• Journal of Animal Science and Technology
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• 제44권3호
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• pp.289-296
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• 2002

본 시험은 yeast culture제제들(Saccharomyces cerevisiae, Pichia pastoris)의 첨가가 육계의 성장, 장내 미생물균총 및 혈청 IgG농도에 미치는 영향을 측정하기 위하여 기초사료(control)에 chlorotetracycline 100ppm(CTC), Saccharomyces cerevisiae 0.3%(YC-SC), Pichia pastoris 0.3% (YC-PP), 정제된 Pichia pastoris culture 0.1% (RPPC-0.1) 및 0.3%(RPPC-0.3)를 각각 첨가하였다. Ross 종 육계 1000수(암․수 각각 500수)를 20개의 floor pen에 50수(암 수 각 25수)씩 수용하여 control, CTC, YC-SC와 RPPC-0.1구는 3반복으로 YC-PP와 RPPC-0.3구는 4반복으로 배치하였다. 증체량은 처리간에 유의한 차이가 없었으나 대조구나 항생제첨가구에 비해 효모배양물의 첨가구(YC-SC, RPPC-0.1 및 RPPC- 0.3)에서 증체량이 약 4-5% 개선되는 효과가 있었다. 항생제와 효모배양물은 첨가한 구가 대조구에 비해 사료효율이 개선되며 폐사율이 감소하는 경향이 있었다. 영양소 이용율은 yeast culture 첨가에 의해 유의한 영향을 받지 않았다. 소장하부 내용물의 Lactobacilli의 수는 효모배양물의 첨가구(YC-SC, RPPC-0.1 및 RPPC-0.3)에서 대조구보다 다소 높은 경향을 보였고, Cl. perfringens의 수는 CTC와 정제된 Pichia pastoris culture의 첨가에 의해 뚜렷이 저하되었다. E. coli의 수는 정제된 Pichia pastoris 구들이 낮았는데 특히 RPPC-0.3가 대조구보다 유의하게(P$\prec$0.02) 낮았다. 혈청 IgG 농도는 처간에 유의한 차이는 없었으나 효모배양물의 첨가구들에서 control구나 항생제 첨구에서보다 높은 경향을 나타내었다. 결론적으로 본시험에 사용된 yeast culture제제는 생산성, 소장내 미생물 균총과 혈청 IgG에 있어서 유의한 차이는 없었으나 항생제(CTC)와 같거나 그 이상의 개선효과를 나타내었다.

• 생명과학회지
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• 제12권4호
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• pp.496-503
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• 2002

곤충에서 유래한 항균 펩티드, defensin을 항균활성이 있는 활성적인 형태로 분비하는 Pichia 균주를 개발하기 위한 일환으로서 MF$\alpha$1 prerpo sequence와 defensin 합성유전자를 pichia 발현 벡터에 재조합하여 형질전환하고 아미노산 histidine을 첨가하지 않은 최소 배지에서 형질전환체를 일차적으로 선별하였다. 선별한 형질전환체를 대상으로 항생제 G-418에 대한 내성과 M. luteus를 시험균으로 사용하여 생육환 저해를 통한 defensin의 세포 외 분비를 조사하여 4 균주를 선택하고 분석하였다. Southern hybridizaion을 통해 숙주의 염색체 DNA에 삽입한 defensin 유전자가 유지됨을 확인하였으며 전체 RNA를 분리하고 RT-PCR을 수행하여 defensin mRNA를 증폭하고 Southern hybridization을 실시한 결과 증폭된 밴드는 probe로 사용한 defensin 유전자에 의해 양성 신호가 나타났다. 배양시간에 따른 4 균주의 세포성장과 항균활성을 비교하기 위해 BMMY 배지에서 96시간 배양하였다. 세포성장은 모두 유사한 양상을 보였다. 세포성장은 48시간 동안 급격하게 증가한 후 그 이후로는 정지기에 도달되었다. 항균활성도 48시간까지 급격히 증가하였으며 항균활성이 가장 높은 형질전환체 균주 3는 72시간 배양 시 550 AU/$m\ell$을 나타내었다.

• 한국식품영양과학회지
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• 제18권4호
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• pp.435-443
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• 1989

Pichia pastoris의 배양조건과 배지의 탄소원에 따른 alcohol-oxidase의 생성기능과 alcohol-oxidase의 기질특이성을 실험하기 위하여 P. pastoris CBS 2612와 P. pastoris CBM 10의 2균주에 대하여 실험하였다. 배양조건에 따른 효소생성은 glucose를 탄소원으로 첨가한 mineral salt medium에서 균체를 정상기까지 배양하여 methanol이 함유된 배지에서 재배양하는 2단계 배양법의 경우가 균체를 직접 methanol배지에 배양한 경우보다 효율적이었으며 생성된 총효소량도 전자의 경우가 후자에 비해 약 1.7배 정도 많았다. 다음 탄소원에 따른 효소생성능을 비교하였다. 먼저 직쇄alcohol을 탄소원으로 사용한 경우 methanol을 제외한 ethanol, propanol, butanol 그리고 pentanol에서는 효소가 생성되지 않았고 또한 이 직쇄alcohol을 methanol과 혼합한 경우에도 극미량의 생성에 그쳤다. 여러가지 탄소화합물(glucose, xylose, lactose, glycerol, galactose, saccharose, sorbose, lactic acid, acetic acid)을 탄소원으로 사용하면 methanol에 의해 생성된 효소량보다 훨씬 작았으나 이들을 methanol과 혼합 사용하면 효소생성량은 급격히 증가하였고, 특히 xylose, lactose 그리고 lactic acid의 경우는 methanol 단독 사용시보다 오히려 다량 생성되었다. 시험 2균주 중에서도 어떤 경우에서든지 P. pastoris CBS 2612가 alcohol-oxidase 생성능이 더 좋은 것으로 나타났다. 효소의 기질특이성은 효소를 기질에 반응시킬때는 교반을, 그리고 효소 활성측정은 alcohol-oxidase가 methanol을 분해하여 생성한 formaldehyde를 직접 정량 하였을 경우 탄소쇄가 7개 이하인 직쇄alcohols과 불포화alcohols, 그리고 일부2급alcohols(isobutyl alcohol, isoamyl alcohol)에도 특이성이 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1363-1370
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• 2016

Rennet, a complex of enzymes found in the stomachs of ruminants, is an important component for cheese production. In our study, we described that yak chymosin gene recombinant Pichia pastoris strain could serve as a novel source for rennet production. Yaks total RNA was extracted from the abomasum of an unweaned yak. The yak preprochymosin, prochymosin, and chymosin genes from total RNA were isolated using gene specific primers based on cattle chymosin gene sequence respectively and analyzed their expression pattern byreal time-polymerase chain reaction. The result showed that the chymosin gene expression level of the sucking yaks was 11.45 times higher than one of adult yaks and yak chymosin belongs to Bovidae family in phylogenetic analysis. To express each, the preprochymosin, prochymosin, and chymosin genes were ligated into the expression vector $pPICZ{\alpha}A$, respectively, and were expressed in Pichia pastoris X33. The results showed that all the recombinant clones of P. pastoris containing the preprochymosin, prochymosin or chymosin genes could produce the active form of recombinant chymosin into the culture supernatant. Heterologous expressed prochymosin (14.55 Soxhlet unit/mL) had the highest enzyme activity of the three expressed chymosin enzymes. Therefore, we suggest that the yak chymosin gene recombinant Pichia pastoris strain could provide an alternative source of rennet production.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.574-579
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• 2014

A lysozyme gene from breast of Tibetan sheep was successfully expressed by secretion using a-factor signal sequence in the methylotrophic yeast, Pichia pastoris GS115. An expression yield and specific activity greater than 500 mg/L and 4,000 U/mg was obtained. Results at optimal pH and temperature showed recombinant lysozyme has higher lytic activity at pH 6.5 and $45^{\circ}C$. This study demonstrates the successful expression of recombinant lysozyme using the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, this study shows the feasibility of subsequent industrial manufacture of the enzyme with this expression system together with a high purity scheme for easy high-yield purification.

• KSBB Journal
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• 제13권3호
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• pp.325-330
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• 1998

The methylotrophic yeast, Pichia pastoris, is known to be a potential host to offer many advantages for production of recombinant proteins. Fermentation parameters were optimized to enhance the heterologous ${\beta}$-galactosidase productivity with P. pastoris. Optimum concentration of methanol, used as inducer, was observed to be 8 g/L and the extent of repression of AOX1 promoter by glycerol was lower than by glucose. The degradation of the gene product ${\beta}$-galactosidase by protease was inhibited as the pH increased from 5 to 8 and the yeast extract(1%) as nitrogen source increased expression level 4 times higher compared to yeast nitrogen base(1%) as nitrogen source increased expression level 4 times higher compared to yeast nitrogen base(1%). Induction method, in which methanol is just added to fermentation medium without centrifugation, was found to be as much effective as the one with centrifugation.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.498-502
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• 2016

3'-Hydroxygenistein can be obtained from the biotransformation of genistein by the engineered Pichia pastoris X-33 strain, which harbors a fusion gene composed of CYP57B3 from Aspergillus oryzae and a cytochrome P450 oxidoreductase gene (sCPR) from Saccharomyces cerevisiae. P. pastoris X-33 mutants with higher 3'-hydroxygenistein production were selected using a periodic hydrogen peroxide-shocking strategy. One mutant (P2-D14-5) produced 23.0 mg/l of 3'-hydroxygenistein, representing 1.87-fold more than that produced by the recombinant X-33. When using a 5 L fermenter, the P2-D14-5 mutant produced 20.3 mg/l of 3'-hydroxygenistein, indicating a high potential for industrial-scale 3'-hydroxygenistein production.

• Journal of Microbiology and Biotechnology
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• 제22권9호
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• pp.1202-1207
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• 2012

A gene, ClCDA, encoding chitin deacetylase from Colletotrichum lindemuthianum, was optimized according to the codon usage bias of Pichia pastoris and synthesized in vitro by overlap extension PCR. It was secretorily expressed in P. pastoris GS115 using the constitutive expression vector pHMB905A. The expression level reached the highest with 110 mg/l culture supernatant after 72 h of methanol induction, which comprised 77.27 U/mg chitin deacetylase activity. SDS-PAGE, mass spectrometry, and deglycosylation assays demonstrated that partial recombinant protein was glycosylated with an apparent molecular mass of 33 kDa. The amino acid sequences of recombinant proteins were confirmed by mass spectrometry.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1264-1269
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• 2011

Interleukin-2 (IL-2) is a vital cytokine secreted by activated T lymphocytes, and plays an important role in the regulation of cellular functions and immunity of animals. In this study, the recombinant duck IL-2 (rduIL-2) was secretory expressed in Pichia pastoris (P. pastoris). The recombinant P. pastoris strain was cultured in shake flasks and then scaled up in a 5.0-l bioreactor. The result showed that the maximal fresh-cell-weight of 594.1 g/l and the maximal $OD_{600}$ of 408 were achieved in the bioreactor. The rduIL-2 was purified by two steps of purification procedures, and approximately 311 mg of rduIL-2/L fermentation supernatant was obtained. SDS-PAGE showed that the purified rduIL-2 constituted a homogeneous band of ~16 kDa or ~14 kDa corresponding to the glycosylated or non-glycosylated duIL-2 protein in size, respectively. The bioactivity of rduIL-2 was determined by lymphocyte proliferation assay. The result indicated that the rduIL-2 greatly promoted the proliferation of ConA-stimulated lymphocytes in vitro. The P. pastoris expression system described here could provide promising, inexpensive, and large-scale production of the rduIL-2, which lays the foundation for development of novel immunoadjuvants to enhance both the immunity of ducks against various infectious pathogens and vaccine efficacy.

• Journal of Microbiology and Biotechnology
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• 제19권2호
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• pp.172-177
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• 2009

A gene(lsd1) encoding dextranase from Lipomyces starkeyi KSM22 has been previously cloned, sequenced, and expressed in Saccharomyces cerevisiae. The gene consisting of 1,824 base pairs and encoding a protein of 608 amino acids was then cloned into and secretively expressed in Pichia pastoris under the control of the AOX1 promoter. The dextranase productivity of the P. pastoris transformant(pPIC9K-LSD1, 134,000 U/I) was approximately 4.2-fold higher than that of the S. cerevisiae transformant(pYLSD1, 32,000 U/I) cultured in an 8-1 fermentor. Over 0.63 g/l of active dextranase was secreted into the medium after methanol induction. The dextranase of the P. pastoris transformant, as analyzed by SDS-PAGE and Western blotting, showed only one homogeneous band. This dextranase of the P. pastoris transformant showed a broad band near 73 kDa. Rabbit monoclonal antibodies against a synthetic LSD1 peptide mix also recognized approximately 73 kDa.