Isolation and identification of radiation-resistant cocci belonging to the genus Deinococcus from sewage sludges and animal feeds.

Ichikawa, Hitoshi; Watanabe, Hiroshi; Takehisa, Masaaki; H, Ito

doi:10.1271/bbb1961.47.1239

Cited by 43 publications

(20 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Synechocystis PCC6803 is also more resistant to gamma rays than Synechococcus PCC7942 and E. coli in that order (the doses yielding 10% survival are 660, 230, and 130 Gy, respectively (Domain et al, 2004). Other cyanobacteria are even more radioresistant, almost as the champion bacterium Deinococcus radiodurans [100% survival at 5kGy (Moseley and Mattingly, 1971; Ito et al, 1983)]. These radiation-resistant cyanobacteria are Chroococcidiopsis [10% survival to 4–5 kGy of gamma rays (Billi et al, 2000)], three Anabaena strains [they can grow at 5 kGy (Singh et al, 2010)] and Arthrospira PCC8005 [it grows at 800 Gy (Badri et al, 2015)].…”

Section: Resultsmentioning

confidence: 99%

Comparative Genomics of DNA Recombination and Repair in Cyanobacteria: Biotechnological Implications

2016

View full text Add to dashboard Cite

Cyanobacteria are fascinating photosynthetic prokaryotes that are regarded as the ancestors of the plant chloroplast; the purveyors of oxygen and biomass for the food chain; and promising cell factories for an environmentally friendly production of chemicals. In colonizing most waters and soils of our planet, cyanobacteria are inevitably challenged by environmental stresses that generate DNA damages. Furthermore, many strains engineered for biotechnological purposes can use DNA recombination to stop synthesizing the biotechnological product. Hence, it is important to study DNA recombination and repair in cyanobacteria for both basic and applied research. This review reports what is known in a few widely studied model cyanobacteria and what can be inferred by mining the sequenced genomes of morphologically and physiologically diverse strains. We show that cyanobacteria possess many E. coli-like DNA recombination and repair genes, and possibly other genes not yet identified. E. coli-homolog genes are unevenly distributed in cyanobacteria, in agreement with their wide genome diversity. Many genes are extremely well conserved in cyanobacteria (mutMS, radA, recA, recFO, recG, recN, ruvABC, ssb, and uvrABCD), even in small genomes, suggesting that they encode the core DNA repair process. In addition to these core genes, the marine Prochlorococcus and Synechococcus strains harbor recBCD (DNA recombination), umuCD (mutational DNA replication), as well as the key SOS genes lexA (regulation of the SOS system) and sulA (postponing of cell division until completion of DNA reparation). Hence, these strains could possess an E. coli-type SOS system. In contrast, several cyanobacteria endowed with larger genomes lack typical SOS genes. For examples, the two studied Gloeobacter strains lack alkB, lexA, and sulA; and Synechococcus PCC7942 has neither lexA nor recCD. Furthermore, the Synechocystis PCC6803 lexA product does not regulate DNA repair genes. Collectively, these findings indicate that not all cyanobacteria have an E. coli-type SOS system. Also interestingly, several cyanobacteria possess multiple copies of E. coli-like DNA repair genes, such as Acaryochloris marina MBIC11017 (2 alkB, 3 ogt, 7 recA, 3 recD, 2 ssb, 3 umuC, 4 umuD, and 8 xerC), Cyanothece ATCC51142 (2 lexA and 4 ruvC), and Nostoc PCC7120 (2 ssb and 3 xerC).

show abstract

Section: Resultsmentioning

confidence: 99%

Comparative Genomics of DNA Recombination and Repair in Cyanobacteria: Biotechnological Implications

2016

View full text Add to dashboard Cite

show abstract

“…Relative humidity within the desiccators was measured as less than 5% with a membrane hygrometer. Samples were revived by washing the cells free of the plate in 1 ml of 10 mM MgSO 4 and plating on TGY agar (7). Plates were placed in a 30ЊC incubator and scored for survivors 5 days later.…”

Section: Methodsmentioning

confidence: 99%

Radioresistance of Deinococcus radiodurans: functions necessary to survive ionizing radiation are also necessary to survive prolonged desiccation

1996

View full text Add to dashboard Cite

Forty-one ionizing radiation-sensitive strains of Deinococcus radiodurans were evaluated for their ability to survive 6 weeks of desiccation. All exhibited a substantial loss of viability upon rehydration compared with wild-type D. radiodurans. Examination of chromosomal DNA from desiccated cultures revealed a time-dependent increase in DNA damage, as measured by an increase in DNA double-strand breaks. The evidence presented suggests that D. radiodurans' ionizing radiation resistance is incidental, a consequence of this organism's adaptation to a common physiological stress, dehydration.The Deinococcaceae are a small family of non-spore-forming bacteria which exhibit a remarkable capacity to resist the lethal effects of ionizing radiation (10,11,18). Well-aerated, exponential-phase cultures of members of this family will survive 5,000 Gy of gamma radiation without loss of viability (14), and survivors are routinely recovered from cultures exposed to as much as 20 kGy (1, 7). Of the five species that make up the Deinococcaceae, Deinococcus radiodurans has been most extensively studied, and it has been determined that the radioresistance of this species is a direct result of its ability to efficiently repair the DNA damage generated during irradiation (10,11,18). In other words, the extreme radioresistance of D. radiodurans-and presumably the other deinococci-appears to be the result of an evolutionary process that selected for organisms that could tolerate massive DNA damage. The reasons for D. radiodurans' ionizing radiation resistance are obscure, however. The deinococci's radioresistance cannot be an adaptation (i.e., an evolutionary modification of a character under selection) to ionizing radiation, because there is no selective advantage to being ionizing radiation resistant in the natural world. There are no terrestrial environments that generate such a high flux of ionizing radiation (20). It must therefore be assumed that the deinococci's radioresistance is an incidental use of the cell's DNA repair capability. In this study, we ask why the DNA repair capabilities of D. radiodurans evolved, and we provide evidence suggesting that they were built by selection for desiccation resistance. MATERIALS AND METHODSBacterial strains and plasmids. The bacterial strains and plasmids used in this study are listed in Table 1. All D. radiodurans strains were grown at 30ЊC in TGY broth (0.5% tryptone, 0.3% yeast extract, 0.1% glucose) or on TGY agar (TGY broth with 1.5% agar).Quantifying desiccation resistance. Cells from an exponential-phase culture of each strain examined were collected by centrifugation, washed in 4 volumes of 10 mM MgSO 4 , and resuspended in an equal volume of 10 mM MgSO 4 . A 100-l aliquot of this suspension was spotted on a sterile glass coverslip, placed inside a sterile petri dish, and dried at 25ЊC in a desiccator over anhydrous CaSO 4 containing a visual indicator. The desiccators were sealed, and the dried cultures were stored undisturbed at 25ЊC for 6 weeks. Relative humidity within the de...

show abstract

“…The most striking characteristic of species of the genus is their extreme resistance to UV light, gamma radiation and desiccation. Deinococcus radiodurans, the type species of the genus, has been shown to survive exposure to doses of gamma radiation greater than 20 kGy (Daly et al, 2004;Ito et al, 1983;Anderson et al, 1956). However, around the time of writing, four psychrophilic, ionizing-radiation-sensitive Deinococcus species were described (Callegan et al, 2008).…”

mentioning

confidence: 99%

Deinococcus xinjiangensis sp. nov., isolated from desert soil

Peng¹,

Zhang²,

Luo³

et al. 2009

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLO

View full text Add to dashboard Cite

A Gram-positive-staining, spherical-shaped and faintly pink-pigmented bacterial strain, X-82 T , was isolated from soil samples collected from a desert in Xinjiang, China. The organism was found to be resistant to UV radiation but sensitive to gamma radiation and desiccation. The optimum growth pH, NaCl concentration and temperature were pH 7.0, 0-1 % NaCl and 30 6C. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain X-82 T is member of a novel species belonging to the genus Deinococcus, with Deinococcus hopiensis KR-140 T as its closest relative (93.5 % similarity). The DNA G+C content (60 mol%), quinone type (MK-8), major cellular fatty acids (16 : 1v7c, 16 : 0 and 17 : 1 iso v9c), the presence of peptidoglycan with L-ornithine and the dominant polar lipid (phosphoglycolipids and glycolipids) support the affiliation of strain X-82 T with the genus Deinococcus. A novel species is proposed, for which the name Deinococcus xinjiangensis sp. nov. is proposed, with the type strain X-82 T

show abstract

Isolation and identification of radiation-resistant cocci belonging to the genus Deinococcus from sewage sludges and animal feeds.

Cited by 43 publications

References 0 publications

Comparative Genomics of DNA Recombination and Repair in Cyanobacteria: Biotechnological Implications

Comparative Genomics of DNA Recombination and Repair in Cyanobacteria: Biotechnological Implications

Radioresistance of Deinococcus radiodurans: functions necessary to survive ionizing radiation are also necessary to survive prolonged desiccation

Deinococcus xinjiangensis sp. nov., isolated from desert soil

Contact Info

Product

Resources

About