Assessing the Effect of Temperature on Streptomyces Griseus Growth and Metabolism

Abstract

With the current rate of population growth, it is estimated that global food production will need todouble over the course of the next century to sustain healthy diets on the global scale. Given the limited amount of arable land that could be used for agriculture, gains in crop production will need to come from improving current practices rather than from expanding farmlands. The Food and Agriculture Organization (FAO) estimates that 20-40% of yearly crop losses can be attributed to pests, with the majority of damages coming from pathogens. Rhizobacteria like Streptomyces griseus can defend plants from pathogens and even promote plant growth, but it is unknown how this bacterium’s growth and metabolism will respond to rising global temperatures. We used a combination of high resolution FTICR-MS and LC-MS/MS to assess changes in bacterial metabolism (including primary and secondary metabolites) as a function of increasing temperature. Analysis of microbial growth curves and metabolomics data revealed that microbial activity, metabolite abundance/diversity, and the production of compounds beneficial to plants were greatest at 22 ??? intermediate at 35 ??? with practically no activity at 4 ?C. These results suggest that as global temperatures rise, S. griseus may confer fewer benefits to plants. If other rhizobacteria respond in similar ways, current methods of pest and pathogen control must be improved, or new methods must be developed, to reduce crop losses to pathogens. Reducing crop losses to pathogens will be paramount to ensure that global food security is achieved by the end of the century and beyond.