| Summary: | 碩士 === 東海大學 === 生物學研究所 === 82 === Skeletonema costatum(Greville)Cleve grows rapidly to reache al
cultures.Soon after reaching its peak,it declines withoutonary
phase.To maintain its exponential phase, it is necessary
touently for the purpose of the preservation of stock culture.
Experimentst to reduce their metabolic activites and induce the
formation ofy various combinations of light,temperature
nutrients,anaerobic conditions.At 15℃in the dark for 18 days,
the Skeletonema cellscytoplasmic contents and their shapes
appeared similar to thosecells.After 33 days,they were still
viable and could rejuveate in ditions.These cellscould
extendtheir exponential phase for morewhen they were
illuminated with 32uEm-2S-1 of intensity on aight and 22.5h
dark.Different wavelengths of light did not inducef resting
cells in S.costatum,but influencedtheir growth rates.Therogen
and phosphrous did not induce the formation of restingeir
vegetative cells shrivelled up when grown in a nitrogenm.They
turnedpaleand lost their chloropasts in the
phosporousdeficientdays after being kept in these conditions,
most of them wereed by bacteria of dead.In an oxygen-depleted
medium,thelsshowed no di- fference from those which were grown
in the oxygen-sufficientThey lost their rejuvenescence even
after the medium wash oxygen.In the desiccation experiment
using differenteSkeleto-nema cells couldnot rejuvenated after
being returned to their standardons.
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