Waste treatment with a combination of denitrifying propionibacterium acidipropionici and protease-producing bacillus

Abstract

Waste such as livestock waste is treated with a combination of protease-producing bacteria and denitrifying bacteria that synergistically reduce nitrogen concentration, and further reduce noxious odors associated with anaerobic decomposition. The protease-producing bacteria break down complex proteins in the waste which enables ammonification by other naturally occurring microorganisms already present in the waste. The denitrifying bacteria then convert products of ammonification such as nitrates and nitrites to nitrogen gas which is released into the atmosphere. The protease-producing bacteria produce neutral and alkaline proteases, and are preferably from the genus Bacillus and include,and,provided at a level of at least approximately 4.5×10,CFU/ml. The denitrifying bacteria produce nitrate reductase, nitrite reductase and nitrous oxide reductase, and is preferably,strain P5 (ATCC 55467) provided at a level of at least approximately 3.0×10,CFU/ml. The protease-producing bacteria and denitrifying bacteria are added to waste as a composition containing both bacteria, or the protease-producing bacteria is added first followed by addition of the denitrifying bacteria. In addition to both bacteria, the composition contains a water soluble carrier such as whey or maltodextrin, and a moisture binding agent such as balith.