Resistance ofSpirulina platensisto Ammonia at High pH Values

摘要

Spirulina platensisis an alkalophilic cyanobacterium, exhibiting optimal growth at pH 9.0 to 10.0. It grows well at pH 11.5 but not at pH 7.0. Unlike many other photosynthetic microorganisms, it is capable of utilizing ammonia3even at high pH values, and is resistant to the ammonia-mediated uncoupling of photosynthesis. The entry of ammonia into the cells isΔpH-dependent, and is limited by a relatively high average internal pH. This high pH value appears to be maintained predominantly by a high intrathylakoid pH