(1-Oxo-2,6,7-trioxa-1-phosphabicyclo­[2.2.2]octan-4-yl)methyl 4-methyl­benzene­sulfonate

In the title compound, C12H15O7PS, the P atom has a distorted tetra­hedral environment. The P—O—C—C torsion angles deviate significantly from zero [average = 12.0 (3)°], indicating that the bicyclic OP(OCH2)3C cage is strained. In the crystal, weak C—H⋯O inter­actions consolidate the packing

1H-1,2,4-Triazol-4-ium 4-nitro­benzene­sulfonate monohydrate

In the 4-nitro­benzene sulfonate anion of the title compound, C2H4N3 +·C6H4NO5S−·H2O, the nitro group is slightly twisted from the plane of the benzene ring [dihedral angle = 2.8 (3)°]. In the crystal, the three components are linked via N—H⋯O, O—H⋯N, O—H⋯O and C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane. A short inter­molecular O⋯N contact of 2.872 (3) Å is also observed between the nitro and sulfonate groups

3-Amino­phenyl naphthalene-1-sulfonate

In the title compound, C16H13NO3S, the plane of the naphthalene ring system forms a dihedral angle of 64.66 (10)° with the benzene ring. The mol­ecular structure is stabilized by weak intra­molecular C—H⋯O inter­actions and the crystal packing is stabilized by weak inter­molecular N—H⋯O and C—H⋯O inter­actions and by π–π stacking inter­actions of the inversion-related naphthalene units [centroid–centroid distance of 3.7373 (14) Å]

6-Formyl-2-meth­oxy-3-nitro­phenyl 4-toluene­sulfonate

In the title compound, C15H13NO7S, the inter­planar angle between the two aromatic rings is 26.04 (3)°. The crystal structure is stabilized by C—H⋯O interactions

Desert Dust as a Source of Iron to the Globally Important Diazotroph Trichodesmium

The marine cyanobacterium Trichodesmium sp. accounts for approximately half of the annual ‘new’ nitrogen introduced to the global ocean but its biogeography and activity is often limited by the availability of iron (Fe). A major source of Fe to the open ocean is Aeolian dust deposition in which Fe is largely comprised of particles with reduced bioavailability over soluble forms of Fe. We report that Trichodesmium erythraeum IMS101 has improved growth rate and photosynthetic physiology and down-regulates Fe-stress biomarker genes when cells are grown in the direct vicinity of, rather than physically separated from, Saharan dust particles as the sole source of Fe. These findings suggest that availability of non-soluble forms of dust-associated Fe may depend on cell contact. Transcriptomic analysis further reveals unique profiles of gene expression in all tested conditions, implying that Trichodesmium has distinct molecular signatures related to acquisition of Fe from different sources. Trichodesmium thus appears to be capable of employing specific mechanisms to access Fe from complex sources in oceanic systems, helping to explain its role as a key microbe in global biogeochemical cycles

A Key Marine Diazotroph in a Changing Ocean: The Interacting Effects of Temperature, CO2 and Light on the Growth of Trichodesmium erythraeum IMS101

Trichodesmium is a globally important marine diazotroph that accounts for approximately 60-80% of marine biological N2 fixation and as such plays a key role in marine N and C cycles. We undertook a comprehensive assessment of how the growth rate of Trichodesmium erythraeum IMS101 was directly affected by the combined interactions of temperature, pCO2 and light intensity. Our key findings were: low pCO2 affected the lower temperature tolerance limit (Tmin) but had no effect on the optimum temperature (Topt) at which growth was maximal or the maximum temperature tolerance limit (Tmax); low pCO2 had a greater effect on the thermal niche width than low-light; the effect of pCO2 on growth rate was more pronounced at suboptimal temperatures than at supraoptimal temperatures; temperature and light had a stronger effect on the photosynthetic efficiency (Fv/Fm) than did CO2; and at Topt, the maximum growth rate increased with increasing CO2, but the initial slope of the growth-irradiance curve was not affected by CO2. In the context of environmental change, our results suggest that the (i) nutrient replete growth rate of Trichodesmium IMS101 would have been severely limited by low pCO2 at the last glacial maximum (LGM), (ii) future increases in pCO2 will increase growth rates in areas where temperature ranges between Tmin to Topt, but will have negligible effect at temperatures between Topt and Tmax, (iii) areal increase of warm surface waters (> 18°C) has allowed the geographic range to increase significantly from the LGM to present and that the range will continue to expand to higher latitudes with continued warming, but (iv) continued global warming may exclude Trichodesmium spp. from some tropical regions by 2100 where temperature exceeds Topt