PMC

Oraganic acid content and exudation in transgenic and untransformed alfalfa lines under neutral pH growth conditions. A and B, Root organic acid content (n = 7); C and D, leaf organic acid content (n = 2); and E and F, organic acid exudation into the rhizosphere (n = 4). Bars = means + se. Note that the figures are drawn to different log scales.

The relationships between environmental factors and pericarp fatty acid composition for different Zanthoxylum species: (a), the relationship between environmental factors and pericarp fatty acid composition for ZA; (b), the relationship between environmental factors and pericarp fatty acid composition for ZB1; (c), the relationship between environmental factors and pericarp fatty acid composition for ZB2; (d), the correlation between environmental factors and pericarp fatty acid composition for ZA; (e), the correlation between environmental factors and pericarp fatty acid composition for ZB1; (f), the correlation between environmental factors and pericarp fatty acid composition for ZB2. RDA is redundancy analyses; Long is longitude; Alt, altitude; AtP, atmospheric pressure; MT, mean temperature; MAP, mean annual precipitation; pH, power of hydrogen; OM, organic matter content in soil; Pt, total phosphorus content in soil; Kt, total potassium content in soil; Pa, available phosphorus content in soil; Ka, available potassium content in soil; Al, aluminium content in soil; Cd, cadmium content in soil; Pb, lead content in soil; Mn, manganese content in soil; C16:0, palmitic acid; C18:0, stearic acid; C20:0, eicosanoic acid; C22:0, behenic acid; C16:1, palmitoleic acid; C18:1n9, oleic acid; C18:1n13t, trans-13-oleic acid; C20:1, cis-11-eicosenoic acid; C18:2, linoleic acid; C18:3, and linolenic acid; * represents medium correlation (0.4–0.6); ** represents strong correlation (0.6–0.8).

Soluble solid content (A), pH value (B), and organic acid content (C) of fermented grains.

Effect of initial pH on the inhibition of organic acids. All organic acids were tested at their respective molar concentrations of the tested organic acids that caused 50% inhibition of the lipid yield. Cultures with 5% inoculum size were incubated at 25°C and 160 rpm for 7 days. Results are expressed relative to controls without organic acids. Biomass, lipid content and lipid yield of cultures lacking organic acids at pH 5.5, pH 6.5 and pH 7.5 were, respectively, 18.4 g/L, 57.2% and 10.5 g/L; 24.0 g/L, 61.7% and 14.8 g/L; and 21.5 g/L, 56.3% and 12.1 g/L. Ac, acetic acid; Fo, formic acid; Le, levulinic acid; Hy, 4-hydroxybenzoic acid; Fu, furoic acid; Ca, caproic acid; Ga, gallic acid; Fe, ferulic acid; Sy, syringic acid; Va, vanillic acid.