• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.708-712
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• 2003

This study was carried out to examine the effects of fermentation conditions on the production of erythritol by osmophilic yeast Candida magnoliae. It was found that sucrose was superior to glucose as carbon source and 109 g/L erythritol was produced from 400 g/L sucrose. When yeast extract was used as nitrogen source, maximum values of yield and productivity for erythritol were obtained at 15 and 20 g/L of yeast extract, respectively. A mixture of 15 g/L yeast extract and 3 g/L ammonium phosphate allowed more efficient utilization of sucrose and hence resulted in 149 g/L of erythritol, 0.37 g erythritol/g sucrose of erythritol yield and $0.78\;g/L{\cdot}hr$ of erythritol productivity. A batch fermentation supplemented with 40 g/L KCl resulted in an erythritol concentration of 167 g/L and an erythritol yield of 0.42 g erythritol/g sucrose.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.312-317
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• 2002

Erythritol is of interest as a low calorie sweetner. Penicillium sp. KJ8l was screened for erythritol producer in nature. The effect of culture conditions on erythritol production by Penicillium sp. KJ81 was examined. This strain produced about 12 g/l erythritol and a small amout of glycerol. Erythritol was not produced from mannitol, arabinose, sorbitol, and xylose but from glucose, sucrose, fructose, mannose, lactose, maltose, and galactose. This strain was able to produce erythritol in a medium containing 60% sucrose but demonstrated the highest productivity of erythritol in a 30% sucrose medium. The highest yield in Penicillium sp. KJ8l was obtained when 0.5% ammonium sulfate was added to the medium containing 30% sucrose and 0.5% yeast extract. Penicillium sp. KJ81 produced 28.2 g/l erythritol when this strain was cultured in the medium containing 30% sucrose, 0.5% yeast extract, 0.5%$(NH_{4})_{2}SO_{4}$ 0.1% $KH_{2}PO_{4}$ and 0.01% $MgCl_{2}$ under the condition of 1 vvm aeration and 200 rpm agitation at $37^{\circ}C$ for 10 days in 5ι jar fermentor.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.91-95
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• 1999

To investigate the effect of salts on the production of erythritol by Torula sp., cells were grown on the media containing various concentrations of KCl or NaCl. Cell growth and glucose consumption rates decreased when KCl or NaCl concentration increased from 0.0 to 0.5M. The production of erythritol, however, was maximal at 0.3M aCl. The erythritol concentration of 54.3g/l in the medium containing 0.3M NaCl and 200g/l glucose was obtained after 120h. The production of erythritol decreased in cultures above 0.3M NaCl or 0.4M KCl due to the inhibition of cell growth. To elucidate the effect of salts more quantitatively, KCl and NaCl concentrations were converted to osmotic pressure. As the osmotic pressure increased, the yield of erythritol from glucose increased regardless of the kinds of salts and the yield of erythritol was approximately 49% at the osmolality of 2.4Os/kg. When the osmotic pressure increased to 2.5Os/kg, the specific growth rate of cells decreased but the production rate of erythritol increased. For the effective production of erythritol, osmotic pressure must be adjusted not to inhibit markedly the growth rate of cells and to stimulate the production rate of erythritol by supplementing salt.

• KSBB Journal
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• v.17 no.6
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• pp.509-514
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• 2002

Experiments were carried out to optimize the fermentation conditions for the production of erythritol by salt-tolerant mutant, Candida magnoliae M26. The optimum conditions of erythritol production showed a 1.0 vvm aeration and 500 rpm agitation at 28$\^{C}$ with an initial medium pH of 7.0. The pH control during the fermentation did not improve the erythritol yield and productivity. The maximum erythritol concentration of 143.3 g/L was obtained with 57% yield and 0.70 g/L-h productivity from 250 g/L of glucose and 5 g/L of yeast extract under an optimum fermentation conditions. The medium containing 0.5 M KCl or 0.5 M NaCl enhanced the production of erythritol and glycerol. However, glycerol production increased and erythrtiol production decreased by increasing the concentration of NaCl or KCl.

• KSBB Journal
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• v.13 no.3
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• pp.331-335
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• 1998

Erythritol is a four-carbon sugar alcohol with a low calorific value and non-cariogenicity. Erythritol is a new functional sweetener which can be used as sugar alternative. Erytheitol dose not cause discomfort such as diarrhoea and flatulence upon ingestion. The purpose of this study is to develope a novel process of erythritol economically in a large scale. To obtain a high erythritol producer, we have screened 3500 colonies from molasses, honey and honey combs. We have selected 40 erythritol-producing microorganisms, one of which yields 140g/L erythritol in 40% glucose medium. We have tested this strain in 5L fermentor to examine the fermentation characteristics. Results of fermentation show that the erythritol production was about 1.4g/L$.$hr in 400g/L glucose media with a 42% conversion. Further improvements require mutation for a higher producer, process optimization to reduce glycerol, and suppression of excessive foaming.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.38-42
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• 1997

For the purpose of obtaining microorganisms producing high amount of erythritol, the screening test was carried out. Productivity of erythritol was analyzed by paper chromatography and HPLC' methods. Among more than two hundred isolates, one strain(KJX1) was selected as an erythritol prtducer from thc soil of corn shock. The isolated strain was identified as Pmicilliurn sp. KJ81 from the morphological and physiological characteristics. Penicillium sp. KJ81 showed white to green colony color, two- to three-stage branching conidiophcvc and flask-shaped phialides.

• KSBB Journal
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• v.18 no.4
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• pp.249-254
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• 2003

Experiments were carried out to select an industrial nitrogen source and optimize erythritol production by Candida magnoliae in fed-batch culture. Among the industrial nitrogen sources tested, light steep water (LSW) was found to be the best nitrogen source for producing erythritol, based on erythritol yield and raw material price. The maximum erythritol concentration obtained a 131.6 g/L, with a 52.6％ yield and 0.52 g/L-hr productivity from a 250 g/L glucose and 43.3 mL/L LSW in batch culture. Two-stage fed-batch culture was chosen to improve the volumetric productivity and the yield of erythritol. High cell density culture in cell growth stage was achieved by batch type culture containing 100 g/L glucose and 500 mL/L LSW. The cell concentration was 71.0 g/L after 23 hours of culture. Erythritol productivity was decreased by increasing glucose concentration in the production stage. But 37.3％ of the maximum erythritol yield was obtained with 185.5 g/L of erythritol and 1.66 g/L-hr of productivity when 820 g of glucose powder was directly added to a concentration of 450 g/L glucose in production stage.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.268-272
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• 2003

Experiments were carried out to investigate the selection of industrial medium and optimization of fermentation process for the production of erythritol by Candida magnoliae SR101. In the batch fermentation, light steep water(LSW) was the best nitrogen source for the industrial production of erythritol. For the optimization of culture condition, the batch culture was performed. When the concentration of LSW was 65 mL/L in the defined medium containing 250 g/L of glucose, 44% of erythritol yield with 110 g/L of erythritol concentration and 0.66 g/L-hr of productivity, respectively were obtained. Two-stage fed-batch culture was performed to improve the volumetric productivity of erythritol. High density cell culture in the growth stage was performed by batch type with 100 g/L glucose and 500 mL/L LSW concentration, respectively. The cell yield was 0.72 g-cell/g-glucose. Productivity of erythritol was increased and concentration of organic acids such as gluconic acid and acetic acid were decreased when initial pH of 6.5 controlled by 28% ammonia water For increasing yield of erythritol, glucose concentration in the production stage was tested. 37% of total erythritol yield with 186 g/L of erythritol concentration and 1.66 g/L-hr of erythritol productivity were obtained when 820 g of glucose powder was directly added for making up 450 g/L of glucose at production stage.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.53-56
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• 2000

Two-stage fed-batch culture was peformed to improve the volumetric productivity of erythritol. In the growth phase dissolved oxygen was maintained to 20% and the feed medium was automatically supplied to the fermenter by pH-stat mode. The cell yield was 0.76 g-cell/g-glucose. In two-stage fed-batch culture, 41% of total erythritol conversion yield with 187 g/L of erythritol concentration and 2.79 g/L-h of maximum erythritol Productivity were obtained when 400 g/L of glucose was directly added in the form of non-sterile powder at production phase. The erythritol productivity increased in parallel with cell mass. The metabolic shift in the biosynthetic pathway of erythritol was caused by dissolved oxygen concentration. The production of gluconic acid was observed when the dissolved oxygen in the medium was maintained over 40% during the production phase, whereas the dissolved oxygen concentration lower than 40% caused the production of citric acid. But the butyric acid was produced independently with dissolved oxygen concentration in the medium. The production of organic acids such as gluconic acid, citric acid, and butyric acid was decreased by addition of mineral salts.

• KSBB Journal
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• v.15 no.6
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• pp.566-572
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• 2000

Experimental studies were carried out to develop an osmotolerant mutant of Candida magnoliae JH and to determine the optimum concentrations of carbon and nitrogen sources to improve erythritol yield and productivity. Mutants of C. magnoliae JH were prepared by treatment with ethylmethane sulfonate, and osmotolerant mutants were isolated from the agar plate colonies containing 2.5 M KCI. Among the mutants isolated, one mutant M26 was finally selected based on erythritol yield and productivity. In shake flask culture, glucose proved to be the best carbon source and the optimum yeast extract concentration was 5 g/L based on 100 g/L glucose. The erythritol yield and productivity of mutant M26 were greater than wild type in 100 g/L glucose medium. in the fermentation experiments, erythritol production increased with increased glucose concentration, up to a limit of 250 g/L. The maximum concentration of erythritol achieved 127.5 g/L, and the yield and productivity of erythritol production were 51.0% and 0.63 g/L-h, respectively.