Journal of Pure and Applied MicrobiologyVol. 8 No. 2

Identification and Fermentation Optimization of an Antibacterial Aspergillus tubingensis Associated with the Crab Portunus triuberbuculatus

Lei Guo1,2*, Wencheng Zhu2 and Anqi Zheng2

1Jiangsu Institute of Marine Resources, Lianyungang 222004, China. 2Ocean School, Huaihai Institute of Technology, Lianyungang 222005, China.

Received on 02 July 2013 and accepted on 19 August 2013

 

ABSTRACT

To identify marine fungus SZX-6 isolated from the inner of Portunus triuberbuculatus with antibacterial activity and to optimize the fermentation conditions of producing antibacterial active substances. Based on its morphological characters and internal transcribed spacer (ITS) sequence analysis results, strain SZX-6 was identified as Aspergillus tubingensis. The optimized fermentation conditions were determined as sucrose 3%, beef extract 1.5%, KCl 0.1%, MgSO4 0.02%, old seawater, inoculum size 1%, 28?C, 160 r/min for 8 d by the the one-factor-at-a-time method, the orthogonal matrix method and the time-bioactivity cources assay. The initial identification data demonstrated that the antibacterial active substances were mainly composed of moderate polar components with plentiful quantity and alkaloid-colored. The strain of A. tubingensis being isolated from the seawater-cultured animal was firstly reported here, and its antimicrobial activity was initially invenstigated in this paper.

Keywords : Aspergillus tubingensis, Antibacterial activity, Identification, Fermentation optimization.