A role for osmotic stress-induced proteins in the osmotolerance of a nitrogen-fixing cyanobacterium, Anabaena sp. strain L-31

Iyer, V.; Fernandes, Tonina; Apte, Shree Kumar

doi:10.1128/jb.176.18.5868-5870.1994

Cited by 11 publications

(4 citation statements)

References 20 publications

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“…Measurement of growth and nitrogenase activity. Growth was usually measured in terms of chlorophyll a content as described by Mackinney (1941), or occasionally as turbidity (OD,,,) or total protein content (determined by the Lowry method). Nitrogenase activity was estimated in 2 ml culture aliquots by the standard acetylene reduction assay, as described earlier (Apte et al, 1987).…”

Section: Methodsmentioning

confidence: 99%

Pleiotropic effects of potassium deficiency in a heterocystous, nitrogen-fixing cyanobacterium, Anabaena torulosa

Alahari

Apte

1998

Microbiology

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Omission of potassium from the growth medium caused multiple metabolic impairments and resulted in cessation of growth of the filamentous, heterocystous, nitrogen-f ixing cyanobacterium Anabaena torulosa, during both diazotrophic and nitrogen-supplemented growth. Prominent defects observed during potassium deprivation were : (i) the loss of photosynthetic pigments, (ii) impairment of photosynthetic functions, (iii) reduced synthesis of dinitrogenase reductase (Fe-protein), (iv) inhibition of nitrogenase activity, and (v) specific qualitative modifications of protein synthesis leading to the repression of twelve polypeptides and synthesis and accumulation of nine novel polypeptides. The observed metabolic defects were reversible, and growth arrested under prolonged potassium deficiency was fully restored upon re-addition of potassium. Such pleiotropic effects of potassium deficiency demonstrate that apart from its well-known requirement for pH and turgor homeostasis, K+ plays other vital specific roles in cyanobacterial growth and metabolism.

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Section: Methodsmentioning

confidence: 99%

Pleiotropic effects of potassium deficiency in a heterocystous, nitrogen-fixing cyanobacterium, Anabaena torulosa

Alahari

Apte

1998

Microbiology

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“…Although environmental-stress-induced modifications of protein synthesis have been observed in bacteria such as Anabaena (Apte and Bhagwat 1989;Iyer et al 1994), Halomonas (Mojica et al 1997) and Listeria (Duché et al 2002), there are no reports on environmental-stress-induced proteins in Streptomyces. Therefore, exploiting the salt-tolerant bacteria will be a great enhancement in the conventional biotreatment and bioremediation systems.…”

Section: Introductionmentioning

confidence: 97%

Responses of a novel salt-tolerant Streptomyces albidoflavus DUT_AHX capable of degrading nitrobenzene to salinity stress

Lü

Guo

2008

Biodegradation

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A novel salt-tolerant strain DUT_AHX, which was capable of utilizing nitrobenzene (NB) as the sole carbon source, was isolated from NB-contaminated soil. Furthermore, it was identified as Streptomyces albidoflavus on the basis of physiological and biochemical tests and 16S ribosomal DNA (rDNA) sequence analysis. It can grow in the presence of NaCl up to 12% (w/v) or NB up to 900 mg/l in mineral salts basal (MSB) medium. The exogenously added osmoprotectants such as glycin, glutamic acid, proline, betaine and ectoine can improve growth of strain DUT_AHX in the presence of 10% (w/v) NaCl. NB-grown cells of strain DUT_AHX in modified MSB medium can degrade NB with the concomitant release of ammonia. Moreover, crude extracts of NB-grown strain DUT_AHX mainly contained 2-aminophenol 1,6-dioxygenase activity. These indicate that NB degradation by strain DUT_AHX might involve a partial reductive pathway. The proteins induced by salinity stress or NB were analyzed by native-gradient polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE. In NB-induced proteins de novo, 141 kDa protein on the native-gradient PAGE gel was excised and electroeluted. Furthermore, enzyme tests exhibit the 2-aminophenol 1,6-dioxygenase activity of purified 141 kDa protein is 11-fold that of the cell-free extracts. The exploitation of strain DUT_AHX in salinity stress will be a remarkable improvement in NB bioremediation and wastewater treatment in high salinity.

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“…At high concentrations, inorganic ions are toxic for the cell and destabilize cell metabolism [6]. During adaptation to salt stress, cells accumulate osmoprotectors and release excessive inorganic ions [4,[7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Genetic Control and Mechanisms of Salt and Hyperosmotic Stress Resistance in Cyanobacteria

Karandashova

Elanskaya

2005

Russ J Genet

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Exposure to high concentrations of environmental NaCl exerts two stress effects on living cells, increasing the osmotic pressure and the concentration of inorganic ions. Salt stress dramatically suppresses the photosynthetic activity in cells of phototrophic organisms, such as cyanobacteria. During salt adaptation, cyanobacterial cells accumulate osmoprotectors, export excessive Na + with the help of Na + /H + antiporters, and actively absorb K + with the help of K + -transporting systems. These physiological processes are accompanied by induction or suppression of several genes involved in salt adaptation. The review considers the main mechanisms responsible for the resistance of cyanobacterial cells to salt and hyperosmotic stresses. Special emphasis is placed on recent achievements in studying the genetic control of salt resistance and regulation of gene expression during adaptation of cyanobacteria to salt and hyperosmotic stresses.

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A role for osmotic stress-induced proteins in the osmotolerance of a nitrogen-fixing cyanobacterium, Anabaena sp. strain L-31

Cited by 11 publications

References 20 publications

Pleiotropic effects of potassium deficiency in a heterocystous, nitrogen-fixing cyanobacterium, Anabaena torulosa

Pleiotropic effects of potassium deficiency in a heterocystous, nitrogen-fixing cyanobacterium, Anabaena torulosa

Responses of a novel salt-tolerant Streptomyces albidoflavus DUT_AHX capable of degrading nitrobenzene to salinity stress

Genetic Control and Mechanisms of Salt and Hyperosmotic Stress Resistance in Cyanobacteria

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