Analysis of Three-dimensional Fluorescence Characteristics of Extracellular Polymeric Substances at Internal Points in MPR at Low Temperature

Through three-dimension excitation emission matrix (EEM) fluorescence spectroscopy and fluorescence regional integration (FRI), the content and composition changes of extracellular polymeric substances (EPS) in different regions in the Micro-Pressure Inner-Loop Bioreactor (MPR) were analyzed, and the law of EPS in spatial points was found. The analysis shows that the high excitation wavelength tryptophan-like Peak T1 and the low excitation wavelength tyrosine-like Peak B appear in the spectra of tightly-bounded EPS (TB-EPS) and loosely-bounded EPS (LB-EPS) at different points. The content of protein substances in EPS is relatively high. In addition, the unique flow pattern in the reactor forms a multi-oxygen zone, which causes the total amount of EPS and the content of various organic substances, especially protein substances, to increase from the center of the reactor to the outside.