Marine Biogeochemistry Division, GEOMAR Helmholtz Centre for Ocean Research, Kiel 24148, Germany.
Research Unit Marine Natural Products Chemistry, GEOMAR Helmholtz Centre for Ocean Research, Kiel 24106, Germany.
Nat Commun. 2017 May 19;8:15465. doi: 10.1038/ncomms15465.
In certain regions of the predominantly nitrogen limited ocean, microbes can become co-limited by phosphorus. Within such regions, a proportion of the dissolved organic phosphorus pool can be accessed by microbes employing a variety of alkaline phosphatase (APase) enzymes. In contrast to the PhoA family of APases that utilize zinc as a cofactor, the recent discovery of iron as a cofactor in the more widespread PhoX and PhoD implies the potential for a biochemically dependant interplay between oceanic zinc, iron and phosphorus cycles. Here we demonstrate enhanced natural community APase activity following iron amendment within the low zinc and moderately low iron Western North Atlantic. In contrast we find no evidence for trace metal limitation of APase activity beneath the Saharan dust plume in the Eastern Atlantic. Such intermittent iron limitation of microbial phosphorus acquisition provides an additional facet in the argument for iron controlling the coupling between oceanic nitrogen and phosphorus cycles.
在以氮限制为主的海洋的某些区域，微生物可能会受到磷的共同限制。在这些区域内，一部分溶解有机磷库可以被微生物利用各种碱性磷酸酶（APase）酶来获取。与利用锌作为辅助因子的 PhoA 家族 APases 不同，最近发现铁是更广泛的 PhoX 和 PhoD 的辅助因子，这意味着海洋锌、铁和磷循环之间可能存在生物化学依赖的相互作用。在这里，我们在低锌和适度低铁的北大西洋西部发现，铁的添加会增强自然群落的 APase 活性。相比之下，我们在东大西洋撒哈拉尘埃羽流下方没有发现 APase 活性受到痕量金属限制的证据。这种微生物磷获取的间歇性铁限制为铁控制海洋氮磷循环耦合的论点提供了另一个方面。
