• KSBB Journal
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• v.20 no.5 s.94
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• pp.350-354
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• 2005

In order to maximize hydrogen production by Enterobacter cloacae YJ-1, anaerobic hydrogen producing bacteria, the medium composition was optimized. Glucose was better than other carbon sources in hydrogen production and its production was 975.4 mL/L at $2\%$ (w/v) for 48 h. Organic nitrogen sources were more effective than inorganic nitrogen sources and also yeast extract among organic nitrogens was the most effective in hydrogen production. Among metal ions, $Na_2MoO_4$ was most effective, and its production was 1753.3mL/L at $0.04\%$ (w/v). Addition of amino acid was very effective with compare to another components of medium, and cystein was most effective among them. Under the optimum medium obtained in batch culture, semi-batch culture in order to produce continuous hydrogen was run. The highest hydrogen production was earned at $3\%$(w/v) of glucose and the amount was 2215.4 mL/L.

• KSBB Journal
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• v.18 no.2
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• pp.149-154
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• 2003

The hydrogen-producing bacterium was isolated from fresh water and identified as Enterobacter cloacae. The isolated was named Enterobacter cloacae YJ-1. In batch culture, The optimum cultivation temperature and pH of strain YJ-1 was 35℃ and 7.5, respectively. All of the added glucose was consumed completely during fermentation even though pH was not controlled. Amount of hydrogen produced on each condition of 2% glucose, 4% sucrose and 5% fructose was 950, 1000 and 948 mL/L, respectively and resulted in increasing hydrogen production approximately 2.5-times more than controlled condition. The maximum hydrogen production was obtained when 50 mM phosphate was added. In repeated-batch culture, hydrogen gas of 1920 mL/L was totally produced for 48. The maximum hydrogen was produced on the condition of 0.5% yeast extract, but the production amount was not changed on the condition of over 0.5%. Most of the organic acids produced during the fermentation were formic and acetic acid, and propionic acid was moiety also generated.

• KSBB Journal
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• v.23 no.3
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• pp.199-204
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• 2008

Culture conditions for biological hydrogen production were investigated in wastewater of Takju manufacturing factory. Rhodobacter spaeroides KCTC1425, photosynthesis bacteria, and Enterobacter cloacae YJ-1, anaerobic bacteria were used. The hydrogen production were $195.3m{\ell}{\cdot}H_2/{\ell}$ broth for Rhodobacter spaeroides KCTC1425 and $271.8m{\ell}{\cdot}H_2/{\ell}$ broth for Enterobacter cloacae YJ-1 during 36 h. The hydrogen production increased with light intensity, and were highest over 12000Lux. In mixed culture of Rhodobacter spaeroides KCTC1425 and Enterobacter cloacae Y J-1, the optimum mixing ratio of hydrogen production was 20 and 80. Adding volume of yeast extract for maximum hydrogen production was 15 $g/{\ell}$, but there was no effect over that. $Na_2MoO_4$ was most effective among the inorganic salts, and the optimum volume was 0.4 $g/{\ell}$. In semi-continuous culture, total hydrogen production was $13086m{\ell}{\cdot}H_2/{\ell}$ broth for 144 h with operating period of 24 h.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.271-271
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.426-427
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• 2005

• KSBB Journal
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• v.19 no.6 s.89
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• pp.446-450
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• 2004

We investigated the effective culture conditions of anaerobic bacteria, Enterobacter cloacae YJ-1 on hydrogen production. It was cultured with 60 mL of working volume at $35^{\circ}C$, 120 rpm for 40 h. With culture time, hydrogen production and cell growth increased, but residual glucose and pH decreased. When the $2\%$ of glucose was used as single carbon source, hydrogen production was 975.1 mL/L. To enhance hydrogen productivity, mixed carbon sources of glucose and sucrose were added. The maximum hydrogen production was earned at the mixing ratio of 25:75, and it was 1319.5 mL/L. When we added 50 mM of phosphate to protect the pH drop in culture broth, hydrogen production increased 1.3 times more than that of initial concentration. The organic nitrogen sources were more effective than inorganic nitrogen for hydrogen production. Among organic nitrogen, yeast extract was the most effective and its hydrogen production was 1691.3 mL/L. Among 9 of mineral sources, Ferric citrate and $NaMoO_4$ were especially effective, and their productions were 1782.3 mL/L and 1784.8 mL/L, respectively.

• KSBB Journal
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• v.18 no.2
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• pp.145-148
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• 2003

The hydrogen-producting bacterium was isolated from fresh water and identified as Enterbacter cloacae. The isolated was named Enterobacter cloacae YJ-1. In batch culture, The optimum cultivation temperature and pH of strain YJ-1 was 35$^{\circ}C$ and 7.5, respectively. All of the added glucose was consumed completely during fermentation even though pH was not controlled. Amount of hydrogen produced on each condition of 2% glucose, 4% sucrose and 5% fructose was 950, 1000 and 948 mL/L, respectively and resulted in increasing hydrogen production approximately 2.5-times more than controlled condition. The macimum hydrogen production was obtained when 50mM phosphate was added. was obtained when 50mM phosphate was added. In repeated0batch culture, yeast extract, but the production amount was not changed on the condition of over 0.5%, Most of the organic acides produced during the fermentation were formic and acetic acid, and propionic acid was moiety also generated.

• KSBB Journal
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• v.20 no.6
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• pp.447-452
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• 2005

The hydrogen production using immobilized cellsl was conducted using fruit wastewaters at various culture conditions. Three kinds of fruit wastewaters, melon, watermelon and pear were used. Sodium alginate was used as immobilization material. Among them, concentration of reducing sugar which was one of the main components in fruit was the highest at watermelon wastewater, and also hydrogen production was the highest as 2319.2 mL/L in it. Although hydrogen production was not much changed according to sodium alginate concentration, its production was the most at 3%(w/v). As bead size as small, hydrogen production was higher. With inspection of interior, it confirmed that the cell grew well in bead. But the addition of amino acids using as agent for metabolite production had almost no affected on hydrogen productivity. The effective range of $FeSO_4$ addition on hydrogen production were up to 1.2 g/L, and above the concentration, it inhibited the productivity. Organic acids produced during watermelon fermentation were mainly lactic acid, butyric acid, abd acetic acid; and a little of propionic acid.