• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.477-481
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• 2003

The community escape response of Rhodobacter sphaeroides is exerted through the action of CerR and CerI, which code for a LuxR-type regulatory protein and acylhomoserine lactone synthase, respectively. Deletion of chromosomal DNA including cerR and cerI (mutant RI) or insertional interruption of cert (mutant AP3) resulted in two-fold increase in the cellular poly-${\beta}$-hydroxybutyrate (PHB) content In comparison with the wild-type under aerobic growth conditions. The PHB synthase (PhbC) activities of the cer mutants were doubled, and the enzyme expression was regulated at the level of phbC transcription. Thus, CerR, possibly in response to autoinducer (AI), appears to modulate the PHB content of aerobically grown cells by downregulating phbC transcription.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.144-147
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• 1999

RAPD technique was employed for the genetic analysis of major Lilium cultivars and horticultural hybrids. As a result of RAPD with 10-mer random primers, total 107 bands were observed within 300bp and 2kb range, and the same band patterns were observed within the same cultivar for different primers. However, Casa Blanca in Orientals and Adelina in Asiatics showed different band patterns with others in the same. Cultivars within L. longiflorum showed different band patterns. RAPD markers produced with random primers OPA- 02, 03, 04, 14, 16 and 17 can be used for the classification of Lilium cultivars.

• Korean Journal of Pharmacognosy
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• v.34 no.1 s.132
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• pp.80-85
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• 2003

Water extract from Astragali Radix (AR) was tested for the safety using Ames, Bacillus subtilis Rec, and umu gene expression mutagenicity tests. Mutagenic activity in any assays we tested was not found. In Ames test, Salmonella typhimurium TA98 and TA 100 were used to identify mutagenic property, and the number of histidine revertants was measured. In the Recassay, Bacillus subtilis ${H-17(Rec^+)\;and\;M-45(Rec^-)}$ strains were used to test DNA damage activity. In the SOS umu test, Salmonella typhimurium TA1535 containing plasmid pSK1002 was used as a test strain, and we monitored the levels of umu operon expression by measuring the ${\beta}-galactosidase$ activity. From the results, there was no DNA damage and mutagenicity of AR. Hepatotoxicity of AR to female ICR mice was also monitored by the measurements of s-GOT, s-GPT, LDH activities after oral feeding for 15 days. AR was not shown any significant changes of s-GOT, s-GPT and LDH activities in mice sera.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.151-167
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• 2000

Objective : The aim of this study is to determine the antimutagenic effect and genetic safety of Buthus martensi Karsch aqua-acupuncture solution(BMKAS) against various chemical carcinogens. Method : Ames(Salmonella typhimurium) test and Rec assay(Bacillus subtilis) were used as indicators for DNA damage and antimutagenesis. Furthermore, the levels of umu operon expression by measuring the ${\beta}$-galactosidase activity wete monitored with the SOS umu test using S. typhimurium 1535 containing plasmid pSK1002. And the host-mediated assay was used to investigate the mutagenicity and antimutagenicity of BMKAS inducing various chemical carcinogens after the activation with in vivo metabolic systems. Results : From the results, BMKAS did not atfect DNA of S. typhimurium and B. subtilis strains and showed no mutagenicity at the all concentrations of tested solution. Furthermore BMKAS dose-dependently protected the mutagenecity by AF-2, 2-AA and B[a]P. These phenomena was also similar to that after metabolic activation of BMKAS in in vivo system. Conclusion : These results suggested that BMKAS did not show the mutagenicity and protected the mutagenesis against various chemical carcinogens by four different methods used in this study.

• Journal of Microbiology
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• v.44 no.2
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• pp.192-199
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• 2006

Pseudomonas putida KL47 is a natural isolate that assimilates benzene, 1-alkylbenzene $(C_1-C_4)$, biphenyl, p-cumate, and p-cymene. The genetic background of strain KL47 underlying the broad range of growth substrates was examined. It was found that the cym and cmt operons are constitutively expressed due to a lack of the cymR gene, and the tod operon is still inducible by toluene and biphenyl. The entire array of gene clusters responsible for the catabolism of toluene and p-cymene/p-cumate has been cloned in a cosmid vector, pLAFR3, and were named pEK6 and pEK27, respectively. The two inserts overlap one another and the nucleotide sequence (42,505 bp) comprising the cym, cmt, and tod operons and its flanking genes in KL47 are almost identical (>99 %) to those of P. putida F1. In the cloned DNA fragment, two genes with unknown functions, labeled cymZ and cmtR, were newly identified and show high sequence homology to dienelactone hydrolase and CymR proteins, respectively. The cmtR gene was identified in the place of the cmtI gene of previous annotation. Western blot analysis showed that, in strains F1 and KL47, the todT gene is not expressed during growth on Luria Bertani medium. In minimal basal salt medium, expression of the todT gene is inducible by toluene, but not by biphenyl in strain F1; however, it is constantly expressed in strain KL47, indicating that high levels of expression of the todST genes with one amino acid substitution in TodS might provide strain KL47 with a means of adaptation of the tod catabolic operon to various aromatic hydrocarbons.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.302-311
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• 2004

Comamonas testosteroni (formerly Pseudomonas sp.) NCIMB 10643 can grow on biphenyl and alkylbenzenes $(C_2-C_7)$ via 3-substituted catechols. Thus, to identify the genes encoding the degradation, transposon-mutagenesis was carried out using pAG408, a promoter-probe mini-transposon with a green fluorescent protein (GFP), as a reporter. A mutant, NT-1, which was unable to grow on alkylbenzenes and biphenyl, accumulated catechols and exhibited an enhanced expression of GFP upon exposure to these substrates, indicating that the gfp had been inserted in a gene encoding a broad substrate range catechol 2,3-dioxygenase. The genes (2,826 bp) flanking the gfp cloned from an SphI-digested fragment contained three complete open reading frames that were designated bphCDorfl. The deduced amino acid sequences of bphCDorfl were identical to 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC), 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (BphD), and OrfI, respectively, that are all involved in the degradation of biphenyl/4-chlorobiphenyl (bph) by Ralstonia oxalatica A5. The deduced amino acid sequence of the orfl revealed a similarity to those of outer membrane proteins belonging to the OmpW family. The introduction of the bphCDorfl genes enabled the NT-l mutant to grow on aromatic hydrocarbons. In addition, PCR analysis indicated that the DNA sequence and gene organization of the bph operon were closely related to those in the bph operon from Tn4371 identified in strain A5. Furthermore, strain A5 was also able to grow on a similar set of alkylbenzenes as strain NCIMB 10643, demonstrating that, among the identified aromatic hydrocarbon degradation pathways, the bph degradation pathway related to Tn4371 was the most versatile in catabolizing a variety of aromatic hydrocarbons of mono- and bicyclic benzenes.

• Journal of Mushroom
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• v.11 no.3
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• pp.171-176
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• 2013

Genomic DNAs of psychrophilic strains of Pleurotus eryngii were analyzed by randomly amplified polymorphic DNA (RAPD) using OP-A, OP-B, OP-L, OP-P, OP-R and OP-S3 primers to develop the strain-specific DNA marker. A unique DNA fragment with the size of 480 bp was yielded by OP-S3 primer from the psychrophilic strain. A sequence characterized amplified region (SCAR) marker, designated as OP-S3-1, was designed on the basis of the determined sequence. The PCR analysis with the OP-S3-1 primer showed that this SCAR marker can clearly distinguish the psychrophilic strains from the control strains.

• Korean Journal of Pharmacognosy
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• v.28 no.3
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• pp.149-155
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• 1997

Antaeum(ATE) has been used as a prescription for threatened abortion, associated with pregnancy in traditional medicine. Because gravida could be administered ATE for a long period, its administration might cause a harmful effect on fetus and gravida during the pregnancy. This study aimed to determine whether exposure to ATE caused mutagenicity or hepatotoxicity during the pregnant period. For mutagenicity test of ATE, Salmonella typhimurium and Bacillus subtilis were used as indications for DNA damage. In the Ames test, Samonella typhimurium TA98 and TA100 were used for mutagenicity testing, and the number of histidine revertants was measured. In Rec-assay, Bacillus subtilis H $17(Rec^+)$ and $M-45(Rec^-)$ strains were used to clarify the DNA damage property. In the SOS umu test, Salmonella typhimurium TA15335 containing plasmid pSK1002 was used as a tester strain, and we monitored the levels of umu operon expression by measuring the ${\beta}-galactosidase$ activity. From the tested results, ATE did not show DNA damage and mutagenicity. On the other hand, hepatotoxicity of ATE to female ICR mice was monitored by the measurements of s-GOT, s-GPT and LDH activities after oral feeding for 15 days. ATE did not show significant change of s-GOT, s-GPT and LDH activities in mice sera.

• YAKHAK HOEJI
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• v.34 no.6
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• pp.447-456
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• 1990

Various methods are available for the production of L-threonine. The microbial production of L-threonine has been achieved by breeding L-threonine analog-resistant auxotrophic mutants of various bacteria. The enzymatic production of L-threonine has been demonstrated by use of threonine metabolic enzymes such as threonine deaminase, threonine aldolase, or threonine dehydrogenase complex. Threonine synthesis from glycine and ethanol seems to be catalyzed by the enzymes Methanol dehydrogenase(MDH) and Serine hydroxymethyltransferase(SHMT), which was also found to catalyze the aldol condensation of glycine with acetaldehyde. The improved production of L-threonine has been achieved by amplifying the genes for the L-threonine biosynthetic enzymes using recombinant DNA techniques.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.9-19
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• 2011

The Bacillus subtilis pyrimidine biosynthetic (pyr) operon encodes all of the enzymes for the de novo biosynthesis of Uridine monophosphate (UMP) and additional cistrones encoding a uracil permease and the regulatory protein PyrR. The PyrR is a bifunctional protein with pyr mRNA-binding regulatory funtion and uracil phosphoribosyltransferase activity. To study the global regulation by the pyrR deletion, the proteome comparison between Bacillus subtilis DB104 and Bacillus subtilis DB104 ${\Delta}$pyrR in the minimal medium without pyrimidines was employed. Proteome analysis of the cytosolic proteins from both strains by 2D-gel electrophoresis showed the variations in levels of protein expression. On the silver stained 2D-gel with an isoelectric point (pI) between 4 and 10, about 1,300 spots were detected and 172 spots showed quantitative variations in which 42 high quantitatively variant proteins were identified. The results showed that production of the pyrimidine biosynthetic enzymes (PyrAA, PyrAB, PyrB, PyrC, PyrD, and PyrF) were significantly increased in B. subtilis DB104 ${\Delta}$pyrR. Besides, proteins associated carbohydrate metabolism, elongation protein synthesis, metabolism of cofactors and vitamins, motility, tRNA synthetase, catalase, ATP-binding protein, and cell division protein FtsZ were overproduced in the PyrR-deficient mutant. Based on analytic results, the PyrR might be involved a number of other metabolisms or various phenomena in the bacterial cell besides the pyrimidine biosynthesis.