Data for: Dissolved organic matter (DOM) offsets the detrimental effects of climate change in the nitrogen fixing cyanobacterium Crocosphaera

Diazotrophs provide a significant reactive nitrogen source in the ocean.
Increased warming and stratification may decrease nutrient availability in
the future, forcing microbial communities to use dissolved organic matter
(DOM). Not depending on reactive nitrogen availability, diazotrophs may be
"winners" in a nutrient depleted ocean. However, their ability
to exploit DOM may influence this success. We exposed cultures of the
widespread Crocosphaera to low (26°C, pH 8.1), moderate (28°C, pH 8.0),
and extreme (30°C, pH 7.9) climate change scenarios, under control or
DOM-amended conditions. Growth was suboptimal in the low and extreme
treatments, and favoured in the moderate treatment. DOM was preferred as a
carbon source regardless of the treatment, and promoted N2 fixation in
extreme conditions. This was reflected in the increased expression of
photosynthesis genes to obtain energy. DOM provides Crocosphaera with a
key ecological advantage, possibly dictating diazotroph-derived nitrogen
inputs in the future ocean.