Growth of Chlorella in Relation to Boron Supply

Growth of Chlorella vulgaris Beijerinck (Columbia strain) was measured by final cell number, growth rate, and dry weight per cell in relation to boron supply. Growth in low-boron media was neither stimulated nor inhibited by the addition of boron in amounts up to 10 mg/liter, nor was growth affected in purified media in which boron had been reduced to 1 μg/liter. Boron was not detected in the inocula. The amount of boron present in nutrient solutions was the same at the start and at the end of the growth period when the cells were cultured in 2-liter polypropylene bottles. The trace amounts of boron found in the cells did not correlate with the concentration of boron in the nutrient media. Boron concentrations in culture media from 0.001 to 10 0 mg/liter did not affect growth of C. vulgaris.