Advanced strategy to produce insecticidal destruxins from lignocellulosic biomass Miscanthus

Ho Myeong Kim,In Min Hwang,Tae Young Shin,Ho Hyun Chun,Hae Woong Park,Junheon Kim,Jong Cheol Kim,Seung Gon Wi,In Seong Choi,Jin-Cheol Kim,Seoyoun Lee,Jae Su Kim

doi:10.1186/s13068-019-1530-8

Ho Myeong Kim, In Min Hwang + Show 10 more

Open Access

https://doi.org/10.1186/s13068-019-1530-8

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Abstract

BackgroundBiorefineries are widely recognized as the most feasible solution to the problem of achieving environmental sustainability along with economic growth. Furthermore, pine wilt disease has caused severe environmental and economic damage worldwide to date. Herein, a highly efficient, advanced process for producing destruxins (DTXs) from Miscanthus (MCT) is reported, along with an application strategy.ResultsThe acetic acid–sodium chlorite pretreatment of MCT (AASC-MCT) is found to improve the monosaccharide production. Through biocatalytic conversion processes (simultaneous saccharification and cultivation), Metarhizium anisopliae JEF-279 can efficiently produce DTXs from 1% (w/v) AASC-MCT, i.e., DTX E (334.8 mg/L), A (288.8 mg/L), and B (48.6 mg/L). Monochamus alternatus (MA, Japanese pine sawyer) is known to act as a mediator transferring Bursaphelenchus xylophilus to pinewood. As B. xylophilus is associated with the occurrence of pine wilt disease, biological control of MA is a major strategy or controlling this disease. In this study, upon the application of a mixture of DTXs and protease-containing culture filtrate (PCF), complete mortality of MA is observed after a 5-day incubation. The MA immune system response is believed to cause an overexpression of actin and tropomyosin as a defense mechanism against the flaccid paralysis induced by the DTXs and PCF treatment.ConclusionsThese results suggest that MCT can be used as a major feedstock in the biorefinery industry and that DTXs can be applied as an insecticide for biological control of pine wilt disease via MA termination.

Highlights

Biorefineries are widely recognized as the most feasible solution to the problem of achieving environ‐ mental sustainability along with economic growth
According to the gas chromatography (GC) analysis, the monosaccharide compositions of the RAWMCT, hydrogen peroxide–acetic acid (HPAC)-MCT, and acetic acid–sodium chlorite (AASC)-MCT mainly consisted of glucose and xylose (Table 1)
The AASC pretreatment more effectively improved the brightness than the HPAC pretreatment because of the efficient removal of lignin

Summary

Introduction

Biorefineries are widely recognized as the most feasible solution to the problem of achieving environ‐ mental sustainability along with economic growth. Pine wilt disease has caused severe environmental and economic damage worldwide to date. The growing demand for chemical-based products constitutes a serious problem for the environment, as fossil fuels are used excessively to manufacture such products. Biorefineries are widely recognized as the most feasible solution to the problem of achieving environmental sustainability, and they promote the growth of the bio-based economy [1]. Pine wilt disease severely damages both environments and economies worldwide, and the pinewood nematode Bursaphelenchus xylophilus is recognized as a major cause of this disease [6]. Overuse of chemical insecticides negatively affects the health of humans and other life forms [7]. Biological control of MA is required to prevent pine wilt disease from spreading

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