Respiration and microalgal growth: a review of the quantitative relationship between dark respiration and growth

Abstract

Hiomass-specifnc, dark resiiiration rates of niicroalfJiao vary by almost two orders ot niaijnitiidc' from OOl lo ()(i d '. In general, dark respiration rates increase witli growth rates in botli lnlraspeeitic and interspeeific comparisons, hut the precise relationship between respiration and growth rate varies. L'nder optimal conditions, respiration rates are aliout 20 30",, of growtli rales, liut the ratio ol respiration to growtli increases under suhoptimal conditions. 'I'he intercept of plots of respiration rate vs. growth rate \aried from < OOl to 0-4 d ', and the slopes of thest' relationships \aried from < 0-1 to IO. .Minimum maintenance metaholic rates of about ()•() 1 d ' ba\e been estimated for some microalgae by extrapolation ot the initial slope of the light cur\e for grow th to a h\'pothetical negative growth rate in darkness. The dimensionless total energy cost of synthesis ami maintenance for heterotr<iphie growth ol microalgae using either endogenoiisly or exogenousK supplied carbohydrates is typically 0'4 1-2 tor growth with atnmonia or urea as a nitrogen source and 0-7 1-4 lor growth with nitrate as the nitrogen souree.

Effects of prolonged darkness and temperature on the lipid metabolism in the benthic diatom Navicula perminuta from the Arctic Adventfjorden, Svalbard

“…Under dark conditions some diatoms reduce their metabolic rate down to the maintenance metabolism, which serves to keep all cell functions ready for photosynthesis after a transfer back to the light (Geider and Osborne 1989). In S. costatum very low maintenance metabolic rates of <0.01…”

“…) were measured (Vårum et al 1986;Geider and Osborne 1989). To meet such energy requirements, storage products, such as lipids and carbohydrates, have to be used (Geider and Osborne 1989).…”

Phytoplankton carbon isotope fractionation during a diatom spring bloom in a Norwegian fjord

“…rate to light carbon assimilation rate, r, to equal 15% for D (Laws & Bannister 1980, Geider & Osborne 1989. The growth rate in the ratio yl/[C02(aq)] was calculated with instantaneous growth rates obtained from temporal changes in S. costaturn cell concentrations.…”

The influence of incubation periods on photosynthesis–irradiance curves

“…However, apparent PQ's substantially higher than expected from considerations of the N source assimilated by phytoplankton have been frequently measured, for instance, Oviatt et al (1986) estimated PQ values as high as 5.0 and Iriarte et al (1996) obtained a mean PQ of 2.2. In this study, a somewhat more standard PQ value of 1.2 was used according to Vollenweider (1974), Geider andOsborne (1989) and Laws (1991). If a PQ of about 1.8 had been considered, the P max values presented here would be lower than the abovementioned limit.…”

“…The former was used in all ecosystems, whereas the latter was applied only in Santo André lagoon in order to assure that the results obtained in this ecosystem were not due to the photosynthesis measurement method used. For the oxygen method three replicates were incubated and a photosynthetic quotient of 1.2 was used to convert oxygen to carbon according to Vollenweider (1974), Geider and Osborne (1989), and Laws (1991). Dissolved oxygen concentration was measured by titration with the azide modification of the Winkler method (Phillips, 1973).…”