Manganese and iron encrustations and other features ofPlanctomyces crassus Hortobágyi 1965, morphotype Ib of theBlastocaulis-Planctomyces group of budding and appendaged bacteria,examined by electron microscopy and X-ray micro-analysis

Water samples collected in August, 1980, from a pond in Budapest, Hungary, have permitted transmission and scanning electron microscopic observations to be made ofPlanctomyces crassus Hortobágyi 1965, which—to remain taxonomically noncommittal—we designated as morphotype Ib of theBlastocaulis-Planctomyces group of appendaged and budding bacteria. The detailed cell morphology of morphotype Ib (cellular shape, size and distribution pattern of crateriform structures, pili, spires) was similar to that of morphotype Ia,Planctomyces bekefii Gimesi 1924. The major appendage—a seemingly tubular, multifibrillar stalk—differed somewhat from the stalk of morphotype Ia, in that the morphotype Ib stalk was generally shorter than the morphotype Ia stalk, was tapered (the morphotype Ia stalk was uniformly cylindrical), and apparently lacked the organizing matrix of the morphotype Ia stalk. Energy-dispersive X-ray spectroscopy of the metallic-oxide encrustations of morphotype Ib rosettes revealed manganese and iron to be the predominant elements present. Moreover, localized differences were found in the relative amounts of the two elements deposited in different rosettes and at different loci on the same rosette.