TY - JOUR

T1 - Characterization of a novel chlorophyll b-containing Prochlorothrix species (Prochlorophyta) and its photosynthetic apparatus

AU - Pinevich, A.V.

AU - Sculberg, O.M.

AU - Matthijs, H.C.P.

AU - Schubert, H.

AU - Willen, E.

AU - Gavrilova, O.

AU - Velichko, N.V.

PY - 1999

Y1 - 1999

N2 - A filamentous nondifferentiated, unbranched bacterium designated strain NIVA-8/90 originating from Lake Malaren, Central Sweden, contained both Chl a and Chl b and was classified as Prochlorothrix sp. The ultrastructural similarity with Prochlorothrix hollandica was evident from (1) the honeycomb-like subterminal aggregates of gas vesicles; (2) the Bayer-type junctions between the cytoplasmic membrane and the outer membrane of the cell envelope; and (3) the thylakoid centre-type orientation of intracytoplasmic lamellae. Among the ultrastructural aspects hitherto not reported in prochlorophytes were (4) 10 nm virodosomes localized with 20 nm periodicity on the outer surface of the thylakoids (the identity of those structures with mini-phycobilisomes was disproved by the absence of detectable phycobiliproteins; and (5) RuBisCO-immunopositive inclusions located in proxomity to the thylakoids (the apparent absence of a membrane shell makes them analogous to pyrenoids). Despite close similarity of molecular details (Chl a:Chl b and PS1:PS2 ratios; the set of carotenoids; the uncommon position of the long wavelength maximum of total Chl), and in accordance with the above microscopic distinctions, this novel prochlorophyte can be distinguished from P. hollandica under the provisional name Prochlorothrix scandica.

AB - A filamentous nondifferentiated, unbranched bacterium designated strain NIVA-8/90 originating from Lake Malaren, Central Sweden, contained both Chl a and Chl b and was classified as Prochlorothrix sp. The ultrastructural similarity with Prochlorothrix hollandica was evident from (1) the honeycomb-like subterminal aggregates of gas vesicles; (2) the Bayer-type junctions between the cytoplasmic membrane and the outer membrane of the cell envelope; and (3) the thylakoid centre-type orientation of intracytoplasmic lamellae. Among the ultrastructural aspects hitherto not reported in prochlorophytes were (4) 10 nm virodosomes localized with 20 nm periodicity on the outer surface of the thylakoids (the identity of those structures with mini-phycobilisomes was disproved by the absence of detectable phycobiliproteins; and (5) RuBisCO-immunopositive inclusions located in proxomity to the thylakoids (the apparent absence of a membrane shell makes them analogous to pyrenoids). Despite close similarity of molecular details (Chl a:Chl b and PS1:PS2 ratios; the set of carotenoids; the uncommon position of the long wavelength maximum of total Chl), and in accordance with the above microscopic distinctions, this novel prochlorophyte can be distinguished from P. hollandica under the provisional name Prochlorothrix scandica.

M3 - Article

VL - 100

SP - 159

EP - 174

JO - Microbios

JF - Microbios

SN - 0026-2633

ER -