An ESR Study of Amino Acid and Protein Free Radicals in Solution - PART II. Identification of Amino Acid Free Radicals Produced by Ti-$H_2O_2$ Flow System

홍순주,Hong, Sun-Joo,Piette, L.H. 생화학분자생물학회 1971 한국생화학회지 Vol.4 No.1

Ti-$H_2O_2$ flow-mixing system에서 만들어진 아미노산 자유기를 ESR법으로 동정하고 이 결과와 방사선에 의해 생성된 경우와를 비교 검투했다. 이 system으로 만들어진 각 아미노산의 자유기는 반드시 한 가지 만은 아님이 밝혀졌는데 이 실험에서 얻은 각 ESR 스펙트럼은 glycine에서는 주로 $\dot{C}H({NH_3}^+)COO^-$, DL-$\alpha$-alanine에서는 주로 $\dot{C}H_2CH({NH_3}^+)COO^-$, $\beta$-alanine에서는 주로 $CH_2({NH_3}^+)\dot{C}H{COO_3}^-$, DL-valine에서는 $(CH_3)_2\dot{C}CH({NH_3}^+)COO^-$와 거의 동율로 $\dot{C}H_2CH(CH_3)\dot{C}H({NH_}^+)COO^-$, DL-serine에서는 $\dot{C}H(OH)CH({NH_3}^+)COO^-$, L-cysteine, cystine 및 gIutathione에서는 주로 $RCH_2\dot{S}$, DL-threonine에서는 주로 $CH_3\dot{C}(OH)CH({NH_3}^+)COO^-$, DL-leucine에서는 주로 $\dot{C}H_2CH(CH_3)CH_2CH({NH_3}^+)COO^-$, DL-methionine에서는 주로 $CH_2SCH_2\dot{C}HCH({NH_3}^+)COO^-$, 그리고 L(+)arginine에서는 주로 $HN=C(NH_2)NHCH_2\dot{C}HCH_2CH({NH_3}^+)COO^-$의 생성을 나타내고 있음을 확인했다. 결국, 방사선에 의한 아미노산 자유거의 생성은 알파위치에서 수소원자를 떼어냄으로서 생성되는데 반해 이 system에서는 일차적으로 생성된 친(親)전자성인 수산기가 아미노산 분자의 guanidium 기, carboxyl 기 또는 proton이 더해진 amino 기에서 가급적 먼 위치에서 수소원자를 떼어 냄으로써 생성됨을 알았다. 본실험에서 수산기수소에 의한 splitting이 선명하게 들어난 것은 특기할 일이며 이 실험에서 다룬 아미노산 중에서 L-cysteine과 DL-methionine을 제외한 모든 아미노산의 경우에는 그의 자유기 생성이 염산에 의해 저해를 받은 반면, 황산은 염산의 경우와 정반대의 영향을 끼친다는 사실을 알았다. Free radicals generated by exposing amino acids to Ti-$H_2O_2$ flow mixing system were identified by electron spin resonance spectroscopy. Hydrogen atom abstraction by the reactive primary radical, having electrophilic character, was found to occur at the carbon atom furthest from the guanidium, carboxyl and protonated amino group, and sulfur atom. The main radical species from DL-leucine, DL-methionine. and L(+)arginine were assigned to be $\dot{C}H_2CH(CH_3)CH_2CH({NH_3}^+)COO^-$, $\dot{C}H_3SCH_2\dot{C}HCH({NH_3}^+)COO^-$ and $NH=C(NH_2)NHCH_2\dot{C}HCH_2CH({NH_3}^+)COO^-$ respectively. The splitting for the hydroxyl hydrogen was also clearly observed in the system for DL-serine free radical, $\dot{C}H(OH)CH({NH_3}^+)COO^-$. Generally, HCl appeared to interfere with the free radical production for most of the amino acids investigatd except L-cysteine and DL-methionine in contrast with $H_2SO_4$ which enhances most signals but not with the latter.

Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos)

H.C. Liu,J.F. Huang,S.R. Lee,H.L. Liu,C.H. Hsieh,C.W. Huang,M.C. Huang,C. Tai,J.P. Poivey,R. Rouvier,Y.S. Cheng 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie (h2 = 0.07±0.03) and M (h2 = 0.07±0.01), moderately low for Dm (h2 = 0.13±0.02), of medium values for H (h2 = 0.20±0.03) and F (h2 = 0.23±0.03). High and favourable genetic correlations existed between F and Dm (rg = 0.93), between F and H (rg = 0.97) and between Dm and H (rg = 0.90). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings’ feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos)

Liu, H.C.,Huang, J.F.,Lee, S.R.,Liu, H.L.,Hsieh, C.H.,Huang, C.W.,Huang, M.C.,Tai, C.,Poivey, J.P.,Rouvier, R.,Cheng, Y.S. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.5

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie ($h^2=0.07{\pm}0.03$) and M ($h^2=0.07{\pm}0.01$), moderately low for Dm ($h^2=0.13{\pm}0.02$), of medium values for H ($h^2=0.20{\pm}0.03$) and F ($h^2=0.23{\pm}0.03$). High and favourable genetic correlations existed between F and Dm ($r_g=0.93$), between F and H ($r_g=0.97$) and between Dm and H ($r_g=0.90$). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

New and noteworthy species of the lichen genus <i>Lecanora</i> (Ascomycota; <i>Lecanoraceae</i>) from South Korea

LÜ,, Lei,JOSHI, Yogesh,ELIX, John A.,LUMBSCH, H. Thorsten,WANG, Hai Ying,KOH, Young Jin,HUR, Jae-Seoun Cambridge University Press 2011 The Lichenologist Vol.43 No.4

<B>Abstract</B><P>Two new species, <I>Lecanora hafelliana</I> L. Lü, Y. Joshi & Hur and <I>L</I>. <I>loekoesii</I> Y. Joshi, L. Lü & Hur, are described as new to science from South Korea and eight species, <I>L. campestris</I> (Schaer.) Hue, <I>L. cenisia</I> Ach., <I>L. nipponica</I> H. Miyaw., <I>L. perplexa</I> Brodo, <I>L. plumosa</I> Müll. Arg., <I>L. polytropa</I> (Hoffm.) Rabenh., <I>L. subrugosa</I> Nyl. and <I>L. sulcata</I> (Hue) H. Miyaw., are recorded from South Korea for the first time. <I>Lecanora hafelliana</I> is characterized by the presence of hafellic acid, which is reported for the first time in this genus, while <I>L. loekoesii</I> is characterized by multispored asci and a thallus containing norstictic acid.</P>

Development of an experimental apparatus and protocol for determining antimicrobial activities of gaseous plant essential oils

Seo, H.S.,Beuchat, L.R.,Kim, H.,Ryu, J.H. Elsevier Science Publishers 2015 International journal of food microbiology Vol.215 No.-

There is a growing interest in the use of naturally-occurring antimicrobial agents such as plant essential oils (EOs) to inhibit the growth of hazardous and spoilage microorganisms in foods. Gaseous EOs (EO gases) have many potential applications in the food industry, including use as antimicrobial agents in food packaging materials and sanitizing agents for foods and food-contact surfaces, and in food processing environments. Despite the potentially beneficial applications of EO gases, there is no standard method to evaluate their antimicrobial activities. Thus, the present study was aimed at developing an experimental apparatus and protocol to determine the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) of EO gases against microorganisms. A sealed experimental apparatus was constructed for simultaneous evaluation of antimicrobial activities of EO gases at different concentrations without creating concentration gradients. A differential medium was then evaluated in which a color change allowed for the determination of growth of glucose-fermenting microorganisms. Lastly, an experimental protocol for the assessment of MIC and MLC values of EO gases was developed, and these values were determined for 31 EO gases against Escherichia coli O157:H7 as a model bacterium. Results showed that cinnamon bark EO gas had the lowest MIC (0.0391μl/ml), followed by thyme-thymol EO gas (0.0781μl/ml), oregano EO gas (0.3125μl/ml), peppermint EO gas (0.6250μl/ml), and thyme-linalool EO gas (0.6250μl/ml). The order of the MLC values of the EO gases against the E. coli O157:H7 was thyme-thymol (0.0781μl/ml)<cinnamon bark (0.1563μl/ml)<oregano (0.3125μl/ml)<peppermint (0.6250μl/ml)=thyme-linalool (0.6250μl/ml). The experimental apparatus and protocol enable rapid and accurate determination of the MIC and MLC values of EO gases and perhaps other types of gaseous antimicrobial agents.

Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

Sheng, Q.K.,Yang, Z.J.,Zhao, H.B.,Wang, X.L.,Guo, J.F. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.8

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide ($H_2S$), and 3-methylindole (skatole). Eighty swine ($50.0{\pm}0.5kg$) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a $3{\times}3$ orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, $H_2S$, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, $H_2S$, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced $H_2S$ production (r = 0.9981). Fructan and Bs significantly interacted in $H_2S$ production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and $H_2S$.

Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

Q.K. Sheng,Z.J. Yang,H.B. Zhao,X.L. Wang,J.F. Guo 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.8

The effects of daily dietary Bacillus subtilis (Bs), and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide (H2S), and 3-methylindole (skatole). Eighty swine (50.0±0.5 kg) were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a 3×3 orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, H2S, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992). L-tryptophan had no effect on the production of ammonia, H2S, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced H2S production (r = 0.9981). Fructan and Bs significantly interacted in H2S production (p = 0.014). Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039). The predominant bacteria were Bacillus spp. CWBI B1434 (26%) in the control group, and Streptococcus alactolyticus AF201899 (36%) in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and H2S.

Combined effects of chlorine dioxide, drying, and dry heat treatments in inactivating microorganisms on radish seeds

Bang, J.,Kim, H.,Kim, H.,Beuchat, L.R.,Ryu, J.H. Academic Press 2011 FOOD MICROBIOLOGY Vol.28 No.1

We determined the combined effectiveness of ClO<SUB>2</SUB> (200 and 500 μg/ml, 5 min), air drying [25 <SUP>o</SUP>C, 40% relative humidity (RH), 2 h], and mild dry heat (55 <SUP>o</SUP>C, 23% RH, up to 48 h) treatments in killing total aerobic bacteria (TAB), Escherichia coli O157:H7, and molds and yeasts (MY) on radish seeds. A 5.1-log reduction in the number of TAB was achieved on radish seeds treated with 200 or 500 μg/ml ClO<SUB>2</SUB> followed by air drying for 2 h and dry heat treatment for 48 h or 24 h, respectively. When radish seeds were treated with 200 and 500 μg/ml ClO<SUB>2</SUB>, air dried, and heat treated for 12 h and 6 h, respectively, the initial population of E. coli O157:H7 (5.6 log CFU/g) on seeds was reduced to an undetectable level (<0.8 log CFU/g). However, the pathogen was detected in 5-day-old sprouts. The reduction of MY (1.2-1.0 log CFU/g) on radish seeds under similar experimental conditions was not changed significantly during subsequent heat treatment up to 48 h. Results show that treating radish seeds with 500 μg/ml ClO<SUB>2</SUB>, followed by air dried at 25 <SUP>o</SUP>C for 2 h and heat treatment at 55 <SUP>o</SUP>C for 36 h achieved a >5-log CFU/g reduction of TAB and E. coli O157:H7. These observations will be useful when developing effective strategies and practices to enhance the microbiological safety of radish sprouts.

Survival and colonization of <i>Escherichia coli</i> O157:H7 on spinach leaves as affected by inoculum level and carrier, temperature and relative humidity

Choi, S.,Bang, J.,Kim, H.,Beuchat, L.R.,Ryu, J.‐,H Blackwell Publishing Ltd 2011 Journal of applied microbiology Vol.111 No.6

<P><B>Abstract</B></P><P><B>Aims: </B> To determine survival and colonization of <I>Escherichia coli</I> O157:H7 on spinach leaves as affected by inoculum level and carrier, temperature and relative humidity (r.h.).</P><P><B>Methods and Results: </B> Spinach leaves were inoculated with suspensions of <I>E.?coli</I> O157:H7 in distilled water (DW) and 0·1% peptone water (PW) and incubated at 4, 12 and 25°C and 43, 85 and 100% r.h. The number of <I>E.?coli</I> O157:H7 on leaves (5·6 or 1·9 log CFU per leaf) inoculated using DW as a carrier medium increased significantly at 25°C and 100% r.h. within 120 h but remained constant or decreased significantly under other test conditions. <I>E.?coli</I> O157:H7 on leaves (5·4 log CFU per leaf) inoculated using PW as a carrier increased significantly within 72 and 24 h, respectively, at 12 or 25°C and 100% r.h.; counts using a low inoculum (2·2 log CFU per leaf) increased significantly within 24 h at 25°C.</P><P><B>Conclusions: </B> <I>Escherichia coli</I> O157:H7 can colonize on spinach leaves at 12 or 25°C in a 100% r.h. environment. Organic matter in the inoculum carrier may provide protection and nutrients which enhance survival and colonization.</P><P><B>Significance and Impact of the Study: </B> Colonization of <I>E.?coli</I> O157:H7 on spinach leaves as affected by organic matter in the inoculum, temperature and r.h. was determined. These observations will be useful when developing strategies to prevent growth of <I>E.?coli</I> O157:H7 on pre‐ and postharvest spinach.</P>

Sanitizing radish seeds by simultaneous treatments with gaseous chlorine dioxide, high relative humidity, and mild heat

Bang, J.,Choi, M.,Son, H.,Beuchat, L.R.,Kim, Y.,Kim, H.,Ryu, J.H. Elsevier Science Publishers 2016 International journal of food microbiology Vol.237 No.-

<P>Sanitizing radish seeds intended for edible sprout production was achieved by applying simultaneous treatments with gaseous chlorine dioxide (ClO2), high relative humidity (RH, 100%), and mild heat (55 degrees C). Gaseous ClO2 was produced from aqueous ClO2 (0.66 ml) by mixing sulfuric acid (5% w/v) with sodium chlorite (10 mg/mL) in a sealed container (1.8 L). Greater amounts of gaseous ClO2 were measured at 23% RH (144 ppm after 6 h) than at 100% RH (66 ppm after 6 h); however, the lethal activity of gaseous ClO2 against naturally occurring mesophilic aerobic bacteria (MAB) on radish seeds was significantly enhanced at 100% RH. For example, when exposed to gaseous ClO2 at 23% RH, the number of MAB on radish seeds decreased from 3.7 log CFU/g to 2.6 log CFU/g after 6 h. However, when exposed to gaseous ClO2 at 100% RH for 6 h, the MAB population decreased to 0.7 log CFU/g after 6 h. Gaseous ClO2 was produced in higher amounts at 55 degrees C than at 25 degrees C, but decreased more rapidly over time at 55 degrees C than at 25 degrees C. The lethal activity of gaseous ClO2 against MAB on radish seeds was greater at 55 degrees C than at 25 degrees C. When radish seeds were treated with gaseous ClO2 (peak concentration: 195 ppm) at 100% RH and 55 degrees C, MAB were reduced to populations below the detectable level (<-0.7 log CFU/g) within 2 h without decreasing the seed germination rate (97.7%). The lethality of combined treatments against artificially inoculated Escherichia coli O157:H7 was also evaluated. When exposed to gaseous ClO2 at 100% RH and 55 degrees C for 6 h, the initial number of E. coli O157:H7 (3.5 log CFU/g) on radish seeds decreased to below the detection limit (0.7 log CFU/g) by direct plating but it was not eliminated from seeds. The germination rate of radish seeds was not significantly (P> 0.05) decreased after treatment for 6 h. The information reported here will be useful when developing decontamination strategies for producing microbiologically safe radish seed sprouts. (C) 2016 Published by Elsevier B.V.</P>