Liquid-gas partitioning of the gasoline oxygenate methyl tert-butyl ether (MTBE) under laboratory conditions and its effect on growth of selected algae.

The partitioning of the widely used gasoline additive methyl tert-butyl ether (MTBE) between liquid growth media and gaseous phase was measured daily under laboratory conditions to determine how closely dissolved MTBE concentrations matched nominal concentrations. Total (gaseous and dissolved) MTBE averaged across 6 days for 29.6, 503.2, and 1005.7 mg L-1 MTBE treatments were 89.9, 90.3, and 73.0% of nominal, respectively, and mean dissolved MTBE in these same treatments were 74.6, 73.8, and 69.6% of total MTBE, respectively. This suggests that dissolved MTBE concentrations can vary substantially from nominal. The effect of MTBE on the growth of selected algae was also evaluated under laboratory conditions. Three unicellular algae, Selenastrum capricornutum (Chlorophyta), Navicula pelliculosa (Bacillariophyta), and Synechococcus leopoliensis (= Anacystic nidulans, Cyanophyta = Cyanobacteria), representative of three taxonomic groups, were used as test organisms. Toxicity tests were acute and increase in cell number was used as an indicator of growth. Algal species were exposed by injection of MTBE into sealed vessels containing defined liquid growth media. The growth of N. pelliculosa and S. leopoliensis was negatively affected at nominal 2400 mg L-1 MTBE, whereas the growth of S. capricornutum was negatively affected at nominal 4800 mg L-1 MTBE and positively affected at nominal 600 mg L-1 MTBE. The differential sensitivity of the growth of these representative species suggests that MTBE may alter algal community composition in the natural environment.

Influence of stabilizer concentration on effectiveness of chlorine as an algicide.

Cyanuric acid, used as chlorine stabilizer in swimming pool waters, has a relatively minor effect on the algicidal efficiency of free chlorine. The toxicity of free chlorine to three swimming pool algae was reduced slightly by 25 mg of cyanuric acid per liter if inhibiting, but less than algicidal, concentrations of chlorine were employed. Higher stabilizer concentrations (50, 100, and 200 mg/liter) generally resulted in no further reduction in the algicidal efficiency of free chlorine beyond that observed at 25 mg/liter.

Cellulose in the cell walls of the bangiophyceae (rhodophyta).

Mechanically isolated cell walls of the conchocelis phase of Bangia fuscopurpurea yield cellulose II (regenerated cellulose) upon treatment with Schweitzer's reagent. X-ray powder analysis and thin-layer chromatography of partial hydrolyzates confirm the presence of cellulose in this extract. Gas-liquid chromatographic analysis of wall hydrolyzates indicates that xylose, mannose, galactose, and glucose are major wall constituents. The presence of cellulose in the conchocelis provides evidence that this bangiophycean life cycle phase represents a transitional form or link between the two classes of red algae, Bangiophyceae and Florideophyceae. This suggests a close affinity of the two classes of the Rhodophyta and supports the hypothesis that bangiophycean algae were precursors of the Florideophyceae.

Laboratory comparison of the effectiveness of several algicides on isolated swimming pool algae.

The most frequently encountered species of algae found in swimming pools in the Phoenix metropolitan area were used to evaluate the laboratory effectiveness of five commercially available pool chemicals used for algal control. The pool algae used were the xanthophyte Pleurochloris pyrenoidosa, the chlorophyte Oocystis sp., and the cyanophytes Phormidium minnesotense and Plectonema sp. Pad Algae Kill (a chlorine derivative) was effective in the control of all test organisms. Algaedyn, a silver-containing algicide, was effective on P. minnesotense and Plectonema sp., but caused only a slight inhibition in the growth of P. pyrenoidosa and Oocystis sp. Quarternary ammonium (Padicide) was more effective in controlling the growth of Phormidium and Plectonema than Pleurochloris and Oocystis. Algimycin (herbicide) only reduced the growth of Oocystis and was ineffective on the other species. Bio-Gard (copper) reduced the growth of Pleurochloris, but had no effect on the other test organisms. The technique used to quantify the influence of algicides on isolated pool algae appears to be adaptable to those algae that form distinct colonies on an agar substratum.

PYROLYSIS-GAS-LIQUID CHROMATOGRAPHIC ANALYSIS OF CHLOROPHYCEAN AND RHODOPHYCEAN ALGAE(1).

Eight chlorococcalean algae and 5 rhodophycean algae have been grown in axenic cultures. These organisms have been "fingerprinted" using a pyrolysis-gas-liquid chromatographic analysis. Each alga has a distinctive pyrogram which characterizes it both quantitatively and qualitatively. The pyrograms are given and the significance for possible future uses of this technique in developmental, evolutionary, and systematic studies with algae is discussed.