American and Indian scientists have examined four bacterial strains from the station and found that the three belonged to a species previously unknown to science.
The rod-shaped bacteria were found roughly five years ago in different locations on the station: one on the surface of a dining table, one on an overhead panel at a research station, and another in the Cupola observatory dome.
As the bacteria are proven to be able to survive the conditions of the ISS, they could contribute to humans growing food in space, according to the researchers.
The discovery was published in the journal Frontiers in Microbiology and NASA believes the species offer enormous potential for growing food on missions to Mars.
The species is involved in a number of essential agricultural processes, including nitrogen fixation, phosphate solubilisation, abiotic stress tolerance, plant growth promotion, and biocontrol activity against plant pathogens.
NASA's Dr Kasthuri Venkateswaran and Dr Nitin Kumar Singh said that the strains might possess "biotechnologically useful genetic determinants" for the growing of crops in space.
However, they cautioned that further experimental biology would be required to prove that the new species of bacteria is as much of a space farming game-changer as they suspect.