• 한국축산식품학회지
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• 제26권2호
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• pp.252-256
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• 2006

본 연구는 기능성 발효유로서 티벳산 발효유에서 분리한 효모(Kluyveromyces marxianus)와 유산균(Lactobacillus bulgaricus)의 혼합스타터를 이용한 발효유를 제조하여 배양 기간별 균수 측정, pH, 적정산도, ethanol 함량, 항암 활성에 대해 알아보았다. 배양은 $30^{\circ}C$에서 curd가 형성되는 시점에 마치게 되는데 이때의 최종 산도는 0.68, pH는 4.5 이었다. 배양 36시간 후의 균수는 K. marxianus는 $5.3{\times}10^9 CFU/mL$, L. bulgaricus는 $3.2{\times}10^9 CFU/mL$ 이었고 ethanol 함량은 0.35%까지 증가하였다. 36시간 배양하여 제조된 발효유의 항종양 활성은 HEp-2에 대해서는 86.6%, HEC-1B에 대해서는 70.3%, SW-156에 대해서는 60.4%, SK-MES-1에 대해서는 57.14%의 항종양 활성을 나타내었다. 이상의 결과 기존의 유산균 발효유에 효모를 첨가한 알코올 발효유의 제조가 가능하며, 제품의 항종양 활성의 측면에서도 높은 기능성을 나타내는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1259-1266
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• 2016

Bioethanol was produced from Kappaphycus alvarezii seaweed biomass using separate hydrolysis and fermentation (SHF). Pretreatment was evaluated for 60 min at 121℃ using 12% (w/v) biomass slurry with 364 mM H₂SO₄. Enzymatic saccharification was then carried out at 45℃ for 48 h using Celluclast 1.5 L. Ethanol fermentation with 12% (w/v) K. alvarezii hydrolyzate was performed using the yeasts Saccharomyces cerevisiae KCTC1126, Kluyveromyces marxianus KCTC7150, and Candida lusitaniae ATCC42720 with or without prior adaptation to high concentrations of galactose. When non-adapted S. cerevisiae, K. marxianus, and C. lusitaniae were used, 11.5 g/l, 6.7 g/l, and 6.0 g/l of ethanol were produced, respectively. When adapted S. cerevisiae, K. marxianus, and C. lusitaniae were used, 15.8 g/l, 11.6 g/l, and 13.4 g/l of ethanol were obtained, respectively. The highest ethanol concentration was 15.8 g/l, with Y_EtOH = 0.43 and Y_T% = 84.3%, which was obtained using adapted S. cerevisiae.

• KSBB Journal
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• 제28권5호
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• pp.315-318
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• 2013

Ethanol fermentations were performed using separate hydrolysis and fermentation (SHF) processes with monosaccharides from pretreated seaweed, Eucheuma spinosum as the biomass. The pretreatment was carried out with 11% (w/v) seaweed slurry and 150 mM $H_2SO_4$ at $121^{\circ}C$ for 40 min. Enzyme hydrolysis after $H_2SO_4$ pretreatment was performed with Celluclast 1.5 L at $45^{\circ}C$ for 24 h. Five % active charcoal were added to hydrolysate to removed 5-hydroxy methylfurfural. Ethanol fermentation with 11% (w/v) seaweed hydrolysate was performed for 72~96 h using Kluyvermyces marxianus, Pichia stipits, Saccharomyces cervisiae and Candida tropicalis. Ethanol concentration was reached to 18 g/L by K. marxianus, 16 g/L by P. stipitis, 15 g/L by S. cerevisiae and 10 g/L by C. tropicalis, respectively. The ethanol yield from total monosugar was obtained 0.50 and ethanol productivity was obtained 0.38 g/L/h by K. marxianus.

• 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.

• 한국미생물·생명공학회지
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• 제22권2호
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• pp.152-157
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• 1994

Inulinase of Kluyveromyces marxianus origin was produced by recombinant yeast Saccharomyces cerevisiae under the control of GAL1 promoter, to examine the expression and localization of inulinase in a repressed(galactose-free) or derepressed(galactose-containinga) medium. The inulinase gene(INU1A) was constitutively expressed at 6.7 units/ml in a repressed medium. When the cell started to utilize galactose in a derepressed medium, the INU1A gene began to be expressed, and the final expression level reached about 45 units/ml. According to be the nondenaturingPAGE analysis, inulinase produced by S. cerevisiae was found to be less glycosylated than the bakers yeast invertase. In addition, its glycosylation pattern was less heterogeneous than the K. marxianus inulinase. The supplementation of inulin or raffinose into the derepressed medium increased the cell growth rate, while the expression of INU1A was repressed. Regardless of the carbon sources examined, most of inulinase activity (more than 98%) was found in the extracellular medium, indicating excellent secretion efficiency.

• Journal of Microbiology and Biotechnology
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• 제20권7호
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• pp.1101-1106
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• 2010

Pulsed electric field (PEF) of 1Hz, 1.5 kV, and 1ms increased the activities of catalase and inulinase over the whole range of applied Se concentrations compared with the non-treated cultures. A significant effect of selenium concentration (in the range of 5-14 ${\mu}g/ml$) on both intra- and extracellular enzyme activities was noted. At a Se concentration of 10 ${\mu}g/ml$, the activities of intra- and extracellular inulinases and extracellular catalase in the PEF-treated cultures reached the maximum of 71 U/g d.m., 46 U/g d.m., and approx. 8 U/ml, respectively. The maximum activity of intracellular catalase of approx. 6 U/ml (with and without PEF) was recorded at 5 ${\mu}g$ Se/ml. Further increasing of selenium concentration caused a decrease in the activity of the enzymes.

• KSBB Journal
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• 제8권3호
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• pp.272-281
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• 1993

유당을 탄소원으로 K. marxianus를 발효하는 경우, 용해산소의 농도와 조엽조건에 따른 발효의 진행 상태를 정확히 예측하였다. 예측에 필요한 고정된 계수를 갖는 양론식의 수를 singular variable decomposition 분석에 의하여 결정하고 발효의 추정에 사용될 수 었는 양론관계를 target test에 의하여 결정하였으며, 발효의 진행상태를 추정하였다 또한, 단세포 단백질을 유당으로부터 연속생산하는 경우 에너지원을 효율적으로 이용하기 위한 조업조건을 제시하였다.

• Applied Biological Chemistry
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• 제30권2호
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• pp.169-178
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• 1987

Kluyveromyces marxianus로 부터 inulase를 생산하고 정제하며 intra 및 extracellular inulase의 성질을 조사하였다. 본 균주는 stationary phase인 24시간째 intra 및 extracelullar enzyme의 생산이 최고에 달했으며 유기 질소원으로 YNB를 사용하고 배양 중 pH를 조절해 줌으로써 효소 생산을 향상시킬 수 있었다. 조효소는 DEAE-cellulose에 의해 intra 및 extracellular inulase 모두 2개의 fraction으로 분리되었고 각 fraction의 전기영동 양상은 비슷하여 주 band를 비롯 모두 3개의 glycoprotein band가 관찰되었으며 이중 주 band만 inulase 및 invertase activity를 보유하고 있었다. 정제 효소의 inulase 및 invertase의 최적 pH는 각각 5.0과 4.5였고 intra가 extracellular enzyme 에 비해 다소 넓은 범위의 pH에서 높은 활성을 나타내었다. 모든 fraction의 최적 온도는 inulase가 $40^{\circ}C$, invertase가 $50^{\circ}C$였으며 intracellular enzyme이 더 넓은 범위의 온도에서 안정하였고 열에 대한 안정성도 intracellular inulase가 extracellular inulase보다 높게 나타났다. Km value는 intra가 $16{\sim}19mM$, extracellular inulase가 $9{\sim}11mM$로써 extracellular inulase가 inulin에 대한 친화력이 더 높았으나 모두 exo-type의 inulase로 판명되었다.

• 유기물자원화
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• 제5권1호
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• pp.1-13
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• 1997

본 연구는 음식물 찌꺼기의 사료화를 목적으로 종균제(YM, 영진환경)와 아프리카산 고온성 효모인 Kl. marxianus를 이용하여 음식물 찌꺼기를 발효시켜 보존성을 연장하기 위해 실시하였다. 6일 동안 발효시, 편성 호기적 또는 혐기적 조건보다는 2일간 호기적 조건으로 발효시킨 뒤 계속하여 4일간 혐기적으로 발효시켰을 때 유기산 생성량이 높았고 생균수도 가장 높았다. 종균제(YM)의 첨가는 무첨가 시료보다 발효 후 잔여 총 생균수를 100배 이상으로 크게 증가시켰으며 여기에 Kl. marxianus 배양액을 추가로 첨가할 경우 총생균수는 더욱 증가시켰으나 효모수를 더 증가시키지는 않았다.

• BMB Reports
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• 제36권5호
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• pp.442-449
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• 2003

NAD(P)H quinone oxidoreductase is a ubiquitous enzyme that is known to directly reduce quinone substrates to hydroquinones by a two-electron reaction. We report the identification of NADPH quinone oxidoreductase from Kluyveromyces marxianus (KmQOR), which reduces quinone substrates directly to hydroquinones. The KmQOR gene was sequenced, expressed in Escherichia coli, purified, and characterized. The open-reading frame of the KmQOR gene consists of 1143 nucleotides, encoding a 380 amino acid polypeptide. The nucleotide sequence of the KmQOR gene was assigned to EMBL under accession number AY040868. The $M_r$ that was determined by SDS-PAGE for the protein subunit was about 42 kDa, and the molecular mass of the native KmQOR was 84 kDa, as determined by column calibration, indicating that the native protein is a homodimer. The KmQOR protein efficiently reduced 1,4-benzoquinone, whereas no activities were found for menadiones and methoxyquinones. These observations, and the result of an extended sequence analysis of known NADPH quinone oxidoreductase, suggest that KmQOR possesses a different action mechanism.