REJUVENATION OF MELOSIRA GRANULATA (BACILLARIOPHYCEAE) RESTING CELLS FROM THE ANOXIC SEDIMENTS OF DOUGLAS LAKE, MICHIGAN. I. LIGHT MIGROSCOPY AND 14C UPTAKE 1

摘要: Resting cells of Melosira granulate (Ehr.) Ralfs were collected from the anoxic sediments Douglas Lake, Michigan. Sediment containing M. granulata was inoculated into distilled water and incubated in a growth chamber for one week during which observations made on cytological differentiation process. Cells classified as “condensed,” i.e. dark brown cytoplasmic mass identified resting cells. The process consisted series gradual changes that included elongation recognition definable organelles to point where non-distinguishable column vegetative Differentiating accumulated large polyphosphate lipid granules. However, these granules disappeared just prior cell division. complete or rejuvenation sequence occurred some less than 24 h. not all dormant rejuvenated at same time it observed lag period increased with age (depth burial sediments). In 14C uptake studies, label initially condensed state gradually progressed more differentiated forms. Total carbon lower rejuvenating cells, but roughly equal populations after 8 h, indicating high metabolic activity between 1