• Applied Biological Chemistry
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• 제36권6호
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• pp.481-487
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• 1993

Acetobacter suboxydans의 휴지균체를 이용한 sorbitol로부터 sorbose 생산계에 대해 검토한 결과 5% sorbitol농도에서 균체를 약 6 mg/ml 농도까지 첨가할 때 sorbose의 생산량이 급격히 증가하였다. Sorbose 생성의 최적 반응 온도는 $30^{\circ}C$, 최적 pH는 6.0이었으며 금속 이온은 1 mM $Al^{+3}$ 이온에 의해 약 12%의 증가를 보인 반면에 $Ni^{+2}$ 이온 첨가시 현저한 sorbose 생산 저해를 보였다. p-aminobenzoic acid를 1.0 mM 첨가시 약 20%의 sorbose생성이 증가되었으며, Ca-pantothenate 첨가는 감소 효과를 나타내었으나 p-aminobenzoic acid와 혼합첨가에 의한 sorbose 생성은 약 7% 증가하였다. 총 반응액 1.5 ml를 50 ml 삼각 프라스크에서 반응시켰을 때, 기질 5% sorbitol은 20시간만에 완전히 sorbose로 전환되었다.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.68-74
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• 1997

The conversion of D-sorbitol to L-sorbose by Gluconobater suboxydans was analyzed, and continuous production of L-sorbose was carried out in immobilized cell reactors. L-Sorbose production by high densities of resting cells was more effective than by conventional batch fermentations. Sorbitol dehydrogenase, an enzyme converting D-sorbitol to L-sorbose, did not suffer from substrate inhibition, but from product inhibition. When L-sorbose production was carried out with Ca-alginate-immobilized cells, about 60 g/l of L-sorbose was obtained. On the other hand, when the corn steep liquor (CSL) concentration of medium was reduced to 0.08%, 80 g/l of L-sorbose was obtained. Outgrowth inside the immobilized carriers was thought to block the pores of the carriers so that substrate could not easily diffuse through the carriers. Continuous production of L-sorbose was well accomplished in a bubble column reactor, and 6. 5 g/l.h of productivity and 81.2% of yield were obtained at a substrate feeding rate of 0.08h$^{-1}$ under the optimum conditions with carrier volume of 55% and aeration rate of 3 vvm.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권5호
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• pp.340-344
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• 2000

Microbial oxidation of D-sorbitol to L-sorbose by Acetobacter suboxydans is of commercial importance since it is the only biochemical process in vitamin C synthesis. The main bottleneck in the batch oxidation of sorbitol to sorbose is that the process is severely inhibited by sorbitol. Suitable fed-batch fermentation designs can eliminate the inherent substrate inhibition and improve sorbose productivity. Fed-batch sorbose fermentations were conducted by using two nutrient feeding strategies. For fed-batch fermentation with pulse feeding, highly concentrated sorbitor (600g/L) along with other nutrients were fed intermittently in four pulses of 0.5 liter in response to the increased DO signal. The fed-batch fermentation was over in 24h with a sorbose productivity of 13.40g/L/h and a final sorbose concentration of 320.48g/L. On the other hand, in fed-batch fermentation with multiple feeds, two pulse feeds of 0.5 liter nutrient medium containing 600g/L sorbitol was followed by the addition of 1.5 liter nutrient medium containing 600g/L sorbitol at a constant feed rate of 0.36L/h till the full working capacity of the reactor. The fermentation was completed in 24h with an enhanced sorbose productivity of 15.09g/L/h and a sorbose concentration of 332.60g/L. The sorbose concentration and productivity obtained by multiple feeding of nutrients was found to be higher than that obtained by pulse feeding and was therefore a better strategy for fed-batch sorbose fermentation.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1976년도 제7회 학술발표회
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• pp.183.4-184
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• 1976

Sorbose is an important raw material for the production of Vitamin C. As part of our endeavor to develop on improved vitamin C process, we first studied the sorbose fermentation process. Several important variables that influence the productivity of sorbose were considered and evaluated. The yield sorbose from sorbitol obtained was greater than 90％. Details of our experimental results will be discussed and a possible new approach to process improvement will be suggested for more efficient sorbose fermentation.

• KSBB Journal
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• 제8권1호
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• pp.10-16
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• 1993

The use of Jerusalem artichoke containing $\beta$-1, 2-fructose oligomer for the production of D-sorbitol and L-sorbose has been studied. The employment of inulinase(0.398%, v/v) for the hydrolysis of 40% (v/w) Jerusalem artichoke juice resulted in 36.7g/1 of glucose and 85.3g/1 of fructose at $50^{\circ}C$. These sugars were utilized as substrates for D-sorbitol and L-sorbose production. Coimmobilization of inulinase and permeabilized cells of Zymomonas mobilis in the mixture of chitin (5%, w/e) and x-carrageenan(4%, w/v) resulted in the production of 30.2g/1 of D-sorbitol by using inulin as a substrate. The process of L-sorbose production from D-sorbitol by Gluconobacter suboxydans was optimized with respect to the substrate concentration, level of dissolved oxygen and glucosic and concentration. Gluconlc acid produced by Zymomonas mobilis from glucose was found to inhibit Gluconobacter suboxtans in conversion of D-sorbitol to L-sorbose. In view of removing such inhibitory effect by gluconic acid, mutants were selected by the NTG (N-methyl-N'-N'-nitro-N-nitrosoguanidlne) treated method. Mutants selected by NTG mutagenesis showed no inhibitory effects of gluconic acrid against L-sorbone production when its concentration increased up to 100g/1. A mutant produced 40.1g/l of L-sorbose in the medium containing 100g/l D-sorbitol and 100g/l-gluconic acid. This result is consider able when compared with L-sorbose concentration (21.7g/1) obtained from the fermentation with wild type strain of Gluconobacter suboxnians.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.696-699
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• 1998

Biological oxidation of D-sorbitol to L-sorbose using permeated and immobilized cells of Gluconobacter suboxydans was carried out to investigate the optimum reaction condition. The stabilization effect of cross-linking agents such as glutaraldehyde, tannic acid, and polyethylene imine to prevent the leakage of enzymes from beads containing permeated and immobilized cells of G. suboxydans was examined by the production of L-sorbose from the mixture of D-sorbitol and gluconic acid. The protein concentration effused from immobilized beads treated with only glutaraldehyde was $5.2\mug/m\ell$ after 20 h. The beads of G. suboxydans immobilized with alginate and cross-linked with 0.3% glutaraldehyde was the most useful for the oxidation of D-sorbitol to L-sorbose.

• KSBB Journal
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• 제5권1호
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• pp.1-8
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• 1990

D-sorbitol을 첨가한 배지에서 G. melanogenus를 배양하였을 때에 D-sorbitold은 L-sorbose를 거쳐 2 keto-L-gulonic acid로 전환되었다. G. cerinus를 D-sorbitol 대신에 포도당을 첨가하여 준 배지에서 배양하였을 때에 포도당은 2-keto-D-gluconic acid, 5-keto-D-gluconic acid, 2.5 diketo-D-gluconic acid로 산화되었다. 2,5-diketo-D-gluconic acid는 포도당이 2-keto-D-gluconic acid를 거쳐 생성되는 것으로 확인되었다. 배양액에 첨가하여 준 탄산칼슘의 양을 증가시키면 5-keto-D-gluconate의 생성이 증가하였고, 탄산칼슘대신에 다른염기를 배양액에 가하여 주었을 때는 2keto-D-gliconate만 생성되었다.

• 미생물학회지
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• 제13권2호
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• pp.45-50
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• 1975

Uptake of $^{14}C$-sorbose and $^{14}C$-3-O-methylglucose by ungerminated conidia of Neurospora crassa was measured by means of the millipore filter technique. Initial rates of jptake of both sorbose and 3-O-methylglucose show a marked dependence optimal pH for uptake of both sugars is close to 4.75. When ungerminated conidia are "starved" with buffer for a prolonged period of time prior to assaying their transport capacity and mycelia, no de-repression of the glucose-repressible sugar transport system is effectuated in contrast to the findings for germinated conidia.d conidia.

• 약학회지
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• 제32권6호
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• pp.386-393
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• 1988

Chemical transformation of D-glucose to 2-keto-L-gulonic acid and L-ascorbic acid has been examined. D-Sorbitol obtained from D-glucose was microbiologically oxidized to L-sorbose by G. suboxydans in 90% yield. On treatment of L-sorbose with acetone in the presence of sulfuric acid, its diacetonide is obtained in 95% yield. This diacetonide is oxidized to the corresponding acid with nickel chloride-hypochlorite, and the acid is directly transformed to L-ascorbic acid. The over all yield of Vitamin C from D-glucose achieved is 54%.

• 약학회지
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• 제44권4호
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• pp.334-339
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• 2000

The present study was carried out to evaluate biologically active components of the rhizomes of Sparganium stoloniferum and to supply the preliminary data for the chemotaxonomy and the medicinal application. Extraction and systematic fractionation of the rhizomes by column chromatography led to the isolation of six compounds from ethylacetate and n-butanol soluble fractions. Elucidation of the chemical structures of these compounds by physicochemical and apectral analysis demonstrated that compound I,II ,III,IV,V and Ⅵ were $\beta$-sitosterol, $\beta$-sitosterol-3-$\beta$-D-glucuronopyranoside, 3- (4-hydroxyphenyl)-2-propenoic acid, sorbose, 1-O-$\beta$-D-glucopyranosyl-(2S, 3R, 4E, 8Z)-2-[(2(R)-hydroxyeicosanoyl)amido]-4,8-octadecadiene-1,3-diol, and $\beta$-sitosterol-3-O-$\beta$-D-glucopyranoside, respectively.