Take one down, pass it around, 99 bottles of biofuel on the wall!

Recent research has examined the use of agave, the plant used in making tequila, to create energy. Breweries too are using production leftovers to serve up alternative fuel, and not just to fuel a night of debauchery.

BLOG: Agave: Not Just for Tequila Anymore

Collected waste from beer-making can be used in methane producing bioreactors.

For example, Anheuser-Busch InBev, makers of Budweiser, collects waste from nine of its U.S. breweries in million-gallon bioreactors. Burning the methane the bioreactors produce recovers 20 percent of the heat energy used in the brewing process. The result is millions of dollars in savings.

Improving that process could help breweries and other industries create more gas and save even more money. So, a team of scientists recently studied the complex mix of organisms creating methane in Anheuser-Busch InBev’s bioreactors.

They found a diverse array of 4,962 types of bacteria making up the gas-belching sludge. In fact, each bioreactor hosted its own distinct mix of microorganisms; 145 of the bacteria were so unique they could be used to predict which bioreactor the bacterial sample came from.

Blog: Ancient Nubians Drank Antibiotic-Laced Beer

Beyond the biodiversity, the researchers also found a set of certain bacteria that seemed tougher than the rest.

“The cool thing we found was that if you’re looking at these thousands of species of bacteria, it’s a very dynamic system with things dying off and replacing them,” said researchers, Jeffrey Werner of Cornell University, in a press release by that school.

“There are certain signature populations that are resilient. Even if they get disturbed, they come right back up,” said Werner.

These bacteria were of a variety known as syntrophs, or organisms that feed off the wastes of others. The bacterial rebound effect suggested to the researchers that resilience was more important to the organisms’ syntrophic survival than competition.

The researchers at Cornell along with colleagues at Washington University and the University of Colorado at Boulder analyzed over 400,000 ribose nucleic acid (RNA) sequences of the critters in the brewery waste sludge.

BLOG: Now We Have A Problem: Global Warming Is Impacting Beer Production

Using those results, they hope to learn how to manipulate the bacteria to produce more carboxylates, a chemical that precedes the formation of alkanes like methane and propane. Another goal is to make the bugs quicker at breaking down the brewery waste.

“We are going to shape these communities so they start making what we want,” lead author Largus Angenent of Cornell said in a press release by that school.

The research was published in the Proceedings of the National Academy of Sciences.

IMAGE: Beer on a wall. Photo by Cerri, Lara/ZUMA Press/Corbis