the photosynthesis: Respiration ratio of some unicellular marine algae

Isolation and axenic culture ofGymnodinium microadriaticumfromTridacna maxima

“…Using this method of calculation we obtained ratios of photosynthesis to dark respiration of about 6-0 for the freshly-isolated cells and 2.0 for the cultured cells. The latter value is lower than that observed by Humphrey (1975) for cultivated A. carterae (ratio 3-5) and ~Gymnodinium splendens Lebour (ratio 4.9).…”

Carbon exchange and 14C tracer methods in a nitrogen-limited diatom, Thalassiosira pseudonana

“…Our apparent respiration rates in the chemostats are among the lowest ever reported; values of 10 to 20 % of maximum gross photosynthesis seem typical for dark respiration (Humphrey, 1975;Burris, 1980;Harris, 1980). There are at least 3 possible explanations for this.…”

Bioengineering Aspects of Inorganic Carbon Supply to Mass Algal Cultures: Final Report

“…Both ~ obliquus and ~ vulgaris belong to this group of acido philic algae and can tolerate pH values down to 4 or less (Emerson and Green, 1938;Osterlind, 1949;. Similarly, although marine algae do not display acidophilic characterisitcs, both ~ tricor~ nutum and Q:.. tertiolecta have been cultured successfully at pH values as low as 6 (Hayward, 1968;Humphrey, 1975). Therefore, our inability to attain steady state pH levels below 7.6 for the marine algae and 7.9 for the freshwater algae was not due to a physiological limitation, but rather was a clear demonstration of how the source of nitrogen, though bio10gi…”

“…In contrast, although data on pH responses by marine algae are limited, a large number of marine species appear to be unable to tolerate pH values much above 9.5 (Humphrey, 1975;Goldman, 1976), and typically grow optimally in a narrow pH range bracketing the pH of seawater which is -8.1 to 8.3 (Kain, 1958 a,b;1960;Hayward, 1968;Humphrey, 1975). Yet, a few marine species, particularly f..:.…”

“…Yet, a few marine species, particularly f..:. tricornutum, seem to behave more like freshwater algae and are capable of growing at pH levels up to and above 10 (Hayward, 1968;Humphrey, 1975;Goldman, 1976), even though their pH optima are closer to 8 (Kain, 1958 a,b;1960;Hayward, 1968).…”