• Journal of Life Science
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• v.12 no.5
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• pp.566-569
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• 2002

Acetobacter strains are bacteria that can synthesize cellulose when grown on an undefined medium containing glucose. Several culture conditions affecting cellulose production by Acetobacter sp. A9 were examined by cultivating cells under shaking cultures. The addition of buffering agents, such as 3-(N-morpholino) propanesulfonic acid (MOPS) and CaCO$_3$, increased cellulose production. It suggests that pH of culture medium is important to an economical mass cellulose production. Addition of bead (Ф10 w) to culture medium stimulated 'disintegrated bacterial cellulose' production.

• 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.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.309-314
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• 1995

Samples were collected from a commercial ethanol production plant to enumerate the bacterial contamination in each step of a starch based ethanol production process. Though the slurry of raw material used in the process carried bacteria with various colony morphology in the order of $10^4$ per ml, only the colonies of white and circular form survived and propagated through the processes to the order of $10^8$ per ml at the end of fermentation. Almost all of the bacterial isolates from the fermentation broth were lactic acid bacteria. Heterofermentative Lactobacillus fermentum and L. salivarius, and a facultatively heterofermentative L. casei were major bacteria of an ethanol fermentation. In a batch fermentation L. fermentum was more detrimental than L. casei to ethanol fermentation. In a cell-recycled fermentation, ethanol productivity of 5.72 g $I^{-1} h^{-1}$ was obtained when the culture was contaminated by L. fermentum, whilst that of the pure culture was 9.00 g $1^{-1} h^{-1}$. Similar effects were observed in a cell-recycled ethanol fermentation inoculated by fermentation broth collected from an industrial plant, which showed a bacterial contamination at the level of 10$^8$ cells per ml.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.697-706
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• 2018

Lactobacillus pentosus K1-23 was selected from among 25 lactic acid bacterial strains owing to its high inhibitory activity against several pathogenic bacteria, including Escherichia coli, Salmonella typhimurium, S. gallinarum, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridium perfringens, and Listeria monocytogenes. Additionally, among 13 strains of Aureobasidium spp., A. pullulans NRRL 58012 was shown to produce the highest amount of ${\beta}$-glucan ($15.45{\pm}0.07%$) and was selected. Next, the optimal conditions for a solid-phase mixed culture with these two different microorganisms (one bacterium and one yeast) were determined. The optimal inoculum sizes for L. pentosus and A. pullulans were 1% and 5%, respectively. The appropriate inoculation time for L. pentosus K1-23 was 3 days after the inoculation of A. pullulans to initiate fermentation. The addition of 0.5% corn steep powder and 0.1% $FeSO_4$ to the basal medium resulted in the increased production of lactic acid bacterial cells and ${\beta}$-glucan. The following optimal conditions for solid-phase mixed culture were also statistically determined by using the response surface method: $37.84^{\circ}C$, pH 5.25, moisture content of 60.82%, and culture time of 6.08 days for L. pentosus; and $24.11^{\circ}C$, pH 5.65, moisture content of 60.08%, and culture time of 5.71 days for A. pullulans. Using the predicted optimal conditions, the experimental production values of L. pentosus cells and ${\beta}$-glucan were $3.15{\pm}0.10{\times}10^8CFU/g$ and $13.41{\pm}0.04%$, respectively. This mixed culture may function as a highly efficient antibiotic substitute based on the combined action of its anti-pathogenic bacterial and immune-enhancing activities.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.5
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• pp.314-324
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• 2011

Algal biomass cultivated by wastewater is potentially useful resource for biodiesel production. However, little is known about algal nutrient metabolism and microbial interaction with bacteria under real municipal wastewater condition. In this work, we characterized nitrogen and phosphorus removals of municipal wastewater by a representative wastewater-growing algal population. Ankistrodesmus gracilis SAG 278-2, and analyzed its ecological interaction with wastewater bacterial communities. Compared to wastewater sludge itself, algal-bacterial co-culture improved nutrient removal. According to bacterial community analysis with 16S rRNA genes, a selective and dominant growth of a Unclassified Alcaligenaceae population resulted from algal growth in the algal-bacterial co-culture. The selectively stimulated bacterial population is phylogenetically close to Alcaligenes faecalis subsp. 5659-H, which is known to be co-present interact with algae in aquatic environment. These findings suggest that algal growth/metabolism may have effects on selection of a specific bacterial population in algal-bacterial co-cultures that can efficiently remove nutrients from municipal wastewater.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.1
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• pp.7-12
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• 2002

During the screening or antiviral substances having inhibitory effect on tobacco mosaic virus(TMV) infection to tobacco plants, we found that a bacterial isolate, KTB61, which was identified as a Pseudomonas sp., strongly inhibited the formation of TMV local lesions. When the culture filtrate from KTB61 was applied on the upper surface of leaves of N. tabaccum Xanthi-nc tobacco at the same time of or 24 hours before TMV inoculation, almost complete inhibition was achieved. Incidence of systemic TMV infection to the susceptible tobacco cultivar, NC82, was reduced by 95% when TMV was inoculated onto the upper surface of leaves 24 hours after spraying the culture filtrate. Also 75∼80% of inhibitory effect was obtained by the inoculation of TMV onto the under surface of the leaves treated with culture filtrate 24 hours beforehand. In field trials, the TMV infection was reduced by 96.5% when the tobacco seedlings, N. tabaccum cv. NC82, were soaked with culture filtrate before transplanting.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.171-178
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• 2011

Bacillus thuringiensis (Bt) is a bacterial biopesticide against insect pests, mainly lepidopterans. Spodoptera exigua and Plutella xylostella exhibit significant decreases in Bt susceptibility in late larval instars. To enhance Bt pathogenicity, we used a mixture treatment of Bt and other bacterial metabolites which possessed significant immunosuppressive activities. Mixtures of Bt with culture broths of Xenorhabdus nematophila (Xn) or Photorhabdus temperata ssp. temperata (Ptt) significantly enhanced the Bt pathogenicity against late larval instars. Different ratios of Bt to bacterial culture broth had significant pathogenicities against last instar P. xylostella and S. exigua. Five compounds identified from the bacterial culture broth also enhanced Bt pathogenicity. After determining the optimal ratios, the mixture was applied to cabbage infested by late instar P. xylostella or S. exigua in greenhouse conditions. A mixture of Bt and Xn culture broth killed 100% of both insect pests when it was sprayed twice, while Bt alone killed less than 80% or 60% of P. xylostella and S. exigua, respectively. Other Bt mixtures, including Ptt culture broth or bacterial metabolites, also significantly increased pathogenicity in the semi-field assays. These results demonstrated that the Bt mixtures collectively names "Bt-Plus" can be developed into potent biopesticides to increase the efficacy of Bt.

• Journal of dental hygiene science
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• v.9 no.2
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• pp.249-255
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• 2009

This study was carried out for the purpose of comparing bacterial culture method, single PCR, and multiplex PCR for identification of F. nucleatum and A. actinomycetemcomitans in subgingival plaque of adult periodontitis. Targeting 20 patients with adult periodontitis, the subgingival plaque was collected in teeth, respectively, for #16, #36, #44. A bacillus was cultivated by painting it over the solid selective media of F. nucleatum and A. actinomycetemcomitans. Bacterial species were detected in 0 tooth with 12 pieces, respectively. Through single PCR and multiplex PCR, the positive reaction was indicated in 43 teeth with 45 pieces, respectively, as for F. nucleatum, and in 1 tooth with 4 pieces, respectively, as for A. actinomycetemcomitans. In the comparative analysis between bacterial identification methods. F. nucleatum showed the more statistically significant difference(p=0.0(0) in comparison between single PCR and multiplex PCR. Even A. actinomycetemcomitans was indicated significantly(p=0.067) in a case that is based on 0.1 in significant level in the comparison between single PCR and multiplex PCR. In conclusion, as a result of comparing the bacterial identification methods, the detection frequency was indicated to be higher in PCR than in bacterial culture method. Single PCR and multiplex PCR showed the mutually similar detection frequency. Accordingly, given thinking of economic efficiency, quickness, and reduction in labor force, it is thought to be more efficient method to use single PCR as the bacterial identification method.

• Mycobiology
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• v.36 no.1
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• pp.13-18
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• 2008

Eight distinct bacteria were isolated form diseased mycelia of the edible mushroom, Pleurotus eryngii. 16S rDNA sequence analysis showed that the isolates belonged to a variety of bacterial genera including Bacillus (LBS5), Enterobacter (LBS1), Sphingomonas (LBS8 and LBS10), Staphylococcus (LBS3, LBS4 and LBS9) and Moraxella (LBS6). Among them, 4 bacterial isolates including LBS1, LBS4, LBS5, and LBS9 evidenced growth inhibitory activity on the mushroom mycelia. The inhibitory activity on the growth of the mushroom fruiting bodies was evaluated by the treatment of the bacterial culture broth or the heat-treated cell-free supernatant of the broth. The treatment of the culture broths or the cell-free supernatants of LBS4 or LBS9 completely inhibited the formation of the fruiting body, thereby suggesting that the inhibitory agent is a heat-stable compound. In the case of LBS5, only the bacterial cell-containing culture broth was capable of inhibiting the formation of the fruiting body, whereas the cell-free supernatant did not, which suggests that an inhibitory agent generated by LBS5 is a protein or a heat-labile chemical compound, potentially a fungal cell wall-degrading enzyme. The culture broth of LBS1 was not inhibitory. However, its cell-free supernatant was capable of inhibiting the formation of fruiting bodies. This indicates that LBS1 may produce an inhibitory heat-stable chemical compound which is readily degraded by its own secreted enzyme.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.1
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• pp.123-134
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• 2006

Objective : This experimental study was performed to investigate the effect of Herbe-medicine used for eye disease(Sean-tang, Jinpi-san, Tangpo-san, Copitdis Rhizoma) on Staphylococcus epidermidis keratitis. Methods : After administering various herbal eye drops on Staphylococcus epidermidis, I measured MIC and the size of inhibition zone. MIC was measured by dropping from 20 to $50{\mu}{\ell}$ according to density. Anti-bacterial potency was measured by the size of inhibition zone with change of volume under 2 days culture condition. Also continuous anti-bacterial potency of herbal eye drops was measured by the size of inhibition zone according to 2 days and 6 days culture each under the $50{\mu}{\ell}$ condition. Results : 1. MIC on Staphylococcus epidermidis in Sean-tang, Jinpi-san was 1%, $50{\mu}{\ell}$ 2. MIC on Staphylococcus epidermidis in Tangpo-san, Coptidis rhizoma was 10%, $50{\mu}{\ell}$ 3. MIC on Staphylococcus epidermidis in Cravit was 0.1%, $20{\mu}{\ell}$. 4. Under the 2 days culture condition, the size of inhibition zone on Staphylococcus epidermidis by volume for Sean-tang was 10.0mm in $50{\mu}{\ell}$, Jinpi-san was 16.0mm in $50{\mu}{\ell}$, Tangpo-san was 17.5mm in $50{\mu}{\ell}$, Coptidis rhizoma was 31.0mm in $50{\mu}{\ell}$ and Cravit was 34mm in $50{\mu}{\ell}$, showed the highest anti-bacterial potency. 5. Under the $50{\mu}{\ell}$ condition, the size of inhibition zone on Staphylococcus epidermidis by 2 and 6 culture days for Sean-tang was 47.5mm in 6days, Jinpi-san was 36.0mm in 6days, Tangpo-san was 45.0mm in 6 days and Cravit was 48.0mm in 6 days, which showed the highest anti-bacterial potency. 6. Under the $50{\mu}{\ell}$ culture condition, the size of inhibition zone on Staphylococcus epidermidis by 2 and 6 culture days for Coptidis rhizoma was 31.0mm in 2 days and 6 days, which showed the same anti-bacteria1 potency. Conclusions : The present author think that Herbe-medicine used for eye disease can be used to cure Staphylococcus epidermidis keratitis and if further study is performed, the use of the Herbe-medicine used for eye disease will be valuable and beneficial in the clinical medicines.