• Journal of Microbiology and Biotechnology
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• v.32 no.2
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• pp.195-204
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• 2022

Chinese chive (Allium tuberosum Rottler) has potential risks associated with pathogenic bacterial contamination as it is usually consumed raw. In this study, we investigated the microbiota of Chinese chives purchased from traditional markets and grocery stores in March (Spring) and June (Summer) 2017. Differences in bacterial diversity were observed, and the microbial composition varied across sampling times and sites. In June, potential pathogenic genera, such as Escherichia, Enterobacter, and Pantoea, accounted for a high proportion of the microbiota in samples purchased from the traditional market. A large number of pathogenic bacteria (Acinetobacter lwoffii, Bacillus cereus, Klebsiella pneumoniae, and Serratia marcescens) were detected in the June samples at a relatively high rate. In addition, the influence of the washing treatment on Chinese chive microbiota was analyzed. After storage at 26℃, the washing treatment accelerated the growth of enterohemorrhagic Escherichia coli (EHEC) because it caused dynamic shifts in Chinese chive indigenous microbiota. These results expand our knowledge of the microbiota in Chinese chives and provide data for the prediction and prevention of food-borne illnesses.

• Bulletin of Food Technology
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• v.24 no.3
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• pp.448-457
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• 2011

• Proceedings of the Korean Nutrition Society Conference
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• 2001.05a
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• pp.259.1-259
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• 2001

• 한국해양학회지
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• v.28 no.2
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• pp.107-113
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• 1993

Interrelationship between bacterial and phytoplankton variables and associations of this relationship with phytoplankton community structure were studied from July, 1990 to October, 1991 in the estuarine system of Mankyung and dongjin Rivers where estuarine mixing is very active. During the study period only bacterial production and chlorophyll were always significantly correlated (r$^2$>0.36, p<0.02), suggesting that phytoplankton-biomass related process seemed to be related to bacterial production in the estuarine waters. However, bacterial production comprised only a small fraction (on average<2.6) of primary production throughout the study period, suggesting that those parameters were uncoupled. this might be partly due that phytoplankton, food particles for zooplankton, food particles for zooplankton, were mostly composed of large and/or chain-forming diatoms.

• Journal of Food Hygiene and Safety
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• v.8 no.4
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• pp.181-188
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• 1993

It is well known that bacterial lipopolysaccharide (LPS) stimulates the prostaglandin (PG) synthesis in various experimental system, but the mechanism and the detailed nature of its action are yet to be understood. Thus, this study was designed to characterize LPS induced PG synthesis in rat alveolar macrophage. Although results were not so much prominent, LPS stimulated PGE2 synthesis in macrophage with short term exposure, and this was thought to be mainly due to the activation of phopholipase A2+ But there was a burst in the PG synthesis 6 hours after the LPS treatment and this was accompanied with the increase of cyclooxygenase activity. This effect was not mediated by tumor necrosis factor (TNF) or platelet activating factor (PAF), and the existence of serum was prerequisite for its action. Growth factors such as epidermal growth factor (EGF) and platelet derived growth factor (PDGF) themselves did not stimulate PG synthesis and the showed stimulatory activities to some extent. Normal rat serum was more effective for the elicitation of the LPS action than growth factors. Thus, considering the amounts of growth fafctors contained in normal serum, it was suggested that another factors like LPS binding protein (LBP) might be involved in the serum effect on LPS action. Conclusively. it was thought that LPS could stimulate PG synthesis through interaction with serum factors such as EGF, PDGF and/or LBP.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.124-132
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• 2010

This study evaluated the effects of gamma ray and electron beam (E-beam) to improve the safety of spices for meat processing. The spices (garlic powder, curry powder, turmeric powder, black pepper, white pepper, oregano, parsley, laurel leaf powder, basil, and rosemary) were irradiated by gamma ray and E-beam at 0, 2, 4, 6, 8, and 10 kGy. Total bacterial populations were then enumerated on total plate count agar, and bacteria isolated from the samples were identified by polymerase chain reaction (PCR). In addition, $D_{10}$ values for Bacillus cereus and Staphylococcus aureus inoculated in spices was determined, and the Ames test was conducted for genotoxicity analysis. The contaminated total bacterial populations in spices ranged from 1.5 to 3.8 Log CFU/g, and most of identified bacteria were Bacillus spp., and Staphylococcus spp. However, the bacterial populations decreased below the detection limit (2 Log CFU/g) after irradiation at 4 kGy except for parsley, which required 6 kGy in gamma ray and 8 kGy in E-beam to decrease total bacterial populations below detection limit. $D_{10}$ values were also higher (p<0.05) in E-beam treated samples than gamma-ray treated samples. No genotoxicity was observed in both conditions with and without metabolic activation. These results indicate that gamma ray (>4 kGy and <6 kGy) could be more useful to improve food safety of meat processing spices compared to E-beam.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.286-289
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• 2000

Mechanol extracts of three cold-tolerant eucalyptus trees-Eucalyptus darlympleana, E. gunnii and E. unigera were screened for antimicrobial activity against twenty two phyto-pathogenic fungi and six food-borne bacterial pathogens. E. unigera showed the antagonistic activity against all the tested pathogens. Among the tested fungal pathogens, Pythium species were highly sensitive to the leaf extracts. Especially, P. vanterpoolii, a causal agent of leaf blight in creeping bentgrass (Agrostis palustris), was completely inhibited by the extracts. The eucalyptus extracts were also effective in inhibiting the fungal growth of Botrytis cinerea and Phomopsis sp. isolated from the lesions of kiwifruit soft rot during post-harvest storage. Escherichia coli O-157 was less sensitive to the inhibition than the other bacterial pathogens tested. It was likely that Gram positive bacteria-Bacillus subtilis and Streptococcus mutans were more sensitive to the eucalyptus extracts than Gram negative bacteria-Escherichia coli, Salmonella enteritidis and Pseudomonas aeruginosa. Our findings suggest that the cold-tolerant eucalyptus species have antimicrobial properties that can serve the development of novel fungitoxic agents or food preservatives.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.161-166
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• 1991

For the production of useful products from microorganism, a bacterial strain producing the biopolymer was isolated from soil. The bacteriological characteristics of the strain were examined and some chemical properties of the biopolymer produced were investigated. The bacterial strain was identified as an alkali-tolerant Bacillus sp. The results of chemical composition, various color reactions and I.R. spectrum revealed that the biopolymer contained high protein content, low amino sugar and no uronic acid. However, the biopolymer was precipitated by treating with cetylpiridinium chloride and was found to be acidic.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.310-320
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• 2005

A membrane-based oligonucleotide array was used to detect predominant bacterial species in human fecal samples. Digoxygenin-labeled 16S rDNA probes were generated by PCR from DNA that had been extracted from fecal samples or slurries. These probes were hybridized to an array of 120 oligonucleotides with sequences specific for 40 different bacterial species commonly found in human feces, followed by color development using an alkaline phosphatase-conjugated antibody and NBT /BCIP. Twenty of the species were detected by this method, but E. coli, which was present at $\~$1 $\times 10$^5$ CFU per gram feces, was not detected. To improve the sensitivity of this assay, reverse transcriptase-PCR was used to generate probes from RNA extracted from fecal cultures. Coupled with a chemiluminescence detection method, this approach lowered the detection limit for E. coli from $\~1$ $\times 10$^6$ to ${\leq}$ 1 $\times 10$^5$ These results indicate that the membrane-array method with reverse transcriptase-PCR and chemiluminescence detection can simultaneously identify bacterial species present in fecal samples at cell concentrations as low as${\leq}$ 1 $\times 10$^5$ CFU per gram.

• Preventive Nutrition and Food Science
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• v.18 no.2
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• pp.111-116
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• 2013

Chrysanthemum indicum is widely used to treat immune-related and infectious disorders in East Asia. C. indicum flower oil contains 1,8-cineole, germacrene D, camphor, ${\alpha}$-cadinol, camphene, pinocarvone, ${\beta}$-caryophyllene, 3-cyclohexen- 1-ol, and ${\gamma}$-curcumene. We evaluated the safety of C. indicum flower oil by conducting acute oral toxicity, bone marrow micronucleus, and bacterial reverse mutation tests. Mortality, clinical signs and gross findings of mice were measured for 15 days after the oral single gavage administration of C. indicum flower oil. There were no mortality and clinical signs of toxicity at 2,000 mg/kg body weight/day of C. indicum flower oil throughout the 15 day period. Micronucleated erythrocyte cell counts for all treated groups were not significantly different between test and control groups. Levels of 15.63~500 ${\mu}g$ C. indicum flower oil/plate did not induce mutagenicity in S. Typhimurium and E. coli, with or without the introduction of a metabolic activation system. These results indicate that ingesting C. indicum flower oil produces no acute oral toxicity, bone marrow micronucleus, and bacterial reverse mutation.