1% - 3 %
||Diatom Phaeodactylum tricornutum
||Hopkinson, B.M., 2014. A chloroplast pump model for the CO2 concentrating mechanism in the diatom Phaeodactylum tricornutum. Photosynthesis research 121, 223-233 p.231 left column 2nd paragraph
||Losh JL, Young JN, Morel FM. Rubisco is a small fraction of total protein in marine phytoplankton. New Phytol. 2013 Apr198(1):52-8. doi: 10.1111/nph.12143PubMed ID23343368
||Primary source abstract: "Quantitative Western blots were performed using commercially available global antibodies and protein standards."
||P.231 left column 2nd paragraph: "P. tricornutum has a Form ID RubisCO with an intermediate affinity for CO2 (K c air = 41 μM) and a moderately-low maximal turnover rate (3.4 s^−1) typical of non-green algae (Badger et al. 1998, Whitney et al. 2001). This enzyme composes 1–3 % of total protein in the cell, which is less than that in land plants, but similar to that in other algae (primary source). Based on RubisCO kinetics and cellular RubisCO content, the enzyme appears to be working near its maximal rate as the estimated maximal rates of carbon fixation are close to observed photosynthetic rates (primary source)."