From Harsh Environments to the Field: Taiwan Develops a Practical Biological Pesticide

Chemical pesticides remain a cornerstone of modern agriculture because they are reliable and effective. However, growing concerns about environmental impact, increasing resistance, and long-term sustainability have intensified the search for safer alternatives. Biological pesticides offer clear advantages, yet many fail to perform consistently in the field, breaking down under strong sunlight or proving difficult to integrate with existing agricultural practices.

At National Kaohsiung Normal University, researchers set out to address this gap by rethinking how biological crop-protection agents are developed. Rather than relying solely on laboratory screening, the team focused on microorganisms that have already adapted to demanding natural environments. Led by Professor Chien-Yan Hsieh, the researchers isolated a strain of Bacillus amyloliquefaciens from mud volcano environments in southern Taiwan—areas characterized by intense sunlight and chemically challenging conditions.

These harsh environments act as a natural filter. Microorganisms that survive there must tolerate stresses similar to those encountered in open agricultural fields. The selected bacterium produces iturin A, a naturally occurring antifungal compound widely reported to be effective against plant diseases and to have low toxicity to humans and animals. While iturin A has been studied internationally for many years, producing it efficiently at scale and ensuring stability under real-world conditions have remained persistent challenges.

To overcome these barriers, the research team optimized fermentation processes across both solid-state and submerged systems, improving production efficiency while incorporating agricultural by-products, such as rice bran, to support more sustainable manufacturing. The formulation was also designed to tolerate ultraviolet exposure and remain compatible with commonly used chemical pesticides, allowing farmers to integrate the biological product into existing pest management programs rather than replacing them entirely.