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Kleptoplastic mixotrophic species of the genus Dinophysis are cultured by feeding with the ciliate Mesodinium rubrum, itself a kleptoplastic mixotroph, that in turn feeds on cryptophytes of the Teleaulax/Plagioselmis/Geminigera (TPG) clade. Optimal culture media for phototrophic growth of D. acuminata and D. acuta from the Galician Rías (northwest Spain) and culture media and cryptophyte prey for M. rubrum from Huelva (southwest Spain) used to feed Dinophysis, were investigated. Phototrophic growth rates and yields were maximal when D. acuminata and D. acuta were grown in ammonia-containing K(-Si) medium versus f/2(-Si) or L1(-Si) media. Dinophysis acuminata cultures were scaled up to 18 L in a photobioreactor. Large differences in cell toxin quota were observed in the same Dinophysis strains under different experimental conditions. Yields and duration of exponential growth were maximal for M. rubrum from Huelva when fed Teleaulax amphioxeia from the same region, versus T. amphioxeia from the Galician Rías or T. minuta and Plagioselmis prolonga. Limitations for mass cultivation of northern Dinophysis strains with southern M. rubrum were overcome using more favorable (1:20) Dinophysis: Mesodinium ratios. These subtleties highlight the ciliate strain-specific response to prey and its importance to mass production of M. rubrum and Dinophysis cultures.

Kleptoplastic mixotrophic species of the genus Dinophysis are cultured by feeding with the ciliate Mesodinium rubrum, itself a kleptoplastic mixotroph, that in turn feeds on cryptophytes of the Teleaulax/Plagioselmis/Geminigera (TPG) clade. Optimal culture media for phototrophic growth of D. acuminata and D. acuta from the Galician Rías (northwest Spain) and culture media and cryptophyte prey for M. rubrum from Huelva (southwest Spain) used to feed Dinophysis, were investigated. Phototrophic growth rates and yields were maximal when D. acuminata and D. acuta were grown in ammonia-containing K(-Si) medium versus f/2(-Si) or L1(-Si) media. Dinophysis acuminata cultures were scaled up to 18 L in a photobioreactor. Large differences in cell toxin quota were observed in the same Dinophysis strains under different experimental conditions. Yields and duration of exponential growth were maximal for M. rubrum from Huelva when fed Teleaulax amphioxeia from the same region, versus T. amphioxeia from the Galician Rías or T. minuta and Plagioselmis prolonga. Limitations for mass cultivation of northern Dinophysis strains with southern M. rubrum were overcome using more favorable (1:20) Dinophysis: Mesodinium ratios. These subtleties highlight the ciliate strain-specific response to prey and its importance to mass production of M. rubrum and Dinophysis cultures.

Immunorecognition magnetic supports for the development of an electrochemical immunoassay for azaspiracid detection in mussels, DOI: 10.1016/j.bios.2017.02.015 URL: http://www.sciencedirect.com/science/article/pii/S0956566317301021 Filiació URV: SI Memòria, As azaspiracids (AZAs) are being reported from the coastal waters of an increasing number of countries on a global scale, the need for rapid, simple and cost-effective methods to detect these marine toxins and protect seafood consumers’ health is becoming evident. A magnetic bead (MB)-based direct immunoassay for the detection of AZAs, using protein G-coated MBs as supports for antibody immobilisation and peroxidase-labelled AZA as a tracer is detailed. A colorimetric approach was first developed to optimise the experimental parameters and establish the cross-reactivity factors for AZA-1–10. The subsequent combination of the immunorecognition MBs with 8-electrode arrays enabled the multiplexed electrochemical detection of AZAs. Naturally-contaminated mussel samples were analysed and the results obtained showed an excellent correlation with LC-MS/MS analysis. The MB-based immunoassay facilitated the quantification of a wide range of AZA concentrations (120–2875 μg AZA-1 equiv./kg), with a limit of detection (63 μg AZA-1 equiv./kg) below the European regulatory threshold, using a protocol that requires very few steps and a short analysis time (~ 15 min). The simplicity, cost-effectiveness, rapidity, robustness, selectivity and precision of the assay provide a valuable tool for the detection of all regulated AZAs and other toxic AZA analogues, suitable for end users in the field of food safety.

The development of the electronic detonator and its clear advantage in accurate delay timing has provided the quarrying, mining and civil blasting sectors with a number of opportunities for significant increases in efficiency. They reintroduce the benefit, lost with the advent of non-electric detonators, of testing the circuit before firing and enable detonators to be individually programmed with a timing accuracy of 0.5-1 ms. Site safety and vibration control are both improved, while potentially the greatest value is in the delivery of improved fragmentation as negative interaction between shock waves is reduced. Direct costs, however, are higher, whereas the saving in cost per ton by regulating output or reducing machinery wear over a period of years is less visible and not so easy to calculate. The best opportunity for cost savings and efficiencies lies in the introduction of electronic initiation systems in association with a wider review of quarrying operations., The development of the electronic detonator and its clear advantage in accurate delay timing has provided the quarrying, mining and civil blasting sectors with a number of opportunities for significant increases in efficiency. They reintroduce the benefit, lost with the advent of non-electric detonators, of testing the circuit before firing and enable detonators to be individually programmed with a timing accuracy of 0.5-1 ms. Site safety and vibration control are both improved, while potentially the greatest value is in the delivery of improved fragmentation as negative interaction between shock waves is reduced. Direct costs, however, are higher, whereas the saving in cost per ton by regulating output or reducing machinery wear over a period of years is less visible and not so easy to calculate. The best opportunity for cost savings and efficiencies lies in the introduction of electronic initiation systems in association with a wider review of quarrying operations.