ISS Algae Experiments Reveal 50% Increase in DNA Mutations

Researchers have determined that growing microscopic algae aboard the International Space Station leads to a significant increase in genetic instability. According to The Times of India, a recent study found that spaceflight conditions caused approximately 50% more DNA polymorphisms in these organisms compared to controls grown on Earth.

The findings raise concerns about using living biological systems for long-duration space missions. While microalgae are considered promising candidates for life-support systems, the observed mutation rates suggest that their genetic stability may be compromised during extended periods in orbit.

Genetic changes outpace ground controls

The experiment involved growing Chlamydomonas reinhardtii, a type of single-celled algae, in the VEGGIE plant growth chamber on the ISS. Over the course of one month, the organisms went through approximately 40 generations. Scientists collected samples every ten generations to track how the genome evolved under space conditions.

Whole-genome sequencing revealed that the space-grown cultures accumulated mutations at a higher rate than their terrestrial counterparts. NASA described the pattern of changes as a novel base substitution signature, indicating that the specific environment of spaceflight induces unique genetic shifts. This trade-off between productivity and genetic stability is a critical factor for future mission planning.

Challenges for biological life support

NASA is investigating these organisms as part of its broader synthetic biology efforts. The goal is to develop biological systems that can provide food, oxygen, and other resources for astronauts on deep-space missions. However, the rapid accumulation of DNA changes suggests that these biological engines may not remain stable over the years required for interplanetary travel.

The instability poses a direct risk to the reliability of life-support systems. If the algae mutate too quickly, they may lose their ability to perform essential functions such as photosynthesis or nutrient production. This necessitates further research into how to protect genetic integrity during long-term exposure to space conditions.

Future focus on edible spirulina

Building on these initial findings, NASA is preparing the Space Algae-2 experiment. This follow-up study will focus on Arthrospira platensis, commonly known as Spirulina, which is an edible cyanobacterium. The objective is to understand how this specific organism evolves over time in space, providing deeper insights into long-term adaptation.

Researchers plan to use multi-omics analyses to examine mutation loads, gene expression, and nutritional composition. By studying the biological responses of Spirulina, scientists hope to identify mechanisms that could stabilize these organisms. This knowledge is essential for creating robust biological systems capable of sustaining human life in deep space.