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GROWTH AND HETEROCYST PRODUCTION IN ANABAENA CYLINDRICA LEMM.
Author(s) -
FOGG G. E.
Publication year - 1944
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1944.tb05012.x
Subject(s) - heterocyst , nitrogen fixation , botany , anabaena , blue green algae , algae , biology , nitrogen , chemistry , nitrogenase , cyanobacteria , bacteria , paleontology , organic chemistry
The isolation of A. cylindrica in pure culture and the culture methods used have been described in a previous paper (Fogg, I942). As before, each stock culture was tested for contaminants before being used as a source of inoculum for experimental cultures. In addition to the culture chamber of the type used by De (Fogg, I942), subsequently referred to as culture chamber A, an apparatus similar to that described by Stoughton (I930) has been used and is designated as culture chamber B. The temperature of the former fluctuated between 2i and c. 270 C. with a mean temperature of 22.50 C. (this value being obtained by integration of thermograph records), whereas the latter was maintained at a temperature of 23-0 + 0.30 C. Illumination in both chambers was for a period of 8 hr. daily. The light intensity in A, as determined by means of a Weston 'Lightometer' model E 703, varied from I20 to i6o foot-candles and that in B, from which daylight was excluded, was of the order of 800 foot-candles at a distance of 50 cm. from the lamp. To eliminate as far as possible the effects of any unequal illumination, the positions of the culture flasks within the chamber were changed at daily intervals.