• Journal of Microbiology
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• 제37권2호
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• pp.102-110
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• 1999

Genetic determinant for the secondary metabolism was studied in heterologous expression in Streptomyces lividans TK-24 using Streptomyces griseus ATCC 10137 as a donor strain. Chromosomal DNA of S. griseus was ligated into the high-copy number Streptomyces shuttle plasmid, pWHM3, and introduced into S. lividans TK-24. A plasmid clone with 4.3-kb BamHI DNA of S. griseus (pMJJ201) was isolated by detecting for stimulatory effect on actinorhodin production by visual inspection. The 4.3-kb BamHI DNA was cloned into pWHM3 under the control of the strong constitutive ermEp promoter in both directions (pMJJ202); ermEp promoter-mediated transcription for coding sequence reading right to left: pMJJ203; ermEp promoter-mediated transcription for coding sequence reading left to right) and reintroduced into S. lividans TK-24. The production of actinorhodin was markedly stimulated due to introduction of pMJJ202 on regeneration agar. The introduction of pMJJ202 also stimulated production of actinorhodin and undecylproidigiosin in submerged culture employing the actinorhodin production medium. Introduction of pMJJ203 resulted in a marked decrease of production of the two pigments. Nucleotide sequence analysis of the 4.3-kb region revealed three coding sequences: two coding sequences reading left to right, ORF1 and ORF2, one coding sequence reading right to left, ORF3. Therefore, it was suggested that the ORF3 product was responsible for the stimulation of antibiotic production. The C-terminal region of ORF3 product showed a local alignment with Myb-related transcriptional factors, which implicated that the ORF3 product might be a novel DNA-binding protein related to the regulation of secondary metabolism in Streptomyces.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.627-636
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• 2016

The causative agent of pandemic cholera, Vibrio cholerae, infects the anaerobic environment of the human intestine. Production of cholera toxin (CT), a major virulence factor of V. cholerae, is highly induced during anaerobic respiration with trimethylamine N-oxide (TMAO) as an alternative electron acceptor. However, the molecular mechanism of TMAO-stimulated CT production is not fully understood. Herein, we reveal that CT production during anaerobic TMAO respiration is affected by glucose fermentation. When the seventh pandemic V. cholerae O1 strain N16961 was grown with TMAO and additional glucose, CT production was markedly reduced. Furthermore, an N16961 Δcrp mutant, devoid of cyclic AMP receptor protein (CRP), was defective in CT production during growth by anaerobic TMAO respiration, further suggesting a role of glucose metabolism in regulating TMAO-mediated CT production. TMAO reductase activity was noticeably decreased when grown together with glucose or by mutation of the crp gene. A CRP binding region was identified in the promoter region of the torD gene, which encodes a structural subunit of the TMAO reductase. Gel shift assays further confirmed the binding of purified CRP to the torD promoter sequence. Together, our results suggest that the bacterial ability to respire using TMAO is controlled by CRP, whose activity is dependent on glucose availability. Our results reveal a novel mechanism for the regulation of major virulence factor production by V. cholerae under anaerobic growth conditions.

• Asian-Australasian Journal of Animal Sciences
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• 제20권4호
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• pp.511-516
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• 2007

This experiment was conducted to evaluate the effects of differently maturing corn hybrids on silage production and milk production per unit area in the northern part of Japan, where grain development occurs under decreasing ambient temperature. Both hybrids were harvested at the same time. The stages of maturity for the early-maturing hybrids (EH; 80 d relative maturity) and the mid-maturing hybrids (MH; 93 d relative day) were early dent and late dough stage, respectively. The plant yields for MH were higher than those for EH. The dry matter (DM) content of MH was lower than that for EH, and the effluent loss for MH silage was greater than that for EH silage. Therefore, the DM yields of prepared silage per area were similar for both treatments. Twelve multiparous mid-lactation Holstein cows ($58{\pm}13$ days in milk) were fed diets based on EH or MH silage in a crossover design with two 3-week periods. Cows were fed 3 kg of hay crop silage (DM basis) and either EH or MH silage ad libitum, and concentrates were supplied to meet NRC requirement for dairy cows. Silage DM intake for EH was found to be higher (p<0.05) than that for MH (10.0 vs. 9.1 kg/day). Milk production and milk composition for EH were similar to those for MH. Feed efficiency per total feed intake was similar in both treatments, although the feed efficiency per concentrate intake tended to be higher for the EH than that for the MH diet. These results indicate that differences in maturation in corn hybrids affect the effluent production of silage and the silage intake of dairy cows. It may be advantageous to plant early hybrid corn with a reduction in effluent production of silage as well as a reduction in purchased feed costs for dairy cows under the climatic conditions of the northern part of Japan.

• 한국작물학회지
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• 제61권2호
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• pp.104-112
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• 2016

A double-cropping system with soybean (Glycine max) following the cultivation of potato, garlic, and onion is widely adopted in the southern region of Korea. For this system, marginal dates for planting must be determined for profitable soybean yields, because the decision to plant soybean as a second crop is occasionally delayed by harvest of the first crop and weather conditions. In order to investigate the effect of planting date on soybean yield, three cultivars (early and late maturity) were planted on seven different dates from May 1 to July 30 in both paddy and upland fields across 2012 and 2013. Soybean yields were significantly different among the planting dates and the cultivars; however, the interaction between cultivar and planting date was not significant. Based on linear regression, the maximum yield of soybean was reached with a June 10 planting date, with a sharp decline in yield for crops planted after this date. The results of this study were consistent with those of a previous one that recommends early and mid-June as the optimum planting period. Regardless of soybean ecotype, a reduction in yield of greater than 20% occurred when soybean was planted after mid-July. Frost during soybean growth can reduce yields, and the late maturity cultivars planted on July 30 were damaged by frost before completing maturation and harvest; however, early maturity cultivars were safely harvested. For sufficient time to develop and reach profitable yields, the planting of soybean before mid-July is recommended.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.68-72
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• 2004

The effects of the addition of yeast on in vitro roughage degradability and methane production were investigated in order to clarify the effects of yeast on the rumen microbes and to establish methods of rumen manipulation. Three roughages (whole crop corn, rice straw and Italian ryegrass) were incubated for 3, 6, 12 and 24 h with or without dried beer yeast following the method described by Tilley and Terry. Using the same method, these roughages were incubated with or without yeast extract, albumin or purified DNA. In vitro methane production was measured with or without dried beer yeast at 12 and 24 h. The degradability of yeast was found to be 57 and 80% at 12 and 24 h, respectively. The rate of degradation of fraction b was 6.16%/h. There was a significant increase in roughage degradability at 6 h (p<0.05), 12 h (p<0.05) and 24 h (p<0.01) by dried yeast addition. The degradability of all three roughages was higher in the samples treated with yeast extract than in the no addition samples except in the case of rice straw incubated for 12 h. Nevertheless, the magnitude of increment was smaller with the addition of yeast extract than without the addition of yeast. With the addition of purified DNA, there were significant increases in roughage degradability at 6 h (p<0.01), 12 h (p<0.01) and 24 h (p<0.05); however, higher degradability values were detected in the samples to which albumin was added, particularly at 6 h. If the degradability values of the no addition samples with those of samples containing yeast, yeast extract, DNA and albumin were compared, the largest difference was found in the samples to which yeast was added, although it is worth noting that higher values were observed in the yeast extract samples than in the DNA or albumin samples, with the exception of the case of rice straw incubated for 24 h. Methane production was significantly increased at both 12 and 24 h incubation. The increment of roughage degradation and methane production brought about by the addition of dried beer yeast to the samples was thought to be due to the activation of rumen microbes. Water soluble fraction of yeast also seemed to play a role in ruminal microbe activation. The increment of degradability is thought to be partially due to the addition of crude protein or nucleic acid but it is expected that other factors play a greater role. And those factors may responsible for the different effects of individual yeast on ruminal microbes.

• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1430-1438
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• 2019

Objective: This experiment was designed to determine the effects of coated cysteamine hydrochloride (CC) on muscle fiber characteristics, amino acid composition and transporters gene expression in the longissimus dorsi muscle (LDM) of finishing pigs. Methods: Two hundred and sixteen Duroc/Landrace/Yorkshire cross-bred male finishing pigs were fed with a corn-soybean basal diet supplemented with 0, 70, and 140 mg/kg cysteamine. Each group contained eight replicates of nine pigs per replicate. After 29 days, one pig was randomly selected from each replicate and slaughtered. Blood and LDM samples were collected and analyzed. Results: The results showed that supplemental dietary CC increased (p<0.05) the muscle fiber density. And CC supplementation also up-regulated (p<0.05) the expression of myosin heavy chain 1 (MyHC1) and MyHC2x mRNA levels, and down-regulated (p<0.05) MyHC2b expression in the LDM. Additionally, supplemental dietary CC reduced (p<0.05) the concentration of total cholesterol in the plasma and enhanced (p<0.05) the concentrations of essential amino acid and total amino acid in the LDM. The relative expression levels of chloramphenicol acetyltransferase 2, $b^{0,+}$ amino acid transporter, and $y^+$-L-type amino acid transporter 1 were upregulated (p<0.05) in the LDM when pigs were fed with the dietary CC of 70 mg/kg. Conclusion: Cysteamine supplementation could increase fiber density and distribution of fiber types. It also improved the deposition of protein in the LDM by up-regulated the expression of amino acid transporters.

• 한국유기농업학회지
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• 제4권1호
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• pp.45-58
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• 1995

This paper studied production characteristics of organic farming products and analyzed management income and production cost of organic farming(rice). In order to analyze these points actually, this study was focused on pruduction activities of a producers' organization, Pulmoo Cooperatives in Hong-Dong Myun, Hong-Seong Region, Chung Nam Province. So the following results were obtained : In 1994, output level and an income rate of rice per unit area(10a) which was produced in organic farming method(O.F.M) was higher than those of general farming method(G.F.M) as about 5%, 7.4%. And management income size of the former was 1.8 times as large as that of the latter. But rice production cost of O.F.M was 1.93 times as much as that of G.F.M, particularily in labor cost and farming equipment cost, light and heat expenses, many other material costs. For the progress of organic farming O.F.M and equipmets should be developed much more, for example, the technics of prevetion against damages by blight and harmful insects and improvement of varieties, natural pesticides, agricultual application of microorganisim, construction of compost heat factory, etc. Since these technics and establishments have taken on the public goods, the development of those should be supported by government.

• 한국축산식품학회지
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• 제33권4호
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• pp.549-554
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• 2013

Food safety is important issue for consumers and recently the usage of food ingredients especially food preservatives are limited by regulations. However, some manufacturers use food preservatives instead of improving their hygienic production. Therefore, the levels of sodium benzoate and potassium sorbate of 147 vacuum packaged Kashar (fresh) cheese samples produced in Black Sea Region, Turkey were investigated and some microbiological properties were determined. Research results demonstrated that the production of vacuumed Kashar cheese in Black Sea Region was not standardized for all production periods depending on the microbiological properties. Coliform and E. coli counts detected in the cheese samples showed that necessary hygienic conditions were not provided for Kashar cheese production. Staphylococcus aureus was not determined in the cheese samples. The sodium benzoate and potassium sorbate were analyzed by HPLC-DAD. Potassium sorbate levels (69.39 mg/kg) of Kashar cheese samples were determined to be lower than the maximum permitted concentration of Turkish Food Codex. Although the utilization of sodium benzoate is prohibited by the Codex, the average level of sodium benzoate of cheese samples was detected to be 68.63 mg/kg. Sodium benzoate can be naturally occurred in fresh cheese at concentrations of up to 50 mg/kg.

• 농업과학연구
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• 제39권4호
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• pp.577-581
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• 2012

The polymorphisms of several genes including Leptin (LEP), beta-lactoglobulin (LGB) and Prolactin receptor (PRLR) have been shown to affect milk composition traits in dairy cattle. But, the effects of these polymorphisms on the milk traits of Philippine water buffalo are still unclear. In the Philippines, buffalo are the major milk producers most of which are the Philippine carabao (PC), the American Murrah Buffalo (AMB) and Bulgarian Murrah Buffalo (BMB). The LEP, LGB and PRLR genes are considered to be associated with milk production traits. The objective of the present study was to identify the single nucleotide polymorphisms (SNPs) in the LEP, LGB and PRLR genes of PC, AMB and BMB and to investigate the effect of the SNPs on milk production traits in these buffalo. Genetic polymorphisms were screened by DNA sequencing and 12 SNPs were detected in BMB; 5 SNPs were in LEP exon3 region (G14227A, G14343A, T14502C, C14526T, G14603A); 5 SNPs were in LGB exon 2 region (G1861C, A1900G, G1901T, T1948C, G1949A); 2 SNPs were in PRLR exon 6 (T59047C, T59109C). Also, 12 polymorphism sites between cattle and buffalo were identified. Our analysis of the association between SNPs and milk production traits should be useful in future studies of buffalo breeding to improve lactation performance.

• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.205-212
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• 2001

It has been proposed that nitirc oxide is involved in the pathogenesis of cerebral ischemia-reperfusion. Because superoxide production is also enhanced during reperfusion, the cytotoxic oxidant peroxynitrite could be formed, but it is not known if this occurs following global forebrain ischemia-reperfusion. We examined whether peroxynitrite generation is increased in the vulnerable regions after forebrain ischemia-reperfusion. Transient forebrain ischemia was produced in the conscious rat by four-vessel occlusion. Rats were subjected to 10 or 15 min of forebrain ischemia. Immunohistochemical method was used to detect 3-nitrotyrosine, a marker of peroxynitrite production. 3-Nitrotyrosine immunoreactivity was enhanced in the hippocampal CA1 area 3 days after reperfusion. Furthermore, in rats subjected to ischemia for 15 min, this change was also observed in the lateral striatal region and the lateral septal nucleus $2{\sim}3$ days after reperfusion. The cresyl violet staining of adjacent sections showed that neuronal cell death was induced in parallel with the nitrotyrosine immunoreactivity in the hippocampal CA1 area and the lateral striatal region. Our findings suggest that oxygen free radical accumulation and consequent peroxynitrite production play a role in neuronal death caused by cerebral ischemia-reperfusion.