• Journal of Food Hygiene and Safety
• /
• v.19 no.4
• /
• pp.209-216
• /
• 2004

Dry rehydratable film methods were compared to conventional methods for the enumeration of microorganisms in Korean traditional foods. Kimchi, doenjang, kochujang, kanjang, takju, sujeongkwa and sikhe were used as Korean traditional foods. $Petrifilm^{TM}$ aerobic count plate, $Petrifilm^{TM}$ coliform count plate, $Petrifilm^{TM}$ E. coli/coliform count plate, $Petrifilm^{TM}$ yeast and mold count plate and $Petrifilm^{TM}$ staph express count plate were compared to plate count agar, most probable number (MPN) for coliform, MPN for E. coli, potato dextrose agar and coagulase test, respectively. Regression analysis indicated that correlation coefficient values were 0.974-0.998, 0.913-0.995, 0.955-0.978, 0.968-0.986 and 0.998-0.999 for total aerobic bacteria, yeast and mold, coliform, E. coli and S. aureus, respectively. There were no significant differences between two methods, suggesting that $Petrifilm^{TM}$ plates can be used as an alternative to conventional method for the determination of microorganisms in Korean traditional foods.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.294-300
• /
• 2005

Contents of total aerobic bacteria, coliform, Escherichia coli, yeast, mold, and Staphylococcus aureus in meat, dairy, and fishery products were analyzed by dry rehydratable film method using 3M $Petrifilm^{TM}$ and compared against those obtained through conventional method. Two methods showed high correlations of 0.990-0.999, 0.975-0.999, 0.979-0.987, 0.978-0.984, and 0.999 for total aerobic bacteria, yeast and mold, coliform, E. coli, and S. aureus, respectively; therefore, dry rehydratable film method using 3M $Petrifilm^{TM}$ offers acceptable alternative to conventional method for enumeration of microorganisms in meat, dairy, and fishery products.

• Korean Journal of Ecology and Environment
• /
• v.49 no.2
• /
• pp.67-79
• /
• 2016

Cyanotoxins in aquatic ecosystems have been investigated by many researchers worldwide. Cyanotoxins can be classified according to toxicity as neurotoxins (anatoxin-a, anatoxin-a(s), saxitoxins) or hepatotoxins (microcystins, nodularin, cylindrospermopsin). Microcystins are generally present within cyanobacterial cells and are released by damage to the cell membrane. Cyanotoxins have been reported to cause adverse effects and to accumulate in aquatic organisms in lakes, rivers and oceans. Possible pathways of microcystins in Lake Suwa, Japan, have been investigated from five perspectives: production, adsorption, physiochemical decomposition, bioaccumulation and biodegradation. In this study, temporal variability in microcystins in Lake Suwa were investigated over 25 years (1991~2015). In nature, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, during water treatment, the use of copper sulfate to remove algal cells causes extraction of a mess of microcystins. Cyanotoxins are removed by physical, chemical and biological methods, and the reduction of nutrients inflow is a basic method to prevent cyanobacterial bloom formation. However, this method is not effective for eutrophic lakes because nutrients are already present. The presence of a cyanotoxins can be a potential threat and therefore must be considered during water treatment. A complete understanding of the mechanism of cyanotoxins degradation in the ecosystem requires more intensive study, including a quantitative enumeration of cyanotoxin degrading microbes. This should be done in conjunction with an investigation of the microbial ecological mechanism of cyanobacteria degradation.

• Journal of Korea Soil Environment Society
• /
• v.1 no.2
• /
• pp.3-13
• /
• 1996

The efficiency of bioremedation can be measured by the enumeration of microorganism, respiration rate and decomposition rate. The side-effect can be measured by using Daphnia, oyster larvae and rainbow trout. Oxygen transfer could be a problem in the on-site treatment. For these, hydrogen peroxide can be used for solvents such as benzenes. Oleophilic nitrogen and phosphorus can be added for the treatment of oil pollution. Mixed microbial population or pure culture can be used for the inoculum. The pure culture used is Pseudomonas and Phanerochate. Sometimes enzymes are added and Photodegadation is coupled to increase the efficiency. For the treatment of oil pollution residue on soil such as waste lubrication oil and machine oil sludges, top soil of 15cm∼20cm depth is plowed and oil residue with approximately 5% concentration is applied. The optimum pH range is 7∼8, the ratio of phosphorus to hydrocarbon is 1:800. Appropriate drainage is necessary. For the treatment of marine oil pollution residue, addition of oleophilic fertilizer is effective. Air pollutiant such as oder can be treated by bioremediation. In this case, biofilters or biosrubbers are used for the reactor.

• Journal of Food Hygiene and Safety
• /
• v.16 no.3
• /
• pp.194-199
• /
• 2001

This study was designed to compare the effectiveness and applicability of the HApS$^{TM}$ (Hazard Analysis process System; HUKO, Seoul, Korea) based on Petrifilm$^{TM}$ (3M, St. Paul, MN, USA) with the AOAC (the Association of Official Analytical Chemists) standard total aerobic count (TAC) method and coliform count (CC) method for meat products. The comparisons were carried out using 230 meat samples collected from various retailers: 80 pork samples, 80 chicken samples, and 70 beef samples. In the comparison of the correlation coefficient (r) between conventional method and HApS$^{TM}$ method by a linear regression analysis, the correlation coefficients in total microorganism were 0.97767, 0.90712, and 0.95594 in pork, beef, and chicken samples, respectively. The correlation coefficients in coliform count were 0.82062, 0.94833, and 0.96839 in pork, beef and chicken samples, respectively. All the independent t-test on measurement values between conventional method and HApS$^{TM}$ method represented no significant differences in the means between two methods at the 0.05 of significance level($\alpha$=0.05). Based on the high correlation between HApS$^{TM}$ and the AOAC standard methods in the TAC and CC, it might be compatible to employ the HApS$^{TM}$ method to measure the microbial contamination in livestock products. HApS$^{TM}$ method was simpler and less time-consuming in sample preparation and procedures faster than the conventional method. These results suggested that the HApS$^{TM}$ method could be substitute for the conventional methods in the analysis of microbial contamination measurement in meat products.n meat products.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.9
• /
• pp.1330-1338
• /
• 2008

This study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut microflora in weaned piglets. A total of sixty pigs were weaned at 21 d of age (BW = $5.64{\pm}0.23kg$) and allocated on the basis of BW and litter to three dietary treatments in a randomized complete block design. The dietary treatments were: control group (basal diet), antibiotics group (basal diet+0.02% colistin), and ASE group (basal diet+0.1% ASE). On d 7, 14 and 28 after consuming the experimental diets, five piglets per group were sacrificed and then the contents from the jejunum, ileum and cecum were collected to determine changes in the microbial community by using a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique and estimating the contents of Lactobacillus and E. coli by in vitro culturing methods. The results showed that the ASE promoted the microflora diversity in the cecum. Enumeration of bacteria in the gut contents showed that the number of Lactobacillus increased (p<0.05), while that of E. coli decreased (p<0.05) when compared with the other 2 groups as the days of age progressed post-weaning. These findings suggested that the ASE, as a substitute for dietary antimicrobial products, could improve the development of the normal gut microflora and suppress bacterial pathogens, and effectively promote a healthy intestinal environment.

• Korean Journal of Poultry Science
• /
• v.49 no.4
• /
• pp.287-298
• /
• 2022

This study evaluated the efficacy of chlorine dioxide (ClO₂) as an oxidant to reduce malodor emission from chicken feces. Two experiments were performed with the following four treatments in parallel: 1) fresh chicken feces with only distilled water added as a control, 2) a commercial germicide as a positive control, and 3) 2,000 or 4) 3,000 ppm of ClO₂ supplementation. Aluminum gas bags containing chicken feces sealed with a silicone plug were used in both experiments, and each treatment was tested in triplicate. In Experiment 1, 10 mL of each additive was added on the first day of incubation, and malodor emissions were then assessed after 10 days of incubation. In Experiment 2, 1 mL of each additive was added daily during a 14-day incubation period. At the end of the incubation, gas production, malodor-causing substances (H₂S and NH₃ gases), dry matter, pH, volatile fatty acids (VFAs), and microbial enumeration were analyzed. Supplementing ClO₂ at 2,000 and 3,000 ppm significantly reduced the pH and the ammonia-N, total VFA, H₂S, and ammonia gas concentrations in chicken feces compared with the control feces (P<0.05). Additionally, microbial analysis indicated that the number of coliform bacteria was decrease after ClO₂ treatment (P<0.05). In conclusion, ClO₂ at 2,000 and 3,000 ppm was effective at reducing malodor emission from chicken feces. However, further studies are warranted to examine the effects of ClO₂ at various concentrations and the effects on malodor emission from a poultry farm.