Microorganisms and plant of Autonomous Biological Systems (ABS) samples

Area of Science:

• Astrobiology
• Microbiology
• Plant Biology

Background:

• Autonomous Biological Systems (ABS) are crucial for understanding life's adaptability.
• Space environments pose unique challenges to biological systems.
• Previous studies have explored microbial and cellular responses to spaceflight.

Purpose of the Study:

• To investigate the distribution of microorganisms within ABS.
• To assess the effects of space environments on cellular structure, particularly chloroplasts in Ceratophyllum demersum.
• To compare microbial cell densities using direct fluorescence microscopy versus traditional methods.

Main Methods:

• Fractionation of ABS samples (suspensions and sediments).
• Direct fluorescence microscopic method for viable cell density measurement.
• Analysis of intracellular chloroplast distribution in Ceratophyllum demersum.
• Comparison of flight samples with ground controls.

Main Results:

• Viable cell densities in ABS fractions were 10-100 times higher than colony forming unit methods.
• No significant difference in vertical microbial distribution between flight and ground samples post-recovery.
• Intracellular chloroplast distribution in Ceratophyllum demersum was disturbed after 10 days of continuous light.
• Complete disintegration of Ceratophyllum demersum after 4 months of continuous light, versus slight deterioration with 16 hours/day light.

Conclusions:

• Direct fluorescence microscopy offers a more sensitive measure of microbial viability in ABS.
• Spaceflight, particularly prolonged continuous light, significantly impacts plant cellular integrity.
• Light cycle duration is a critical factor in mitigating cellular damage in space-flown plants.