• Korean Journal of Microbiology
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• v.52 no.4
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• pp.495-499
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• 2016

In order to identify the biochemical characteristics of LuxG, the luxG gene from bioluminescence bacteria of Photobacterium leiognathi ATCC 25521 was isolated by PCR-Amplification and inserted into pQE30 vector containing the T5 promoter and 6X His-tag system. The resulting recombinant plasmid was transformed into Escherichia coli to over-express the luxG gene and purify the gene product. The purified LuxG protein demonstrated ferric iron reductase activity and the kinetic parameters of $K_m$ and $V_{max}$ for FMN as well as the NADPH substrates of ferric iron reductase were determined, respectively.

• Journal of Microbiology
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• v.42 no.3
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• pp.194-199
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• 2004

Investigation of the expression of the riboflavin (rib) genes, which are found immediately downstream of luxG in the lux operon in Photobacterium phosphoreum, provides more information relevant to the evolution of bioluminescence, as well as to the regulation of supply of flavin substrate for bacterial bioluminescence reactions. In order to answer the question of whether or not the transcriptions of lux and rib genes are integrated, a transcriptional termination assay was performed with P. phoxphoreum DNA, containing the possible stem-loop structures, located in the intergenic region of luxF and luxE ($\Omega$$\_$A/), of luxG and ribE ($\Omega$$\_$B/), and downstream of ribA ($\Omega$$\_$c/). The expression of the CAT (Chloram-phenicol Acetyl Transferase) reporter gene was remarkably decreased upon the insertion of the stem-loop structure ($\Omega$$\_$c/) into the strong lux promoter and the reporter gene. However, the insertion of the structure ($\Omega$$\_$B/) into the intergenic region of the lux and the rib genes caused no significant change in expression from the CAT gene. In addition, the single stranded DNA in the same region was protected by the P. phosphoreum mRNA from the Sl nuclease protection assay. These results suggest that lux genes and rib genes are part of the same operon in P. phosphoreum.

• Journal of Photoscience
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• v.11 no.1
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• pp.41-45
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• 2004

The key riboflavin synthesis genes are located immediately downstream of luxG in the lux operon from Photobacterium leiognathi. It is of interest that a site capable of forming a rho-independent terminator does not appear to be present between luxG and ribE in our previous data. These results raise the question of whether the transcription of lux and rib genes is integrated or not. In order to answer the question, in vivo transcriptional assay and Southern blot were examined. These studies demonstrate that neither transcriptional terminator nor promoter site is present in the intergenic region between of lux and rib genes as well as that the riboflavin genes are single copy in a chromosome of Photobacterium leiognathi.

• The Korean Journal of Mycology
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• v.36 no.1
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• pp.31-35
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• 2008

To elucidate optimum light conditions for artificial cultivation of Grifola frondosa, the effects of light quality (blue, green, white) and light intensity (200, 500, 800, 1200 lux) on primordium formation, morphological properties and yield of fruiting bodies of G. frondosa using bag cultivation method were tested. Among three light sources, white light source ($400{\sim}620\;nm$) had a higher mushroom yield (242 g/bag) and a shorter cultivation period (52 days) than those of the others. In particular, blue light source ($400{\sim}560\;nm$) induced the morphology of wide and deep colored pilei in G. frondosa fruiting body. The experimental results on the appropriate light intensity indicated that 500 lux light was the most effective on mushroom production, whereas primordium formation was effective at 200 lux.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.48-54
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• 2005

A comparison of promoter fusions with the luxCDABE genes from Vibrio fischeri and Photorhabdus luminescens was made using promoters from several genes (katG, sodA, and pqi-5) of E. coli that are responsive to oxidative damage. The respective characteristics, such as the basal and maximum bioluminescence and the relative bioluminescence, were compared. E. coli strains carrying fusions of the promoters to P. luminescens lux showed higher basal and maximally induced bioluminescent levels than strains carrying the same promoter fused to the luxCDABE genes from V. fischeri. The sensitivities between the strains were similar, regardless of the luciferase used, but lower response ratios were seen from strains harboring the P. luminescens lux fusions. Furthermore, using the two katG::lux fusion strains, the bioluminescence from the P. luminescens lux fusion strain, DK1, was stable after reaching a maximum, while that of strain DPD2511 decreased very rapidly due to substrate limitation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.543-547
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• 1995

This study was conducted to light intensity and night interruption on leaf production in perilla. Using two cultivars ; og-dong and Yeup-sil. The present studies were conducted to investigate effect of the light intensity and night interruption for prolongation of vegetative growth by flowering inhibition in the National Honam Crop Experiment Station, R. D. A, Iri, Korea. The results are summarized as followes, varietal differences of days to flower initiation were not significant by the light intensity and night interruption, however differences of days to flower initiation light intensity or night interruption treatment were higly significant. Flowering of perilla was prolongated in high light intensity and in long night interruption. Between the factors treated flowering of perilla was more influenced by light intensity than night interruption. Days to flower initiation of perilla were light intensity(0.5∼1 Lux) in 30 mins night interruption, however 3∼10 light intensity in 60 mins night interruption and 30∼100 Lux light intensity in 10, 30, 60 mins night interruption treatment were not flowering. Plant height, leaf area and dry weight of perilla were the highest in 30∼100 Lux light intensity treatment than in the other treatments. The results would be avaliable establish year-round production methods for low cost of perilla leaf.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.1-7
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• 2000

The genes involved in riboflavin synthesis (ribI, II, III, and IV) were found immediately downstream of luxG in the lux operon from Photobacterium species. The single stranded DNA containing the intergenic region of lux genes and rib genes from Photobacterium phosphoreum was fully protected by P. phosphoreum mRNA from the S1 nuclease mapping assay suggesting that a transcriptional terminator was not present in the region. In addition, the levels of riboflavin synthase activity in P. phosphoreum was increased during the development of bacterial bioluminescence in the same fashion as the luciferase and fatty acid reductase activities. Insertion of the Photobacterium leiognathi DNA extending from luxB to ribII, between a strong lux promoter and a reporter gene (chloramphenicol acetyltransferase, CAT) and transferred by conjugation into P. leiognathi, did not affect expression of reporter gene. Moreover the CAT gene was not expressed in an analogous construct missing the lux promoter indicating that a promoter was not present in this region. Based on the data here, it can be concluded that the lux genes and rib genes in Photobacterium species are under common regulation.

• Journal of Mushroom
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• v.8 no.4
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• pp.137-141
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• 2010

This experiment was carried out to clarify the effect of light qualities on the growth characteristics and yield of fruiting body in the cultivation of Lyophyllum ulmarium. The intensity of illumination by light qualities was in the order of white light(2,270Lux), yellow light(1,750Lux), blue light(460Lux) and red light(400Lux). An investigation of fruiting body showed these results that the pileus size and stipe diameter of fruiting body on CBM(Chungbuk mushroom)-1757 were much larger than Hypsizigus marmoreus, and an effect of yellow light seemed to be better than those of another light. In comparison with Hypsizigus marmoreus, the growth duration of CBM-1757 was shortened by 8 days which included 2 days for mycelial culture, 1 day for first pinning requirement and 1 day for growth. The growth duration in yellow light illumination was about 70 days showing the tendency of 2~4 days reduction. There were no differences in results such as number of effective stem and fresh weight. The yield of fruiting body per bottle in CBM-1757(95.6g) was little higher than Hypsizigus marmoreus(94.8g). By a white light's standard, the yields of blue and red light illumination were decreased by 2~9%, but that of yellow light illumination was increased by 8%. The chromaticity results showed that brightness, red and yellow coloration of CBM-1757 were higher than those of Hypsizigus marmoreus, and yellow light treatment was more effective than another light.

• Journal of the Korean Chemical Society
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• v.64 no.4
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• pp.225-230
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• 2020

• Science of Emotion and Sensibility
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• v.18 no.2
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• pp.45-54
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• 2015

This study carried out an experiment to identify subject's work effectiveness and energy saving effect using LED light. Towards this end, this study configured nine various lighting environments in order to control PWM (Pulse Width Modulation) and illuminance (lux), which are the characteristics of LED light. The PWM ratio of LED light was set as R:G:B=1:1:1, R:G:B=4:1:5, and R:G:B=8:7:7, respectively, and illuminance (lux) was set as 400 lx, 700 lx, and 1000 lx, respectively. In addition, the indoor environment was set temperature $20-24^{\circ}C$, humidity 50%-60%, and the amount of clothing 1. This study analyzed work effectiveness and energy consumption in nine lighting environments, each. Error correction was performed for work effectiveness analysis, and cumulative power consumption was measured in each lighting environment for energy consumption analysis. According to experiment results through the lighting environments suggested in this study, accuracy and spent time effectiveness were good in 700lux and higher than 400lux. For spent time, the best effectiveness was revealed in the suggested PWM ratio, R:G:B=8:7:7. The lowest power consumption on each illuminance (lux) was revealed in the order of R:G:B=8:7:7, RGB=1:1:1, and R:G:B=4:1:5. Therefore, pulse-width modulation effect is proposed in this paper was found to affect the efficiency and energy saving.