Subject index to volumes 108–112

Abstract

Pavlova lutheri (Droop) Green was grown in chemostat culture; the three different N sources used were ammonium, nitrate or glycine and the cultures were also grown under N and P limitation. A number of biochemical and physiological measurements were made on these cultures growing at high and low dilution rates. Elemental composition of the cells remained relatively constant, C content increasing only under conditions of phosphate limitation, while N and P content decreased under their respective limiting conditions. DNA content showed little variation but RNA content declined significantly under both N and P limitation. The largest effect of nutrient limitation to the biochemical parameters measured were to carbohydrate and lipid concentrations which increased significantly. Amino acid concentrations increased more than six times when the cultures were phosphate-starved.Dilution rate, as well as nutrient status, affected the physiological measurements; assimilation numbers were highest at high dilution rates and were reduced under phosphate limitation and when glycine was the sole N source. Photosynthetic efficiency was similar for all growth conditions, except N limitation when values increased. Under both N and phosphate limitation, the proportion of 14C label in low molecular weight intermediates increased, with a decrease of the label in protein. There were significant variations in Chla,c1c2 and chlorophyllide a under nutrient limitation but carotenoid pigments showed less variation.A multiple intercomparison was carried out by principal component analysis, which indicated that the biochemical composition measurements tended to be related to the growth-limiting factor, whereas the physiological measurements were related to growth rate.