Expanding the nutrition ecology framework: Microbes as a mechanism regulating resource acquisition and utilization by primary and secondary consumers

Nutrition ecology provides a framework to investigate nutrient-organism relationship within an ecological scope, which integrates ontology, distribution, adaptation, and evolution for understanding food web dynamics. However, the roles of microbes have largely been ignored. For example, most nutrition ecology research focus on nutrition ratio impacts, such as protein to carbohydrate ratio, on organism. Since the announcement of the Human Microbiome Project in 2008, microbial factors in such processes have received more attention as their relationship with other multi-cellular organisms in an ecosystem are better understood. The research being presented examined the significance of microbes in the nutrition ecology framework. Specifically, the microbes-nutrition interaction effects on the life-history of the blow fly, Lucilia sericata (Diptera: Calliphoridae) was examined fed a diet varying in protein:lipids (27:3, 25:5, and 23:7) or PBS control in combination with Proteus mirabilis (commensal with L. sericata) at 10⁷ and 10⁴ cfu/g or Salmonella typhimurium (commonly associated with L. sericata larval environment) at Survivorship and development time to pupal stage and adult stages, pupal weight, and adult longevity were measured. Results indicated lower protein diet reduces the survivorship and increases development time of blow fly. However, low concentration (10⁴ cfu/g) of P. mirabilis increases survivorship of blow fly on low protein diet comparing with PBS treatment. Previous study indicated P. mirabilis attraction for L. sericata oviposition. We hypothesize P. mirabilis at specific concentration may assist L. sericata in overcoming nutritional stress. This also provided a possible insight to integrating microbial factors into the nutrition ecology framework.