The coccosphere of the heavy calcifying coccolithophore Coccolithus braarudii provides defense against bacteria
[Translation unavailable] The coccosphere of the heavy calcifying coccolithophore Coccolithus braarudii provides defense against bacteria
Sophie T. Zweifel, Richard J. Henshaw, Roberto Pioli et al.
摘要 Coccolithophores produce 40–60% of marine calcium carbonate, largely through biomineralization of plates which encase cells in a ‘coccosphere’. Despite the importance of coccolithophore calcification in ocean biogeochemistry, its function remains unresolved. A hypothesis suggesting it acts as a physical deterrent has been investigated in grazers and viruses, but not in bacteria. Here we show bacterial pathogenicity in heavily-calcified 布氏梭菌 治疗用 赫胥氏地藻 细菌病原体， 抑制褐杆菌 , is only observed with decalcified algae, leading to algal-cell death within as little as 15 hours.脱钙藻细胞死亡率为 抑制假单胞菌 -specific and likely requires close proximity, since treatment with bacterial supernatant or growth-inhibiting concentrations of indole-3-acetic acid shows no detrimental effect. Additionally, scanning electron microscopy shows visible bacterial attachment only on decalcified 布氏梭菌 。 These findings provide the first experimental evidence that the coccosphere can act as a barrier against specific bacteria, highlighting its defensive role in coccolithophores.