Iron and Harmful Algae Blooms: Potential Algal-Bacterial Mutualism Between Lingulodinium polyedrum and Marinobacter algicola

Abstract

Phytoplankton blooms can cause acute effects on marine ecosystems either due to their production of endogenous toxins or due to their enormous biomass leading to major impacts on local economies and public health. Despite years of effort, the causes of harmful algal blooms (HAB) are still not fully understood. Our hypothesis is that bacteria that produce photoactive siderophores may provide a bioavailable form of iron to commensally associated phytoplankton, which could in turn affect algal growth and bloom dynamics. Here we report a laboratory-based study of binary cultures of the dinoflagellate Lingulodinium polyedrum, a major HAB species, with Marinobacter algicola DG893, a phytoplankton-associated bacterium that produces the photoactive siderophore vibrioferrin. Comparing binary cultures of L. polyedrum with both the wild type and the vibrioferrin minus mutant of M. algicola shows that bacteria are necessary to promote dinoflagellate growth and that this growth promotion effect is at least partially related to the ability of the bacterium to supply bioavailable iron via the siderophore vibrioferrin. These results support the notion of a carbon for iron mutualism in some bacterial-algal interactions.

Algicidal Bacteria: A Review of Current Knowledge and Applications to Control Harmful Algal Blooms

“…Many algal-bacterial interactions have crystalized around metal exchanges ( Amin et al, 2017 ; Yarimizu et al, 2018 ; Johansson et al, 2019 ), suggesting a role for metal chelators in algicidal interactions. Iron, in particular, is a crucial trace metal that limits microbial growth in the ocean ( Moore et al, 2013 ).…”

Characterization and Genomic Analysis of Marinobacter Phage vB_MalS-PS3, Representing a New Lambda-Like Temperate Siphoviral Genus Infecting Algae-Associated Bacteria

“…A novel Marionbacter phage vB_MalS-PS3 was isolated from the western Pacific Ocean, serving M. algicola DG893(T) as its host. Phytoplankton blooms can cause acute effects on marine ecosystems, one hypothesis is that bacteria producing photoactive iron carriers can provide a bioavailable form of iron for symbiotic phytoplankton, which in turn will affect the growth and bloom dynamics of algae ( Yarimizu et al, 2018 ). M. algicola DG893(T) is a phytoplankton-associated bacterium that produces the photoactive siderophore vibrioferrin ( Romano et al, 2013 ).…”

“…Marinobacter genus is one of the important algal-associated bacterial groups in marine environments ( Gonzalez et al, 2000 ; Buchan et al, 2014 ). Marinobacter algicola DG893(T) was isolated from paralytic shellfish toxin-producing dinoflagellates ( Green et al, 2006 ), and had been proposed to generate photoactive siderophores that may offer a bioavailable form of iron to commensally associated phytoplankton, affecting algal growth and bloom dynamics ( Yarimizu et al, 2018 ). In addition, petroleum pollution has become a serious environmental problem in the sea, along with the occasional and various release routes such as oil mining, accidental oil spills, shipping transportation, and industrial activities ( Cui et al, 2008 ).…”

Exploring New Frontiers in Marine Radioisotope Tracing – Adapting to New Opportunities and Challenges

“…Other studies have linked trace elements, such as Li, Se, and Ni, to HAB species (Kudela et al, 2010). Algalbacterial interactions may also be involved in bloom dynamics, with siderophore-producing bacteria potentially supplying iron to HAB species (Yarimizu et al, 2018). Given the potential links between various trace metals and HAB toxin production, the use of sensitive radiotracers, such as 59 Fe, would enable experiments with environmentally relevant concentrations of elements potentially implicated in HAB initiation, biotoxin production, and physiology.…”