Biosciences, University of Exeter, Exeter, UK.
Nat Ecol Evol. 2019 Aug;3(8):1206-1216. doi: 10.1038/s41559-019-0944-9. Epub 2019 Jul 22.
Microbes commonly deploy a risky strategy to acquire nutrients from their environment, involving the production of costly public goods that can be exploited by neighbouring individuals. Why engage in such a strategy when an exploitation-free alternative is readily available whereby public goods are kept private? We address this by examining metabolism of Saccharomyces cerevisiae in its native form and by creating a new three-strain synthetic community deploying different strategies of sucrose metabolism. Public-metabolizers digest resources externally, private-metabolizers internalize resources before digestion, and cheats avoid the metabolic costs of digestion but exploit external products generated by competitors. A combination of mathematical modelling and ecological experiments reveal that private-metabolizers invade and take over an otherwise stable community of public-metabolizers and cheats. However, owing to the reduced growth rate of private-metabolizers and population bottlenecks that are frequently associated with microbial communities, privatizing public goods can become unsustainable, leading to population decline.
微生物通常采用一种有风险的策略从环境中获取营养物质，这种策略涉及到产生昂贵的公共物品，而这些公共物品可以被邻近的个体利用。既然有现成的无剥削替代方案，即私人拥有公共物品，为什么还要采用这种策略呢？我们通过检查酿酒酵母在其自然状态下的代谢情况，并通过创建一个新的三菌株合成群落来解决这个问题，该群落采用了不同的蔗糖代谢策略。公共代谢物在外部消化资源，私人代谢物在消化前将资源内化，而骗子则避免消化的代谢成本，但会利用竞争对手产生的外部产品。数学建模和生态实验的结合表明，私人代谢物会入侵并接管原本由公共代谢物和骗子组成的稳定群落。然而，由于私人代谢物的生长速度较慢，并且微生物群落经常出现种群瓶颈，将公共物品私有化可能变得不可持续，导致种群减少。
