• 한국미생물·생명공학회지
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• 제38권2호
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• pp.222-226
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• 2010

This study was carried out to isolate and characterize the Lactobacillus plantarum with bile salt deconjugation activity that was isolated from Kimchi. Some isolates were selected and identified as L. plantarum by 16S rRNA gene sequence and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of whole cell protein patterns. They were assayed to determine their capacities to express bile salt hydrolase (BSH) activity. Among the identified strains, L. plantarum CIB 001 showed the highest level of BSH activity. Then, resistance to gastric acidity and bile condition were analyzed for further characterization. This strain was able to maintain viability for 1h at pH 2.0 and to survive in a MRS (deMan, Rogosa, and Sharpe) broth with 1.0% of bile acids. L. plantarum CIB 001 would potentially be useful in the food industry as probiotics.

• Journal of Applied Biological Chemistry
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• 제57권2호
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• pp.183-188
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• 2014

In order to increase the nutritional quality of soybean meal (SBM) as an animal feed, Bacillus subtilis TP6, a previously isolated strain from an Indonesian traditional fermented soybean food, Tempeh, was used as a starter organism for solid-state fermentation. In the pre-treated SBM with water content of 60% (v/w), B. subtilis TP6 was grown to a maximum viable cell number of $3.5{\times}10^9CFU/g$. Compared to control, crude protein in Bacillus fermented SBM was increased by 16%, while raffinose, stachyose, and trypsin inhibitors were reduced by 31, 37, and 90%, respectively. The Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that proteins in the fermented SBM were remarkably hydrolyzed into smaller molecular masses, resulting in a decrease in large sized proteins. Our data suggested that B. subtilis fermentation could increase the nutritive value of SBM through reduction of anti-nutritive factors and improvement of protein quality by hydrolysis of soy protein. In addition, B. subtilis TP6 produced a functional ingredient, poly-${\gamma}$-glutamic acid which has various health benefits.

• 한국어병학회지
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• 제34권1호
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• pp.111-115
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• 2021

Immunoglobulin M (IgM) of sevenband grouper (Epinephelus septemfasciatus) was purified by mannan-binding protein (MBP) affinity column. The purified IgM had an apparent molecular weights of 76 (heavy chain) and 28 (light chain) kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Eight hybridoma clones secreting monoclonal antibodies (mAbs) against sevenband grouper IgM were established. Antibody detection enzyme-linked immunosorbent assay (ELISA) with bovine serum albumin (BSA, antigen) and the 8 mAbs revealed that optical density (OD) values were clearly different between sera from BSA-immunization and non-immunization of sevenband grouper. These results suggest that the produced mAbs in this study are specifically reacted with IgM of sevenband grouper.

• Journal of Animal Science and Technology
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• 제63권2호
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• pp.405-416
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• 2021

The aim of the study was to determine the effect of whole milk powder (WMP) as heterologous proteins on chicken breast emulsion-type sausages. The quality properties of WMP on such chicken breast emulsion-type sausages were investigated by measuring the proximate composition, pH, color, cooking yield, protein solubility, and by applying other methods, such as texture profile analysis (TPA), microphotograph, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and electronic nose. The crude fat, protein, and ash contents of 15% WMP samples were significantly higher than the control samples (p < 0.05). The redness of the cooked samples significantly increased with an increase in the WMP contents (p < 0.05). The cooking yield of WMP treated samples was significantly higher than the control sample (p < 0.05). Additionally, the hardness, gumminess, and chewiness of WMP treated samples were significantly higher than the control sample (p < 0.05). The sarcoplasmic and myofibrillar proteins of samples containing 15% WMP were significantly higher than the control samples (p < 0.05). The result of SDS-PAGE showed that the C protein, sarcoplasmic protein, actin, and tropomyosin increased with an increase in the WMP contents. The principal component analysis plot of WMP-treated samples was clearly different from that of the control samples. Based on these results, it was predicted that WMP could be useful as heterologous protein on emulsion-type sausage.

• 한국미생물·생명공학회지
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• 제50권1호
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• pp.71-80
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• 2022

Lipases (triacylglycerol acylhydrolases [EC 3.1.1.3]) are water-soluble enzymes. They catalyze the hydrolysis of fats and oils. A cold-active lipase from marine Bacillus cereus HSS, isolated from the Mediterranean Sea, Alexandria, Egypt, was purified and characterized. The total purification depending on lipase activity was 438.9 fold purification recording 632 U/mg protein. The molecular weight of the purified lipase was estimated to be 65 kDa using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The optimum substrate concentration, enzyme concentration, pH, and temperature were 1.5 mM, 100 µl, pH 6 and 10℃, respectively. The lipase was tolerant to NaCl concentrations ranging from 1.5 to 4.5%. The lipase was affected by the tested metal ions, and its activity was inhibited by 16% in the presence of 0.05 M SDS. The application of the cold-active lipase for the removal of an oil stain from a white cotton cloth showed that it is a promising biological agent for the treatment of oily wastes and other related applications. To the best of our knowledge, this is the first report of the purification and characterization of a lipase from marine B. cereus HSS isolated from the Mediterranean Sea.

• 한국축산식품학회지
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• 제42권1호
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• pp.73-83
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• 2022

The aim of this study is to determine the effects of using emulsion manufactured with soybeans (ES) to substitute chicken breast in Vienna sausages. Four types of Vienna sausages (S1: 10% ES and 50% chicken, S2: 20% ES and 40% chicken, S3: 30% ES and 30% chicken, and S4: 40% ES and 20% chicken) for this study were made. The pH, color, proximate composition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), microphotographs, cooking yields, and texture profile analysis of sausages were examined. The pH value of uncooked and cooked sausages increased significantly with increasing ES content (p<0.05). The crude protein contents of S2, S3, and S4 were significantly higher than that of the control (p<0.05). Furthermore, the SDS-PAGE results showed that α-conglycinin, β-conglycinin, and the acidic subunit of glycinin all increased with increasing ES content. Microphotographs revealed that increasing the ES content decreased the size of fat globules. The cooking yields of samples increased significantly with increasing ES content (p<0.05). The hardness values of ES treated samples were significantly lower than that of the control (p<0.05). Therefore, 30% substitute of chicken breast with ES can improve the quality and structure of Vienna sausage, without inducing critical defects.

• Journal of the Korean Wood Science and Technology
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• 제50권3호
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• pp.159-166
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• 2022

CO₂ emissions are the primary reason for global warming; hence, biological and chemical technologies for converting CO₂ into useful compounds are being actively studied. Biological methods using enzymes can convert CO₂ under mild conditions. Formate dehydrogenase (FDH) is a representative CO₂ conversion enzyme. Its function was revealed after isolation from bacteria, yeast, and plants. In this study, we evaluated the CO₂ conversion potential of FDH isolated from wood-rotting fungi. After isolating the FDH gene (TvFDH) from Trametes versicolor, we cloned the full-length FDH from T. versicolor and expressed it in a cell-free expression system. The gene encoding TvFDH was identified as 1,200 bp open reading frame (ORF) and the expected molecular weight of the protein was approximately 42 kDa. Overexpression of the recombinant crude protein including TvFDH was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Enzyme activities and metabolite analyses confirmed the efficiency of TvFDH for CO₂ reduction.

• 한국축산식품학회지
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• 제43권5호
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• pp.877-888
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• 2023

We studied the proteolysis and conducted a sensory evaluation of fermented sausages using strains derived from Kimchi [Pediococcus pentosaceus-SMFM2021-GK1 (GK1); P. pentosaceus-SMFM2021-NK3 (NK3)], Doenjang [Debaryomyces hansenii-SMFM2021-D1 (D1)], and spontaneous fermented sausage [Penicillium nalgiovense-SMFM2021-S6 (S6)]. Fermented sausages were classified as commercial starter culture (CST), mixed with GK1, D1, and S6 (GKDS), and mixed with NK3, D1, and S6 (NKDS). The protein content and pH of GKDS and NKDS were significantly higher than those of CST on days 3 and 31, respectively (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the NKDS had higher molecular weight proteins than the GKDS and CST. The myofibrillar protein solubility of the GKDS and NKDS was significantly higher than that of the CST on day 31 (p<0.05). The GKDS displayed significantly higher pepsin and trypsin digestion than the NKDS on day 31 (p<0.05). The hardness, chewiness, gumminess, and cohesiveness of the GKDS were not significantly different from those of the CST. The GKDS exhibited the highest values for flavor, tenderness, texture, and overall acceptability. According to this study, sausages fermented using lactic acid bacteria (GK1), yeast (D1), and mold (S6) derived from Korean fermented foods displayed high proteolysis and excellent sensory evaluation results.

• Journal of Microbiology and Biotechnology
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• 제33권5호
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• pp.656-661
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• 2023

The aims of this study were to optimize the preparation of low-molecular-weight collagen using a proteolytic enzyme (alcalase) derived from the feet of Korean native chickens, and to characterize the process of collagen hydrolysis. Foreign bodies from chicken feet were removed using ultrasonication at 28 kHz with 1.36 kW for more than 25 min. The hydrolytic pattern and molecular weight distribution of enzyme-treated collagen from chicken feet were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography, respectively. Ideally, chicken feet should be treated at 100℃ for 8 h to obtain a high collagen content using hot water extraction. The collagen content of the chicken foot extract was 13.9 g/100 g, and the proportion of low-molecular-weight collagen increased with increasing proteolytic enzyme concentration and reaction time. When treated with 1% alcalase, the average molecular weight of collagen decreased rapidly to 4,929 Da within 5 h and thereafter decreased at a slower rate, reaching 4,916 Da after 7 h. Size exclusion chromatography revealed that low-molecular-weight collagen peptides of approximately 1,000-5,000 Da were obtained after hydrolysis with 1% alcalase for 1 h.

• 한국산학기술학회논문지
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• 제17권10호
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• pp.199-203
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• 2016

아포리포포린-III (apoLp-III)를 꿀벌부채명나방 종령 유충 혈림프로부터 KBr 농도구배 초원심분리와 겔크로마토그래피(Sephadex G-100)를 이용하여 분리, 정제하였다. KBr 농도구배 초원심분리가 끝난 후, 리포포린을 제외한 분획 (lipophorin-free fractions)을 겔크로마토그래피 시료로 사용하였으며, 겔크로마토그래피를 행한후 sodium dodecyl sulfate (SDS)-전기영동으로 apoLp-III의 정제를 확인하였다. 또한, 본 연구에서는 유충 혈림프로부터 정제된 apoLp-III가 꿀벌부채명나방의 성충 정소에 의해 흡수되는 지를 조사하였다. 우화한 지 1일 또는 2일된 성충으로부터 성충 정소를 차가운 링거액에서 분리한 후 조직 배양의 시료로 사용하였다. 순수 정제한 apoLp-III를 dimethyl sulfoxide (DMSO)에 녹인 형광물질 fluorescein isothiocyanate (FITC)와 상온에서 계속 저어가면서 1시간 동안 배양하였다. FITC로 표지된 apoLp-III (FITC-labeled apoLp-III)를 Sephadex G-25 PD-10 column을 이용하여 정제하고 확인하였다. 정제된 FITC-labeled apoLp-III와 성충 정소 조직을 상온에서 30분간 배양하였다. 배양 후 형광현미경 (fluorescence Axioskop microscope)과 SDS-전기영동을 이용하여 FITC-labeled apoLp-III가 정소 조직으로 들어가는 지의 여부를 확인하였다. 그 결과 FITC-labeled apoLp-III가 성충 정소로 흡수된다는 사실을 알 수 있었다.