As the need for crops escalates, the application of chemicals against plant pathogens drastically increases, swaying the ecosystem balance. Biocontrol utilizing the bacteria strain Chitinophaga pinensis as an alternative provides a more sustainable solution to prevent fungal and oomycete diseases from attacking vulnerable crops. The project goal is to further investigate and quantify actual antagonizing effects of C. pinensis, which has been shown in preliminary data to be capable of some pathogen antagonism. This project also plans to develop a conceptual mechanism to explain the antagonism, including the role of cell wall degrading enzymes. Though being a pilot study, this project lays a firm groundwork for future development at all aspects with results obtained.

The clear pattern of Inhibition Effects (IE) exhibited by C. pinensis regarding thethree pathogens of choice, Aphanomyces cochlioides, Aphanomyces euteiches, and Phytophthora capsici, was shown from Agar Plate Inhibition Test (APIT) and enzyme activity assay results. There is high likelihood that the IE observed in these labscale microbiological experiments can be translated into an efficient protection strategy for plants. The extracellular secretome of C. pinensis appeared inhibitory as expected,which aligned well with previous proteomic predictions. The supplementation of different Carbon Source (CS)s did seemingly induce different enzymes and differences in bacterial growth rate, where future mass spectrometry analyses can reveal the actual enzyme composition to help perfect the model of Cell Wall (CW) degradation. Nonetheless, the profound IE observed with living C. pinensis cells and some isolated secretomes suggested that growth on certain CS could prime the bacterium for a stronger biocontrol response especially in CW degradation that contributes to pathogen inhibition. The C. pinensis growth rate in precultivation is thus found to be partly predictive of IE.

More research is essential to finely put together this delicate theoretical model. Both in planta pathogen IE and mycological fluorescent microscopy for closeup oomycete-bacteria interaction are also recommended for, intriguingly, some bacteria contaminants in APIT were found thriving on Oomycete Cell Wall (OCW) substances presented, depicting the complexity of this welltuned microcommunity. Efforts should be spent to ultimately promote biocontrol to markets, where a resilient soil microstatus is created via bacterial supplementation, suppressing pathogen invasion with symbiosis rather than additional chemicals.

In future food industrial application, the biocontrol model stands for sustainability as well as reempowers the natural resilience, through which the food justice highlighted in Sustainable Development Goals (SDGs) 2: Zero Hunger, can be embodied with the expected higher crops yields.