Observations on the Relationship between the Formation of Photopigments and the Synthesis of Protein in Rhodopseudomonas spheroides

Sistrom, W. R.

doi:10.1099/00221287-28-4-599

Cited by 52 publications

(17 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Paracoccus denitrificans was raised in liquid medium from frozen stock at 20°C under aerobic conditions. Culturing of cells was always performed in 120 ml serum vials containing a triangular magnetic stirring bar and 50 ml of modified Sistrom's medium (Sistrom, 1960; 1962), where Co(NO 3 ) 2 had been replaced by CoCl 2 , and with 5 mM succinic acid. To avoid aggregation and heterogeneous conditions, all cultures were continuously stirred at 700 rpm to ensure complete dispersal, thus optimizing the conditions for measuring as precisely as possible the actual gas concentrations experienced by the individual cells.…”

Section: Methodsmentioning

confidence: 99%

Transcriptional and metabolic regulation of denitrification in Paracoccus denitrificans allows low but significant activity of nitrous oxide reductase under oxic conditions

Bakken

Molstad

et al. 2016

Environmental Microbiology

View full text Add to dashboard Cite

Oxygen is known to repress denitrification at the transcriptional and metabolic levels. It has been a common notion that nitrous oxide reductase (N2 OR) is the most sensitive enzyme among the four N-oxide reductases involved in denitrification, potentially leading to increased N2 O production under suboxic or fluctuating oxygen conditions. We present detailed gas kinetics and transcription patterns from batch culture experiments with Paracoccus denitrificans, allowing in vivo estimation of e(-) -flow to O2 and N2 O under various O2 regimes. Transcription of nosZ took place concomitantly with that of narG under suboxic conditions, whereas transcription of nirS and norB was inhibited until O2 levels approached 0 μM in the liquid. Catalytically functional N2 OR was synthesized and active in aerobically raised cells transferred to vials with 7 vol% O2 in headspace, but N2 O reduction rates were 10 times higher when anaerobic pre-cultures were subjected to the same conditions. Upon oxygen exposure, there was an incomplete and transient inactivation of N2 OR that could be ascribed to its lower ability to compete for electrons compared with terminal oxidases. The demonstrated reduction of N2 O at high O2 partial pressure and low N2 O concentrations by a bacterium not known as a typical aerobic denitrifier may provide one clue to the understanding of why some soils appear to act as sinks rather than sources for atmospheric N2 O.

show abstract

Section: Methodsmentioning

confidence: 99%

Transcriptional and metabolic regulation of denitrification in Paracoccus denitrificans allows low but significant activity of nitrous oxide reductase under oxic conditions

Bakken

Molstad

et al. 2016

Environmental Microbiology

View full text Add to dashboard Cite

show abstract

“…Protein was measured by the method of Lowry et al (27) with crystalline bovine serum albumin used as a standard. All samples were maintained at 40 C for 60 min in 0.5 N NaOH prior to the color reaction (48). Bacteriochlorophyll a content was calculated from the absorbance at 770 nm of acetone-methanol (7:2, vol/vol) extracts (9) with the extinction coefficient of Clayton (6).…”

Section: Methodsmentioning

confidence: 99%

Membranes of Rhodospirillum rubrum: isolation and physicochemical properties of membranes from aerobically grown cells

Collins¹,

Niederman²

1976

J Bacteriol

View full text Add to dashboard Cite

Highly purified preparations of cytoplasmic and outer membrane were isolated from aerobically grown Rhodospirillum rubrum lysed by sequential treatment with lysozyme, ethylenediaminetetraacetate, and Brij 58. The membranes were resolved and separated from other cellular constituents by a combination of velocity and isopyknic sedimentation in sucrose density gradients. On the basis of their appearance in electron micrographs and their protein profiles in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, these preparations appear to be quite similar to those obtained from other gram-negative bacteria. The cytoplasmic membrane fraction contained the majority of the total membranebound succinic dehydrogenase activity and was 10-fold enriched in b-and c-type cytochromes with respect to the outer membrane. The latter fraction was characterized by a much greater carbohydrate content and the presence of arachidic acid, which is typical ofR. rubrum lipopolysaccharide. Their protein, fatty acid, and overall chemical compositions suggested that these preparations were freer from cross-contamination than those obtained from R. rubrum with currently available methods.

show abstract

“…The extent of pigment formation is inversely proportional to light intensity or to the 0, tension under semi-aerobic conditions. Formation of bacteriochlorophyll is strictly dependent upon protein synthesis (Sistrom, 1963; Bull & Lascelles, 1963). This is in part explained by the fact that certain enzymic activities associated with bacteriochlorophyll formation increase in parallel with the ability to form photopigments (Lascelles, 1959; Gibson, Neuberger & Tait, 1963).…”

Section: Introductionmentioning

confidence: 99%

RNA Metabolism of Rhodopseudomonas spheroides during Preferential Photopigment Synthesis

Lessie¹

1965

Journal of General Microbiology

View full text Add to dashboard Cite

SUMMARYDuring anaerobic growth of Rhodopseudornonas spheroides the specific RNA content (pg. RNA/,ug. protein) of cultures was directly proportional to the light intensity in which they were grown. Cultures subjected to a step-up in light intensity preferentially synthesized RNA until their specific RNA content increased to the value characteristic of growth at the higher light intensity. Conversely following a step-down in light intensity the rate of RNA synthesis fell below the rate of protein synthesis, and cellular RNA was diluted out to the value characteristic of growth at the lower light intensity. Adjustment of the differential rate of RNA synthesis in response to a change in light intensity was thus opposite to that of the differential rate of photopigment synthesis. Although a decrease in light intensity drastically decreased RNA synthesis some RNA continued to be formed. The RNA synthesized, like that in cultures maintained at a constant light intensity, consisted of soluble and ribosomal RNA and unstable RNA with sedimentation behaviour like m-RNA. Aerobic cultures of R. spheroides subjected to a marked decrease in 0, tension synthesized photopigments de novo without appreciably increasing their net content of RNA, but continued to synthesize small amounts of all the usual classes of RNA.

show abstract

Observations on the Relationship between the Formation of Photopigments and the Synthesis of Protein in Rhodopseudomonas spheroides

Abstract: SUMMARYCells of Rhodopseudomonas spheroides cannot increase their specific photopigment content in the absence of protein synthesis. The significance of this finding for an understanding of the structure of the photosynthetic apparatus in bacteria is discussed.

Cited by 52 publications

References 6 publications

Transcriptional and metabolic regulation of denitrification in Paracoccus denitrificans allows low but significant activity of nitrous oxide reductase under oxic conditions

Transcriptional and metabolic regulation of denitrification in Paracoccus denitrificans allows low but significant activity of nitrous oxide reductase under oxic conditions

Membranes of Rhodospirillum rubrum: isolation and physicochemical properties of membranes from aerobically grown cells

RNA Metabolism of Rhodopseudomonas spheroides during Preferential Photopigment Synthesis

Contact Info

Product

Resources

About