNCs have a narrow particle size of 416±35 nm (based on dynamic light scattering). TEM characterization showed the CNCs was perfect whisker morphology. Also, the obtained CNCs exhibited superior dispersion stability in water due to the introduction of carboxyl group on the surface of CNCs by oxalate esterification. Thermogravimetric analyses revealed that the resultant CNCs showed a much higher thermal stability (315 °C) than the traditional sulfuric acid hydrolyzed CNCs. In addition, over 90% of oxalic acid could be recovered by a simple recrystallization step. Thus, the present work demonstrated an efficient and green preparation method of CNCs with high yield and high thermal stability.

Quality characteristics of soy yogurt produced using proteases and mixed microbial consortia

박미정,이숙영 한국응용생명화학회 2015 Applied Biological Chemistry (Appl Biol Chem) Vol.58 No.5

In this study, we examined the quality characteristics of soy yogurts produced using two proteases( FlavourzymeandNeutrase) and themixedmicrobial consortia of Lactobacillus bulgaricus and Streptococcus thermophilus (two-mixed) and Lactobacillus acidophilus, Bifidobacterium lactis, and S. thermophilus (three-mixed). The viscosity was the highest in the untreated yogurt. Among the proteolyzed samples, those treated with Flavourzyme for 20 min showed the highest viscosity, whereas the samples treated with Neutrase for 30 min and cultured with threemixed microbial consortia showed the lowest viscosity. The numbers of viable bacteria in the Flavourzyme-treated samples were slightly greater than those in the Neutrase- treated samples. The number of viable bacteria increased as hydrolysis time increased.The organic acid contentwas higher in the three-mixed group than in the two-mixed group, and it was higher in the Flavourzyme-treated samples than in the Neutrase-treated samples.Among theFlavourzyme-treated samples, the three-mixed group showed higher total free amino acid content than the two-mixed group. In contrast, among the Neutrase-treated samples, those cultured with both mixed microbial consortia produced the similar amounts of free amino acids. The above results showed that proteolytic treatment promoted the growth of lactic acid-producing bacteria. Soy yogurts produced using Flavourzyme and threemixed microbial consortia were thought to be more desirable because ofmore organic acids and free amino acids than those produced usingNeutraseand two-mixedmicrobial consortia.

Effects of Organic Acids Mix and Modified Atmosphere Packaging on the Storage Quality of Sliced Bacon

Muhlisin, Muhlisin,Kang, Sun-Moon,Choi, Won-Hee,Lee, Keun-Taik,Cheong, Sung-Hee,Lee, Sung-Ki Korean Society for Food Science of Animal Resource 2011 한국축산식품학회지 Vol.31 No.5

The effects of organic acids mix (0.4%) and modified atmosphere packaging (MAP) on the storage quality of sliced bacon were investigated. Pork bellies were treated with or without organic acids at the curing stage. The organic acids mix comprised 35% sodium acetate, 25% salt, 15% calcium lactate, 11% trisodium citrate, 7% ascorbate, and 7% citric acid. The cured pork bellies were smoked and packaged with 50% $CO_2$ + 50% $N_2$ (50% $CO_2$-MAP) and 100% $N_2$ (100% $N_2$-MAP), and stored at $5^{\circ}C$ for 14 d. The 50% $CO_2$-MAP showed a higher pH value (p<0.05) up to 10 d, a lower protein deterioration (p<0.05) as measured by volatile basic nitrogen (VBN) from 6 to 14 d, and a higher color value of lightness (CIE $L^*$) compared to 100% $N_2$-MAP. The development of lipid oxidation measured by thiobarbituric acid reactive substance (TBARS) values seemed to be effectively controlled throughout the storage period in both 50% $CO_2$-MAP and 100% $N_2$-MAP regardless of the application of organic acids. The 50% $CO_2$-MAP inhibited the growth of aerobic and anaerobic bacteria (p<0.05) both in non-added and bacon added with organic acids mix. The 50% $CO_2$-MAP alone seemed to be effective in delaying the growth of bacteria since the use of organic acids mix gave no additional effects. The addition of organic acids mix lowered the pH value (p<0.05), effectively retarded the protein deterioration (p<0.05), and showed a higher color value of lightness (CIE $L^*$) value (p<0.05) and lower color value of redness (CIE $a^*$) value (p<0.05). In conclusion, 50% $CO^2$-MAP showed better quality and self-life of sliced bacon during storage. However, the beneficial effect of organic acids mix was not noticed in the concentration used in this experiment.

Effects of Organic Acids Mix and Modified Atmosphere Packaging on the Storage Quality of Sliced Bacon

Muhlisin,강선문,최원희,이근택,정성희,이성기 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.5

The effects of organic acids mix (0.4%) and modified atmosphere packaging (MAP) on the storage quality of sliced bacon were investigated. Pork bellies were treated with or without organic acids at the curing stage. The organic acids mix comprised 35% sodium acetate, 25% salt, 15% calcium lactate, 11% trisodium citrate, 7% ascorbate, and 7% citric acid. The cured pork bellies were smoked and packaged with 50% CO_2 + 50% N_2 (50% CO_2-MAP) and 100% N_2 (100% N_2-MAP), and stored at 5℃ for 14 d. The 50% CO_2-MAP showed a higher pH value (p<0.05) up to 10 d, a lower protein deterioration (p<0.05) as measured by volatile basic nitrogen (VBN) from 6 to 14 d, and a higher color value of lightness (CIE L^*) compared to 100% N_2-MAP. The development of lipid oxidation measured by thiobarbituric acid reactive substance (TBARS)values seemed to be effectively controlled throughout the storage period in both 50% CO_2-MAP and 100% N_2-MAP regardless of the application of organic acids. The 50% CO_2-MAP inhibited the growth of aerobic and anaerobic bacteria (p<0.05) both in non-added and bacon added with organic acids mix. The 50% CO_2-MAP alone seemed to be effective in delaying the growth of bacteria since the use of organic acids mix gave no additional effects. The addition of organic acids mix lowered the pH value (p<0.05), effectively retarded the protein deterioration (p<0.05), and showed a higher color value of lightness (CIE L^*) value (p<0.05) and lower color value of redness (CIE a^*) value (p<0.05). In conclusion, 50% CO_2-MAP showed better quality and self-life of sliced bacon during storage. However, the beneficial effect of organic acids mix was not noticed in the concentration used in this experiment.

국내 유통되는 커피 크리머와 커피믹스에 함유된 지방의 지방산 조성 및 관능적 특성

이봄이(Bomee Lee),이희재(Hee Jae Lee),조은애(Eunae Cho),황금택(Keum Taek Hwang) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.3

본 연구에서는 국내 유통되는 커피 크리머와 커피믹스의 수분 함량과 지방 함량을 측정하고 지방의 지방산 조성을 분석하였고 관능평가를 수행하였다. 커피 크리머의 수분 함량은 1.9∼4.5%, 지방 함량은 15.4∼28.5%이었다. 인스턴트 커피믹스의 수분 함량은 1.1∼2.8%, 지방 함량은 7.7∼14.0% 이었다. 14개 커피 크리머 제품 중 12개 제품의 지방은 포화지방산이 90% 이상으로 조성되어 있었는데, lauric acid, myristic acid, palmitic acid 순서로 많았다. 나머지 2개 제품의 지방은 포화지방산이 50%, 단일불포화지방산이 39%, 다중불포화지방산이 10%로 이루어져 있었다. 커피믹스 11개 제품의 지방은 포화지방산이 99∼100%를 차지하고 있었는데, lauric acid, myristic acid, palmitic acid의 순서로 많았다. Lauric acid와 myristic acid의 함량이 높은 제품은 coconut oil이나 palm kernel oil에서 유래되었다고 볼 수 있으며, palmitic acid, oleic acid, linoleic acid의 함량이 높은 제품은 palm oil(PO)을 지방 원료로 사용하였다고 볼 수 있다. 지방산 조성 분석을 바탕으로 지방산 조성의 특성에 따라 5가지 제품을 선택하여 관능 평가를 수행한 결과, 향과 맛 그리고 전반적인 기호도는 lauric acid가 많이 함유된 커피 크리머를 첨가한 커피가 유의적으로 좋은 평가를 받았으며(p<0.05), palmitic acid, oleic acid, linoleic acid의 함량이 높은 커피크리머는 전반적인 기호도 면에서 유의적으로 낮은 평가를 받아(p<0.05), PO의 원료를 많이 함유할수록 커피의 맛에 안 좋은 영향을 주는 것을 알 수 있었다. Hydrogenated coconut oil(HCO)과 PO의 배합 비율을 다르게 하여 제조한 커피 크리머로 만든 커피를 관능 평가한 결과, HCO의 비율이 높을수록 전반적인 기호도에서 높은 평가를 받았다. 따라서 커피 크리머에 함유된 지방이 커피의 맛에 영향을 주는 것을 알 수 있었다. This study examined the fatty acid compositions of the fats extracted from 14 commercial coffee creamers and 11 instant coffee mixes, and evaluated the sensory characteristics of the coffees using different coffee creamers. The fat content in the 14 coffee creamers and 11 coffee mixes was 15~28% and 8~14%, respectively. The fats in 12 coffee creamers consisted of 34~45% lauric, 15~19% myristic and 10~18% palmitic acids. The fats in the other 2 coffee creamers consisted of 43% palmitic, 39% oleic and 10% linoleic acids. The fatty acids of the fats in the 11 coffee mixes were almost all saturated with lauric acid being the most abundant (44~45%). Coconut oil or palm kernel oil might have been used to manufacture the 12 coffee creamers and 11 coffee mixes, which had a higher lauric acid content. Palm oil (PO) might be a fat source for the other 2 coffee creamers. The sensory characteristics of five coffee mixes were evaluated based on their fatty acid compositions. The coffees with the creamers, which had a higher lauric acid content, were significantly more acceptable than those with a higher palmitic acid (p<0.05). The sensory evaluation of the coffees made with the creamers composed of hydrogenated coconut oil (HCO) and PO at different ratios showed that the acceptability increased with increasing HCO content. This suggests that PO may have a negative impact on the sensory characteristics.

인공적인 고고도와 중고도 환경에서의 혼합형 저산소 트레이닝이 최대 하 운동 시 혈액가스에 미치는 영향

박훈영(Park, Hun-Young),선우섭(Sunoo, Sub),남상석(Nam, Sang-Seok) 한국체육과학회 2016 한국체육과학회지 Vol.25 No.5

The purpose of our study was investigated the effect of mixed hypoxic training on acid-base balance capacity during submaximal exercise. For purpose of our study, 33 male college students were randomly assigned into control group; training at sea-level during 4 weeks, fixed IHT group; training at 2,000 m simulated altitude during 4 weeks, and mixed IHT group; training at 3,000 m simulated altitude until 2 weeks and training 2,000 m simulated altitude since 3 weeks. We compared their exercise load, respiratory gas, blood lactate level, and blood gas during 80% HRmax submaximal bicycle exercise before and after 4 weeks training. The training consisted of bicycle exercise (30 min) and treadmill exercise (30 min) within 80% HRmax. Exercise frequency was 1 hour, 3 days per a week, and during 4 weeks. We obtained the follow results: First, the possibility of improving exercise performance was presented increase tendency at mixed IHT group. Second, CO₂ production through breathing and blood lactate level were presented increase tendency at fixed and mixed IHT group. Third, despite the increase in exercise load, mixed and fixed IHT group were showed a similar metabolic acidosis compared with control group. In conclusion, mixed IHT is effective on improvement of acid-base balance capacity compared with training at sea-level, but it is difficult to evaluate as effectively compared with fixed IHT method. In addition, we consider that acid-base balance capacity was improved by hypoxic ventilatory response through increase of CO2 production at mixed and fixed IHT group compared with control group. Therefore, we confirm that submaximal exercise performance was increased by improvement of acid-base balance capacity through fixed and mixed IHT.

Butyric Acid Fermentation of Sodium Hydroxide Pretreated Rice Straw with Undefined Mixed Culture

( Binling Ai ),( Jianzheng Li ),( Xue Chi ),( Jia Meng ),( Chong Liu ),( En Shi ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.5

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at 50°C for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.