• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.187-191
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• 2005

발효기에서의 균사체 생장과 세포외다당류의 생산을 위한 최적 배양조건을 조사하기 위하여 회분식 반응기를 이용하여 연구한 결과 최적 회전속도와 통기량은 각각 200 rpm과 1.5 vvm 었다. 최적 배양 환경하에서 5L발효기(working volume 2 L)에서 배양한 결과 각각 10.21 g/L 와 3.56 g/L의 mycelial growth와 exo- polysaccharide를 얻었다.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.482-486
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• 1996

Batch fermentations of lactic acid were performed with Lactobacillus casei to investigate the effect of pH on cell growth and production of lactic acid and by-products. Maximum productivity of lactic acid increased with increasing pH from 5.0 to 6.5, and the extent of D-lactate production was different at each pH. Acetate and D-lactate concentrations increased even after the complete consumption of glucose in the medium. While a pH range of 6.0-6.5 was optimal for cell growth and lactic acid production, superior results were achieved at pH 6.0 when both maximum lactic acid productivity and minimum by-product formation were considered.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.482-487
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• 1999

The Pseudomonas sp. strain NGK1 (NCIM 5120) was immobilized in calcium alginate, agar, and polyacrylamide gel matrices. The salicylic acid-producing capacity of freely suspended cells was compared with immobilized cells in batches with a shake culture and continuous culture system in a packed bed reactor. Freely suspended cells ($4\times10^{10}cfu/ml$) produced 12 mM of salicylic acid, whereas cells immobilized in calcium alginate ($1.8\times10^{11}$cfu/g beads), agar ($1.8\times10^{11}$cfu/g beads), and polyacrylamide ($1.6\times10^{11}$cfu/g beads) produced 15, 11, and 16mM of salicylic acid, respectively, from naphthalene at an initial concentration of 25 mM. The continuous production of salicylic acid from naphthalene was investigated in a continuous packed bed reactor with two different cell populations. The longevity of the salicylic acid-producing activity of the immobilized cells from naphthalene was also studied in semi continuous fermentations. The immobilized cells could be reused 18, 13, and more than 20 times without losing salicylic acid-producing activity in calcium alginate-,agar-, and polyacrylamide-entrapped cells, respectively. The study reveals a more efficient utilization of naphthalene and salicylic acid production by the immobilized Pseudomonas sp. strain NGK1 as compared to the free cells.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.191-196
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• 1981

고량주박을 원료로 한 식초생산 조건을 검토하여 다음과 같은 결과를 얻었다. 1.고량주박의 추출물을 사용하여 제조한 식초의 품질은 냉수침출방법에 의한 추출물이 온수침출방법의 경우보다 색, 향 및 발효속도 면에서 우수하였다. 2.고량주박의 추출조건은 고량주박량에 대하여 가수량 3배, 냉침 60시간 추출이 최적이었다. 3 표면발효에서 냉수침출액의 최적 첨가량은 20～30% 였다. 4. 액침배양의 경우 대수기의 초산 생성속도는 0.16g/100$m\ell$.hr.였고 발효수율은 91.17%, 발효소요시간은 약40시간이었다. 5. 본 시제품은 관능검사 결과 색과 향취면에서 시판품에 비교하여 우수하였고 공업적 생산성이 있다고 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제1권3호
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• pp.212-219
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• 1991

Four species of yeast, Saccharomyces cerevisiae, Candida utilis, Saccharomycopsis flbuligera, and Schwanniomyces castellii were evaluated for their ability to bioconvert potato processing waste water into microbial protein and the resulting single-cell proteins were evaluated as protein sources for rainbow trout, using in vitro analyses. The studies indicated that Schwanniomyces castellii, which utilizes starch dircetly and converts it into cell mass efficiently, was suitable for the bioconversion. In the single-stage continuous bioconversion, the yield S. castellii cell mass, which contained approximately 37% protein, was 77%, at dilution rate 0.25 $h^{-1}$. Reduction of total carbohydrate was 81%. During batch fermentations, cell mass yield was about 72% and total carbohydrate reduction was 81%. Among the yeasts tested, S. castellii possessed the most fragile cell wall and had a favorable amino acid profile for salmonid fish; protein score of 86% (Met). In an in vitro pepsin digestibility test 80% digestibility (23~38% above control) was observed when cells were pre-heated in a steam bath for 30 min. Results presented should be regarded as being preliminary in nature because they were derived from single experiments.

• 한국미생물·생명공학회지
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• 제22권1호
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• pp.85-91
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• 1994

The characteristcs of monascus fermentation using a hyperpigment-producing mutant, Monascus sp. J101, were analyzed, and the extractive fermentations employing permeabilizing agents and resin were carried out to increase the productivity of red pigment. And the kinetic analysis was also carried out in case of the monascus fermentation using Amberlite XAD-7. The extracellular content of the red pigment produced by Monascus sp. J101 was about 17% of the total, and the production of pigment was regulated by its own product. The cell growth reached a stationary phase at 48 hours ofter inoculation, whereas the pigment production continued up to 100 hours, which showed the pattern of a mixed growth-associated type. During the fermentation, various permeabilizing agents were added to the culture medium and their effects on pigment production were examined. By adding 0.05% Triton X-100 at 48 hours of cultivation, about an 18% increase in pigment production was accomplished as compared to the control, 12% ethyle acetate and 15% for 0.05% deoxycholate, respectively. When a nonionic adsorbent, Amberlite XAD-7 was added to the culture medium at a concentration of 12.0% at 48 hours of cultivation, the pigment production was enhanced by about 48.9% as compared to the control.

• KSBB Journal
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• 제30권3호
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• pp.125-131
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• 2015

Kluyveromyces marxianus is a well-known thermotolerant yeast. Although Saccharomyces cerevisiae is the most commonly used yeast species for ethanol production, the thermotolerant K. marxianus is more suitable for simultaneous saccharification and fermentation (SSF) processes. This is because enzymatic saccharification usually requires a higher temperature than that needed for the optimum growth of S. cerevisiae. In this study, we compared the fermentation patterns of S. cerevisiae and K. marxianus under various temperatures of fermentation. The results show that at a fermentation temperature of $45^{\circ}C$, K. marxianus exhibited more than two fold higher growth rate and ethanol production rate in comparison to S. cerevisiae. For SSF using starch or corn stover as the sole carbon source by K. marxianus, the high temperature ($45^{\circ}C$) fermentations showed higher enzymatic activities and ethanol production compared to SSF at $30^{\circ}C$. These results demonstrate the potential of the thermotolerant yeast K. marxianus for SSF in the industrial production of biofuels.

• 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.

• Food Science and Biotechnology
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• 제15권6호
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• pp.877-883
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• 2006

The immunostimulatory activities of Lactobacillus plantarum, the major microorganism in kimchi fermentations were investigated. Five strains of L. plantarum exhibited weak immunopotentiating activity, but L. plantarum PS-21 showed as strong a mitogenic activity as Bifidobacterium adolescentis M101-4, a known positive strain. It is of interest that, L. plantarum PS-21 stimulated proliferation of Peyer's patch cells, one of the most important tissues in the gut-associated lymphoreticular system. Cell' wall fractions from L. plantarum PS-21 also showed strong mitogenic activity compared with the soluble cytoplasmic fraction. A peptidoglycan fraction (PG) extracted from the cell wall of L. plantarum PS-21 was identified as an active mitogenic component when used in murine lymph node and spleen cell test systems. PG showed dose-dependent mitogenic activity and significantly enhanced antibody production in lymph node cells when studied in vitro. The lysosomal enzyme activity of murine peritoneal macrophages was increased when analyzed following injection of PG to the host animal. Furthermore, PG enhanced the production of cytokines such ($TNF-{\alpha}$ and IL-6) in the in vitro culture of RAW 264.7 macrophage cells.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.873-878
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• 2005

Emissions of nitrous oxide (N$_2$O) and methane (CH$_4$) from poultry enteric fermentation were investigated using a respiration chamber. Birds were placed in a respiration chamber for certain intervals during their growing period or for the whole life cycle. The accumulated gas inside the chamber was sampled and analyzed for N$_2$O and CH$_4$ production. A curve for gas production during a life cycle was fitted. The calculated area under the curve estimated the emission factor of poultry enteric fermentation on a life cycle basis (mg bird$^{-1}$ life cycle$^{-1}$). This method can be used to estimate CH$_4$ or N$_2$O emissions from different types of avian species taking into account factors such as diet, season or thermal effects. The CH$_4$/N$_2$O emission factors estimated for commercial broiler chickens, Taiwan country chickens and White Roman Geese were 15.87/0.03, 84.8/16.4 and 1,500/49 (mg bird$^{-1}$ life cycle$^{-1}$), respectively, while the calculated CH$_4$/N$_2$O emission from enteric fermentations were 3.03/0.006, 14.73/2.84 and 9.5/0.31 (Mg year$^{-1}$), respectively in Taiwan in the year of 2000. The described method is applicable to most poultry species and the reported emission factors were applicable to meat type poultry only.