GROWTH INTERACTIONS BETWEEN CHLAMYDOMONAS GLOBOSA SNOW AND CHLOROCOCCUM ELLIPSOIDEUM DEASON AND BOLD UNDER DIFFERENT EXPERIMENTAL CONDITIONS, WITH SPECIAL ATTENTION TO THE ROLE OF pH

The influence of Chlamydomonas globosa and Chlorococcum ellipsoideum on each other’s growth was studied with two different experimental techniques. The first is a newly developed filter culture method in which two separate cultures of different species are connected via a filtering system through which medium is exchanged while the cells themselves are kept separate. Under these circumstances Chlorococcum inhibits the growth of Chlamydomonas but not vice versa. In the second technique, traditional mixed cultures, Chlorococcum inhibits Chlamydomonas only in unbuffered medium. In medium buffered at p H 8.1 there is a slight stimulation of one or both species. The role of p II in the relation between the species seems therefore to be very important.