Co-producing iturin A and poly-γ-glutamic acid from rapeseed meal under solid state fermentation by the newly isolated Bacillus subtilis strain 3-10.

Dehui Yao, Zhixia Ji, Changjun Wang, Gaofu Qi, Lili Zhang, Xin Ma, Shouwen Chen

Index: World J. Microbiol. Biotechnol. 28(3) , 985-91, (2012)

Full Text: HTML

Abstract

The strain 3-10 was isolated from soil and identified as B. subtilis according to morphological and physiological characteristics and nucleotide sequence of 16S rRNA. It co-produced anti-fungal iturin A and fertilizer synergist of poly-γ-glutamic acid (γ-PGA) under solid state fermentation (SSF) with rapeseed meal. The co-production of iturin A and γ-PGA reached 5.3 and 51.3 g/kg-dry weight culture, respectively, and the number of viable cells reached 1.9 × 10(10) CFU/g-dry weight culture. In pot tests, the shoot length and dry weight of watermelon seedlings treated by the SSF culture improved by 48.0 and 30.8%, respectively compared to the control; and its biocontrol effect on watermelon fusarium wilt achieved 89.6%. These results highlight a novel strategy to exploit the low-cost and widely available rapeseed meal as dual-functional bio-organic fertilizer under SSF by B. subtilis.