Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i>
Algae are key components of aquatic food chains. Consequently, they are internationally recognised test species for the environmental safety assessment of chemicals. However, existing algal toxicity test guidelines are not yet optimized to discover molecular modes of action, which require highly-rep...
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doaj-94a469f2df4e422c9a632e377f5c4d2e2020-11-25T01:23:18ZengMDPI AGMetabolites2218-19892019-05-01959410.3390/metabo9050094metabo9050094Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i>Stefan Schade0Emma Butler1Steve Gutsell2Geoff Hodges3John K. Colbourne4Mark R. Viant5School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UKSafety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook MK44 1LQ, UKSafety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook MK44 1LQ, UKSafety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook MK44 1LQ, UKSchool of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UKSchool of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UKAlgae are key components of aquatic food chains. Consequently, they are internationally recognised test species for the environmental safety assessment of chemicals. However, existing algal toxicity test guidelines are not yet optimized to discover molecular modes of action, which require highly-replicated and carefully controlled experiments. Here, we set out to develop a robust, miniaturised and scalable <i>Chlamydomonas reinhardtii</i> toxicity testing approach tailored to meet these demands. We primarily investigated the benefits of synchronised cultures for molecular studies, and of exposure designs that restrict chemical volatilisation yet yield sufficient algal biomass for omics analyses. Flow cytometry and direct-infusion mass spectrometry metabolomics revealed significant and time-resolved changes in sample composition of synchronised cultures. Synchronised cultures in sealed glass vials achieved adequate growth rates at previously unachievably-high inoculation cell densities, with minimal pH drift and negligible chemical loss over 24-h exposures. Algal exposures to a volatile test compound (chlorobenzene) yielded relatively high reproducibility of metabolic phenotypes over experimental repeats. This experimental test system extends existing toxicity testing formats to allow highly-replicated, <i>omics</i>-driven, mode-of-action discovery.https://www.mdpi.com/2218-1989/9/5/94synchronisationalgaebioassaybiomarkerkey eventadverse outcome pathway |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Stefan Schade Emma Butler Steve Gutsell Geoff Hodges John K. Colbourne Mark R. Viant |
spellingShingle |
Stefan Schade Emma Butler Steve Gutsell Geoff Hodges John K. Colbourne Mark R. Viant Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i> Metabolites synchronisation algae bioassay biomarker key event adverse outcome pathway |
author_facet |
Stefan Schade Emma Butler Steve Gutsell Geoff Hodges John K. Colbourne Mark R. Viant |
author_sort |
Stefan Schade |
title |
Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i> |
title_short |
Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i> |
title_full |
Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i> |
title_fullStr |
Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i> |
title_full_unstemmed |
Improved Algal Toxicity Test System for Robust <i>Omics</i>-Driven Mode-of-Action Discovery in <i>Chlamydomonas reinhardtii</i> |
title_sort |
improved algal toxicity test system for robust <i>omics</i>-driven mode-of-action discovery in <i>chlamydomonas reinhardtii</i> |
publisher |
MDPI AG |
series |
Metabolites |
issn |
2218-1989 |
publishDate |
2019-05-01 |
description |
Algae are key components of aquatic food chains. Consequently, they are internationally recognised test species for the environmental safety assessment of chemicals. However, existing algal toxicity test guidelines are not yet optimized to discover molecular modes of action, which require highly-replicated and carefully controlled experiments. Here, we set out to develop a robust, miniaturised and scalable <i>Chlamydomonas reinhardtii</i> toxicity testing approach tailored to meet these demands. We primarily investigated the benefits of synchronised cultures for molecular studies, and of exposure designs that restrict chemical volatilisation yet yield sufficient algal biomass for omics analyses. Flow cytometry and direct-infusion mass spectrometry metabolomics revealed significant and time-resolved changes in sample composition of synchronised cultures. Synchronised cultures in sealed glass vials achieved adequate growth rates at previously unachievably-high inoculation cell densities, with minimal pH drift and negligible chemical loss over 24-h exposures. Algal exposures to a volatile test compound (chlorobenzene) yielded relatively high reproducibility of metabolic phenotypes over experimental repeats. This experimental test system extends existing toxicity testing formats to allow highly-replicated, <i>omics</i>-driven, mode-of-action discovery. |
topic |
synchronisation algae bioassay biomarker key event adverse outcome pathway |
url |
https://www.mdpi.com/2218-1989/9/5/94 |
work_keys_str_mv |
AT stefanschade improvedalgaltoxicitytestsystemforrobustiomicsidrivenmodeofactiondiscoveryinichlamydomonasreinhardtiii AT emmabutler improvedalgaltoxicitytestsystemforrobustiomicsidrivenmodeofactiondiscoveryinichlamydomonasreinhardtiii AT stevegutsell improvedalgaltoxicitytestsystemforrobustiomicsidrivenmodeofactiondiscoveryinichlamydomonasreinhardtiii AT geoffhodges improvedalgaltoxicitytestsystemforrobustiomicsidrivenmodeofactiondiscoveryinichlamydomonasreinhardtiii AT johnkcolbourne improvedalgaltoxicitytestsystemforrobustiomicsidrivenmodeofactiondiscoveryinichlamydomonasreinhardtiii AT markrviant improvedalgaltoxicitytestsystemforrobustiomicsidrivenmodeofactiondiscoveryinichlamydomonasreinhardtiii |
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