• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.358-360
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• 1999

The effect of pectinase on menthol production by Mentha piperita in shake flasks was investigated. The optimum concentration of pectinase and period of elicitation for menthol production were 15 U/1 and 9 days, respectively. Pectinase elicitation at 15 U/1 for 9 days using a Lin-Staba medium with 2,4-dichlorophenoxyacetic acid (2,4-D) enhanced menthol production 37-fold (211.5 ㎎ menthol/l) with the specific menthol concentration (menthol concentration per unit weight of cells) of 27.5 ㎎/g dry cell weight (DCW). Our results also indicate that pectinase elicitation may activate the conversion of pulegone to menthol.

• 한국표면공학회지
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• 제25권1호
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• pp.1-7
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• 1992

The formation of manganese ferrite has been performed to investigate some properties according to the variation of compositions, pH, current density by electrolysis. It has been found that the amount of oxidized weight of anode were increased with increasing current density. The amount of oxidized weight of anode were most in pH 10. As the result of X-ray diffraction Mn Fe₂O₄ crystal composition in pH13. When the particles of Mn/sub x/ Fe/sub 3-x/O₄ were heated at 300℃, it has been shown typical Mn Fe₂O₄(JCPDS Card No. 10-319) in X=1 composition. As the result of SEM observation, the size of MnFe₂O₄ particles were about 0.1㎛, the shape of particles were spherical type. According to the above mentioned experimental condition, 0.1-0.5㎛ sub-micron particles of manganese ferrite were formed from the wasted manganese dry cell, through washing → reduction → electrloysis.

• KSBB Journal
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• 제17권1호
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• pp.26-32
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• 2002

세포의 다당류 xanthan을 생산하기 위하여 호기성 박테리아 X. campestris를 9 L 삼상유동층 생물반응기에서 연속적으로 배양하였다. 고점도 배양액에서 공기 기포를 분쇄하기 위하여 직경 8 mm 유리 유동입자를 사용하였다. 반응기 희석률을 증가시킴에 따라 세포 단위질량 당 xanthan 생성속도 및 생성된 xanthan의 분자량은 증가하였다. 산소공급제한이 발생하지 않을 경우 연속발효에서의 xanthan 비생성속도는 회분식 발효에서 제안된 상관식의 예측결과 보다 상당히 높은 값을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1630-1639
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• 2019

Objective: Sixty Pengbo semi-wool sheep ewes (approximately 1.5-years-old; $31.33{\pm}0.43kg$) were randomly assigned to two groups, either grazing (G) or dry lot feeding (D), to examine the effects of traditional daily grazing and dry lot feeding on performance and blood metabolites during the cold season in Tibetan Plateau. Methods: The ewes in the G group were grazed continuously each day and housed in one shed each evening, while the ewes in the D group were housed in another shed all day. All animals were fed 400 g/d of commercial concentrate, and grass hay was available freely throughout the experimental period. Results: Compared with the G group, the ewes in the D group had higher (p<0.05) live weight and weight gain. The D group ewes had greater (p<0.05) numbers of white blood cells and platelets, while they had lower (p<0.05) platelet-large cell ratios, cholesterol, high-density lipoprotein cholesterol and glutathione peroxidase, as compared with the G group ewes. Additionally, three serum metabolites, abscisic acid, xanthoxin and 3,4-dihydroxy-5-polypren, were upregulated (p<0.05) in the G group in comparison with the D group. Conclusion: In conclusion, a dry lot feeding regime during the winter and spring period will increase the productivity of sheep and improve blood physiological and biochemical profiles.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1524-1528
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• 2006

A total of 437 animals, comprising lambs aged between 3 and 12 months and adults of either sex of Muzaffarnagari sheep maintained at the Central Institute for Research on Goats, Makhdoom, Farah, Mathura, India were screened to assess the prevalence of Haemonchus contortus infection following natural infection and to identify the various factors affecting faecal egg count (FEC) and packed cell volume (PCV) of ewes and their genetic control. The relationships between FEC, PCV and body weight were also estimated. The prevalence rate for H. contortus infection in the flock under study was 15.7% indicating much lower occurrence of worm infection in lambs up to one year of age. On the other hand, a large proportion i.e., 67.7% of sheep was refractive to natural H. contortus infection. The random effect of sire significantly contributed (p<0.01) variation in log-transformed FEC (LFEC) of ewes. The season of birth had a significant (p<0.01) effect on LFEC of ewes. The lactating ewes had significantly (p<0.01) higher faecal egg counts compared to dry and pregnant ewes. The linear regression effects of the age of ewes on LFEC of animals were significant (p<0.01) in the present study. The heritabilities of LFEC, PCV and body weights of ewes during the course of infection were moderate to high in magnitude and ranged from 0.24 to 0.47. The LFEC of ewes was significantly (p<0.05) and negatively correlated with PCV at both genetic and phenotypic level. The genetic and phenotypic relationships between LFEC and body weights of ewes were -0.26 and -0.06 for this breed. The genetic correlation of PCV and body weight of ewes was positive and high (0.58) and statistically significant (p<0.05) but it was negatively correlated (-0.01) with body weight at the phenotypic level.

• Asian-Australasian Journal of Animal Sciences
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• 제9권3호
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• pp.303-307
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• 1996

The degree of autolysis and presence of cell-wall degrading enzymes in an anaerobic ruminal fungus, Piromyces communis OTSI, grown in liquid medium, was monitored to evaluate the effect of self-digestion on fungal biomass. After a 30 days incubation period fungal dry weight decreased by 45% and the cell wall component chitin decreased by 22%. Chitinase activity detected in the supernatant was mainly of the endotype and peaked at day 6 of the incubation. ${\beta}-1$, 3-glucanase was detected from day 4 and increased throughout the incubation period. Autolysis was a slow process, and under natural conditions it is unlikely that it plays a significant role in the degradation of the spent fungal vegetative stage in the rumen.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.523-526
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• 2000

A novel cell surface display system was developed by employing the Escherichia coli outer membrane protein C (OmpC) as an anchoring motif. Poly-histidine (poly-His) peptides of 19, 32, 45, 84, and 162 amino acids (aa) could be successfully displayed by inserting them into the seventh exposed loop(L7) of OmpC. Recombinant cells displaying poly-His of 19, 32, 45, and 84 aa could absorb 18.9, 23.9, 26.1, and 32.0 ${\mu}mol$ of $Cd^{2+}$ per gram cell dry weight, respectively and therefore, would be useful as the biosorbents of heavy metals.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1159-1163
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• 2005

The production of hydrogen by Chlamydomonas reinhardtii UTEX 90, a marine green alga, was performed under dark fermentation. The effects of initial nitrogen and phosphorus concentration on the cell growth and the production of hydrogen and organic substances were investigated. In the growth stage, the maximum dry cell weight (DCW) was 3 g/l when the initial ammonium concentration was 15 mM. In the dark fermentation, the maximum hydrogen production was $3.5\;{\mu}mol/\;mg$ DCW when the initial nitrogen concentration was 7.5 mM. The nitrogen concentration had a greater effect on organic compound and hydrogen production than the phosphorus concentration during the dark fermentation. An investigation of the duration of dark fermentation showed that, at least until three days, dark fermentation should be prolonged for maximum hydrogen production.

• KSBB Journal
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• 제30권3호
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• pp.119-124
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• 2015

Arthrospira platensis (A. platensis) is a microscopic and filamentous cyanobacterium that derives its name from the spiral or helical nature of its filaments. In this study, we induced mutants of A. platensis through NMU treatment and selected two strains by level of ipid contents. We named mutant '1-9', '2-5', and they were cultivated in the same way with the wild type. During 12 days cultivation, cell growth, dry cell weight, pigment content, and lipid content were measured for characteristics of mutants. As a result, pigment and lipid content of mutants were increased about 3.6, 1.8 times compared with wild type, respectively. It was shown that total flavonoid and polyphenol contents of mutants were increased about 1.5 times compared with wild type. And radical scavenging effect of mutants were increased about 10% compared with wild type.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.722-725
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• 1999

Filamentation-suppressed recombinant Escherichia coli strain harboring the Alcaligenes latus polyhydroxyalkanoate (PHA) biosynthesis genes and the E. coli ftsZ gene was constructed and cultivated for the production of poly(3-hydroxybutyrate) [P(3HB)] with high concentration and high content. By the pH-stat fed-batch culture of this recombinant E. coli strain XL1-Blue(pJC5), the final cell concentration and P(3HB) concentration obtained in 44.25h were 172.2g cell dry weight/l and 141.9g P(3HB)/l, respectively, resulting in productivity of 3.21g P(3HB)/l-h. More importantly, the P(3HB) content obtained was 82.4 wt %, which was significantly higher than that obtained with the recombinant E. coli harboring only the PHA biosynthesis genes.