LONDON, Jan. 29 (Xinhua) -- Scientists have found a potential food source for astronauts, using microbes to convert human waste into Marmite-like food, local media reported.

According to British online newspaper The Independent, researchers at Pennsylvania State University outlined a method to break down solid and liquid waste for producing protein and fat-rich substance from human waste in their study published in the quarterly scientific journal Life Sciences in Space Research.

"We envisioned and tested the concept of simultaneously treating astronauts' waste with microbes while producing a biomass that is edible either directly or indirectly, depending on safety concerns," said Christopher House, professor of geosciences and director of the Penn State Astrobiology Research Center.

"It's a little strange, but the concept would be a little bit like Marmite or Vegemite, where you're eating a smear of microbial goo," the professor added.

Food supply is a major hurdle when planning lengthy space flights. Recycling waste into nutritious food is one solution to this problem.

According to House and his colleagues, the method involves anaerobic digestion, a process that refers to the breakdown of materials in the absence of oxygen. It is considered an efficient way of breaking down biodegradable matter.

The researcher said while their method is not ready for application yet, it provides a new model for creating food on board spacecraft.

"Imagine if someone were to fine-tune our system so that you could get 85 percent of the carbon and nitrogen back from waste into protein without having to use hydroponics or artificial light," said House.