Production of antifungal iturins from vegetable straw: A combined chemical-bacterial process

Yuan Yuan, Depeng Chu, Jiajun Fan, Zhenzhen Cui, Rui Wang, Han Zhang, Xiangwei You, Yiqiang Li, Xiaoqiang Wang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


A combined chemical-bacterial process was developed to convert vegetable straw waste to high value antifungal iturins. Straws from three widely cultivated vegetable (cucumber, tomato and pepper) were evaluated as feedstocks for iturin production. Microwave assisted hydrolysis with very dilute acid (0.2% w/w H2SO4) achieved efficient reducing sugar recovery. The high glucose concentration in non-detoxified hydrolysate from pepper straw facilitated the optimal growth of Bacillus amyloliquefaciens strain Cas02 and stimulated the production of iturin. The fermentation parameters were optimised to enhance the iturin production efficiency. The obtained fermentation extract was further purified using macroporous adsorption resin, resulting in an iturin-rich extract that exhibited strong antifungal activity against Alternaria alternata with an IC50 of 176.44 μg/mL. Each iturin homologue was identified using NMR. Overall, 1.58 g iturin-rich extract containing 164.06 mg/g iturins was obtained from 100 g pepper straw, illustrating the great potential of valorising pepper straw via this process.

Original languageEnglish
Article number129010
Number of pages9
Early online date1 Apr 2023
Publication statusPublished - Jun 2023

Bibliographical note

Funding Information:
This work was supported by the Key Laboratory of Tobacco Pest Monitoring & Integrated Management(KLTMMIMT2022-09), by the International Foundation of Tobacco Research Institute of CAAS (IFI202103), by the Major Tobacco Science and Technology Projects(110202101054(LS-14), 20220007, YXYC2022008), by the Agricultural Science and Technology Innovation Program of China (ASTIP-TRIC04, ASTIP-TRIC06).

Publisher Copyright:
© 2023 Elsevier Ltd


  • B. amyloliquefaciens
  • Fermentation
  • Hydrolysis
  • Iturin
  • Pepper straw

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