Did anyone else looking at the front page of HN jump to the conclusion that if this strain or similar of E. coli could be developed to live of human faeces India could become a future bio-fuel giant
Feces are about 2% carbohydrate by weight, a person produces about 0.75 kg/day, and there are 1.3 billion Indians. You could likely create a few thousands of liters of biodiesel daily. There's just not enough free energy.
Doing the math, as I'd indicated with my earlier post.
1.3 billion Indians generating 0.75 kg feces each per day, comprised of 3.8% carbohydrate, containing 4 kcal/g. Assume that the biofuel process is typical of other trophic levels, and roughly 10% efficient.
Fecal energy content is 148,200,000,000 kcal, or 6.2048376e+14 joule, or 172,357 MWh.
One tenth of that is 17,000 MWh.
Diesel fuel has an energy densigy of 46.2 MJ/kg, or about 0.0128 KWh/kg.
17,000 MWh is 1,324,675 kg of diesel. At 0.832 kg/l, that's 1,592,157 liters. OK, that's a couple orders of magnitude higher than I'd anticipated.
It's about 0.0012 liters per person per day. At 5 liters/100km (roughly 50 MPG), it's enough fuel to carry one person 0.026 km.
Used in a 40-seat bus, at half the fuel efficiency (that's a very efficient bus, or there are more than 40 people on it, this is, after all, India), it would be good for about 0.5 km of commute.
The world ain't gonna run on poop. At least not human poop alone. And even if you could boost the feedstock by some reasonable multiple (say, 2-16x) by including livestock waste, the numbers don't change enough to make it effective except for very, very heavily overloaded short-haul mass transit.
