[Identification of ammonia oxidation Streptomyces strain A2 and study of its autotrophic ammonium oxidation characteristics].
Streptomyces strain A2 was isolated from a nitrification reactor. According to the characteristics of morphology, cultivation, physiology, (G + C)mol% content, 16S rDNA sequence and DNA-DNA hybridization. it was identified as Streptomyces bikiniensis. Strain A2 could heterotrophically grow on YD medium and could also autotrophically grow on inorganic medium. The heterotrophical growth rate (0.39mg/L.d) was higher than the autotrophical growth rate (0.22mg/L.d). During heterotrophical growth ammonia was mainly assimilated. During autotrophical growth, however, one part of ammonia was assimilated and other part of ammonia was converted into nitrite. When grown on the inorganic medium, the maximum ammonium oxidation rate reached at ammonium concentration of 118mgN/L. The optimal pH for growth and ammonia oxidation was 9.36 and 9.29, respectively. The optimal temperature for growth and ammonia oxidation was 31 degrees C and 40.6 degrees C, respectively. A high concentration of dissolved oxygen was good for growth and ammonia oxidation, and growth was more sensitive to dissolved oxygen change than to ammonia oxidation.
Department of Environmental Engineering, Zhejiang University, Hangzhou 310029, China. blhu@zju.edu.cn
Bao-lan
BL
Hu
Ping
P
Zheng
Xiao-ying
XY
Wu
Liang
L
Yin
D000641:Ammonia / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013302:Streptomyces / Q000145:classification* / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature
D003470:Culture Media; D000641:Ammonia