• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.73-79
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• 1994

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus subsp. mycoides were 35$\circ $C and 48 hrs, respectively. The addition of egg albumin and casein to the basal medium increased the enzyme production. The enzyme was purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography. specific activity of the purified enzyme was 82.37 U/mg protein and yield of theenzyume activity was 62.1%. The purified enzuyme showed a single band on ployacrylamide disc gel electrophoresis and its molecular weight was estimated to be 66.,000 by SDS-polyacrylamide disc gel electrophoresis. The isoelcular point for the purified enzyme was pH 5.0. The optimum temperature and pH were 50$\circ $C and pH 6.5, respectively. The purified enzyme was stable below 40$\circ $C and in the pH range of 6.5~10.0 The pullulanase activity was greatly inhited by Ag$^{+}$, Hg$^{2+}$ and EDTA, and its heat stability was increased by the addition of Ca$^{2+}$. The tydrolysis product with the enzyme on pullulan was maltotriose.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.208-214
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• 2009

To avoid ambiguity in counting the number of colony, about 1,500 of colonies grown on B. cereus selective agar plates were grouped into 12 types by morphological difference and then identified by biochemical and 16S rDNA nucleotide sequence. Among them, seven colony types with 11 to 15 mm diameters of halo were identified as B. cereus or B. cereus subsp. cytotoxis. Five mm sized colonies with no halo, which have not been considered as B. cereus according to the manufacturer's manual, were identified as B. cereus. A colony type with double halos of only 6 mm in diameter was also B. cereus. Other three types were proven to be Enterococcus sp., Brevibacillus sp., and B. subtilis, respectively. PCR results showed that only 9 types that are identified as B. cereus strains harbor at least one of B. cereus toxin genes.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1472-1478
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• 2004

The effects of microorganisms inoculated in beef, pork and chicken on the production of various biogenic amines (BA) were examined. Acinetobacter haemolyticus, Aeromonas hydrophila subsp. hydrophila, Alcaligenes faecalis subsp. faecalis, Bacillus cereus, Bacillus subtilis, Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Lactobacillus alimentarius, Lactobacillus curvatus, Leuconostoc mesenteroides subsp. Mesenteroides, Proteus mirabilis, Proteus vulgaris, Pseudomonas aerugina, Salmonella enteritidis and Salmonella typhimurium were inoculated into beef, pork and chicken and incubated for 24 h at optimum temperatures of each bacterium. In ground beef, total amount of amines (TAA) produced was highest in the sample inoculated with Bacillus cereus, followed by Enterobacter cloacae. In ground pork, TAA was highest in the sample inoculated with Alcaligenes faecalis, followed by Enterobacter cloacae, Proteus vulgaris and Bacillus cereus. TAA of chicken breast was highest in the sample inoculated with Alcaligenes faecalis, followed by Bacillus cereus and Lactobacillus alimentarius while in chicken leg was the sample inoculated with Proteus vulgaris, followed by Enterobacter aerogenes, Enterobacter cloacae and Alcaligenes faecalis. Among biogenic amines produced, cadaverine (CAD) was detected at the highest level, followed by putrescine (PUT) and tyramine (TYM), their order being reversed by the kind of microorganism in beef and pork. In chicken breast and leg, CAD level was still the highest but PUT, TYM or PHM was the second highest, depending upon the kind of microorganism inoculated. In total, Alcaligenes faecalis, Enterobacter cloacae and Bacillus cereus were ones that produced a larger amount of BAs regardless of meat sources from different species.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.195-200
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• 2000

Bacillus cereus BS229 was identified as a bacteriocin producer with a bactericidal activity against Bacillus thuringiensis subsp. Thomsoni BR-40. Bacillus cereus BS229 and cerein BS229, named tentatively as the bacteriocin produced by Bacillus cereus BS229, showed a narrow spectrum of actibity against Gram-positive and Gram-negative bacteria, along with yeast and molds. Production of cerein BS229 in a 5-1 fermenter followed typical kinetics of primary metabolite synthesis. The antibacterial activity of cerein BS229 on sensitive indicator cells disappeared completely by ${\alpha}-chmotrypsin$ or proteinase K, which indicates its proteinaceous nature. Cerein BS229 seemed to be very stable throughout the pH range of 2.0 of 9.0 and it was relatively heat labile, despite the fact that bacteriocin activity was still detected after being boied for 30min. Cerein BS229 actibity has been changed with some of the organic solvents such as toluene, ethanol, and chloroform. Direct detection of cerein BS229 actibity on SDS-PAGE suggested that it had an apparent molecular mass of about 8.2 kDa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.2
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• pp.215-221
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• 2005

The antibacterial effects of electrolyzed reduced water on the bacterial growth were studied in this investigation. Upon treating with electrolyzed reduced water for 2 minutes, about 70% Escherichia coli and 61% Bacillus cereus were controlled. When these two bacteria were exposed to electrolyzed reduced water for 30 minutes, about 89% Escherichia coli and 94% Bacillus cereus were controlled. About 55% Pseudomonas aeruginosa was also controlled upon treateing with electrolyzed reduced water for 2 minutes, and 65% Pseudomonas aeruginosa was controlled during 4 hour incubation. When Staphylococcus epidermidis was treated with electrolyzed reduced water for 4 hours, 73% of the bacterial growth was inhibited, while only 44% Staphylococcus aureus.subsp.aureus was controlled with electrolyzed reduced water for 4 hours.

• Journal of Ecology and Environment
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• v.29 no.4
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• pp.381-387
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• 2006

We analyzed the total yields and composition of essential oils in leaf extracts of Nepeta cataria by Gas Chromatography Mass Spectrometry (GC-MS). Thirty-six compounds representing 97.0% of total oil were detected. The major constituents of essential oils in Nepeta cataria were nepetalactone (90.9%), unidentified compound (Retention time 17.35; 1.82%), 1,8-cineol (1.49%), ${\beta}-caryophyllene$ (1.12%), and ${\beta}-pinene$ (1.078%). The volatile compounds in leaf extracts of N. cataria concentrated to nepetalactone ($88.83{\sim}93.33%$) remarkably. In the essential oil of N. cataria cis,trans-nepetalactone ($30.2{\sim}37.8%$) and cis,cis-nepetalactone ($31.5{\sim}37.0%$) were found as the main constituents. The effects of essential oil of N. cataria on the growth of six microorganisms (Bacillus cereus, B. subtilis, B. amyloliquefaciens, Escherichia coli, Staphylococcus aureus subsp. aureus, and Pseudomonas aeruginosa) were investigated. The essential oil of N. cataria had strong inhibitory effect on the growth of three fungal species (Bacillus cereus, B. subtilis, and B. amyloliquefaciens). The essential oil from N. cataria was found to have a low antimicrobial activity against Staphylococcus aureus subsp. aureus, while no activity were found against Escherichia coli and Pseudomonas aeruginosa. Results indicate the significant antimicrobial effect, which may be depended on the yield of nepetalactone.

• Korean journal of food and cookery science
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• v.33 no.1
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• pp.65-71
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• 2017

Purpose: This study was carried out to investigate the availability of raw Astragalus membranaceus as a food ingredient. Methods: Raw and dried A. membranaceus water extracts were used to examine the free radical scavenging activity, polyphenol and flavonoid contents, and antimicrobial activity. Also, the sensory characteristics of each water extracts were evaluated. Results: The free radical scavenging activity and total polyphenol and flavonoid contents of raw A. membranaceus extracts were higher than those of dried A. membranaceus extracts. The antimicrobial activities of raw and dried A. membranaceus extracts were examined against several food borne illness-causing microorganisms using the paper disc diffusion method. Inhibition zones were observed in Staphylococcus aureus subsp. aureus, Bacillus subtilis, Pseudomonas aeruglnosa, Salmonella enterica subsp. enterica, Escherichia coli and Bacillus cereus treated with raw extracts. Inhibition zones were observed in B. subtilis, P. aeruglnosa and S. enterica subsp. enterica treated with dried extracts. Raw A. membranaceus extracts had higher scores than dried extracts in sensory evaluation. Conclusion: Raw A. membranaceus was better in antioxidative, antimicrobial activities, and sensory characteristics than dried one.

• Journal of Dairy Science and Biotechnology
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• v.37 no.3
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• pp.187-195
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• 2019

Seeds and leaves of Raphanus raphanistrum subsp. sativus (radish) are known to contain "raphanin," which has the potential to inhibit pathogenesis associated with foodborne pathogenic bacteria and fungi. In this study, ethanol extracts from R. raphanistrum subsp. sativus (radish) powder was evaluated for antimicrobial action against 6 different foodborne pathogenic bacteria. The current study demonstrated the potential of R. raphanistrum subsp. sativus (radish) in inhibiting the growth of Salmonella enteritidis 110, Cronobacter sakazakii KCTC 2949, Bacillus cereus ATCC 10876, and Staphylococcus aureus ATCC 6538. However, these antimicrobial action were not observed against Listeria monocytogenes ATCC 51776 and Escherichia coli 23716. Hence, this study indicates that R. raphanistrum subsp. sativus (radish) could be used as a natural biopreservative with antimicrobial effects for improving food safety, and as a functional food in the commercial food industry.

• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.335-340
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• 2009

To evaluate the availability of Cudrania tricuspidata Bureau as a natural source of antimicrobials, the antimicrobial activity of methanol extracts of harvested parts was investigated using the paper disc diffusion method. The extracts from leaves and root bark had broad antimicrobial activity against various bacteria, including Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Enterobacter aerogenes, Enterococcus faecalis, Salmonella choleraesuis subsp. choleraesuis, Vibrio vulnificus, and Pseudomonas aeruginosa and inhibited Bacillus cereus, Staphylococcus aureus, and Listeria monocytogenes, agents of food poisoning especially well. The extract from ripe fruit had a very high antimicrobial activity against Staphylococcus aureus with a 20.2 mm of clear zone at 50 mg/mL sample concentration. These results indicated that Cudrania tricuspidata could be used as new source for developing natural antimicrobial agents.

• The Plant Pathology Journal
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• v.30 no.3
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• pp.288-298
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• 2014

We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN) Meloidogyne hapla in carrot (Daucus carota subsp. sativus) and tomato (Solanum lycopersicum). Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.