TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Process: The hydrogen is removed from the cells by sparging with an inert gas. The hydrogen is removed from the cells by applying a reduced pressure. The inert gas is nitrogen alone or combined with at least one other inert gas. The inert gas is sparged continuously or discontinuously. The inert gas is sparged at a gas flow rate of 0.01-1 volume per volume per minute (vvm). A reduced pressure is applied in-situ to the liquid within the cell so that hydrogen is removed from the liquid as hydrogen gas. The applied reduced pressure is 0.3-2 atmospheres below an initial pressure of the liquid within the cell. First a portion of the liquid in the cell is transferred out of the cell; secondly a reduced pressure is applied ex-situ to a portion of liquid so that hydrogen is removed from the liquid as hydrogen gas; thirdly a portion of liquid is transferred back into cell. The applied reduced pressure is 0.3-2 atmospheres below an initial pressure of the liquid within the cell.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The inert gas is selected from nitrogen, helium, neon and/or argon.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: At least one methanogenesis inhibitor is selected from sodium bromoethenesulfonate (BES), 2-bromoethane sulfonic acid (2-BESA), lumazine, 2-chloroethanesulfonate, 2-mercaptoethanesulfonate and other coenzyme M structural analogs, propynoic acid, ethyl 2 butynoate, other hydroxymethyl glutaryl Coenzyme A (HMG-CoA) reductase inhibitors, methyl chloride, chloroform, methyl fluoride, fluoroacetate, ethylene, acetylene, nitrate, nitrite, nitroethane, 2-nitropropanol, phosphate, medium and long chain fatty acids, mevastatin, fluvastatin, and/or lovastatin. At least one methanogenesis inhibitor is sodium bromoethenesulfonate alone or combined with at least one other methanogenesis inhibitor. At least one methanogenesis inhibitor is added in a concentration of 5-100 mM (preferably 10-30 mM). EXAMPLE - No suitable example given.