Applications of Parallel Factor Analysis in Feature Extraction of Excitation-Emission Matrix Spectrum of Dissolved Organic Matter in Red Tide Algae Growth Process
Ten kinds of red tide algae were cultured under laboratory conditions. Parallel factor analysis was used to extract the features of excitation-emission matrix spectra of dissolved organic substances in red tide algae growth process. The characteristic spectra of each alga were obtained. Then the similarities and dissimilarities of characteristic spectra of each alga were compared,to provide a basis for the identification of red tide algae based on the excitation-emission matrix spectra of dissolved organic substances in red tide algae growth process. The relationships between the fluorescence intensities and algae growth phases were also investigated. The results show that the characteristic spectrum of each alga is different from each other. In the exponential phase,the positive relationships between the protein-like,humic-like fluorescence intensities and cell densities were observed. It implied that the fluorescent substances accumulated during the exponential phase. In the stationary and decadency phases,the protein-like and humic-like fluorescence intensities increased quickly,which suggested that the two kinds of fluorescent substances were produced by the broken algal cells and the degradation by marine bacteria. The results show that PARAFAC model can be successfully applied to extract the fluorescent spectra features of dissolved organic substances in red tide algae growth process and can be used to investigate the relationship between fluorescence intensities and algae growth phase.