CHLORELLA SP AND ARSENIC COMPOUNDS - AN ATTEMPT TO PREPARE AN ALGAL REFERENCE MATERIAL FOR ARSENIC COMPOUNDS

The growth of Chlorella Bohm, Chlorella kessleri and Chlorella 108 in media containing sodium arsenate at 200 or 2000 mg As dm(-3) was inves tigated, The cell densities in the stationary phases were 40% higher f or Chlorella Bohm (5.6 x 10(5) cells cm(-3)) and Chlorella kessleri (4 .5 x 10(5) cells cm(-3)) grown in the 2000 mg As dm(-3)) arsenate medi a compared with the arsenic-free media, The growth of Chlorella 108 wa s depressed by arsenate. Dimethylarsinic acid fat concentrations never exceeding 1.2 mg As dm(-3)) and arsenite (similar to 0.2 mg As dm(-3) ) were detected in the growth medium, The cells harvested during the s tationary phase had 2400 mg arsenic associated with 1 kg dry mass. A w ater/methanol (80:20) mixture extracted all the arsenic from the cells . Most of the arsenic (99%) was arsenate. Arsenite, methylarsonic acid and dimethylarsinic acid accounted for the remaining arsenic, Cadmium in the arsenic-containing growth media (50 mu g to 100 mg dm(-3)) red uced the yield of algal cells and induced the formation of an unidenti fied arsenic compound in Chlorella Bohm. (C) 1997 by John Wiley & Sons , Ltd.