Abstract

Monitoring of bacterial cell numbers is of great importance not only in microbiological industry but also for control of liquids contamination in the food and pharmaceutical industries. Here we describe a novel low-cost and highly efficient technology for bacterial cell monitoring during cultivation process. The technology incorporates previously developed monitoring device and algorithm of its action. The devise analyses light scattered by suspended bacterial cells. Current stage utilizes monochromatic coherent light and detects amplitudes and durations of scattered light impulses, it does not require any labeling of bacterial cell. The system is calibrated using highly purificated bacteria-free water as standard. Liquid medial are diluted and analyzed by the proposed technology to determine presence of bacteria. Detection is done for a range of particle size from 0.1 to 10 um, and thus particles size distribution is determined. We analyzed a set of different bacterial suspensions and also their changes in quantity and size distribution during cultivation. Based on the obtained results we conclude that proposed technology can be very effective for bacteria monitoring during cultivation process, providing benefits of low simplicity and low cost of analysis with simultaneous high detection precision. Keywords: bacteria, monitoring, cultivation, particles size distribution, light csattering.

© 2007 SPIE