both mixing and aeration functions in a stationary system a review of the prior art shows that there are no devises or methods available that fulfill these preferred embodiment features one or more sections of perforated tubing can be interconnected to form the mesh structure of the invention fig1 illustrates an example of a mesh structure having three sections the gas inlet 1 is connected to the perforated tubes 3 through cross connectors 5 and t connectors 7 the sections can be joined with connector tubes 2 the mesh structure can also be anchored to the bioreactor using elbow shaped anchors 4 and or t shaped anchors 6 fig2 illustrates a single section without anchors in the present invention the use is made of ordinary perforated tubes that can be made of a flexible material such as polyethylene polyurethane polypropylene polytetrafluoroethylene polyvinylidene fluoride ethylvinyl acetate polycarbonate or nylon mesh or an inflexible material such as ceramic metal fiberglass or plastic the only requirement is that the tubes be perforated to allow flow of gases as a continuous stream the opening or perforations in the tubes must be of such size as to create a uniform flow of bubbles without any u201c leaking u201d that comes if the pores are too large the leaking also causes a drop in pressure in the tube preventing uniform aeration coming from the entire mesh an appropriate.