Recognition of algae by microcontact-imprinted polymers modulates hydrogenase expression

Abstract

Because the extracellular matrix is known to affect animal cell metabolism, there is good reason to explore whether physical and chemical environments might similarly affect algal cell metabolism and, consequently, hydrogen production, which can be used for electricity generation in miniature biofuel cells. In this work, green algae were microcontact-imprinted onto a poly(ethylene-co-vinyl alcohol) (EVAL) film. Scanning electron microscopy was used to characterize the surface morphology, and Raman spectroscopy was used to assay for algal cytochrome species involved in electron transfer and hydrogen production. The production of hydrogen by algae was measured electrochemically. The power and current density of algal biofuel cells that use algae-imprinted, or non-imprinted EVAL-coated and control electrodes were measured and compared. Finally, hydrogenase mRNA levels in algae on various substrates were measured using quantitative reverse transcription polymerase chain reaction (qRT-PCR), providing direct evidence that culturing algae on the imprinted substrate leads to increased hydrogenase gene expression.