Utilization of light for nitrogen fixation by a new synechocystis strain is extended by its low photosynthetic efficiency.

Performance of photosynthesis and nitrogenase activity in a novel cyanobacterium, Synechocystis sp. strain BO 8402, isolated from Lake Constance, located at the northern fringe of the Alps in central Europe, and of a stable derivative, strain BO 9201, were examined. Strain BO 8402 is characterized by an extraordinarily high level of autofluorescence originating from paracrystalline phycobiliprotein-linker complexes located in inclusion bodies (W.

Structure, composition, and assembly of paracrystalline phycobiliproteins in Synechocystis sp. strain BO 8402 and of phycobilisomes in the derivative strain BO 9201.

The phycobiliproteins of the unicellular cyanobacterium Synechocystis sp. strain BO 8402 and its derivative strain BO 9201 are compared. The biliproteins of strain BO 8402 are organized in paracrystalline inclusion bodies showing an intense autofluorescence in vivo.

Core substructure of the hemiellipsoidal phycobilisome from the red alga Porphyridium cruentum.

The allophycocyanin core of hemiellipsoidal phycobilisomes from the red alga, Porphyridium cruentum, was isolated by chromatography on hydroxylapatite and subsequent density gradient centrifugation. Electron microscopy of negatively stained core complexes revealed a tricylindrical structure with a width of 21 to 23 nm in face view and a depth of 12 to 14 nm in side view. Fluorescence emission spectra of these complexes were similar to those of whole phycobilisomes confirming the presence of the two "terminal energy acceptors" allophycocyanin B (APB) and the high molecular linker polypeptide LCM.

Core substructure in phycobilisomes of red algae. II. The central part of the tricylindrical core--APCM--a constituent of hemidiscoidal phycobilisomes of Rhodella violacea.

The central part of the tricylindrical core of phycobilisomes from Rhodella violacea was isolated by hydroxylapatite adsorption chromatography followed by density gradient centrifugation. In the electron microscope negatively stained APCM complexes showed a tricylindrical face view with an edge length of 20 to 24 nm and a thickness of 9 to 10 nm in profile view. These complexes had a M(r) of 900,000, and a sedimentation coefficient 24S.

Isolation of allophycocyanin B from Rhodella violacea results in a model of the core from hemidiscoidal phycobilisomes of rhodophyceae.

Two 'trimeric' allophycocyanin complexes could be isolated from the hemidiscoidal phycobilisomes of Rhodella violacea. AP = (alpha *AP alpha 2AP beta 2AP beta *AP) and APB = (alpha *AP alpha AP alpha APB beta 2AP beta *AP). Lc13.