Appellants win in Ex parte SPORMANN

Ex parte SPORMANN

A claim at issue


13. A method of expressing a functional oxygen-sensitive protein
under ambient oxic conditions, the method comprising:

introducing into a diazotrophic filamentous cyanobacteria, of the
genus Nostoc or Anabaena, polynucleotide sequences encoding a
heterologous oxygen-sensitive protein operably linked to a promoter
selectively active in microoxic cells;
culturing said diazotrophic cyanobacteria under conditions that induce
microoxic cell formation;
selectively expressing said oxygen-sensitive protein in said microoxic
cells,
wherein said oxygen-sensitive protein is expressed as a functional
protein in said microoxic cells.



A relevant reference: James W. Golden and Ho-Sung Yoon, Heterocyst development in
Anabaena, 6 CURRENT OPINION IN MICROBIOLOGY 557-563 (2003):


Golden discloses that “[m]any filamentous nitrogen-fixing
cyanobacteria protect nitrogenase from oxygen in differentiated cells called
heterocysts,” which are “specialized cells that create a microoxic
environment for nitrogen fixation” (FF 7). However, Golden does not
disclose using this microoxic environment to express a heterologous oxygensensitive
protein. Thus, we agree with Appellants that Golden does not
overcome the deficiencies of Szalay.