Although probiotics have been shown to improve health when consumed, recent studies have reported that they can cause unwanted side effects due to bacterial-human interactions. Therefore, the importance of prebiotics that can form beneficial microbiome in the gut has been emphasized. This study isolated and identified bacteria capable of producing biopoymer as a candidate prebiotic from traditional fermented foods. The isolated and identified strain was named WCYSK01 (Wissella sp. strain YSK01). The composition of the medium for culturing this strain was prepared by dissolving 3 g K2HPO4, 0.2 g MgSO4, 0.05 g CaCl2, 0.1 g NaCl in 1 L of distilled water. The LMBP(low molecular weight biopoymers) produced when fermentation was performed with sucrose and maltose as substrates were mainly consisted of DP3 (degree of polymer; isomaltotriose), DP4 (isomaltotetraose), DP5 (isomaltopentaose), and DP6 (isomaltoheptaose). The optimization of LMBP (low molecular weight of biopolymer) production was performed using the response surface methodology. The fermentation process temperature range of 18 to 32oC, the fermentation medium pH in the range of 5.1 to 7.9. The yield of LMBP production by the strain was found to be significantly affected by q fermentation temperature and pH. The optimal fermentation conditions were found at the normal point, and the production yield was more than 75% at pH 7.5 and temperature of 23oC.

Collagen is one of the most widely used biological materials in medical design. Collagen extracted from marine organisms can be a good biomaterial for tissue engineering applications due to its suitable properties. In this study, collagen is extracted from fish skin of Ctenopharyngodon Idella; then, the freeze drying method is used to design a porous scaffold. The scaffolds are modified with the chemical crosslinker N-(3-Dimethylaminopropyl)-N'-ethyl carbodiimide hydrochloride (EDC) to improve some of the overall properties. The extracted collagen samples are evaluated by various analyzes including cytotoxicity test, SDS-PAGE, FTIR, DSC, SEM, biodegradability and cell culture. The results of the SDS-PAGE study demonstrate well the protein patterns of the extracted collagen. The results show that cross-linking of collagen scaffold increases denaturation temperature and degradation time. The results of cytotoxicity show that the modified scaffolds have no toxicity. The cell adhesion study also shows that epithelial cells adhere well to the scaffold. Therefore, this method of chemical modification of collagen scaffold can improve the physical and biological properties. Overall, the modified collagen scaffold can be a promising candidate for tissue engineering applications.

배양액으로부터 isopropyl alcohol로 침전하여 얻은 crude biopolymer를 gel chromatography와 음이온교환수지인 DEAE-cellulose로 ion exchange chromatography를 행한 결과 분자량은 대략 9.65×105 Da였으며 5%(w/w)의 중성당 (PSI)과 95%(w/w)의 산성 당(PSII)을 함유하고 있었다. Crude biopolymer의 총 당 함량은 57%, acyl group 0.88%, uronic acid인 CO2의 함량은 17.5%임을 알 수 있었다. CPC와 crude biopolymer와의 착물형성에 따라 NaCl과 CaCl2의 염을 사용하는 분리정제를 위한 임계농도는 두 가지 염 모두 0.4에서 0.5 M의 농도범위를 나타내었다. CPC를 사용하여 산성당과 중성당을 각각 분리하여 분석한 결과 중성당은 glucose, arabinose, mannose를 함유하였고 산성당은 glucose, xylose, galactose, arabinose, mannose 의 구성당을 함유하고 있었다. Crude biopolymer의 95%를 차지하고 있는 산성당(PSII)의 molarity 비율은 glucose: xylose:galactose : arabinose :mannose = 32.8 : 0.48 : 8.91 : 1 : 24.98의 비율로 계산되어 glucose와 mannose와 galactose가 주요 구성당이라고 할 수 있었다. 당 결합 양상은 smith degradation 결과, product로 glucose glycerol, erythritol이 생성되어 1, 6 및 1, 4 결합으로 구성되어진 다당으로 추정하였다. 중화당량은 372로 분석되어 2.3 잔기당 음이온이 한 개 존재하는 biopolymer임을 알 수 있었다.

For the study of the production and availability of biopolymer from Bacillus polymyxa YU-101, its rheological properties were investigated in comparison with other polysaccharides. The intrinsic viscosity of the biopolymer was 35.18 dL/g, showing the characteristics of the polyelectrolyte. The chain stiffness of the biopolymer was 0.55, which was expected to be extremely flexible, and the coil overlap parameter and the critical concentration were 0.722 and 0.15 dL/g, respectively. The activation energy of the biopolymer calculated by intrinsic viscosity showed two linear relationships at 50oC. Biopolymer showed pseudoplastic flow characteristics with increasing shear rate. At a concentration of 0.5% (w/w), the consistency index was 660.39 mPa·S and the flow behavior index was 0.765 and 0.4 at the shear rates of 0-11.7 s-1 and 11.7-105.3 s-1, respectively, similar to guar gum. At the shear rate of 58.5 s-1, the apparent viscosity of the biopolymer with the change of pH showed an abrupt increase in the range of acidity. In addition, the apparent viscosity of the biopolymer showed the maximum value at the 0.3%(w/w) concentration of salt, increased only by sucrose in the tested sugars.

Curcumin is a natural polyphenolic phytochemical, which has a number of potential benefits in biological activities. However, curcumin has extremely low water solubility and low bioavailability, which makes it difficult to incorporate into many food products. In this study, we investigated the effects of biopolymer emulsifier type and environmental stress on the physical stability of nanoemulsions containing curcumin. Nanoemulsion containing curcumin stabilized by sodium caseinate (SC), whey protein isolate (WPI), modified starch (MS), and gum arabic (GA) were prepared using microfludizer. The droplet size of nanoemulsions decreased significantly from 1028 nm to 169 nm as emulsifier concentration increased (p<0.05). The optimum concentration of emulsifiers for stable curcumin nanoemulsions were determined to be 1% of SC and 1% of WPI, respectively. The storage study showed that the nanoemulsions were physically stable for 5 weeks at 25oC. In addition, nanoemulsions were physically stable against heat, freeze-thaw, pH, and NaCl solution. However, extensive droplet aggregation occurred in protein-stabilized nanoemulsions at CaCl2 solution, which was attributed to hydrophobic interaction between droplets.

고추장에서 점물질을 생산하는 세균을 분리하고 Bacillus licheniformis로 동정하였다. 본 균주는 sucrose 6%, Yeast extract 0.1%, peptone 0.1%, NaC1 3%의 배지조성에서 pH를 6으로 조정하였을 때 점물질 생산량이 가장 높았고 생산량은 34mg/250ml였다. 이 점물질은 1%농도에서 필름 형성능이 있었고, 0.25-1.00%의 시험범위에서 Kaolin을 침전시키고, 유산균 현탁액을 안정화시키는 능력을

초산전분과 미생물이 생산하는 biopolymer를 사용하여 smoked pork sausage를 제조하고 이들이 소시지 품질에 미치는 영향을 조사한 결과, 기계적 물성의 경도는 대조구에 비해 SA, SB, SC 모두 유의적으로 적었고, 응집성은 초산전분 단독으로 0.6%첨가한 시료 SA가 유의적으로 적게 나타났다. 점착성은 biopolymer을 첨가한 시료 SA와 SC가 유의적으로 크게 나타났고, 탄성은 대조구에 비해 모두 작게 나타났다. 껌성과 씹힘성은 4가지 시료 모두가 서로 유의적으로 다른 값을 가지므로써 초산전분과 biopolymer는 껌성과 씹힘성에 크게 영향을 미치는 것으로 나타났다. 기계적 물성의 상관관계에서 경도는 탄성, 껌성, 씹힘성과 서로 정의 상관관계로 나타났으며, 점착성과는 부의 상관관계로 나타났다. 절곡시험에서 초산전분 0.6%를 첨가한 시료 SB가 가장 좋았으며, VBN 함량은 biopolymer와 초산전분을 함께 첨가한 시료가 대조구에 비해 약 65% 정도 적게 생성되었다. 관능적 물성의 기호도 조사 결과, 껌성은 biopolymer을 첨가한 시험구 SA와 SC가 유의적으로 좋게 나타났고 (p<0.001), 소시지의 전체적인 기호도는 부서짐성과 씹힘성, 그리고 껌성이 기호도에 큰 영향을 미치는 것으로 나타남에 따라 biopolymer를 첨가한 시료가 유의적으로 좋게 나타났다(p<0.001). 전체적인 기호도의 상관관계에서는 관능검사의 씹힘성과 기계적 물성의 껌성이 서로 유의차를 갖는 것으로 나타났다(p<0.05).

Recently, a great social damage has been caused by the sargassum homeri, which has flowed from China in the Jeju and Namhae coasts. In this study, biopolymer was prepared by using sargassum homeri and applied to bridge pavement concrete. The performance of chloride ion penetration resistance of the bridge pavement concrete made of biopolymer was evaluated. As a result, excellent penetration resistance performance was shown.

본 연구에서는 다당류와 단백질의 이온 결합으로 구성된 마이크로캡슐 및 에멀젼을 제조하여 다당류, 단백질의 비율에 따른 마이크로캡슐과 에멀젼의 안정도를 평가하였으며, 마이크로캡슐의 내부 오일도 종류별로 실험하였다. 에멀젼 입도를 줄여 안정도를 높여주기 위해 고압유화기를 이용하여 에멀젼을 제조하였으며 내부 담지 물질로 코엔자임 Q10 안정화를 관찰한 결과 대조군 대비 역가 하락이 없었다. 석유 유래 계면활성제가 아닌 천연 유래 원료만으로 안정한 마이크로캡슐 제조에 성공한 것이다. 광학현미경, 투과전자현미경을 이용하 여 마이크로캡슐 및 에멀젼의 물리적 안정도를 관찰하고 에멀젼의 구조분석을 하였으며, 입자의 표면전위 측정 을 통하여 pH 조절에 의해 제조되는 다당류/단백질 마이크로캡슐의 제조 메커니즘을 설명한다.

In order to develop bacterial cellulose (BC) with antimicrobial activity against pathogenic microorganisms, silver and chitosan were incorporated into BC, respectively. Experiment results showed that antimicrobial activity against pathogenic microorganisms was improved with increasing silver concentration. Chitosan also showed a direct proportion between its concentration and antimicrobial activity. These results suggest that antimicrobial effects of BC using silver and chitosan are well proven to be effective. We also tested the stainability of BC with natural colorant for the application of food industry. Stainability of BC was enhanced with increasing natural colorant concentration. Decolorization of BC stained was observed by dipping it into distilled water with one hour-intervals. As a result, there was no significant difference. Combination of natural colorant-stainability and antibiosis of BC is expected to be useful in making colored antibiotic BC in various industrial application areas, considering its antimicrobial activity, high stainability and low decolorization tendency.

The rheological Voperties of biopolymers produced by Bacilli sp. K-1 and its mutant strains(KM-21, KM-83) were studied at the temperature ranges with 20∼80, at the concenration of 2∼6%, at the pH ranges from 3.0 to 9.0 and at the shear rate of 9.3-930sec-1 The apparent viscosity of biopolymers was decreased with increasing shear rate, and thereby biopolymers showed pseudoplastic characteristics. It was found that the apparent viscosity models respected 19 temperature, concentration and both temperature and concentration were expressed by Arrhenius Model, Exponential Model and combined of the above two Models. Therefore, the apparent viscosity could be predictable by Arrhenius and Exponential Models with high R2.