Energy Citations Database

Bibliographic Citation

 
Document
For copies of Journal Articles, please contact the Publisher or your local public or university library and refer to the information in the Resource Relation field.
For copies of other documents, please see the Availability, Publisher, Research Organization, Resource Relation and/or Author (affiliation information) fields and/or Document Availability.
Title Influence of pH, O/sub 2/, and temperature on the absorption properties of the secondary light-harvesting antenna in members of the family Rhodospirillaceae
Creator/Author Uffen, R.L.
Publication Date1985 Sep 01
OSTI IdentifierOSTI ID: 6378374
Other Number(s)CODEN: JOBAA
Resource TypeJournal Article
Resource RelationJ. Bacteriol. ; Vol/Issue: 163:3
Research OrgMichigan State Univ., East Lansing
Subject550700 -- Microbiology ;550200 -- Biochemistry; OXYGEN-- RESPONSE MODIFYING FACTORS;PH VALUE-- RESPONSE MODIFYING FACTORS;RHODOPSEUDOMONAS-- PHOTOSYNTHESIS;TEMPERATURE EFFECTS-- RESPONSE MODIFYING FACTORS; ANAEROBIC CONDITIONS;CHLOROPHYLL;INFRARED SPECTRA;PHOTOCHEMICAL REACTIONS;PHOTOSYNTHETIC MEMBRANES;PHOTOSYNTHETIC REACTION CENTERS;RHODOSPIRILLUM;SORPTIVE PROPERTIES
Related SubjectBACTERIA;CARBOXYLIC ACIDS;CHEMICAL REACTIONS;ELEMENTS;HETEROCYCLIC ACIDS;HETEROCYCLIC COMPOUNDS;MEMBRANES;MICROORGANISMS;NONMETALS;ORGANIC ACIDS;ORGANIC COMPOUNDS;ORGANIC NITROGEN COMPOUNDS;PHOTOCHEMICAL REACTIONS;PHYTOCHROMES;PIGMENTS;PORPHYRINS;SPECTRA;SURFACE PROPERTIES;SYNTHESIS
Description/Abstract Results show that holochrome B800-860 (LH II) exhibits unstable light absorption properties in whole cells.^This was observed in Rhodopseudomonas capsulata grown anaerobically in light in weakly buffered carbohydrate medium.^The whole cell spectrophotometric changes were attributed to mild acid conditions generated during sugar metabolism.^LH II absorbency was also destroyed in both R. capsulata and Rhodopseudomonas gelatinosa when cultures growing at neutral pH were acidified to a pH value around 5.0.^In contrast, during the same time period of exposure to pH 5.0, only a 50% decrease in Rhodopseudomonas sphaeroides LH II B800 absorbency was measured.^At neutral pH, LH II absorbency in suspensions of nongrowing Rhodopseudomonas spp. was also sensitive to O/sub 2/ exposure and to incubation at 30 to 40/sup 0/C.^During treatment with O/sub 2/, the rate of LH II B800 absorption decrease in R. gelatinosa and R. sphaeroides was 60 and 40% per h, respectively, compared with their absorbency maximum around 860 nm.^Both 860-nm absorbency and the total bacteriochlorophyll content of the cells remained unchanged.^On the other hand, no significant decrease in B800 of LH II in R. capsulata occurred during O/sub 2/ exposure, but a 20% absorption decay rate per h of B800 was observed in cells incubated anaerobically at 40/sup 0/C.^The near-infrared absorption spectrum of Rhodospirillum rubrum, which does not form LH II, was not significantly influenced by these different pH, aerobic, or temperature conditions.
Country of PublicationUnited States
LanguageEnglish
FormatPages: 943-950
System Entry Date2001 May 13

Top