How bacteria could help power the future

Hydrogen is the cleanest and most abundant fuel there is, but extracting it from water or organic material is currently not a very efficient process. Scientists are therefore studying certain bacteria that exhale hydrogen as part of their normal metabolism.

“The production of hydrogen by microorganisms is intimately linked to their cellular processes, which must be understood to optimize bioenergy yields,” said Amy VanFossen of North Carolina State University.

Of particular interest are microbes that thrive in hot temperatures, near the boiling point of water. VanFossen and her colleagues carried out a detailed DNA study of one of these thermophilic (heat-loving) bacteria called Caldicellulosiruptor saccharolyticus, which was first found in a hot spring in New Zealand.

The results, presented last week at the American Chemical Society meeting in Philadelphia, indicate which genes allow C. saccharolyticus to eat plant material, referred to as biomass, and expel hydrogen in the process.

Fuel cell vehicles are starting to be available for lease in California and the New York area. They run off of hydrogen gas and emit only water vapor out the tail pipe.

hydrogen

Hydrogen can be found everywhere: it’s the “H” in H2O and a major element in biological processes. The problem is that it takes quite a bit of energy to separate the hydrogen from the molecules it is found in.

However, certain organisms, such as the bacteria in cow stomachs , get energy from food through a chemical reaction that releases hydrogen gas. Often this hydrogen is immediately taken up by other bacteria, called methanogens , that convert it to methane .

One of the challenges, therefore, of producing hydrogen from bacteria is to prevent the methanogens from gobbling up the gas. The advantage of thermophiles is that they operate at temperatures that are typically too hot for methanogens. C. saccharolyticus, for example, prefers a toasty 160 degrees Fahrenheit (70 degrees Celsius).

Furthermore, the chemistry of hydrogen formation is easier at these higher temperatures, said Servé Kengen from Wageningen University in the Netherlands.

“In general, thermophiles have a simpler fermentation pattern compared to [lower temperature] mesophiles, resulting in fewer byproducts,” he said.

Bionic microbe
Kengen is part of a European Union project called Hyvolution, which is developing decentralized hydrogen production that can be performed near where biomass is grown.

“Biological hydrogen production is well suited for decentralized energy production,” Kengen said. “The process is performed at almost ambient temperature and pressure, and therefore it is expected to be less energy intensive than thermochemical or electrochemical production methods [which are alternative ways to get hydrogen].”

Kengen said that C. saccharolyticus, or what he calls “Caldi,” is very attractive for this application. It is unique in that it eats a wide range of plant materials, including cellulose , and can digest different sugars (technically carbohydrates) at the same time.

Comments (1)

  • Caca
    December 1, 2015 at 3:56 pm

    1. Yes, they kill bacireta in your body, but also where ever there is bacireta. On agar plates (used to grow bacireta) antibiotics will kill them if the bacireta are not resistant to them. On oranges when they mold, bacireta will be killed where the mold is (think penicillin). I want you to know though, that the problems today that we have with resistant bacireta stem from the fact that we use too many antibiotics. Antibiotics are overused in today’s society making the conditions right for superbugs like MRSA to grow and divide without competition from other bacireta.2. You do not want bacireta in your food to grow to a level that makes the food spoil, so you must either keep it cold or cooked so that the bacireta is slow in growing or killed. Even when you cook food, new bacireta get on it and begin dividing so any food should be kept cold after a certain point to make sure that the baciretal growth doesn’t exceed a certain point. You should either keep the food that is perishable cold or the non perishable bagged up so that it doesn’t go bad.3. Not sure which alcohol you’re talking about here, but 70% Alcohol or rubbing alcohol will generally kill bacireta on surfaces and skin, but it cannot be used in food since it first of all, evaporates when cooking and secondly it induces throwing up. The alcohol we drink cannot be used to kill bacireta on food because it evaporates quickly when cooked and also since food doesn’t taste that good with, let’s say vodka, in it. Unless it’s an oyster shot or bloody mary, of course! But seriously, the amount of alcohol in alcoholic beverages is too low to be significant in killing bacireta. I hope that helps.

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