Abstract: A disposable bioreactor for culturing microorganisms and cells is provided. The bioreactor is suitable for use by individuals not skilled in microbiology or aseptic technique. It is constructed of flexible or semi-flexible waterproof sheets to form a container designed to provided mixing and gas exchange to microorganisms cultured therein. Mixing and gas exchanged are achieved by bubbling gas through the culture, either from a single locus at the lowermost apex of a container having a wedge-shaped or rounded bottom, or from multiple loci across a flat-bottomed container. Also provided is a kit for culturing a selected microorganism, preferably an entomopathogenic nematode or other organism useful as a biopesticide.