Acetate synthesis from 2 CO2 in acetogenic bacteria: is carbon monoxide an intermediate?
CO has been observed in the pneumatocysts of Nereocystis lutkeana (9) where it varied from 0.4 to 12.2 % of the total gases in the air bladders, depending on the specimen and the time of day. CO was not detected in the dead plant or macerated tissues which had been left to dlecompose or autolyse. These findings have been, in general, confirmed (11), although it has been found that the daily fluctuations in CO were due to pressure changes of the total gas, the relative concentrations of CO and nitrogen remaining constant. The production of CO has been reported in other plants. It is produced by the growing leaves and stems of Medicago (16) and by Anacystis nidulans during illumination (4). Production during the enzymic degradation of rutin has been described (13, 15), and it has been detecte(d during seed germination (12). The assimilatory fixation of CO by higher plants has been reported (1,7). Wittenberg (17) has reported the presence of CO in the floats of the Portuguese man-of-war and its production by a gas gland in the float when DLserine was used as a substrate. The present study describes experiments designed to gain information on the source of this unusual metabolite in algae, particularly in the brown alga, Egregia nmenzies.