The Growth and Inorganic Nutrition of Scenedesmus obliquus in Mass Culture.

Abstract

S. obliquus, strain WH 50. was cultured in 300 1. vats in an air conditioned chamber equipped with batteries of incandescent and fluorescent lamps. Quantitative relationships between cell count, dry weight, and packed cell volume were shown to vary under conditions of micronutrient deficiency. Analyses for N, P, S, Mg, K, and Ca established the inorganic composition of cells grown in complete and micronutrient deficient cultures. These data provide a basis for replacement of nutrients absorbed during growth. A daily harvest of 45 g. dry wt. per vat was calculated to be the maximum theoretical yield under continuous artificial illumination of a vat having a total surface area of 2 m.2 and a depth of 15 cms. The requisite level of the algal population which must be maintained to effect this yield is 7.5 x 106 cells/ml or a dry wt. of 150 mg./liter. Evidence indicates that a major limiting factor in growth is the reduction in availability of micronutrients accentuated by the regimen of continuous harvest.