NOVELTY - Producing methane-utilizing microorganisms in a confined apparatus comprises collecting methane gas that has been exhaled through ruminant animal exhalation, providing methane-utilizing microorganisms, which can use the methane as a source of carbon and/or energy for growth, and providing a growth-culture medium which promotes the growth of the microorganisms.    USE - The method is useful for producing methane-utilizing microorganisms in a confined apparatus.    DETAILED DESCRIPTION - Producing methane-utilizing microorganisms in a confined apparatus comprising using the methane exhaled through ruminant animal exhalation as a source of carbon and/or energy for the growth of the microorganisms comprises:    (A) collecting methane gas that has been exhaled through ruminant animal exhalation;    (B) providing methane-utilizing microorganisms which can use the methane as a source of carbon and/or energy for growth;    (C) providing a growth-culture medium which promotes the growth of the microorganisms, including a nutrient substrate and/or a microorganism immobilization means;    (D) providing a means for the directed mutual-exposure of the methane, the microorganisms, and the growth culture medium, including a means for the capture and conveyance of the methane and a means for confining the microorganisms, the growth-culture medium, and the methane to a specified apparatus existing outside of the digestive tract of a ruminant animal; and    (E) mutually-exposing the methane, the microorganisms, and the growth-culture medium to cause the microorganisms to grow in the apparatus using the methane and the growth-culture medium, where the methane contained within the ruminant animal exhalation is utilized for the sustained growth of the microorganisms in a specified apparatus, where the methane, an environmentally-destructive material and previously unusable source of energy, is used to produce a useful end-product, and where the microorganisms can be harvested and utilized following growth, adding economic incentive to a ruminant animal methane emissions reduction effort.