Additional file 1 of Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion

Additional file 1: Figure S1. E. gracilis and C. vulgaris were grown under photoautotrophic and sterile conditions. As the treatment group, EG1, 2, 3 represent three biological replicates of E. gracilis (EG); as the control group, CV1, 2, 3 represent three biological replicates of C. vulgaris (CV), respectively. The scale bar represents 5 cm. Figure S2. OPLS-DA analysis and composition of DOM in the aquatic environment from EG compared to CV in the positive ion mode. A, the OPLS-DA analysis; B, the composition of DOM from C. vulgaris’ cultivated media; C, the composition of DOM from E. gracilis’ cultivated media; DOM, dissolved organic matter. Composition of DOM in the aquatic environment from E. gracilis (EG) compared to C. vulgaris (CV) in the positive ion mode. As the test group, EG1, 2, 3 represent three biological replicates of EG; as the control group, CV1, 2, 3 represent three biological replicates of CV, respectively. Figure S3. Heat map of differential metabolites. A, the heat map of E. gracilis (EG) differential metabolites between intracellular (IEG) and extracellular (EE); B, the heat map of differential metabolites from the aquatic environment between C. vulgaris (CV) and EG; All metabolites were detected in positive ion mode (POS mode); BKs, represent candidate biomarkers metabolites

Comparison of <i>V_max</i> (µM g⁻¹ DM h⁻¹), <i>K_S</i> (µM) values and substrate range (µM) for several Chlorophyta and Rhodophyta species in the marine or estuarine environment.

—<p>means linear, rate-unsaturated response.</p>+<p>means not clear.</p><p>*means no report.</p><p>Comparison of <i>V_max</i> (µM g⁻¹ DM h⁻¹), <i>K_S</i> (µM) values and substrate range (µM) for several Chlorophyta and Rhodophyta species in the marine or estuarine environment.</p

Ammonium (NH₄⁺) uptake rates by <i>G. tenuistipitata</i> at different time intervals and different substrate concentration.

<p>Phosphate (30 µM) was added in all treatments.</p

Additional file 2 of Microalgal photoautotrophic growth induces pH decrease in the aquatic environment by acidic metabolites secretion

Additional file 2. All metabolites of E. gracilis and C. vulgaris cells were detected in the NEG and POS modes via comparative metabolomics method

Kinetic parameters (<i>V_max</i> and <i>K_s</i>) of the Michaels-Menten equation obtained from the rates for uptake of Nitrate (NO₃⁻) by <i>G. tenuistipitata</i> at different time intervals.

<p>Kinetic parameters (<i>V_max</i> and <i>K_s</i>) of the Michaels-Menten equation obtained from the rates for uptake of Nitrate (NO₃⁻) by <i>G. tenuistipitata</i> at different time intervals.</p

PCA analysis of WT <i>E</i>. <i>gracilis</i> (a) and OflB2 (b) against light treatment.

PCA analysis of WT E. gracilis (a) and OflB2 (b) against light treatment.</p

The <i>G. tenuistipitata</i> in OCT North Lake.

<p>A,B,C) The <i>G. tenuistipitata</i> bloom in OCT North Lake, D) The salvaged <i>G. tenuistipitata</i>, E) Samples of <i>G. tenuistipitata</i> collected, F) Observation and identification of macroalgae.</p

Heat map of WT <i>E</i>. <i>gracilis</i> (a) and OflB2 (b) metabolites after light stimulation.

Heat map of WT E. gracilis (a) and OflB2 (b) metabolites after light stimulation.</p

The absorption spectrum of the pigments in WT <i>E</i>. <i>gracilis</i> and OflB2.

The absorption spectrum of the pigments in WT E. gracilis and OflB2.</p

Nitrate (NO₃⁻) uptake rates by <i>G. tenuistipitata</i> at different time intervals and different substrate concentration.

<p>Phosphate (30 µM) was added in all treatments.</p