• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.152-156
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• 2011

Viable bacteria on water-insoluble airborne particles were detected in the urban atmosphere of Kumamoto ($134^{\circ}45'E$, $32^{\circ}28'N$), Japan, in autumn 2008. Airborne particles were collected onto film-covered Cu meshes under clear weather conditions. The samples were stained by fluorescent stains, and then viewed and photographed with an epifluorescent microscope. Non-biological and bacterial parts in particles larger than 0.8 ${\mu}m$ were distinguished by their morphologies, fluorescent colors and fluorescent intensities. Bacterial viable statuses were discriminated according to cell membrane damage. In total, 2681 particles were investigated and it was found that 78 airborne particles were associated with bacteria. Viable bacteria were identified on 48 particles. A few particles carried multiple viable bacteria. These results provide the evidence that airborne particles act as carriers of viable bacteria in the atmosphere.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.180-185
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• 2002

The direct viable count (DVC) and plate count (PC) methods was used to measure the number of bacteria in potable groundwater samples collected from bottled water from the market, mineral water, and edible groundwater near the urban areas and the stock farming congested areas. As a result, the number of living bacteria by DVC was comprised 30~80% of the total direct count (TDC), whereas the number of living bacteria by PC was around l~30% of DVC. Such results show that viable but non-culturable (VBNC) bacteria exist in the potable groundwater with high percentages. On the other hand, upon measuring the value from the conventional nutrient broth (NB), $10^-2$ fold diluted nutrient broth (DNB), and R2A broth, the values from the DNB and R2A showed 2~50 times higher than the conventional NB medium. These results indicate that oligotrophic bacterial groups which can multiply in the low nutrient broth abundantly exist in the oligotrophic environment like potable groundwater.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10241-10244
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• 2015

Objective: To investigate the efficacy and side effects of Bifidobacterium tetragenous viable bacteria tablets in treating cancer patients with functional constipation during chemotherapy. Methods: A consecutive cohort of 100 cancer patients with functional constipation were divided into two equal groups: patients in the experimental group were given Bifidobacterium tetragenous viable bacteria tablets combined with chemotherapy, while patients in the control group received chemotherapy alone. After 4 weeks, the efficacy and side effects in treating functional constipation were evaluated. Results: Constipation in 48 patients in experimental group was controlled (9 returned to normal), with a total response rate of 96%, and 1 patient reported diarrhea (2%). In contrast only 16 patients in the control group demonstrated improvement and 34 were still constipated after chemotherapy, with a response rate of 32%. The difference in response rate was statistically significant (P<0.05). Conclusion: This study suggested that Bifidobacterium tetragenous viable bacteria tablets are effective and safe in treating cancer patients with functional constipation during chemotherapy.

• Journal of Dairy Science and Biotechnology
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• v.41 no.4
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• pp.157-162
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• 2023

In the field of microbiology, numerous types of bacteria live dormant to survive stresses such as pasteurization and antibiotics. Some bacteria become 'persisters' by inactivating their ribosomes, allowing them to 'sleep' through stress and revive when the stress has been removed. Under stress, some cells morph into hollow, lifeless structures known as 'cell shells.' In microbiology, these cells have been confused with viable cells in the 'viable but non-culturable cells' phenomenon. Therefore, this review addressed the concept that when revival occurs, the always-viable persister cells revive, instead of the dead cell husks.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.181-186
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• 2003

This study was performed to analyze quantitatively the number of living bacteria in forest soil samples collected from Mt. Keryong using improved direct viable count (DVC) and plate count (PC) methods. The number of living bacteria by DVC comprised 18～44% of the total direct count (TDC), whereas the number of living bacteria by PC was less than 1% of TDC. These results showed that viable but non-culturable (VBNC) bacteria existed in the soil with high percentages. Besides, DVC was proved to make it possible to make a quantitative detection of the VBNC bacteria. On the other hand, upon measuring the value from the conventional nutrient broth (NB) and $10^{-2}$ folded diluted nutrient broth (DNB), the values from the DNB showed 5 to 10 times higher than those from the conventional NB medium. These results indicate that oligotrophic bacterial groups, which could multiply in the low nutrient broth, abundantly exist in the soil ecosystem. It would also be possible to apply this kind of method to other substrate to make a quantitative detection of soil bacterial groups.

• Food Science of Animal Resources
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• v.20 no.1
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• pp.21-29
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• 2000

This study was carried out to investigate the fermentation characteristics and storage of set-type yoghurt added mugwort extracts(AME) such as pH, growth of lactic acid bacteria, number of viable cells, viscosity, and sensory characteristics during 24 hours fermentation and 15 days storage. Addition of mugwort extracts was grown rapidly of lactic acid bacteria rather than that of control and also 4 or 8% AME groups were grown similar to control. The drop of AME pH of broth was less compared with control during incubation of lactic acid bacteria. The growth of lactic acid bacteria during incubation of AME yoghurt was not different of viable cell count between AME group and control in beginning time, but the viable cell count of AME groups were increased depended opon addition quantity of AME in ending time. Addition of mugwort extracts was not affect on pH change during yoghurt fermentation and increased a lactic acid bacteria number as well as no effect of yoghurt fermentation in ending time. The viscosity of yoghurt was almost not changed 3 hours after yoghurt mix and increased rapidly 6 hours after yoghurt mix. Although control and 0.5% AME group showed maximum viscosity at 18 hours of fermentation, 1 and 2% AME group showed linear increase until 24 hours of fermentation. Mugwort did not affect pH and viable cel number of lactic acid bacteria during 15 days storage 24 hours after fermentation. Sensory evaluation of the AME yoghurt showed that flavour, texture and acid taste were not affected by addition of mugwort. However, the appearance and taste were dropped by addition of mugwort.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.995-1004
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• 2017

Culture-dependent methods, such as heterotrophic plate counting (HPC), are usually applied to evaluate the bacteriological quality of hemodialysis water. However, these methods cannot detect the uncultured or viable but non-culturable (VBNC) bacteria, both of which may be quantitatively predominant throughout the hemodialysis water treatment system. Therefore, propidium monoazide (PMA)-qPCR associated with HPC was used together to profile the distribution of the total viable bacteria in such a system. Moreover, high-throughput sequencing of 16S rRNA gene amplicons was utilized to analyze the microbial community structure and diversity. The HPC results indicated that the total bacterial counts conformed to the standards, yet the bacteria amounts were abruptly enhanced after carbon filter treatment. Nevertheless, the bacterial counts detected by PMA-qPCR, with the highest levels of $2.14{\times}10^7copies/100ml$ in softener water, were much higher than the corresponding HPC results, which demonstrated the occurrence of numerous uncultured or VBNC bacteria among the entire system before reverse osmosis (RO). In addition, the microbial community structure was very different and the diversity was enhanced after the carbon filter. Although the diversity was minimized after RO treatment, pathogens such as Escherichia could still be detected in the RO effluent. In general, both the amounts of bacteria and the complexity of microbial community in the hemodialysis water treatment system revealed by molecular approaches were much higher than by traditional method. These results suggested the higher health risk potential for hemodialysis patients from the up-to-standard water. The treatment process could also be optimized, based on the results of this study.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.5
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• pp.525-535
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• 2002

The purposes of this study were to evaluate the adherence of bacteria on various denture base resin materials and effects of chitosan, added to denture base materials on bacterial adherence. PMMA denture base resin such as heat-cured Vertex-RS, self-cured Vertex-SC and 4-META denture base resin such as heat-cured Meta-Dent, self-cured Meta-Fast were used in this study Samples were divided into two groups the denture base resin with chitosan, without chitosan Streptococcus mutans and Lactobacillus casei were used in this study. The surface of samples was observed by SEM. When chitosan was added to M17 and MRS broth, viable cell count of bacteria was reduced. Viable cell count of Streptococcus mutans on the samples decreased as follows : Meta-Dent, Vertex-SC, Meta-Fast, Vertex-RS. Viable cell count of Lactobacillus casei on the samples decreased as follows: Vertex-RS, Meta-Dent, Meta-Fast, Vertex-SC. The resin with chitosan showed lower adherence of bacteria than without chitosan. The images of SEM showed that the surface of the resin with chitosan was rougher than that of without chitosan. These results showed that the denture base resin materials with chitosan have rougher surface than without chitosan, but less bacteria adhered on them.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.118-123
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• 2008

A new method for antimicrobial susceptibility testing of vitro-cultured bacteria on an ordinary fluorescence spectrometer was developed. The viable bacteria reduced 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to produce insoluble particles that displayed intense resonance scattering light. The assay showed a linear relationship between the number of viable bacteria and the intensity of resonance scattering light. Dead bacteria were unable to reduce MTT. Methicillin-resistant Staphylococcus aureus exposed to flavonoids from Marchantia convoluta showed a flavonoids concentration-dependent inhibition of the ability to reduce MTT. In the assay, less than 12 h was required to attain susceptibility results and fewer bacteria were utilized than in traditional methods. The RLS technique could, in combination with the MTT assay, be a rapid and sensitive measuring method to determine the in vitro activity of new antimicrobials.