Carbon Dioxide as a Growth Factor for Mutants of Escherichia coli

Abstract

SUMMARYThis report shows that some auxotrophic mutants of Escherichia coli can grow on a minimal medium without growth factors when the gas phase is supplemented with carbon dioxide. Mutants which respond to CO, are called CO, mutants. The CO, mutants of E. coli resemble those already known in Neurospora. When the gas phase is not supplemented with CO, most of the mutants respond to other specific growth factors such as arginine, uracil, adenine, succinate or isoleucine + valine, depending upon the locus of their mutation. One mutant is an obligate CO, mutant. The CO, effects shown by these mutants are discussed in relation to the general problem of CO, effects in micro-organisms.

The Occurrence and Genetics of Some CO2 Mutants in Streptomyces coelicolor

“…A possible alternative explanation of the CO, response in cdx-vi is considered in the Discussion. DISCUSSION CO, mutants have previously been investigated in the mould Neurospora crassa (Broadbent & Charles, 1965;Broadbent, 1965;de Serres, 1966), and in the eubacterium Escherichia coli (Charles & Roberts, 1968). The present study has shown that they can also be isolated in Streptomyces coelicolor, a protokaryote not closely related to E. coli, suggesting that CO, mutants are probably of general occurrence in microorganisms.…”

“…So far the C 0 2 mutants that are most easily understood are those defective in the incorporation of CO, into a biosynthetic sequence, for example that of adenine (Broadbent, 1965;de Serres, 1966) or arginine (Charles, 1962Charles & Roberts, 1968). The adenine/CO, mutant of Streptomyces coelicolor may be of this type.…”

“…Mutations at uraD result in a requirement for arginine +uracil (Hopwood, 1967) probably due to defective CAP synthesis. In Escherichia coli some mutations at the equivalent locus cause a CO, requirement (Charles & Roberts, 1968;M. Mergeay, personal communication) and this should also be true of uraD in Streptomyces coelicolor, in which case there may be a functional relationship between cdxA and uraD.…”

“…Escherichia coli (Charles & Roberts, 1968). The Streptomyces coelicolor mutant differed from the mutants in N .…”

Characterization of carbonic anhydrase from diversified genus for biomimetic carbon-dioxide sequestration

“…The increase in activity during lag and early log phase could be attributed to the phenomenon of sparking effect, whereby CO 2 is required to meet the biosynthetic demand and is important for organisms to overcome the lag phase [19]. A high load of CO 2 and bicarbonate could result in decreased CA activity during maximum growth.…”