Microbial fermentation methods and compositions

A method for obtaining a Methylobacterium preparation comprising:

• preparing a culture medium comprising a mono-culture or co-culture of Methylobacterium, wherein said medium comprises a liquid phase and a solid phase, wherein the liquid and solid phase are provided as sterile components, wherein the solid phase comprises a plurality of particles which are suspended in the liquid phase, wherein the particles are about 1 micron to about 1000 microns in average length or average diameter, and wherein the solid phase does not comprise viable photosynthetic microorganisms;
• (ii) growing said Methylobacterium from an initial titer in said culture medium, wherein said culture medium is essentially free of microorganisms other than Methylobacterium, wherein said particles provide for a decrease in doubling time of said Methylobacterium grown in said culture medium relative to the doubling time of the Methylobacterium grown in liquid media alone, and wherein the Methylobacterium titer in said culture medium is increased at least ten-fold relative to the initial titer of the Methylobacterium in the culture medium;
• (iii) producing a fermentation broth with a Methylobacterium titer of at least 5×108 colony-forming units per milliliter;
• and
• (iv) harvesting the Methylobacterium from said fermentation broth, thereby obtaining the Methylobacterium preparation.