Currently there is an increase search for microorganisms as a potential
source of biofuels and other bioproducts with commercial interest. A way to reduce
microbial cultivation costs consists of using low-cost feedstocks, such as
lignocellulosic materials, industrial by-products, effluents and wastewaters to cultivate
microbes which, in some cases, allow the simultaneous effluent biological treatment
and the production of high value-added products. However, such feedstocks may
contain, or their pre-treatment may release inhibitory compounds that affect microbial
metabolism, thus the process efficiency. Multi-parameter flow cytometry (FC) is an
advanced and powerful technique that has been used for bioprocess monitoring,
showing many advantages over the conventional microbiological/analytical techniques
that are still currently used in most laboratories for process control. This chapter will
describe the cell stress response to the most known inhibitors present in low-cost
feedstocks, emphasizing the advantages of using the at-line FC technique in these
process monitoring.
Keywords: Crude Glycerol, Cell Membrane Damage, Enzymatic Activity, Flow
Cytometry, Hydrophobic Wastes, Inhibitors, Intracellular pH, Intracellular
Products, Low-Cost Feedstocks, Lignocellulosic Materials, Microorganisms,
Reactive Oxygen Species, Wastewaters.
