MSB: Do cheaters ever win? Examining microbial competition and extracellular enzyme production

微生物具有高度多样性，在所有生态系统中发挥着关键作用。这些功能之一是将死去的植物和动物的碳和营养物质循环回活的生物体可以使用的形式。微生物通过产生胞外酶来催化这一过程，胞外酶在细胞外运作并释放小分子作为食物来源。然而，酶的生产是昂贵的，进化可能有利于微生物？作弊？通过从邻居那里截取资源而不支付酶生产的成本。该项目的目的是确定作弊微生物是否能在竞争中战胜酶生产者，以及竞争是否取决于环境因素。研究人员将用假单胞菌和海洋中的细菌分离物来解决这个问题。这个项目很重要，因为全球碳和营养循环依赖于微生物酶生产者。胞外酶为农作物、森林和海洋浮游生物提供营养，支持陆地和海洋食物网。如果人类活动以促进作弊微生物的方式改变微生物群落，这些关键功能可能会受到影响。酶的生产还控制着死亡植物和动物碳的比例，这些碳以二氧化碳的形式返回大气。因此，这项研究的结果可以帮助预测未来温室气体的浓度。

Microorganisms are highly diverse and perform critical functions in all ecosystems. One of these functions is the cycling of carbon and nutrients from dead plants and animals back into forms that living organisms can use. Microbes catalyze this process by producing extracellular enzymes that operate outside the cell and release small molecules that serve as a food source. However, enzyme production is expensive, and evolution may favor microbes that ?cheat? by intercepting resources from their neighbors without paying the cost of enzyme production. The aim of this project is to determine whether cheater microbes can outcompete enzyme producers, and whether competition depends on environmental factors. The researchers will address this question with Pseudomonas bacteria and bacterial isolates from the ocean.This project is important because global carbon and nutrient cycles depend on microbial enzyme producers. Extracellular enzymes supply nutrients to crop plants, forests, and marine plankton that support land and ocean food webs. If human activities alter microbial communities in ways that promote cheater microbes, these critical functions could be affected. Enzyme production also controls the fraction dead plant and animal carbon that returns to the atmosphere as carbon dioxide. Therefore, the results from this research could help predict future concentrations of greenhouse gases.