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Biology subjects

Pillot, G.

Publications and source records attributed to Pillot, G..

2 recordsLinked to original sources

Resource-efficiency of cyanobacterium production on Mars: Assessment and paths forward

Space agencies and private companies strive for a permanent human presence on the Moon and ultimately on Mars. Bioprocesses have been advocated as key enablers due to their ability to transform locally available resources into added-value materials. However, the resource-efficiency and scaling of space biosystems remain poorly understood, hindering quantitative estimates of their potential performance. We leveraged extensive cultivation experiments, where a cyanobacterium (Anabaena sp. PCC 7938) was subject to conditions attainable on Mars, to develop a model that can estimate bioprocess productivity and resource-efficiency as a function of water, light, temperature, regolith minerals and perchlorates, and atmospheric carbon and nitrogen. We show that a breakeven can be reached within a few years. We discuss research lines to improve both resource efficiency and the accuracy of the model, thereby reducing the need for costly tests in space and eventually leading to a biotechnology-supported, sustained human presence on Mars. TEASERBioprocess modeling shows that cyanobacterium-based biotechnologies can be a sustainable basis for resource production on Mars.

microbiology↗

Implication of exofacial thiol groups in the reducing activity of Listeria monocytogenes

Listeria monocytogenes growing in BHI in anaerobic condition leads a decrease of redox potential at pH7 (Eh7) from 0 to -250 mV. An investigation of mechanisms involved in this reducing activity shows the implication of thiol groups located on the bacterial cell surface. Indeed, after reduction of media to -250 mV, only thiol-reactive reagents could restore the initial Eh7 value. Moreover, the growth of L. monocytogenes in anaerobic condition is characterized by a reduction then acidification phases. This suggests a sensor mechanism of environmental Eh7 to convert the metabolism way from the first phase to the second. Finally, the concentration of exofacial thiol still increase strongly during the acidification phase of L. monocytogenes, even after reach the minimal value of Eh7. These results suggest that maintaining the exofacial thiol (-SH) groups in a reduced state do not depend on an active mechanism. Thiol groups appear to be displayed by membrane proteins or cell wallbound proteins and may participate in protecting cells against oxidative stress.

microbiology↗