• KSBB Journal
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• v.18 no.2
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• pp.94-99
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• 2003

The effect of medium composition on the production of bacterial cellulose (BC) by Gluconacetobacter hansenii PJK was investigated. The addition of yeast extract and peptone in the medium increased the production yield (Y/sub p/s/) of BC. The amount of BC produced by G. hansenii PJK was constant if the initial pH of the medium was in the range 4.5 to 6.0. Strains from the supernatant of the culture medium produced more BC than those from inside the BC. BC production was dependent on glucose metabolism, and the addition of fructose or lactate as a carbon source converted cells to Cel/sup -/ mutants. Cel/sup -/ mutants produced by the addition of fructose or lactate to the medium caused 73% or 30% decreases in BC production, respectively. The addition of succinate, which is one of the constituents of the TCA cycle, did not affect the production of BC.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.83-88
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• 2003

A cellulose-producing strain isolated from rotten apples was identified as Gluconacetobacter hansenii based on its physiological properties and the 16S rDNA complete sequencing method, and specifically named Gluconacetobacter hansenii PJK. The amount of bacterial cellulose (BC) produced by G. hansenii PJK in a shaking incubator was 1.5 times higher than that produced in a static culture. The addition of ethanol to the medium during cultivation enhanced the productivity of bacterial cellulose, plus the supplementation of 1% ethanol into the culture medium made the produced BC aggregate into a big lump and thus protected the bacterial-cellulose-producing G. hansenii PJK cells in the shear stress field from being converted into non-cellulose-producing (Cel) mutants. Cells subcultured three times in a medium containing ethanol retained their ability to produce BC without any loss in the production yield.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.115-115
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• 2003

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.52-57
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• 2006

Bacterial cellulose (BC) was produced by Gluconacetobacter hansenii PJK (KCTC 10505 BP) strains using the waste of beer fermentation broth. It contained more C and N than a basal medium with a small amount of S and more than 4％ ethanol. The amount of BC produced in a shaking culture using the waste of beer fermentation broth was nearly the same as that of a basal medium. The production of BC decreased in a shear stress field in a jar fermenter although the conversion of cellulose producing ($Cel^+$) cells to non-cellulose producing ($Cel^-$) mutants was not severe. This study showed that the waste of beer fermentation broth is an inexpensive carbon, nitrogen source with ethanol and thus a worthy substitute for the conventional medium for BC production.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.451-456
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• 2004

The effects of variation in composition of the medium on the conversion of Gluconacetobacter hanseii PJK cells producing cellulose ($Cel^+$) to non-cellulose producing ($Cel^-$) mutants and the production of bacterial cellulose (BC) in an agitated culture were investigated. The impeller speed greater than 500 rpm was required to decrease the population of $Cel^-$ mutants to minimum in a basal medium containing $1.5\%$ ethanol because the optimum impeller speed to minimize the population of $Cel^-$ mutants increased with the concentration of ethanol added to a basal medium. Ethanol fed-batch culture could not increase the BC production in an agitated culture unlike that of a shaking culture. The amount of BC produced in a basal medium containing $1\%$ ethanol was $39\%$ more than that of the same medium with $0.27\%\;Na_{2}HPO_4$. Increase in the concentration of acetic acid in a basal medium decreased the BC production. The pH control of the culture broth increased the cell mass in the batch culture and improved the production yield of water-soluble polysaccharide (WSPS), but did not affect the production of BC.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.356-357
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• 2005

• Korean Chemical Engineering Research
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• v.47 no.4
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• pp.506-511
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• 2009

In order to improve the bacterial cellulose(BC) production yield, centrifugal and inclined centrifugal impellers were developed. A 6 flat-blade turbine impeller was used as a control system. The flow pattern in the fermenter and volumetric oxygen transfer coefficient($k_La$) of these fermentation systems were studied. Fermentations were carried out for the production of BC by G. hansenii PJK in a 2-L jar fermenter equipped with new impellers. Liquid medium was circulated from the bottom, through the cylinder of the impeller and to the wall. The volumetric oxygen transfer coefficients, $k_La$, of inclined centrifugal and centrifugal impeller systems at 100 rpm were 23 and 15% of the conventional turbine impeller system, respectively. However, the conversion of microbial cells to cellulose non-producing mutant decreased and this results in the increase in BC production at low rotating speed of impellers.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.237-237
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• 2003

• KSBB Journal
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• v.18 no.2
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• pp.127-132
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• 2003

The effect of 4 kinds of alcohols was investigated on the production of bacterial cellulose (BC) by Gluconacetobacter hansenii PJK. The addition of alcohols and acetic acid to medium caused the pellets of bacterial cellulose to aggregate into a lump, which could be easily separated from the culture medium. The growth rate of cells and the production yield of BC increased in the medium containing ethanol. Other alcohols in the medium decreased cell growth and the cellulose production rate, because of their toxic effects. The addition of ethanol depressed the conversion of a $\textrm{Cel}^{+}$ cell to a $\textrm{Cel}^{-}$ mutant in shaking culture. Cells subcultured three in a medium containing ethanol produced BC without any loss of BC production yield.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.383-388
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• 2004

The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.