scholarly journals Radiation sensitivity of Acinetobacter spp. and their radicidation for preservation of meat at low temperature

2009 ◽  
Vol 35 (2) ◽  
pp. 33-40 ◽  
Author(s):  
Sahadev Chandra Saha ◽  
Balu Anand Chopade

Acinetobacter spp. isolated from meat to gamma radiations. Seven species of Acinetobacter viz. A. lwoffii M1; A. baumannii M8; A. calcoaceticus M19; A. junii M20; A. johnsonnii M23; A. haemolyticus M27 and A. radioresistens M25 isolated from meat were exposed to gamma radiation at the dose level of 0.1 to 10 KGy. The D10 value of Acinetobacter was found highest 1.25 KGy in A. radioresistens M25, which was 4 to 8 times higher than other genospecies of Acinetobacter. Acinetobacter radioresistens M25 contains one plasmid of 45 Kb. The radicidation dose of 4 KGy gamma radiations was found to be sufficient to eliminate the natural contamination of meat and contamination by Acinetobacter. To eliminate radiation resistant Acinetobacter contamination a dose of 4 to 5 KGy was required. Development of the radicidation process for preservation of meat to eliminate Acinetobacter as contaminants at low temperature is one of the new and interesting phenomena. Attempts of finding the appropriate radicidation dose for preservation of meat at low temperature will open up new avenues for commercial preservation of meat.DOI: http://dx.doi.org/10.3329/bmrcb.v35i2.2490Online: 11 August 2009Bangladesh Med Res Counc Bull 2009; 35: 33-40

1972 ◽  
Vol 104 (10) ◽  
pp. 1551-1556 ◽  
Author(s):  
John H. Brower ◽  
Hilda C. Scott

AbstractThe effects of seven gamma radiation dosages from 5 to 100 krad on all metamorphic stages of the spider beetle, Gibbium psylloides (Czenpinski), were studied. Five kilorads prevented development of adults from treated eggs and larvae. Some adults emerged from the pupal cocoon at all treatment levels except 50 and 100 krad, but their longevity was greatly reduced. Adults were fairly resistant to sterilizing effects of the radiation. Twenty kilokrads was not completely sterilizing to either males or females, but fecundity was greatly reduced. The longevity of treated adults was significantly reduced, but some survived for 20 weeks after a 20-krad exposure. Adults and pupae of this species were more radiation resistant than were most other stored-product Coleoptera.


1989 ◽  
Vol 52 (9) ◽  
pp. 610-613 ◽  
Author(s):  
C. N. HUHTANEN ◽  
R. K. JENKINS ◽  
D. W. THAYER

Seven strains of Listeria monocytogenes were irradiated in culture media or in mechanically deboned chicken meat. The survivor plots were quadratic curves when cultures were in the log phase of growth or when they were irradiated in chicken meat; cultures in the senescent phase of growth showed linear responses to irradiation. Cultures from cells surviving an irradiation dose of 1.5 kGy were no more radiation resistant that those which had had no previous exposure to irradiation. Cultures centrifuged and resuspended in water were more sensitive to radiation than those resuspended in solutions containing organic materials. These studies indicated that a dose of 2 kGy was sufficient to destroy 1 × 104 cells of L. monocytogenes.


2014 ◽  
Vol 64 (2) ◽  
pp. 163-164
Author(s):  
Pinaki Chaudhuri ◽  
Rupak K. Sengupta ◽  
Partha D. Ghosh

Gamma-radiation sensitivity was studied on <i>in vitro</i> condition in <i>Hordeum vulgare</i> L. The variation of callusing response assessed with the increasing level of gamma-radiation treatment and regeneration delayed at higher dose level.


2021 ◽  
pp. 002199832110293
Author(s):  
Armando Cirilo de Souza ◽  
Flavio Aristone ◽  
Adriana Fatima Gomes Gouvea ◽  
Hedielly Brasil Fernandes ◽  
Adailto Miyai ◽  
...  

This research has been carried on to analyze the capability of a new composite to be effectively used as shielding of gamma radiation. The preparation of a metal-organic composite formed by tungsten and Kraft lignin is presented. Samples have been characterized through X-rays and scanning electron microscopy measurements. The results led to the study of the different phase formations. The microscopic analyzes indicate that two different phases are present in the composite. The absence of oxidation in the process even after the temperature treatment imposed to form the sample has also been noticed. Measurements of the attenuation have been performed to study its ability to absorb gamma radiation. A sample of cobalt 60 (Co-60), for which the peak energies are at 1173 keV and 1332 keV, was used as a source of gamma radiation in the experiment of attenuation. The measured attenuation of gamma radiations when the composite is placed to act as a shield is only 16% smaller than the attenuation obtained for standard pure tungsten. This is a clear indication that the new metal-organic composite is suitable for the fabrication of devices dedicated to shielding radiation, with the advantage of being easier to manipulate.


2021 ◽  
Vol 1024 ◽  
pp. 127-133
Author(s):  
Matteo Ferrari ◽  
Aldo Zenoni ◽  
Yong Joong Lee ◽  
Alberto Andrighetto

Lubricants and O-rings are necessarily used for the construction of many accelerator-driven facilities as spallation sources or facilities for the production of radioactive isotopes. During operation, such component will absorb high doses of mixed neutron and gamma radiation, that can degrade their mechanical and structural properties. Experimental radiation damage tests of these components are mandatory for the construction of the facility. Methodologies for irradiation in nuclear reactor mixed fields and post-irradiation examination of lubricating oils, greases and O-rings were developed and are here presented. Samples were characterized with standard mechanical and physical-chemical tests. Parametric studies on the dose rate effects have been performed on O-rings. A case studies for a specific O-ring application in a gate valve has been developed. Some of the tested samples showed a dramatic change of their properties with dose, while others remain stable. Results were collected on nine commercial greases, on one oil and on four commercial elastomeric O-rings. The most radiation resistant among the selected products are now considered for application in facilities under construction. The main mechanisms of neutron and gamma radiation damage on these polymers were investigated at the mechanical and structural level.


2003 ◽  
Vol 66 (11) ◽  
pp. 2093-2096 ◽  
Author(s):  
S. P. CHAWLA ◽  
D. H. KIM ◽  
C. JO ◽  
J. W. LEE ◽  
H. P. SONG ◽  
...  

Kwamegi (semidried raw Pacific saury) is traditional seafood available in Korea. It has water activity in the range of 0.90 to 0.95. Spoilage and the growth of most pathogenic bacteria is retarded because of low water activity, low temperature, and packaging. However, it is contaminated with bacteria of public health significance and poses a hazard to the consumer because it is consumed raw without any cooking. The effectiveness of these hurdles in preventing the growth of Staphylococcus aureus, Bacillus cereus, Salmonella Typhimurium, and Escherichia coli and the efficacy of irradiation treatment in eliminating these bacteria from kwamegi using inoculated pack studies was examined. Radiation sensitivity of S. aureus, B. cereus, Salmonella Typhimurium, and E. coli in kwamegi was investigated. D10-values of these organisms in kwamegi were 590 ± 13.6, 640 ± 14.9, 560 ± 45.4, and 550 ± 8.6 Gy, respectively. The growth of all four test organisms inoculated into these foods during 4 weeks of storage at an ambient winter temperature (ranging from −5°C to +5°C) was recorded. All four pathogens (inoculated at 106 CFU/g) were eliminated by irradiation at 4 kGy. These studies unequivocally demonstrate that irradiation, with a combination of low water activity and low temperature, results in microbiologically safe kwamegi.


2017 ◽  
Vol 42 (6) ◽  
pp. 2220-2229 ◽  
Author(s):  
Li-Peng Jiang ◽  
Zhi-Tu Zhu ◽  
Yue Zhang ◽  
Chun-Yan He

Background: The present study sought to explore the role of microRNA-330 (miR-330) in predicting the radiation response and prognosis of patients with brain metastasis (BM) from lung cancer (LC). Methods: Patients with BM from LC were identified and classified into radiation-sensitive and radiation-resistant groups according to the overall survival rate, local and distant recurrence rate after conventional whole-brain radiation therapy. Quantitative realtime polymerase chain reaction (qRT-PCR) was used to detect miR-330 expression in serum. Receiver operating characteristic (ROC) curves were used to evaluate the prognostic value of miR-330 for the radiation sensitivity of brain metastasis from LC. Related clinical factors for radiation sensitivity were assessed by logistic regression analysis, and a survival analysis was conducted using COX regression and the Kaplan-Meier method. Results: MiR-330 exhibited lower expression in the radiation-sensitive group than in the radiation-resistant group. The area under the ROC curve of miR-330 for predicting radiation sensitivity was 0.898 (optimal cut-off value, 0.815), with a sensitivity of 71.7% and a specificity of 90.1%. After radiation therapy, patients with low miR-330 expression, compared to patients with high miR-330 expression, displayed a lower survival rate and a median survival time. MiR-330 expression was correlated with extracranial metastasis, maximum BM diameter, tumor-node-metastasis (TNM) stage and node (N) stage. Logistic regression and COX regression analyses revealed that extracranial metastasis, TNM stage, N stage and miR-330 expression were factors that influenced both radiation sensitivity and individual prognostic factors in patients with BM from LC. Conclusions: These findings indicate that the downregulation of miR-330 correlates with radiation sensitivity and poor prognosis in patients with BM from LC.


2013 ◽  
Vol 51 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Jae-Jin Lee ◽  
Hyun Ji Lee ◽  
Gi Seon Jang ◽  
Ja Myoung Yu ◽  
Ji Yoon Cha ◽  
...  

2021 ◽  
Author(s):  
Ji Hee Lee ◽  
Jong-Hyun Jung ◽  
Min-Kyu Kim ◽  
Han Na Choe ◽  
Sangyong Lim

Abstract An aerobic, Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, and light pink-colored bacterial strain, designated TS19T, was isolated from a sand sample obtained from a coastal sand dune after exposure to 3 kGy of gamma radiation. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the isolate was a member of the genus Hymenobacter and was most closely related to H. wooponensis WM78T (98.3% similarity). Strain TS19T and H. wooponensis showed resistance to gamma radiation with D10 values (i.e., the dose required to reduce the bacterial population by tenfold) of 7.3 kGy and 3.5 kGy, respectively. The genome of strain TS19T consists of one contig with 4,879,662 bp and has a G+C content of 56.2%. The genome contains 3,955 protein coding sequences, 44 tRNAs, and 12 rRNAs. The predominant fatty acids of strain TS19T were iso-C15:0, summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B), summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), and C16:1 ω5c. The major polar lipids were phosphatidylethanolamine, and one unknown aminophospholipid. The main respiratory quinone was menaquinone-7. Based on the phylogenetic, physiological, and chemotaxonomic characteristics, strain TS19T represents a novel species, for which the name Hymenobacter taeanensis sp. nov. is proposed. The type strain is TS19T (=KCTC 72897T =JCM 34023T).


Sign in / Sign up

Export Citation Format

Share Document