US Patent 9,096,875 to Montana State University (Bozeman, MT) : Bicarbonate trigger for inducing lipid accumulation in algal systems
From the "summary of invention":
The present invention provides methods of inducing lipid accumulation in an algae growth system. In some embodiments, the methods comprise adding one or more composition into the algae growth system, wherein the composition can influence the ability of an algae cell to complete a growth cycle, but is not completely toxic and does not result in cell death. In some embodiments, the composition comprises bicarbonate, and/or one or more compounds that provide bicarbonate after the composition (i.e., a bicarbonate containing and/or bicarbonate producing composition) is added into the algae growth system.
The present invention is based on the instant discovery that addition of bicarbonate (HCO.sub.3), at key growth points, is a metabolic trigger for inducing accumulation of TAG in algal growth systems. Furthermore, by using this bicarbonate trigger, TAG is produced to a much larger degree (tenfold so far) and total culture time is decreased (by several days) when compared to non-triggered systems. Therefore, the present invention discloses compositions and methods of utilizing this triggering mechanism, which has strong industrial application in biofuel production or secondary market production when algal growth systems are used.
The first claim:
1. A method of inducing lipid accumulation in an algae growth system, wherein the algae growth system is under light-dark cycling, said method comprising adding a triggering composition when algae cells in the growth system are in exponential growth stage, but prior to nutrient depletion of the growth system, wherein said triggering composition comprises bicarbonate, and/or one or more compounds that provide bicarbonate after the composition is added into the algae growth system, and wherein algae replication in the growth system is inhibited at the time when the triggering composition is added.