• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.193-202
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• 2002

The polymerase chain reaction(PCR) of target lacZ and uidA genes were used to detect total coliform and Escherichia coli for determining water quality, respectively. Of 109 spring waters, coliform were detected from 38 spring waters by lacZ PCR method but 21 spring waters by culture method accepted by the Ministry of Environment for water quality monitoring. The lacz PCR method gave the results statistically equivalent to those of the culture method(kappa=0.62, McNemar=17.00). The uidA PCR method gave the same results to those of the culture method. The sensitivity and specificity of coliform and E. coli by PCR method were 100% and 80.7%, respectively. Therefore, PCR can be used for the rapid identification of Escherichia coli and coliform in potable water using uidA and lacZ.

• Microbiology and Biotechnology Letters
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• v.21 no.3
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• pp.229-238
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• 1993

An nlp (Ner like protein) gene from E. coli was previously cloned and sequenced. Here we show that expression of the sugar metabolism related genes, lacZ, malQ and malP, increased 2.5-to 8.3-fold in the presence of a plasmid containing the nlp gene. This suggested that the nlp gene could induce maltose- and lactose-metabolism coordinately with crp*1 in the absence of cAMP. Using the nlp-lacZ fusion gene, it was possible to show the promoter of nlp was active in vivo.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.352-357
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• 1999

Enterobacter sp. B54 inhibited growth of the fungus Phytophthora capsici on potato dextrose agar (PDA). Three mutants with antifungal activities (denoted M54-47, M54-113, and M54-329) which were lost or increased, through Pl::Tn5 lac mutagenesis, were used to isolate genes responsible for fungal inhibition on PDA. Two clones were selected from the partially EcoR1-digested genomic library of the wild-type strain by probing with genomic flanking sequences of each mutant. We have isolated a 20-kb EcoR1 genomic DNA fragment from this strain that contains genes involved in hyphal growth inhibition of P. capsici on PDA. Subcloning and expression analysis of the above DNA fragment identified a 8-kb region which was necessary for antifungal activities. A 8-kb HindⅢDNA fragment covers three genomic loci inserted by Tn5 lac in each mutant. This suggested that all genes which are related to antifungal activities might be clustered in simple forms of at least 5-8 kb sizes.

• Korean journal of food and cookery science
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• v.7 no.1
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• pp.15-25
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• 1991

The effects of lactic acid bacteria on the chemical and microbial changes of fermented kimchi at various temperatures were studied. Kimchi was homogenized and was sterilized by ultra violet, then Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococcus acidilactici, Lactobacillus brevis and the mixture of there bacteria inoculated on sterilized kimchi, respectively. The measurement of pH and total acidity, quantitative analysis of volatile organic acids and nonvolatile organic acids by gas chromatography were investigated while inoculated kimchi were fermented at $30^{\circ}C$, $21^{\circ}C$, $14^{\circ}C$ and $7^{\circ}C$. Sample I (original kimchi homogenate), Sample III (inoculated with Leuconostoc mesenteroides) and Sample Ⅵ (inoculated with mixed lactic acid bacteria) were alike in that changes of pH and total acidity and especially, these phenomena were prominent at $14^{\circ}C$. Formic, acetic and heptenoic acid as volatile organic acid were detected by GC, and these acids formed mainly by Leuconostoc mesenteroides and lactobacillus brevis. Sample III was more higher content than other samples at $14^{\circ}C$. As nonvolatile organic acid, lactic acid in all samples, citric acid in sample III at $21^{\circ}C$and $14^{\circ}C$, succinic acid in sample I at $30^{\circ}C$, $21^{\circ}C$, $14^{\circ}C$ and sample V at $30^{\circ}C$ were detected by GC.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.152-159
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• 2010

The influence of urushiol, as an allergen on laccase property of Fomitella fraxinea was investigated. The enzyme production was reached to the highest level after 10 days, cultivation and the activity and mycelial biomass were increased by 2.5 and 1.5 folds, respectively, by adding urushiol in the culture medium. In liquid cultures using a Cu Mn-free medium, laccase lactivity was decreased by 3.8-9.2 folds, with similar dry cell weight. Two isoenzymes, were purified using anion exchange, hydrophobic interaction and size-exclusion chromatographies. Both isoenzymes are monomeric proteins, with $M_W$ around 67 kDa(Lac1) and 66 kDa(Lac2), and isoelectric points of 3.67 and 3.81. The optimal conditions for purified isoenzymes were found to be pH 4.5-5.0 and $30-35^{\circ}C$. Activity decreased by the addition of $Fe^{2+}$, $Mg^{2+}$, $Na^+$, and strongly inhibited by EDTA and sodium azide.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.208-214
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• 1993

Ginseng-whey beverages were prepared with rennet whey, ginseng, sweetener, honey and Japanese apricot, inoculated with different strains of lactic acid bacteria or unfermented partly. The samples were stored at 4$^{\circ}C$ or 30$\pm$1$0^{\circ}C$ and then physicochemical and microbiological properties were investigated. The yield of whey was 78.8%. The pH-values reduced and acidities increased during the storage period. The contents of solid-substances, ash and lipid in ginseng-whey beverages were 7.90~8.20%, 0.62~0.66% and 0.16%, respectively. The protein contents of ginseng-whey beverages were 0.42~0.56% and the contents were not changed during the storage period. The lactose contents of fermented beverages were higher than those of unfermented beverages. During the storage period (1~5 weeks), the ranges of D(-) - and L(+)- lactic acid contents in fermented ginseng-whey beverages (17.3~156.1 mg/100g, 347.3~1894.2mg/100g) were higher than those of unfermented ginseng-whey beverages (6.2~82.8mg/100g, 7.1~885.5mg/100g). The contents of total saponin in unfermented sample and fermented sample (Lac. casei sub-sp. casei+Str. salivarius sub-sp. thermophilus) were increased during the storage period. But, those of the fermented sample(Lac. acidophilus+Lac. delbrueckii sub-sp. bulgaricus) were reduced. In the electrophoretic results of ginseng-whey beverages, an $\alpha$-lactalbumin and a $\beta$-lactoglobulin bands were shown apparently and there were no changes observed during the storage period. During the storage period (1~3 week) the coliform was not detected and total plate counts and psychrotrophs were increased according to the storage period.

• The Microorganisms and Industry
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• v.14 no.1
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• pp.12-16
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• 1988

Allantoin 분해 유전자들중 highly inducible 한 DAL7, DUR1,2및 constitutive한 DAL5 gene의 promoter를 deletion 방법에 의해 발현에 필요한 최소 DNA seqyence 부위를 정한후 이 DNA seqyence를 다시 oligonucleotide 합성방법에 의해 합성하여 Cyc 1-LacZ expression vector에 삽입하여 효모내에서 LacZ의 발현이 삽입한 DNA sequence에 의해 영향을 받는 정도를 측정하여 (.betha.-galactosidase activity) deletion 방법에 의해 결정한 이 DNA dequence들이 직접 발현유도에 관여하는가를 조사하였다.

• Korean journal of food and cookery science
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• v.11 no.5
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• pp.511-520
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• 1995

The growth extent of Leuconostoc mesenteroides and Lactobacillus plantarum in the medium which contain sterilized extract of each kimchi minor ingredient (green onion, garlic, ginger, raw red pepper, and red pepper powder) was examined. All minor ingredients decreased the growth of Lac. plantarum, and this effect of garlic is the most distinctive, ginger had the positive effect on the growth of Leu. mesenteroides, and garlic had the negative effect on the growth of Leu. mesenteroides. When the growth extent of two bacteria in the medium which contain sterilized successive extracts of each of garlic, ginger and red pepper powder was examined, the butanol fraction of garlic was reprsented the negative effect on the growth of Leu mesenteroides and Lac. plantarum, and the water fraction of ginger and red pepper powder were represented the positive effect on the growth of Leu. mesenteroides.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.159-161
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• 2005

Hypovirus infection of the chestnut blight fungus Cryphonectria parasitica is a useful model system to study the hypoviral regulation of fungal gene expression. The hypovirus is known to downregulate the fungal laccase1 (lac 1), the modulation of which is tightly governed by the inositol triphosphate ($IP_3$) and calcium second messenger system in a virus-free strain. We cloned the gene cplc1 encoding a phosphatidyl inositol-specific phospholipase C (PLC), in order to better characterize the fungal gene regulation by hypovirus. Sequence analysis of the cplc1 gene indicated that the protein product contained both the X and Y domains, which are the two conserved regions found in all known PLCs, with a 133 amino acid extension between the 2nd ${\beta}$-strand and the ${\alpha}$-helix in the X domain. In addition, the gene organization appeared to be highly similar to that of a ${\delta}$ type PLC. Disruption of the cplc1 gene resulted in slow growth and produced colonies characterized by little aerial mycelia and deep orange in color. In addition, down regulation of lac1 expression was observed. However, temperature sensitivity, osmosensitivity, virulence, and other hypovirulence-associated characteristics did not differ from the wild-type strain. Functional complementation of the cplc1-null mutant with the PLC1 gene from Saccharomyces cerevisiae restored lac1 expression, which suggests that the cloned gene encodes PLC activity. The present study indicates that the cplc1 gene is required for appropriate mycelial growth, and that it regulates the lac1 expression, which is also modulated by the hypovirus. Although several PLC genes have been identified in various simple eukaryotic organisms, the deletion analysis of the cplc1 gene in this study appears to be the first report on the functional analysis of PLC in filamentous fungi.

• Journal of Microbiology and Biotechnology
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• v.13 no.6
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• pp.976-983
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• 2003

Seven Escherichia coli cells defective with aerobic growth were isolated by the insertion of ${\lambda}placMu53$, a hybrid bacteriophage of ${\lambda}$ and Mu, which created a transcriptional fusion to lacZY. These insertion mutant cells were tested on an XG ($5-bromo-4-chloro-3-indolyl-{\beta}-D-galactopyranoside$) medium for anaerobic expression of lacZ by fusion to a promoter. The chromosomal DNA from these strains were digested by EcoRI, and the EcoRI fragments that contained the fused gene and lacZ sequence were identified by Southern hybridization, using lacZ containing plasmid as a probe. The EcoRI fragment from each strain was cloned and sequenced. The sequence data were compared with the GenBank database. The mutated gene of three strains, CYT4, CYT5, and OS11, was found to be identical, and it was nrdAB that encoded ribonucleoside diphosphate reductase. The gene nrdAB was at min 50.5 on the Escherichia coli linkage map and 2,348,084 on the physical map, and is involved in hemAe-related reduction-oxidation reaction. OS6 and OS14 mutant strains had insertion at min 8.3 and the mutated gene was hemB. The hemB encodes 5-aminolevulinate dehydratase or porphobilinogen synthase. The OS3 mutant had insertion in cydB at min 16.6. The cydAB encodes cytochrome d oxidase. In the case of OS1, the fusion was made with sucA, the E1 component of ${\alpha}-ketoglutarate$ dehydrogenase.