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Exploring Rhodospirillum rubrum response to high doses of carbon monoxide under light and dark conditions
Journal article   Open access   Peer reviewed

Exploring Rhodospirillum rubrum response to high doses of carbon monoxide under light and dark conditions

Manuel S. Godoy, Irene Verdú, Santiago R. de Miguel, José D. Jiménez and M. Auxiliadora Prieto
Applied microbiology and biotechnology, v 108(1), pp 258-258
01 Dec 2024
PMID: 38466440
url
https://doi.org/10.1007/s00253-024-13079-5View
Published, Version of Record (VoR) Open

Abstract

Applied Microbial and Cell Physiology Biomedical and Life Sciences Microbial Genetics and Genomics Biotechnology Life Sciences Microbiology
Environmental concerns about residues and the traditional disposal methods are driving the search for more environmentally conscious processes, such as pyrolysis and gasification. Their main final product is synthesis gas (syngas) composed of CO, CO 2 , H 2 , and methane. Syngas can be converted into various products using CO-tolerant microorganisms. Among them, Rhodospirillum rubrum is highlighted for its biotechnological potential. However, the extent to which high doses of CO affect its physiology is still opaque. For this reason, we have studied R. rubrum behavior under high levels of this gas (up to 2.5 bar), revealing a profound dependence on the presence or absence of light. In darkness, the key variable affected was the lag phase, where the highest levels of CO retarded growth to more than 20 days. Under light, R. rubrum ability to convert CO into CO 2 and H 2 depended on the presence of an additional carbon source, such as acetate. In those conditions where CO was completely exhausted, CO 2 fixation was unblocked, leading to a diauxic growth. To enhance R. rubrum tolerance to CO in darkness, a UV-accelerated adaptive laboratory evolution (UVa-ALE) trial was conducted to isolate clones with shorter lag phases, resulting in the isolation of clones 1.4-2B and 1.7-2A. The adaptation of 1.4-2B was mainly based on mutated enzymes with a metabolic function, while 1.7-3A was mostly affected at regulatory genes, including the anti-repressor PpaA/AerR. Despite these mutations having slight effects on biomass and pigment levels, they successfully provoked a significant reduction in the lag phase (−50%). Keypoints • CO affects principally R. rubrum lag phase (darkness) and growth rate (light) • CO is converted to CO 2 /H 2 during acetate uptake and inhibits CO 2 fixation (light) • UVa-ALE clones showed a 50% reduction in the lag phase (darkness) Graphical Abstract

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UN Sustainable Development Goals (SDGs)

This publication has contributed to the advancement of the following goals:

#7 Affordable and Clean Energy
#6 Clean Water and Sanitation
#12 Responsible Consumption & Production

Source: SDGs in the Output

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Collaboration types
Domestic collaboration
International collaboration
Web of Science research areas
Biotechnology & Applied Microbiology
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