• BMB Reports
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• 제38권6호
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• pp.661-667
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• 2005

Since conflicting results have been reported on non-specific immune response in type 1 diabetes, this study evaluates polymorphonuclear neutrophil (PMN) functions in the infection free Long Evan diabetic rats (type 1) by using tests that include: polarization assay, phagocytosis of baker's yeasts (Saccharomyces cerevisiae) and nitroblue tetrazolium (NBT) dye reduction. Polarization assay showed that neutrophils from diabetic rats were significantly activated at the basal level compared to those from the controls (p < 0.001). After PMN activation with N-formyl-methionyl-leucyl-phenylalanine (FMLP), control neutrophils were found to be more polarized than those of the diabetic neutrophils and the highest proportions of polarization were found to be 67% and 57% at $10^{-7}\;M$ FMLP, respectively. In the resting state, neutrophils from the diabetic rats reduced significantly more NBT dye than that of the controls (p < 0.001). The percentages of phagocytosis of opsonized yeast cells by the neutrophils from control and diabetic rats were 87% and 61%, respectively and the difference was statistically significant (p < 0.001). Evaluation of the phagocytic efficiency of PMNs revealed that control neutrophils could phagocytose $381{\pm}17$ whereas those from the diabetic rats phagocytosed $282{\pm}16$ yeast cells, and the efficiency of phagocytosis varied significantly (p < 0.001). Further, both the percentages of phagocytosis and the efficiency of phagocytosis by the diabetic neutrophils were inversely related with the levels of their corresponding plasma glucose (p = 0.02; r = -0.498 and p < 0.05; r = -0.43, respectively), which indicated that increased plasma glucose reduced the phagocytic ability of neutrophils. Such relationship was not observed with the control neutrophils. These data clearly indicate that PMN functions are altered in the streptozotocin (STZ) - induced diabetic rats, and hyperglycemia may be the cause for the impairment of their functions leading to many infectious episodes.

• 한국수산과학회지
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• 제36권6호
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• pp.606-613
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• 2003

This study investigated the effects of food type (condensed freshwater Chlorella, dried Chlorella, dried Spirulina, dried Schizochytrium, baker's yeast and $\omega-yeast$) and amount, and supplementation of vitamin $B_{12}$ on the growth of freshwater rotifer (Brachionus calyciflorus) in high density culture. Growth of rotifers fed condensed freshwater Chlorella was the highest and its density ranged $7.65-8.14{\times}10^3\;inds./mL.$ The primary lipid acids of rotifers fed condensed freshwater Chloyella were linoleic and linolenic, and their amount ($\%$ of total fatty acids) were $48.8\%\;and\;26.8\%,$ respectively. This suggests that condensed freshwater Chlorella would be an effective diet for high quality and quantity rotifers, which in turn serve as live food for freshwater fish larvae. Growth rate of rotifers with Chlorella supplementation increased as amount of supplementation increased up to 1.5 and 2.5 mg at 28 and $32^{\circ}C$, respectively. However, undissolved ammonia toxicity and packing volume of Chlorella in culture medium, reached the optimal conditions for the stable and effective cultivation of rotifers when amount of condensed freshwater Chlorella was 1.5 mg in dry weight per 1,000 rotifers at $28^{\circ}C\;and\;32^{\circ}C$ Growth of rotifers in condensed freshwater Chlorella with vitamin $B_{12}$ supplementation was significantly higher than that of rotifers without supplementation. However, no significant difference was found among the different concentrations of vitamin $B_{12}.$ Therefore, vitamin $B_{12}$ could improve the growth of rotifers (B. calyciflorus).

• Journal of Microbiology and Biotechnology
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• 제19권8호
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• pp.845-850
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• 2009

Bioethanol derived from lignocellulosic biomass has the potential to replace gasoline. Cellulose is naturally recalcitrant to enzymatic attack, and it also surrounded by the matrix of xylan and lignin, which enhances the recalcitrance. Therefore, lignocellulosic materials must be pretreated to make the cellulose easily degraded into sugars and further fermented to ethanol. In this work, hydrothermal pretreatment on corn stover at $195^{\circ}C$ for 15 min with and without lower concentration of formic acid was compared in terms of sugar recoveries and ethanol fermentation. For pretreatment with formic acid, the overall glucan recovery was 89% and pretreatment without formic acid yielded the recovery of 94%. Compared with glucan, xylan was more sensitive to the pretreatment condition. The lowest xylan recovery of 55% was obtained after pretreatment with formic acid and the highest of 75% found following pretreatment without formic acid. Toxicity tests of liquor parts showed that there were no inhibitions found for both pretreatment conditions. After simultaneous saccharification and fermentation (SSF) of the pretreated corn stover with Baker's yeast, the highest ethanol yield of 76.5% of the theoretical was observed from corn stover pretreated at $195^{\circ}C$ for 15 min with formic acid.

• 한국수산과학회지
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• 제35권4호
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• pp.342-347
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• 2002

섬모충은 윤충류보다 다양한 크기를 가지고 있으며, 얇은 세포벽, 느린 운동성, 빠른 번식률로 새로운 동물성 먹이생물로써 개발가능성을 가지고 있다. 한국 연안 수역인 수영만, 광양만 및 경기만 소래 염전지역에서 식물성 플랑크톤 네트를 이용하여 6종의 섬모충을 채집하였으며, capillary pipette로 분리 $\cdot$배양하였다. 먹이생물로써의 개발가능성을 파악하기 위하여 크기, 운동성, 배양밀도 및 부유능력을 평가하였으며, 채집된 섬모충류 가운데 광양만에서 채집된 Euplotes sp. (K-1)가 가장 적합한 것으로 평가되었다. MErds 기본배지에 glycine, glucose, yeast extract을 각 0.1 g씩 첨가하여 변형한 MErds-2 배지는 기본배지보다도 약 6배의 번식률을 보여, Euplotes sp.를 비롯한 기타 섬모충 배양배지로도 유용하였다. Euplotes sp. (K-1)은 수온 $22.5^{\circ}C$, pH 8,조도 2,000 lux에서 각각 최고의 번식률을 보였으며, 이들 환경조건에 대해 비교적 폭넓은 환경적응력을 나타내었다. 한편, 빵효모 1.0 g/L의 첨가에 의해서도 대량배양이 가능하였다. 본 연구에서의 섬모충은 종보관이 용이하며 폭넓은 환경 적응력과 간단한 방법의 대량배양이 가능하여 초기 동물성 먹이생물로써의 높은 잠재력을 가지고 있는 것으로 평가되었다.

• 한국식품조리과학회지
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• 제20권5호
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• pp.529-536
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• 2004

이에 본 연구에서는 시판 국내외산 효모 11종을 구입하여 발효특성 및 제빵성을 비교하여 효모 생산사업의 향상을 위한 기초자료를 제시하고자 하였다. 효모의 $CO_2$ 생성량, 반죽 팽창력, maltose 발효력 등을 측정하였고, 무당ㆍ저당ㆍ고당 반죽에 적용시켜 발효력 측정 및 실제 빵을 제조하여 관능평가를 실시하였다. 또한 배양한 효모의 maltase activity와 freeze tolerance rate를 측정하여 균주 특성을 비교하였다. 이 균주들은 동정하여 다음과 같은 결과를 얻었다. Meissle 발효관을 이용하여 시판 빵효모가 저당반죽에서 3시간 동안 $CO_2$를 생성한 양을 측정한 결과 Y7이 가장 높은 값을 나타냈고, Y5와 Y4가 그 뒤를 이었다. M-Cylinder를 이용하여 측정한 11종의 효모의 반죽 팽창력은 Y7, Y4,. Y5 등의 순으로 $CO_2$ 생성량을 측정한 결과와 일치하여 우수 균주로 Y7을 선별하여 이하의 실험에 이용하였다. ASF 합성배지에서의 maltose 발효 능력은 Y5, Y7, Y4 등의 순으로 나타나 $CO_2$ 생성량, 반죽 팽창력과는 약간의 차이가 있었다. 이때 선별된 Y7에 대해 비교 균주로 국내산 효모 K의 반죽종류에 따른 발효력을 비교한 결과 Y7이 K보다 무당, 저당 반죽에서 더욱 우수한 것으로 나타났다. Y7과 K를 이용하여 바게트(무당빵), 식빵(저당빵), 모닝롤(고당빵)을 제조한 후 빵의 품질을 측정한 결과 바게트에서는 K의 용적이 Y7보다 많이 부풀었으며, 비용적도 조금 더 높았다. 그러나, 식빵에서는 Y7의 용적이 K에 비해 더 많이 부풀었으며, 비용적도 더 높아서 Y7이 식빵 제조에 더 적합한 것으로 보였다. 모닝롤에서는 K와 Y7의 용적, 비용적이 매우 유사하여 두 균주가 모두 모닝롤 제조에 적합한 것으로 생각되었다. 또한 이 빵들을 이용하여 관능평가한 결과 바게트의 전반적인 기호도는 K와 Y7이 동점으로 유의적인 차이를 보이지 않았다. 식빵은 외상의 모든 항목과 색에서 K가 높은 점수를 얻었다. 모닝롤은 외상의 껍질 색, 질, 두 항목에서 K가 더 높은 점수를 얻으며 유의적인 차이를 보였고, 전반적인 기호도에서는 또한 유의적인 차이를 보이지 않았다.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.73-77
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• 2002

The Sec61 trimeric complex ($\alpha$,$\beta$, and ${\gamma}$ subunits) is one of the Sec-complex responsible for post-translational protein translocation across the endoplasmic reticulum membrane in diverse organisms. In this study, a cDNA encoding the Sec61p ${\gamma}$ subunit homologue was isolated from the cDNA library of the mole cricket, Gryllotalpa orientalis. Sequence analysis of a 442-bp cDNA clone showed it to contain an open reading frame of 68 amino acid residues consisted of 204-bp. The homologues of the gene were found in the GenBank database in a diverse organism including insect, mammals, fungi, and plants. The deduced amino acid sequence of Sec61p ${\gamma}$ subunit homologue of the mole cricket showed the highest homology to the gene of the singly known insect, Drosophila melanogester (93% identity), and the least homology to that of the baker's yeast, Saccharomyces cerevisiae (37.2%). Phylogenetic analysis also confirmed a close relationship between the insect Sec61p ${\gamma}$ subunit homologues of G. orientalis and D. melanogester. Hydropathy analysis of the cricket mole and published other data suggested that the hydrophobic segment close to C-terminus is predicted to be the putative membrane anchor, Multiple alignment of the Sec61p ${\gamma}$ subunit homologue among several organisms showed the presence of several conserved domains including the conserved proline at position 28.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.921-927
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• 2008

Discovery of $\alpha$-glucosidase inhibitors has been actively pursued with the aim to develop therapeutics for the treatment of diabetes and the other carbohydrate mediated diseases. As a method for the discovery of new novel inhibitors of $\alpha$-glucosidase, we have addressed the performance of the computer-aided drug design protocol involving the homology modeling of $\alpha$-glucosidase and the structure-based virtual screening with the two docking tools: FlexX and the automated and improved AutoDock implementing the effects of ligand solvation in the scoring function. The homology modeling of $\alpha$-glucosidase from baker’s yeast provides a high-quality 3-D structure enabling the structure-based inhibitor design. Of the two docking programs under consideration, AutoDock is found to be more accurate than FlexX in terms of scoring putative ligands to the extent of 5-fold enhancement of hit rate in database screening when 1% of database coverage is used as a cutoff. A detailed binding mode analysis of the known inhibitors shows that they can be stabilized in the active site of $\alpha$- glucosidase through the simultaneous establishment of the multiple hydrogen bond and hydrophobic interactions. The present study demonstrates the usefulness of the automated AutoDock program with the improved scoring function as a docking tool for virtual screening of new $\alpha$-glucosidase inhibitors as well as for binding mode analysis to elucidate the activities of known inhibitors.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.429-435
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• 1999

An adenosine 5'-monophosphate deaminase (AMP aminohydrolase, EC 3.5.4.6) was purified to homogeneity from the cell-free extract of Saccharomyces cerevisiae DKCTC7248. The molecular mass of subunit was estimated to be 80 kDa on SDS-PAGE, and that of the holoenzyme was shown to be 240 kDa by gel filtration. The isoelectric point of the enzyme (AMP deaminase D) was determined to be 6.2. The AMP deaminase D was specific towards AMP with an apparent $K_m$ value of 4.1 mM and a Hill coefficient, $n_H$, of 2.2. Both ATP and ADP were positive allosteric effectors of the AMP deaminase D: The apparent $K_{m}$ was decreased to 1.6 mM and 3.3 mM in the presence of 0.1 mM ATP and ADP, respectively, lowering $n_{H}$ to 1.0. Univalent cations like $K^+, Na^+ and Li^ +$ activated the enzyme but some divalent cations such as $Cu^{ 2+} and Cd^{2+}$ showed strong inhibitory effects. This enzyme displayed optimum activity at $30^{\circ}C$ and pH 7.0. In addition, it was stable up to $45^{\circ}C$ and over a wide pH range(pH 5.5-9.0). Amino acid sequences of its N-terminal region were analyzed to be ADYKMQMFADDA.

• Food Science and Biotechnology
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• 제17권4호
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• pp.766-771
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• 2008

The proteolytic enzyme from Saccharomyces sp. B101 was purified to homogeneity by ammonium sulfate fractionation, ultrafiltration, diethyl aminoethyl (DEAE)-Sephadex A-50 ion-exchange chromatography, and Sephadex G-100 gel filtration chromatography from the culture supernatant of Saccharomyces sp. B101. The specific activity and the purification fold of the purified enzyme were 4,688.9 unit/mg and 18, respectively. The molecular weight of the purified enzyme was estimated to be 33 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature for the enzyme activity were pH 8.5 and $30^{\circ}C$, respectively. The enzyme activity was relatively stable in the pH range of 6.5-8.5 at below $35^{\circ}C$. The salt-tolerance and stability for the enzyme activity were relatively stable even at NaCl concentrations of 10 and 15%. The activity of enzyme was inhibited by $Ag^{2+}$ and $Fe^{2+}$, and activated by $Mn^{2+}$. In addition, the enzyme activity was potently inhibited by ethylenediaminetetraacetic acid (EDTA) and phenylmethyl sulfonylfluoride (PMSF). Based on these findings we concluded that the purified enzyme was a serine protease. Km and Vmax values for hammastein milk casein were 1.02 mg/mL and 278.38 unit/mL, respectively.

• 한국식품과학회지
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• 제31권3호
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• pp.658-664
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• 1999

GOD (glucose oxidase)나 제빵용 효모를 사용하여 포도당이 제거된 육계와 돼지 혈장분의 상온 저장중 색깔, biuret 단백질 함량, 용해도, 기포력과 pH의 변화를 조사하였다. 혈장분의 종류와 혈당 제거 법과는 상관없이 실험기간 동안 혈당이 제거된 혈장분은 해당 대조구보다 "L" 값이 같거나 높았으며 "a" 값과 "b"값은 낮았다(P<0.05). 축종 또는 혈당 제거 방법과는 상관없이 탈당된 모든 시료의 단백질 함량과 용해도는 상온 저장중 해당 대조구보다 항상 높았고 저장 기간이 경과할수록 감소하는 경향을 보였다(P<0.05). 대체적으로 탈당된 육계와 돼지 혈장분 기포력은 해당 대조구와 비슷하거나 높았다. 그러나 돼지 혈장분의 기포력은 육계 혈장분과는 다르게 실험기간 동안 탈당된 돼지 혈장분과 상응하는 대조구는 큰 차이를 나타내지 않았다(P<0.05). 육계 대조구와 GOD로 혈장 포도당을 제거한 육계 혈장분의 pH는 저장기간이 지남에 따라 감소하였지만 효모로 포도당을 제거한 육계 혈장분과 모든 돼지 시료의 pH는 실험 기간중 증가하였다가 감소하였다. GOD로 포도당을 제거한 육계 혈장분이 해당 육계 시료 보다 낮은 pH값을 보인 반면 돼지 혈장분에서는 대조구가 상응하는 실험구보다 항상 낮은 pH 값을 나타내었다(P<0.05). 육계와 돼지 혈장의 포도당을 제거한 후 혈장을 건조시키면 혈장분의 색깔, biuret 단백질 함량, 용해도 그리고 기포력을 증진시킬 수 있었다.