Marine microbes drive biogeochemica

Marine microbes drive biogeochemical transformations in the ocean. Coles et al. (2017) used a PLM to simulate multiple microbes with different functions (e.g., light harvesting, nitrification, and heterotrophy) in the Atlantic. Each function was represented by a model gene and matched to one or more real genes. For example, the model gene pcb-hl (light harvesting, low nutrient, high light adapted) was matched to psbA, pufL, and pufM. The model gene pcaH (heterotrophy, degradation of aromatic hydrocarbons, often terrestrially derived organic matter) was matched to pcaH, vanA, tannase, and bglA. The authors compared modeled gene and transcript levels with observations on an absolute (genes per liter) and relative basis, respectively. The model was able to reproduce several observed patterns, such as the increase in pcaH (degradation of lignin-related or aromatic compounds) transcript levels with the concentration of colored dissolved organic matter (Figure 9).