title: Solubilization of Waste Activated Sludge and Nitrogenous Compounds Transformation During Solubilization by Thermophilic Enzyme (S-TE) Process.
abstract: A representative thermophilic bacterial strain (AT06-1) capable of secreting protease was isolated from thermophilic aerobic digestion reactor, and 16S rRNA gene analysis indicated that it was Bacillus sp. The isolated strain was inoculated in waste activated sludge (WAS) to evaluate the performance of solubilization by thermophilic enzyme (S-TE) process under aerobic or microaerobic conditions at different temperatures (55-70 °C). Results showed that the inoculation of specific thermophilic strain significantly affected the volatile suspended solids (VSS) removal. At the optimal temperature of 65 °C, the maximum VSS removal of 43.6 % and highest SCOD of 4475 mg/L was achieved during microaerobic S-TE process. Compared to the noninoculation, more soluble protein was released during S-TE process due to the higher protease activity associated with the protein hydrolysis originated from cell lysis. The protease activity at aerobic and microaerobic S-TE process was respectively 1.73 and 1.88 times that of the noninoculation. Ammonia was the end nitrogenous compound of protein hydrolysis during S-TE process, which was stripped from the digestion system through continuous aeration.
authors: College of Environmental Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.
authors: Qi
authors: Q
authors: Yang
authors: Kun
authors: K
authors: Luo
authors: Xiao-ming
authors: XM
authors: Li
authors: Yu
authors: Y
authors: Zhong
authors: Hong-bo
authors: HB
authors: Chen
authors: Guo-jing
authors: GJ
authors: Yang
authors: Yan-wei
authors: YW
authors: Shi
authors: Guang-ming
authors: GM
authors: Zeng
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001407:Bacillus / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D001711:Biotransformation; D006868:Hydrolysis; D009584:Nitrogen / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology*; D012995:Solubility; D014835:Volatilization
chemical_list: D011506:Proteins; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D000641:Ammonia; D010447:Peptide Hydrolases; D009584:Nitrogen