STARCH SYNTHESIS IN CHLORELLA VULGARIS

Abstract

Chlorella z~ulgaris was found to deposit starch, in amounts up to 20% of the dry weight of the cells, when grown in a medium containing glucose. 'The cells clid not contain cellulose or chitin. 'The starch was difficult to eutract, being associated with an alkali-soluble, dextrorotatory, cell-wall polysaccharide. 'I'he starch, after extraction by a 26% sotution of calcium chloride a t 120°C., had properties quite similar to starches from higher plants. I t \\.as composed of aiilylose (30-10%) ancl a~nylopectin. Glucose-1-C14 \\.as incorporated into the starch, by growing cells, without much breakdown and resynthesis. Cellfree extracls, obtained from the alga, contained a phosphorylase and a branching enzyme similar to those of the potato. These brought about the synthesis of an amylopectin-glycogen type polysaccharide from glucose-1-phosphate. It is concl~~ded that the mechanism of starch syilthesis in Chlorella vulgaris is essentially the same as in higher plants.

Effects of cell motility and morphology on the rheology of algae suspensions

“…into the suspending medium. As a chlorophyte, Chlorella is a strong producer of starch (Bailey and Neish, 1954), and starch solutions are well known to have shear-thickening rheology (Barnes et al, 1989); thus if the starch were to somehow enter the suspending medium, perhaps as a result of cell damage at high strain rates, this could explain the clear shear-thickening behaviour observed here. However, Kaplan et al (1987) found that after several days, only about 10% of the polysaccharide produced by Chlorella stigmatophora dissolved into the suspending medium, with the rest remained bound to the cell.…”

Extraction of proteins other than myosin from the isolated rabbit myofibril

“…Tropomyosin was prepared as described by Bailey (1948), further purified by ethanol precipitation as suggested by Bailey (1951) and recrystallized twice. This preparation, which was used to obtain the standard curve for the viscometric assay of tropomyosin, was homogeneous after electrophoresis for 7 hr.…”