ISSN 2736-1756
Advanced Journal of Microbiology Research ISSN 2241-9837 Vol. 13 (3), pp. 001-009, March, 2019. © International Scholars Journals
Full Length Research Paper
Isolation and characterization of high caffeine-tolerant bacterium strains from the soil of tea garden
Fang-Yuan Fan1, Yan Xu1, Yue-Rong Liang1, Xin-Qiang Zheng2, Devajit Borthakur1,3 and Jian-Liang Lu1*
1Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
2Key Laboratory of Horticultural Plants Growth, Development and Biotechnology, Agricultural Ministry of China, Hangzhou 310058, China.
3Tocklai Experimental Station, Tea Research Association, Jorhat, Assam 785001, India.
Accepted 11 January, 2019
Abstract
Microbial biodegradation is an important and promising decaffeination approach because of its low cost and high security. The efficiency of this approach mainly depends on the characteristics of the strain. Twenty bacterium strains were isolated from soil of tea garden and exhibited high caffeine-tolerance, and these strains could grow on the medium supplemented with 20 g L-1 caffeine as the sole source for nitrogen and carbon. According to the physiological-biochemical characteristics and 16S rRNA gene sequence blast, two of them (CT25 and CT75) were identified as Pseudomonas putida. The results also showed that caffeine was not the preferential nutrition source for growth of strain CT25, and high level caffeine inhibited the bacterium amplification although caffeine could be metabolized by this strain. The CT25 grew well in agitated liquid medium when the incubation temperature was around 30°C. High initial concentration of strain inoculums would improve the efficiency of caffeine degradation.
Key words: Caffeine-tolerant bacterium, identification, 16S rRNA gene, caffeine biodegradation, growth condition.