Yeasts and bacteria that produce lactic acid and alcohol in preserved foods make up a fermentation ecosystem that includes the succession of species, partitioning of resources, disturbance and equilibrium found in larger ecosystems. Fermentation ecosystems can be used as an instructional tool to both explain and study ecological concepts, resulting in a more detailed understanding of the ecology of human nutrition. The ZAMFERM (Experimental evolution of microbial eco-systems in traditional Zambian fermented products) project employed traditional fermented products as a natural model system that could be experimentally manipulated to test evolutionary hypotheses. Researchers established which factors affect ecosystem evolutionary dynamics and tested hypotheses on the repeatability of ecosystem evolution. The project also tested predictions based on the long-standing ‘competitive exclusion’ hypothesis, which states that two species that compete for the exact same resources cannot stably coexist. These important questions regarding evolutionary biology were addressed using classical comparative methods as well as approaches based on laboratory experimental evolution. Once field interviews about processing techniques had been conducted with local people a series of field experiments were set up and carried out. During these experiments the microbial communities in the traditional fermented products were extensively sampled at various stages of the production process. These samples were then analysed in the laboratory to determine their composition. Project work represents a significant advance beyond the current state of the art by using traditional fermented products to take experimental evolution outside the laboratory and extend it to include the complexity of entire microbial ecosystems. ZAMFERM work highlights the importance of the indoor, microbial ecology of fermented foods. This truly unique and innovative study provided manipulatable, natural experimental systems that were previously lacking, in order to directly test evolutionary hypotheses. It also highlighted the importance of evolutionary process in shaping ecosystems.
Traditional fermented products, Zambia, evolution, microbial ecosystems, ZAMFERM