• The Plant Pathology Journal
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• 제24권2호
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• pp.164-170
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• 2008

Carbon utilization by Chryseobacterium strain KJ1R5 was studied to enhance its biocontrol activity against Phytophthora capsid. Chryseobacterium strain KJ1R5 has previously been shown to control Phytophthora blight of pepper (Capsicum annuum L.). Strain KJ1R5 could utilize carbon sources such as L-arabinose, D-cellobiose, ${\beta}-lactose$ and D-galactose well. P. capsici could utilize D-glucose well, showing the absorbencies ranged from 0.577 to 0.767 at 600nm. When 2% L-arabinose, which could only be utilized by the bio-control strain KJ1R5, was amended into the bacterial suspension, the efficacy of biological control increased. Among the amendments of various carbon sources into bacterial suspension, L-arabinose and D-(+)-glucose significantly enhanced biological control activity, resulting in a reduction of disease incidence to 6.9%, compared to 21.9% for the strain KJ1R5 alone and 81.3% for P. capsici inoculation alone, indicating that amendment with specific carbon sources could increase the biological control activity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.288-305
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• 2000

A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects-the basics of yeast flocculation, the development of "new" flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast flocculation is reported. The construction of flocculating yeast strains includes not only the recombinant constitutive flocculent brewer's yeast, but also recombinant flocculent yeast for lactose metabolisation and ethanol production. Furthermore, recent work on the heterologous $\beta$-galactosidase production using a recombinant flocculent Saccharomyces cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties, mainly associated with a high solid phase hold-up, a section dedicated to its operation is presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor hydrodynamics and mass transfer properties of flocculating cell cultures are considered. Finally, the paper concludes describing some of the applications of high cell density flocculating bioreactors and discussing potential new uses of these systems.e systems.

• 대한수의학회지
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• 제37권3호
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• pp.547-554
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• 1997

Galectin-3 is known as an animal ${\beta}$-galactoside-binding lectin charicterized with S-type carbohydrate recognition domain. It plays a role in growth, adherence and movement of cells. It is, also, related to the cell transformation and metastasis of tumor cells. In this study, we have expressed and purified recombinant human galectin-3 (rHgalectin-3) using E coli system and asialofetuin affinity chromatography for the future development of monoclonal antibody to Hgalectin-3, which is suggested as the tumor marker for the gastric and thyroid gland cancers. Expressed protein was confirmed as the Hgalectin-3 by immunoblot with cross-reactive murine monoclonal antibody. Lectin activity and specificity of purified protein were, also, confirmed by the competitive inhibition with galectin-3 specific carbohydrate, lactose. Like physiological galectin-3, lectin activity of the molecule was not changed in nonreduced condition. Dimer formation, furthermore, was observed at high concentration of the protein even in the reduced condition, which is well known in physiological galectin-3. These results showed purified rHgalectin-3 has the same activity and molecular nature compared to the physiological galectin-3.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.393-397
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• 1999

The gene (galE) encoding UDP-galactose-4-epimerase, operative in the galactose metabolic pathway, was cloned together with the $\beta$-galactosidase gene (lacZ) from Lactococcus lactis ssp. lactis ATCC7962 (L. lactis 7962). galE was found to have a length of 981 bps and encoded a protein with a molecular mass of 36,209 Da. The deduced amino acid sequence showed a homology with GalE proteins from several other microorganisms. A Northern analysis demonstrated that galE was constitutively expressed by its own promoter. When galactose or lactose was added into medium, the galE transcription was induced by several upstream promoters. The structure of the gal/lac operon of L. lactis 7962 was partially characterized and the gene order around galE was galT-lacA-lacZ-galE-orfX.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.733-738
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• 2007

An extracellular exoinulinase($2,1-\beta-D$ fructan fructanohydrolase, EC 3.2.1.7), which catalyzes the hydrolysis of inulin into fructose and glucose, was purified 23.5-fold by ethanol precipitation, followed by Sephadex G-100 gel permeation from a cell-free extract of Kluyveromyces marxianus YS-1. The partially purified enzyme exhibited considerable activity between pH 5 to 6, with an optimum pH of 5.5, while it remained stable(100%) for 3 h at the optimum temperature of $50^{\circ}C$. $Mn^{2+}\;and\;Ca^{2+}$ produced a 2A-fold and 1.2-fold enhancement in enzyme activity, whereas $Hg^{2+}\;and\;Ag^{2+}$ completely inhibited the inulinase. A preparation of the partially purified enzyme effectively hydrolyzed inulin, sucrose, and raffinose, yet no activity was found with starch, lactose, and maltose. The enzyme preparation was then successfully used to hydrolyze pure inulin and raw inulin from Asparagus racemosus for the preparation of a high-fructose syrup. In a batch system, the exoinulinase hydrolyzed 84.8% of the pure inulin and 86.7% of the raw Asparagus racemosus inulin, where fructose represented 43.6mg/ml and 41.3mg/ml, respectively.

• 대한수의학회지
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• 제35권3호
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• pp.497-504
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• 1995

Isolation of Staphylococcus hyicus subsp. hyicus from the skin of healthy chickens was performed and biochemical characteristics of the isolates were examined. Staphylococcus hyicus subsp hyicus was isolated from 129(14.8%) of 874 healthy chickens. The rate of isolation of this organism from chickens was found to vary depending upon the poultry farms at the isolation rate of 0% to 38.7% and this organism was isolated more frequently from adult chickens of over 1 year old than young chickens. All of the isolates were negative for haemolysis on rabbit, sheep, pig and chicken blood agars, protein A and ${\beta}$-glucuronidase, but positive for coagulase using pig plasma, heat-stable DNase, phosphatase and Tween 80 hydrolysis. Hyaluronidase was positive in 97.7% of isolates, but their reaction was weaker than that of swine strains of Staphylococcus hyicus subsp hyicus. The isolates were biotyped on the basis of the reactions for protease, urease, nitrate, galactose, trehalose and lactose, and 11 biotypes were found among the 129 isolates of Staphylococcus hyicus subsp hyicus.

• BMB Reports
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• 제38권5호
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• pp.609-618
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• 2005

$\gamma$-Glutamyl transpeptidase (GGT, EC 2.3.2.2.) catalyzes the transfer of the $\gamma$-glutamyl moiety from $\gamma$-glutamyl containing ompounds, notably glutathione (GSH), to acceptor amino acids and peptides. A second gene (GGTII) encoding GGT was previously isolated and characterized from the fission yeast Schizosaccharomyces pombe. In the present work, the GGTII-lacZ fusion gene was constructed and used to study the transcriptional regulation of the S. pombe GGTII gene. The synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene was significantly enhanced by NO-generating SNP and hydrogen peroxide in the wild type yeast cells. The GGTII mRNA level was increased in the wild-type S. pombe cells treated with SNP. However, the induction by SNP was abolished in the Pap1-negative S. pombe cells, implying that the induction by SNP of GGTII is mediated by Pap1. Fermentable carbon sources, such as glucose (at low concentrations), lactose and sucrose, as a sole carbon source, enhanced the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in wild type KP1 cells but not in Pap1-negative cells. Glycerol, a non-fermentable carbon source, was also able to induce the synthesis of $\beta$-galactosidase from the fusion gene, but other non-fermentable carbon sources such as acetate and ethanol were not. Transcriptional induction of the GGTII gene by fermentable carbon sources was also confirmed by increased GGTII mRNA levels in the yeast cells grown with them. Nitrogen starvation was also able to induce the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in a Pap1-dependent manner. On the basis of the results, it is concluded that the S. pombe GGTII gene is regulated by oxidative and metabolic stress.

• 한국식품영양과학회지
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• 제15권4호
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• pp.40-46
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• 1986

제1보에서 보고한 Aspergillus niger CAD 1의 beta-galactosidase를 cellulose triacetate를 담체로 하여 고정화조건을 검토하였던바, 13%(v/v)의 정제된 효소와 10%(w/v)의 cellulose triacetate를 30분간, 150stroke/min으로 진탕하면서 포괄시킨 고정화 효소의 활성이 가장 좋았다. 고정화 효소의 최적온도는 $45^{\circ}C$, 최적 pH는 4.5로서수용성 효소의 것과 같았다. 기질로서 ONPG와 유당에 대한 Km값은 각각 $8.3{\timess}10^{-3}$과 $117.0{\times}10^3M$, Vmax값은 각각 $30.3{\times}10^3M$과 $5.0{\times}10^3M$이였다. 본 고정화 효소는 $4^{\circ}C$에서 90일간 저장시에 90%, $45^{\circ}C$에서 5회 사용후에 70%의 잔존활성을 나타냈으며 유당분해율도 좋았다.

• 한국식품과학회지
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• 제47권2호
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• pp.191-197
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• 2015

본 연구는 국내에서 주로 판매되고 있는 망고 품종의 이화학적 특성과 망고의 휘발성 향기성분의 화합물 조성을 비교하였다. 품종이 다른 대만 산 애플 망고와 필리핀 산 카라바오 망고의 조회분을 제외한 일반성분은 대부분 유의한 차이를 보였고, 수분과 조지방은 애플 망고에서 높았으며, 조단백과 탄수화물은 카라바오 망고에서 높았다. 유리당 함량은 두 품종에서 sucrose, fructose, glucose의 순으로 높게 검출되었으나 함량에서는 유의적 차이를 보였다. 그러나 maltose, lactose, galactose는 검출되지 않았다. SPME 추출법으로 확인된 휘발성 향기성분은 대만 산 애플 망고, 필리핀 산 카라바오 망고에서 각각 56종, 59종을 확인할 수 있었고, 휘발성 향기성분을 분석한 함량은 각각 59.45, 37.25%이 추출되었다. 휘발성 향기성분의 종류 및 함유량에서 테르펜류 및 그 유도체의 종류 및 함유량 모두가 높았고 ester류 화합물이 다음으로 높았으며 함유량에서는 품종에 따라 차이를 보였다. 테르펜류와 그 유도체 함유량은 대만 산 애플 망고에서 94.42%로 높게 나타나는 특징을 보였고, 필리핀 산 카라바오 망고에서는 63.79%로 차이를 보였다. 필리핀 산 카라바오 망고는 acetic acid, hexanoic acid, octanoic acid, palmitic acid 등의 acid류 화합물이 품종이 다른 대만 산 애플 망고의 휘발성 향기성분과 비교하여 종류 및 함유량에서 높게 나타나는 특징을 보였다. 대만 산, 필리핀 산 망고 모두에서 ${\delta}$-3-carene의 함량이 각각 17.78, 8.11%로 확인되어 동정된 화합물 중 가장 높은 함량을 보였다. 대만 산애플 망고의 경우 ${\alpha}$-copaene, ${\alpha}$-guaiene, germacrene D, ${\alpha}$-bulnesene, ${\gamma}$-gurjunene 등이, 필리핀 산 카라바오 망고는 ${\beta}$-myrcene, ${\alpha}$ 및 ${\beta}$-phellandrene, ${\alpha}$-terpinolene, cis-3-hexenyl butyrate 등이 특징적인 화합물로 확인되어 이는 품종에 따른 망고 향기성분의 특징을 구분하는데 기여할 것으로 생각된다.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.287-295
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• 2020

Lactobacillus zymae GU240 was previously isolated from Kimchi, a Korean fermented vegetable, as a strong GABA producer. The strain showed β-galactosidase (β-Gal) activity on MRS agar plates with X-gal. When growth and β-Gal activities of GU240 were measured using MRS (glucose, 2%, w/v) and MRSL (lactose, 2%, w/v) broths, cells were found to grow slowly in MRSL, and the β-Gal activity (36 units at 4 h) was lower than that of cells grown in MRS (94 units at 16 h). The highest OD₆₀₀ value of the culture in MRS was 1.6 at 24 h at 37℃, whereas that of the culture in MRSL was 0.6 at 16 h. β-Gal activity of the culture in MRS reached the maximum (95.6 u/ml) at 16 h, decreased thereafter, and was not detected at 48 h. β-Gal activity for culture in MRSL reached its highest (36 u/ml) at 4 h and decreased gradually, but some activity (11.05 u/ml) still remained at 72 h. The structural gene encoding β-Gal in L. zymae GU240 was cloned as a 3.1 kb fragment, and DNA sequencing confirmed the presence of complete lacLM genes. lacLM genes from L. zymae GU240 showed 98-99% homologies in nucleotide sequences with other lacLM genes from L. brevis. Reverse transcription (RT)-PCR confirmed the operon structure of lacLM. The results indicated that L. zymae GU240 might be in the process of losing the ability to grow rapidly on lactose-containing medium, such as milk, due to adaptations to plant environments, including kimchi.