...
- Getting another organism to take away the byproducts that hinder hydrogen production
- combining dark fermentation and photo fermentation - Combined fermentation
- getting an organism to consume the acetate
- containment - making the bacteria dependent on each other to survive
- syntrophic exchange (http://www.pnas.org/content/111/20/E2149.short?rss=1)
- down-regulate the pathways except for the hydrogen production pathway