RT info:eu-repo/semantics/doctoralThesis
T1 Detection of ammonia toxicity in microalgae by chlorophyll fluorescence
A1 Izawa, Yuto
A2 Universidad de Valladolid. Escuela de Ingenierías Industriales
K1 Ammonia inhibition
K1 Chlorophyll fluorescence
K1 Microalgae
K1 Multivariate analysis
K1 Saturation pulse
K1 3206.11 Toxicidad de Los Alimentos
AB To improve the specificity and accuracy of ammonia detection in Chlorella vulgarisunder high temperature, high light, and ammonia stress conditions, fast chlorophyll afluorescence induction (OJIP) curve was measured using varying saturation pulse intensitiesand analyzed through multivariable statistical methods. The OJIP curve shapes alone showedlimited discriminative power, as the fluorescence signals at the J and I phases were similaracross the three stress conditions. Quantitative evaluation using OJIP parameters revealedrelatively high correlations between ammonia concentration and specific parameters such as VLand VK (R² = 0.683 and 0.642, respectively). Moreover, the application of multivariable analysisusing a broader set of OJIP parameters significantly improved both prediction accuracy andcorrelation (0.84 and 0.92, respectively). Additionally, the use of different saturation pulseintensities enabled clearer detection of the L- and K-bands, enhancing the reliability of thesefluorescence features. These precisely captured parameters contributed to the improvedperformance of ammonia detection (prediction accuracy and correlation were 0.91 and 0.96).On the other hand, the model generated at different saturation pulse intensity largelymisestimated ammonia concentration.
YR 2025
FD 2025
LK https://uvadoc.uva.es/handle/10324/78292
UL https://uvadoc.uva.es/handle/10324/78292
LA spa
NO Departamento de Ingeniería Química y Tecnología del Medio Ambiente
DS UVaDOC
RD 12-feb-2026