We describe a flow-through biosensor for online continuous water toxicity monitoring. At the heart of the device are disposable modular biochips incorporating agar-immobilized bioluminescent recombinant reporter bacteria, the responses of which are probed by single-photon avalanche diode detectors. To demonstrate the biosensor capabilities, we equipped it with biochips harboring both inducible and constitutive reporter strains and exposed it to a continuous water flow for up to 10 days. During these periods we challenged the biosensor with 2-h pulses of water spiked with model compounds representing different classes of potential water pollutants, as well as with a sample of industrial wastewater. The biosensor reporter panel detected all simulated contamination events within 0.5-2.5 h, and its response was indicative of the nature of the contaminating chemicals. We believe that a biosensor of the proposed design can be integrated into future water safety and security networks, as part of an early warning system against accidental or intentional water pollution by toxic chemicals.

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Marine macroalgae are an attractive source for biorefineries as an alternative to terrestrial crops, and new, sustainable macroalgae biomass fractionation methods are needed. One of the least investigated macroalgae-derived products is starch. In this work, we report on a device and a protocol for pretreatment for starch extraction from a green macroalga Ulva ohnoi (U. ohnoi) with an emerging, nonthermal, and environmental friendly technologypulsed electric field (PEF). Using the custom-made insulated gate bipolar transistor-pulsed generator combined with a gravitation press-electrode device, we show that 200 pulses with a field strength of 1 kV cm −1 , pulse duration of 50 μs, and pulse repetition rate of 3 Hz concentrate the starch in the U. ohnoi biomass by 59.38% by removing the salts, proteins, and other small molecules. The starch extraction yield from the PEF-pretreated biomass is 59.54 ± 1.34%, compared to 52.31 ± 3.21% from untreated biomass. In addition, PEF combined with pressing increased the coextracted macroalgae protein by more than 4 times and ash by 1.5 times in comparison with pressing alone. These results indicate the potential of PEF pretreatment for challenging macroalgae biomass fractionation in the sustainable marine biorefinery.

A major concern in tissue biopsies with a needle is missing the most lethal clone of a tumor, leading to a false negative result. This concern is well justified, since needle-based biopsies gather tissue information limited to needle size. In this work, we show that molecular harvesting with electroporation, e-biopsy, could increase the sampled tissue volume in comparison to tissue sampling by a needle alone. Suggested by numerical models of electric fields distribution, the increased sampled volume is achieved by electroporation-driven permeabilization of cellular membranes in the tissue around the sampling needle. We show that proteomic profiles, sampled by e-biopsy from the brain tissue, ex vivo, at 0.5mm distance outside the visible margins of mice brain melanoma metastasis, have protein patterns similar to melanoma tumor center and different from the healthy brain tissue. In addition, we show that e-biopsy probed proteome signature differentiates between melanoma tumor center and healthy brain in mice. This study suggests that e-biopsy could provide a novel tool for a minimally invasive sampling of molecules in tissue in larger volumes than achieved with traditional needle biopsies.

Optimization of protocols is required for each specific type of biomass processed by electroporation of the cell membrane with high voltage pulsed electric fields (PEF). Such optimization requires convenient and adaptable laboratory systems, which will enable determination of both electrical and mechanical parameters for successful electroporation and fractionation. In this work, we report on a laboratory PEF system consisting of a high voltage generator with a novel asymmetric voltage multiplying architecture and a treatment chamber with sliding electrodes. The system allows applying 29 pulses of up to 4 kV and 1 kA with a pulse duration between 1 μs and 100 μs. The allowable energy 30 dissipated per pulse on electroporated biomass is determined by the conditions for cooling the biomass in the electroporation cell. The device was tested on highly conductive green macroalgae 32 from Ulva sp., a promising but challenging feedstock for the biorefinery. Successful electroporation 33 was confirmed with bioimpedance measurements. Industrial relevanceSeaweed biomass is an emerging feedstock for biorefineries with already 30 million tons per year of global industrial production. However, most of the biomass produced today is lost. Pulsed electric field (PEF) extraction could allow saving energy on biomass drying, deashing and it could allow extracting various organic compounds. However, the parameters needed to seaweed biomass treatment with PEF are not known and will differ from species to species. Furthermore, very high salt content challenges most of the available laboratory PEF devices, limiting the ability for parameters optimization in the lab. The developed laboratory scale PEF system coupled to bioimpedance measurement provides a necessary set of tools and methods for PEF parameters optimization required for process scale-up.