An investigation of techniques in isolation and culture of the algal flora of soils

1- The literature concerning the taxonomy and ecology of soil algae was reviewed extensively. The lack of established, controlled cultural conditions, and the lack of facile isolation techniques in the literature was pointed out.

2- An incubator featuring a controlled environment of 2-40 foot candles of continuous, white, fluorescent light and 25-30 °C was constructed and described.

3- Three composite soil samples were collected and inoculated into cultures of varying chemical and physical characteristics. The primary enrichment cultures thus established were incubated in the incubator at approximately 15 foot candles of light and at 25-30 °C.

4- The mixed algal flora produced in the primary enrichment cultures were separated into unialgal cultures by a technique combining mechanical maceration with bacteriological pour plating. Eighty such unialgal cultures were established. The equipment and the technique were described.

5- Three experiments utilizing small groups of organisms were set up to investigate the general effect of light intensity and agarized media upon algal growth. The results indicated that algal growth is hastened by lighting near the 30 foot candle range and the presence of 0.3-0.7% agar in the medium.

6- The Rhodes centrifuge technique for the staining of protozoa was modified to produce a rapid staining schedule for soil algae. This schedule involves killing and fixing in “hot” Schaudinn’s fluid, chlorophyll extraction in ether, and staining in Harris’ hematoxylin. The entire technique requires less than 90 minutes.

7- A tentative listing of 21 gianera was reported as having been established in the uni algal culture.