Isolation of Thermophilic Ammonium-tolerant Bacterium and Its Application to Reduce Ammonia Emission during Composting of Animal Wastes

Abstract

A thermophilic bacterium, strain TAT105, was isolated from compost made of animal wastes. TAT105 had high tolerance to ammonium nitrogen up to 1200 mM, and highly assimilated nitrogen during the growth on swine feces. The strain was classified into Bacillus, close to Bacillus pallidus. To evaluate the effect of adding TAT105 to ammonia (NH3) emission during the composting process of animal wastes, laboratory scale composting was done. NH3 emission tended to be lower and nitrogen loss was smaller in the TAT105-added material than in the control material to which TAT105 was not added. Thermophilic ammonium-tolerant bacteria in the TAT105-added material increased to about 8x10(9) CFU/g of dry matter on the average during the tests, and most of them were judged to be TAT105 from morphological colony discrimination. These results suggested the possibility of reducing NH3 emission from composting of animal wastes by adding TAT105.

Utilization of Bacillus sp. strain TAT105 as a biological additive to reduce ammonia emissions during composting of swine feces

“…In our previous study, composting was performed for 18 days to evaluate the effect of TAT105 using the present system, 22) and it was confirmed that 70-80% of the TN loss as NH 3 gas from the composted material occurred within the first seven days of composting in this system. After the first seven days, the difference in nitrogen loss between the treatments with and without TAT105 showed little difference.…”

“…22) A solid medium for the TAT105 additive was prepared as follows: 375 g of wheat bran, 125 g of coaled pulp sludge (Cellash, Nippon Kakoh Seishi Co., Ltd., Takahagi), and 7.5 g of soluble starch were mixed with a solution containing 1.5 g of yeast extract (Difco), 0.5 g of Na 2 HPO 4 , 0.67 g of NH 4 Cl, and 0.5 mL of a 10 mM MnCl 2 ·4H 2 O solution in 500 mL of distilled water. Portions (250 g) of the medium were placed in several 2-L Erlenmeyer flasks capped with cotton plugs and autoclaved at 121°C for 30 min.…”

“…Three composting tests, Tests 1, 2, and 3, were carried out using laboratory-scale composting equipment ("Kaguyahime," Fujihira Kogyo Co., Ltd., Tokyo), as described in our previous report. 22) Table 1 shows the settings of treatments for the composting tests. The materials for composting were 3.6 kg of swine feces, 0.6 kg of sawdust, 0.1 L of water, and a specific weight of the TAT105 additive.…”

“…In our previous study, 22) we isolated Bacillus sp. strain TAT105 (TAT105), a thermophilic ammoniumtolerant bacterium that grows well in swine feces and assimilates ammonium nitrogen (NH þ 4 -N) at high concentration, and evaluated reduction of NH 3 emissions by adding TAT105 liquid culture in the laboratory-scale composting of swine feces.…”

“…Therefore, an enumeration method for the microorganism should be developed. 23,24) In the composting tests in the previous study, 22) thermophilic ammonium-tolerant bacteria (TAT) in the composted materials were enumerated by measuring colony formation on an agar medium with 0.5 M NH 4 Cl at 55°C. Most of the appeared colonies on the agar medium were morphologically identical with the TAT105 colony.…”