Journal of Pure and Applied MicrobiologyVol. 8 No. Special Edition Nov. 2014

Molecular Characterization of Actinomycetes Isolated from Terrestrial Environment and their Synthesis of Geosmin and 2-MIB

Yu-jin Lee1,a, Bong-Soo Kim2,a, Min-jeong Kim1, Sehee Nam1, Sung-Ae Oh1, Yun. S. Kim1, Ilhwan Choi1, Jong-Geun Park3, and Gyu-Cheol Lee1*

1Department of Microbiology, Water Quality Research Center, K-water, Daejeon 306-711, Republic of Korea. 2Chunlab, Inc., Seoul 151-742, Republic of Korea, and 3Department of Environmental Education, College of Education, Daegu University, Gyeongsan 712-214, Republic of Korea.

Received on 10 August 2014 and accepted on 21 October 2014

 

ABSTRACT

The occurrence of Actinomycetes, their molecular characteristics, and their release of synthesized odor compounds into soil and the water systems were investigated. The average numbers of Actinomycetes was 9.0 × 105 CFU/g in the soil and 4.8 CFU/mL in the water. The average numbers of Actinomycetes in the soil was highest at the Yangpyeong (YP) testing site (2.2 × 106 CFU/g), followed by the Gyeongan (GA), Paldang (PD), and Cheongpyeong (CP) sites. The Streptomyces genus, which can produce odor compounds such as geosmin and 2-Methylisoborneol (MIB), was dominant (67.6%). An enhanced proportion of Streptomyces with plant soil was also observed by independent pyrosequencing results of cultures. The bacterial diversity of GA and CP was greater than those of YP and PD, and pyrosequencing detected diverse genera of Actinobacteria. The rain leaching model experiment suggested that geosmin and 2-MIB produced by the Actinomycetes could be released into the water systems by rainfall. The concentrations of the geosmin and 2-MIB leached from the planted soils were 2.6 times and 2.8 times greater than those from the unplanted soil. Moreover, the concentration of Streptomyces positively correlated with the amount of geosmin and 2-MIB (R2 = 0.809 and 0.847, respectively).

Keywords : Actinomycetes, Geosmin, 2-MIB, 16S rDNA, pyrosequencing.