ABSTRACT
A low-cost microBR (microbioreactor) made from PTFE [poly(tetrafluoroethylene)] was used to cultivate a model organism, Pseudomonas aeruginosa DS10-129. The progress of bioprocessing was monitored by comparing the growth of the organism in a microBR, a conventional bench scale bioreactor and a shake flask. Under the microBR conditions, the organism produced 23 mg/ml of pyocyanin that had antimicrobial effects against Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas teessidea and Pseudomonas clemancea. Furthermore, it produced a total of 106 microg/ml of effective biosurfactants consisting of dirhamnolipids (RL2) and monorhamnolipids (RL1). The biosurfactants reduced the surface tension of distilled water from 72 to 27.9 mN/m and emulsified kerosene by 71.30%. The pyocyanin and rhamnolipids were produced during the exponential and stationary phases of growth respectively. The results of the microBR were comparable to those obtained using conventional scale methods.
Subject(s)
Anti-Bacterial Agents/metabolism , Bioreactors , Glycolipids/metabolism , Microfluidics/instrumentation , Pseudomonas aeruginosa/metabolism , Pyocyanine/metabolism , Surface-Active Agents/metabolism , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Equipment Design , Pyocyanine/pharmacology , Surface-Active Agents/pharmacologyABSTRACT
A simple microbioreactor for high-throughput bioprocessing made from low cost polymer polytetrafluoroethylene (PTFE) tubes with a working volume of 1.5 ml is described. We have developed a microfluidic system that handles a small population of cells of a model microorganism, Pseudomonas aeruginosa DS10-129. Under the conditions of the microbioreactor, the organism produced extracellular secondary metabolites by using nutrient broth modified with glycerol. Pyocyanins were isolated from the fermented medium as a metabolite of interest. Antibiotic properties of pyocyanin were effective against a number of microorganisms such as Staphylococcus aureus, S. epidermis, Bacillus subtilis, Micrococcus luteus and Saccharomyces cerevisiae. Batch fermentation of the model organism in the microbioreactor was compared to shake-flask and conventional bench fermenter methods. Results obtained from the microbioreactor compared favourably with the conventional processes.
