• Title/Summary/Keyword: acid sensitivity

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Screening of Radio-resistant Lactic Acid Bacteria

  • Hwang, E-Nam;Kang, Sang-Mo;Kim, Jae-Kyung;Lee, Ju-Woon;Park, Jong-Heum
    • Food Science of Animal Resources
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    • v.33 no.3
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    • pp.335-340
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    • 2013
  • This study screened for radio-resistant strains lactic acid bacteria (LAB) by evaluating their capability to survive exposure to ionizing radiation. Ten strains of LAB - Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pediocuccos pentosaceus - were selected and subcultuted twice. The LAB was then further cultured for 3 d at $37^{\circ}C$ to reach 7-10 Log colony-forming units (CFU)/mL prior to irradiation and immediately exposed to gamma rays or electron beams with absorbed doses of 0, 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Gamma irradiation gradually decreased the number of the tested viable LAB, and the effect was irradiation dose dependent. A similar effect was found in electron beam-irradiated LAB. Radiation sensitivity of LAB was calculated as $D_{10}$ values, which ranged from 0.26 kGy to 0.9 kGy and 0.5 kGy to 1.44 kGy with exposure to gamma and electron beam irradiation, respectively, in all tested LAB. L. acidophilus was the most resistant to gamma and electron beam irradiation, with $D_{10}$ values of 0.9 kGy and 1.44 kGy, respectively. These results suggest that L. acidophilus might be suitable for the preparation of probiotics as direct-fed microbes for astronauts in extreme space environments.

Physiological Responses of Rice Seedlings to Butachlor (Butachlor에 대한 벼 유묘의 생리적 반응)

  • Tsai, Wen-Fu
    • Korean Journal of Weed Science
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    • v.15 no.4
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    • pp.247-253
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    • 1995
  • The herbicide butachlor [N-(butoxymethyl)-2-chloro-N-(2,6-di-methylphenyl) acetamide] is widely used by farmers as a tool for weed management of transplanted rice(Oryza sativa L.) in Taiwan. The herbicide did not stop germination of rice and weed seeds, but strongly inhibited the subsequent growth of young shoots and roots. The inhibition was also strong on established seedlings. However, they could recover to normal growth after the herbicide effect disappeared. Butachlor greatly decreased the endogenous indole-3-acetic acid (IAA) but increased the endogenous abscisic acid (ABA) contents of rice seedlings. Addition of lAA into growth medium (Hoagland's solution) partly relieved growth inhibition. Pretreatment of both gibberellic acid ($GA_3$) and IAA 24 hours before butachlor treatment almost completely alleviated the butachlor-interfere with GA and/or IAA metabolism or their action resulting in the growth inhibition of rice. Butachlor was readily absorbed by rice roots. During 24 hours of uptake experiment, 32% of the applied herbicide was absorbed. Pretreatment of the herbicide for 2 days did ncx affect the absorption. Of the absorbed herbicide, 80% remained in roots, only 20% transported into shoots, and more than 50% was metabolized to water soluble substances. Thin-layer chromatographic (TLC) analysis indicated that the Rf value of the most abundant metabolite was butachlor-glutathione conjugate. Rice, barnyardgrass (Echinochloa crus-galli (L.) Beauv.), and monochoria (Monochoria vaginalis Presl) seedlings contained relatively high level of non-protein thiols, while the glutathione S-transferase (GST) activity was found highest in rice, barnyardgrass the next, monochoria the lowest. The difference in GST activity among these species might be related to their sensitivity to butachlor.

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Physiological Characteristics and Immunomodulation Activity of Lactobacillus fermentum 450 isolated from Raw Milk (원유에서 분리한 Lactobacillus fermentum 450의 생리적 특성과 면역활성)

  • Han, Noori;Park, Sun-Young;Lim, Sang-Dong
    • Journal of Dairy Science and Biotechnology
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    • v.33 no.2
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    • pp.93-102
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    • 2015
  • The aim of this study was to investigate the physiological characteristics and immunomodulatory activity of Lactobacillus fermentum 450 isolated from raw milk. L. fermentum 450 showed optimum growth at $40^{\circ}C$ and exhibited immunomodulatory effects on $interleukin-1{\alpha}$, tumor necrosis $factor-{\alpha}$, and nitrous oxide at concentrations of >2,500 pg/mL, >2,000 pg/mL, and $11.55{\pm}2.95{\mu}M$, respectively. Of the 16 antibiotics tested, L. fermentum 450 exhibited the highest sensitivity to rifampicin, followed by penicillin-G, and the highest resistance to kanamycin, followed by neomycin and polymyxin B. The strain showed high acid phosphatase activity and was comparatively tolerant to bile juice and acid. Moreover, the strain displayed high resistance to Salmonella Typhimurium (63.86%). These results demonstrate that L. fermentum 450 has potential for use as a probiotic with immunomodulatory activity.

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Increased Abiotic Stress Tolerance by Over-expressing OsABF2 in Transgenic Arabidopsis thaliana (OsABF2를 과발현시킨 애기장대에서 비생물학적 스트레스에 대한 내성 증가)

  • Park, Phun Bum
    • Journal of Life Science
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    • v.22 no.11
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    • pp.1515-1522
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    • 2012
  • The phytohormone abscisic acid (ABA) plays an important role in the adaptive response of plants to abiotic stresses. ABA also regulates many important processes, including seed dormancy, germination, inhibition of cell division, and stomatal closure. OsABF2 (Oryza sativa ABRE binding factor2) is one of the bZIP type transcription factors, which are involved in abiotic stress response and ABA signaling in rice. Expression of OsABF2 is induced by ABA and various stress treatments. Findings show that survival rates of OsABF2 over-expressing Arabidopsis lines were increased under drought, salt, and heat stress conditions. The germination ratio of OsABF2 over-expressing Arabidopsis lines was decreased in the presence of ABA. Results indicate that OsABF2 over-expressing Arabidopsis lines have enhanced abiotic stress tolerance and have increased ABA sensitivity.

Serum Levels and Glycosylation Changes of Alpha-1-Acid Glycoprotein According to Severity of Breast Cancer in Korean Women

  • Choi, Jae Woong;Jeong, Ki-Ho;You, Ji Won;Lee, Jun Woo;Moon, Byung-In;Kim, Hyoung Jin;Kim, Hong-Jin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.9
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    • pp.1297-1304
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    • 2020
  • Elevated serum levels of alpha-1-acid glycoprotein (AGP) are known to be associated with several types of cancer. In addition, some reports have indicated that changes in glycosylation of AGP are associated with cancer progression. However, changes in AGP levels of serum and changes in glycosylation of AGPs in breast cancer have not been specifically studied. In the present study, serum AGP levels in benign (BN) cancer and breast cancer stage I (BC I), BC IIA, BC IIB, and BC III in Korean women were measured using an enzyme-linked immunosorbent assay (ELISA). AGP was purified from individual sera by hot phenol extraction and then subjected to AGP glycosylation analysis. Three types of AGP glycosylation (fucosylation, high-mannose-type and sialylation) were detected using enzyme-linked lectin assays (ELLAs). Serum AGP levels were higher in BC I, BC IIA, BC IIB, and BC III, than in the BN group, and the level in BC I and BC IIA was high enough to be distinguished from BN. Meanwhile, terminal fucosylation and high-mannose-type glycans appeared to be lowest in BC I. The glycosylation levels of BC I provide sensitivity and specificity that make BC I clearly distinguishable from BC IIA, BC IIB, and BC III as well as BN. Therefore, determination of serum AGP or AGP glycosylation level could be useful for detecting the early stages of breast cancer.

Direct Quantitation of Amino Acids in Human Serum Using a Stepwise-Dilution Strategy and a Mixed-Mode Liquid Chromatography-Tandem Mass Spectrometry Method

  • Lee, Jaeick;Lee, Seunghwa;Kim, Byungjoo;Lee, Joonhee;Kwon, Oh-Seung;Cha, Eunju
    • Mass Spectrometry Letters
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    • v.9 no.1
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    • pp.30-36
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    • 2018
  • A quantitation method for free amino acids in human serum was developed using a stepwise-dilution method and a bimodal cation exchange (CEX)/hydrophilic interaction liquid chromatography (HILIC)-tandem mass spectrometry system equipped with an electrospray ionization source (ESI/MS/MS). This method, which was validated using quality control samples, was optimized for enhanced selectivity and sensitivity. Dithiothreitol (DTT) was used as a reducing agent to prevent the oxidation of a serum sample ($50{\mu}L$), which was then subjected to stepwise dilution using 3, 30, and 90 volumes of acetonitrile containing 0.1% formic acid. Chromatographic separation was performed on an Imtakt Intrada Amino Acid column ($50mm{\times}3mm$, $3{\mu}m$) in mixed mode packed with CEX and HILIC ligands embedded in the stationary phase. Underivatized free amino acids were eluted and separated within 10 min. As a result of the validation, the precision and accuracy for the inter- and intraday assays were determined as 2.11-11.51% and 92.82-109.40%, respectively. The lowest limit of quantification (LLOQ) was $0.5-4.0{\mu}g/mL$ and the matrix effect was 80.22-115.93%. The proposed method was successfully applied to the quantitative analysis of free amino acids in human serum.

Physiological Characteristics and Anti-Diabetic Effect of Pediococcus pentosaceus KI62

  • Kim, Seulki;Hong, Sang-pil;Lim, Sang-Dong
    • Food Science of Animal Resources
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    • v.41 no.2
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    • pp.274-287
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    • 2021
  • The purpose of this study is to examine the physiological characteristics and anti-diabetic effects of Pediococcus pentosaceus KI62. The α-amylase and α-glucosidase inhibitory activity of P. pentosaceus KI62 was 94.86±3.30% and 98.59±0.52%, respectively. In MRS broth containing 3% maltodextrin inoculated by P. pentosaceus KI62, the amounts of short chain fatty acids (SCFA) were propionic acid 18.05±1.85 mg/kg, acetic acid 1.12±0.07 g/100 mL, and butyric acid 2.19±0.061 g/kg, and those of medium chain fatty acids (MCFA) were C8 0.262±0.031 mg/kg, C10 0.279±0.021 mg/kg, and C12 0.203±0.009 mg/kg. Compared to sixteen antibiotics, P. pentosaceus KI62 had the highest sensitivity to penicillin-G and rifampicin, as well as the highest resistance to vancomycin and ampicillin. The strain also showed higher leucine arylamidase and valine arylamidase activities than other enzyme activities, but it did not produce β-glucuronidase which is carcinogenic enzymes. The survival rate of P. pentosaceus KI62 in 0.3% bile was 91.67%. Moreover, the strain showed a 98.63% survival rate in pH 2.0. P. pentosaceus KI62 exhibits resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at rates of 29.41%, 38.10%, 51.72%, and 50.47%, respectively. P. pentosaceus (23.31%) showed a similar adhesion ability to L. rhamnosus GG, the positive control (24.49%). These results show that P. pentosaceus KI62 has possibility as a probiotic with anti-diabetic effects.

The Effect of Gd-EOB-DPTA on the Stiffness Value of Magnetic Resonance Elastography in Evaluating Hepatic Fibrosis (간 섬유화 평가를 위한 MR elastography의 경직도에 대한 Gd-EOB-DTPA의 영향)

  • Lee, Jeong Eun;Lee, Jeong Min;Lee, Ye Ji;Yoon, Jeong-Hee;Lee, Kyung Bun;Han, Joon Koo;Choi, Byung Ihn
    • Investigative Magnetic Resonance Imaging
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    • v.17 no.3
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    • pp.215-223
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    • 2013
  • Purpose : To evaluate the effect of gadoxetic acid on the measurement of the stiffness value of MR elastography (MRE) used to evaluate hepatic fibrosis (HF). Materials and Methods: MRE was obtained in 32 patients with clinically suspected chronic liver disease, both before and after injection of gadoxetic acid. Two independent reviewers measured the stiffness values of the liver parenchyma on elastograms. The mean liver stiffness values were compared in the pre- and post-contrast MREs using the paired t-test. Intra-rater and inter-rater correlation was assessed using the intraclass correlation coefficient (ICC). The accuracy, sensitivity, and specificity of both pre- and post-contrast MREs was evaluated for the diagnosis of significant HF (${\geq}F2$) using cut off value of 3.1 kPa. Results: There were no significant differences in the stiffness values of the liver parenchyma on pre- and post-contrast MREs (p = 0.15 and 0.38 for each reader, respectively). Regarding intra-rater correlation, excellent agreement was noted on rater 1(ICC = 0.998) and rater 2 (ICC = 0.996). Excellent correlation regarding the measured stiffness values was noted on both pre- and post-contrast MREs (ICC = 0.988 for pre-contrast, ICC = 0.993 for post-contrast). The accuracy, sensitivity, and specificity of the pre- and post-contrast MREs for differentiating significant HF (${\geq}F2$) from ${\geq}F1$ were same as 71%, 60%, and 100%, respectively. Conclusion: As there was no significant difference in the stiffness measurements seen on MREs before and after administration of gadoxetic acids, it is therefore acceptable to perform MRE after contrast injection in order to evaluate HF.

Studies on Inhibition Factors and the Role of Phytochrome in the Floral Induction in Short-day Plants (단일식물의 개화유도를 조절하는 개화억제요소의 규명과 Phytochrome의 역할에 관한 연구)

  • 맹주선
    • Journal of Plant Biology
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    • v.19 no.1
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    • pp.14-18
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    • 1976
  • Inhibition of flowering in Lemna perpusilla 6746 by 30 mM sucrose was reversed by the addition of acetylcholine (>$10^{-4}M) supplemented with 10^{-4}M$ ascorbic acid to 1/10-strength Hunter's growth medium. The reversible effect of acetylcholine was found to be greater at early stages of flowering than in the later period. Promotive effects of both acetylcholine ($10^{-3}M) and eserine(10^{-5}M$) on flowering in the short-day plant under various photoperiodic conditions were studied. It was indicated that the application decreased length of the critical dark period for the floral induction, and it was also shown that the endogenous status of acetylcholine was involved in the floral response which had a correlation with phytochrome. Interruption of inductive dark periods by red irradiation (1min) immediately followed by far-red light (1 min) completely inhibited flowering, while the addition of acetylcholine and eserine to the medium under the same condition slightly promoted flowering, indicating possible involvement of phytochrome system in acetylcholine activity for photoperiodic sensitivity of floral response in Lemna perpusilla 6746.

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Characterization of a paraquat resistance of Ochrobactrum anthropi JW-2. (Ochrobactrum anthropi JW-2의 paraquat 내성에 관한 특성)

  • 원성혜;이병현;조진기
    • Microbiology and Biotechnology Letters
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    • v.28 no.1
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    • pp.1-7
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    • 2000
  • The bacterial strain JW-2 which conferred resistance against paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was isolated from soil. The strain was identified as an Ochrobactrum anthropi based on its morphological, physiological, biological and fatty acid composition, and was designated as Ochrobactrum anthropi JW-2. We compard paraquat resistance of O. anthropi JW-2 with Escherichia coli J105. In the presence of 100mM paraquat, E. coli JM105 was not grown whereas the growth rate of O. anthropi was about 70% of control. We compared the sensitivity of O. anthropi JW-2 and E. coli J105 to redox-cycling compounds such as paraquat, plumbagin or menadione, which are known to exacebate wuperoxide generation. O. anthropi JW-2 did not show cross-resistance to plumbagin or menadione. superoxide dismutase activity was increased in paraqunt-treated E. coli JM105 while it was not increased in O.anthropi JW-2. These results suggest that the mechanism of paraquat resistance in O.anthropi JW-2 is probably due to selectively decreased permeability toward paraquat by membrane protein.

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