In the absence of plentiful oxygen, aerobic bacteria were prevented from decaying the organic matter after it was buried under a layer of sediment or water. However, anaerobic bacteria were able to reduce sulfates and nitrates among the matter to HS and N respectively by using the matter as a source for other reactants. Due to such anaerobic bacteria, at first, this matter began to break apart mostly via hydrolysis: polysaccharides and proteins were hydrolyzed to simple sugars and amino acids respectively. These were further anaerobically oxidized at an accelerated rate by the enzymes of the bacteria: e.g., amino acids went through oxidative deamination to imino acids, which in turn reacted further to ammonia and α-keto acids. Monosaccharides in turn ultimately decayed to CO and methane. The anaerobic decay products of amino acids, monosaccharides, phenols and aldehydes combined into fulvic acids. Fats and waxes were not extensively hydrolyzed under these mild conditions.