The production of
biomass or a desired product from a
cell can be improved by inducing conversion of ATP to ADP without primary effects on other cellular metabolites or functions which is achieved by expressing an uncoupled
ATPase activity in said
cell and incubating the
cell with a suitable substrate to produce said
biomass or product. This is conveniently done by expressing in said cell the soluble part (F1) of the
membrane bound (F0F1 type) H+-
ATPase or a portion of F1 exhibiting
ATPase activity. The
organism from which the F1 ATPase or portions thereof is derived, or in which the F1 ATPase or portions thereof is expressed, may be selected from prokaryotes and eukaryotes. In particular, the
DNA encoding F1 or a portion thereof may be derived from
bacteria and eukaryotic microorganisms such as
yeast, other fungi and cell lines of higher organisms and be selected from the group consisting of the
gene encoding the F1
subunit beta or a portion thereof and various combinations of said
gene or portion with the genes encoding the other F1 subunits or portions thereof. The method can be used i.a. for optimizing the formation of
biomass or a desired product by a cell by expressing different levels of uncoupled
ATPase activity in the cell, incubating the cell on a suitable substrate, measuring the conversion rate of substrate into biomass or the desired product at each level of ATPase expression, and choosing a level of ATPase expression at which the conversion rate is optimized.