Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion
Abstract Background Microalgae can absorb CO2 during photosynthesis, which causes the aquatic environmental pH to rise. However, the pH is reduced when microalga Euglena gracilis (EG) is cultivated under photoautotrophic conditions. The mechanism behind this unique phenomenon is not yet elucidated....
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BMC
2022-10-01
|
| Series: | Biotechnology for Biofuels and Bioproducts |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13068-022-02212-z |
| _version_ | 1811257020004696064 |
|---|---|
| author | Mingcan Wu Guimei Wu Feimiao Lu Hongxia Wang Anping Lei Jiangxin Wang |
| author_facet | Mingcan Wu Guimei Wu Feimiao Lu Hongxia Wang Anping Lei Jiangxin Wang |
| author_sort | Mingcan Wu |
| collection | DOAJ |
| description | Abstract Background Microalgae can absorb CO2 during photosynthesis, which causes the aquatic environmental pH to rise. However, the pH is reduced when microalga Euglena gracilis (EG) is cultivated under photoautotrophic conditions. The mechanism behind this unique phenomenon is not yet elucidated. Results The present study evaluated the growth of EG, compared to Chlorella vulgaris (CV), as the control group; analyzed the dissolved organic matter (DOM) in the aquatic environment; finally revealed the mechanism of the decrease in the aquatic environmental pH via comparative metabolomics analysis. Although the CV cell density was 28.3-fold that of EG, the secreted-DOM content from EG cell was 49.8-fold that of CV (p-value < 0.001). The main component of EG’s DOM was rich in humic acids, which contained more DOM composed of chemical bonds such as N–H, O–H, C–H, C=O, C–O–C, and C–OH than that of CV. Essentially, the 24 candidate biomarkers metabolites secreted by EG into the aquatic environment were acidic substances, mainly lipids and lipid-like molecules, organoheterocyclic compounds, organic acids, and derivatives. Moreover, six potential critical secreted-metabolic pathways were identified. Conclusions This study demonstrated that EG secreted acidic metabolites, resulting in decreased aquatic environmental pH. This study provides novel insights into a new understanding of the ecological niche of EG and the rule of pH change in the microalgae aquatic environment. |
| first_indexed | 2024-04-12T17:49:55Z |
| format | Article |
| id | doaj.art-74314fcca1ca48dfb1098ef1c6516a13 |
| institution | Directory Open Access Journal |
| issn | 2731-3654 |
| language | English |
| last_indexed | 2024-04-12T17:49:55Z |
| publishDate | 2022-10-01 |
| publisher | BMC |
| record_format | Article |
| series | Biotechnology for Biofuels and Bioproducts |
| spelling | doaj.art-74314fcca1ca48dfb1098ef1c6516a132022-12-22T03:22:32ZengBMCBiotechnology for Biofuels and Bioproducts2731-36542022-10-0115111310.1186/s13068-022-02212-zMicroalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretionMingcan Wu0Guimei Wu1Feimiao Lu2Hongxia Wang3Anping Lei4Jiangxin Wang5Shenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen UniversityState Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan UniversityState Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan UniversityCenter for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of SciencesShenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen UniversityShenzhen Key Laboratory of Marine Bioresource and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen UniversityAbstract Background Microalgae can absorb CO2 during photosynthesis, which causes the aquatic environmental pH to rise. However, the pH is reduced when microalga Euglena gracilis (EG) is cultivated under photoautotrophic conditions. The mechanism behind this unique phenomenon is not yet elucidated. Results The present study evaluated the growth of EG, compared to Chlorella vulgaris (CV), as the control group; analyzed the dissolved organic matter (DOM) in the aquatic environment; finally revealed the mechanism of the decrease in the aquatic environmental pH via comparative metabolomics analysis. Although the CV cell density was 28.3-fold that of EG, the secreted-DOM content from EG cell was 49.8-fold that of CV (p-value < 0.001). The main component of EG’s DOM was rich in humic acids, which contained more DOM composed of chemical bonds such as N–H, O–H, C–H, C=O, C–O–C, and C–OH than that of CV. Essentially, the 24 candidate biomarkers metabolites secreted by EG into the aquatic environment were acidic substances, mainly lipids and lipid-like molecules, organoheterocyclic compounds, organic acids, and derivatives. Moreover, six potential critical secreted-metabolic pathways were identified. Conclusions This study demonstrated that EG secreted acidic metabolites, resulting in decreased aquatic environmental pH. This study provides novel insights into a new understanding of the ecological niche of EG and the rule of pH change in the microalgae aquatic environment.https://doi.org/10.1186/s13068-022-02212-zMicroalgaeEuglena gracilisAquatic environmental pHHumic acidsAcidic metabolites |
| spellingShingle | Mingcan Wu Guimei Wu Feimiao Lu Hongxia Wang Anping Lei Jiangxin Wang Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion Biotechnology for Biofuels and Bioproducts Microalgae Euglena gracilis Aquatic environmental pH Humic acids Acidic metabolites |
| title | Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion |
| title_full | Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion |
| title_fullStr | Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion |
| title_full_unstemmed | Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion |
| title_short | Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion |
| title_sort | microalgal photoautotrophic growth induces ph decrease in the aquatic environment by acidic metabolites secretion |
| topic | Microalgae Euglena gracilis Aquatic environmental pH Humic acids Acidic metabolites |
| url | https://doi.org/10.1186/s13068-022-02212-z |
| work_keys_str_mv | AT mingcanwu microalgalphotoautotrophicgrowthinducesphdecreaseintheaquaticenvironmentbyacidicmetabolitessecretion AT guimeiwu microalgalphotoautotrophicgrowthinducesphdecreaseintheaquaticenvironmentbyacidicmetabolitessecretion AT feimiaolu microalgalphotoautotrophicgrowthinducesphdecreaseintheaquaticenvironmentbyacidicmetabolitessecretion AT hongxiawang microalgalphotoautotrophicgrowthinducesphdecreaseintheaquaticenvironmentbyacidicmetabolitessecretion AT anpinglei microalgalphotoautotrophicgrowthinducesphdecreaseintheaquaticenvironmentbyacidicmetabolitessecretion AT jiangxinwang microalgalphotoautotrophicgrowthinducesphdecreaseintheaquaticenvironmentbyacidicmetabolitessecretion |