Growth of bioluminescent bacteria under modelled gravity of different astronomical bodies in the Solar system

TL;DR

This study investigates how different simulated gravitational environments, including lunar, Martian, and Jovian gravities, affect the growth of bioluminescent bacteria, revealing that lunar gravity optimizes bacterial growth.

Contribution

First to simulate and compare the effects of various astronomical body gravities on bacterial growth using a novel clinostat-centrifuge system.

Findings

Higher growth under lunar and Martian gravities in optical density

No significant difference in viable bacterial counts across gravities

Jovian gravity slightly retards bacterial growth

Abstract

Spaceflights and clinostats have been used extensively to study the effects of microgravity on various biological systems ranging from microbes to plants. Similarly hypergravity studies have been carried out using centrifuges where growth retardation has been observed. However, no studies have been carried out yet on how the gravity of astronomical bodies, e.g. Moon having 1/6th the gravity of Earth, affects biological systems. Such studies are important with missions to Moon and Mars to be carried out in future. Also, a comparative study to see the effects of gravity that exists on astronomical bodies such as Moon, Mars and Jupiter on any organism using simulation have not been reported so far. This paper discusses the effects of modelled gravity on the growth of Vibrio harveyi using the clinostat-centrifuge system designed and developed in-house. Results showed that though growth as measured by optical density was significantly higher for simulated microgravity and lunar and Martian gravities, there was no significant difference in viable counts. This is because the relative death rate is also higher for these gravities. Jovian gravity was found to slightly retard the growth. This study also shows that simulated lunar gravity is relatively most suited for the growth of Vibrio harveyi.