Optogenetic technology, which utilizes light to control genetically encoded light sensitive ion channels and pumps, has made a significant impact on neuroscience and neurotechnology since it allows to modulate selective neurons. Even though it is an ideal technology for numerous biological researches, irreversible and permanent gene modifications of biological tissues by lentriviral vectors in optogenetics hinder many real biological systems that require no gene modifications. Here, we present online optical regulation and photocurrent sensor for monitoring microalgal bioreactor system without permanent gene modifications. We accomplish a real-time, in-situ and noninvasive microalgae culture sensor for cell growth and high-value metabolite production monitoring based on electrophysiological response via optical regulation of microalgae. We develop a dual-compartment sensor system to monitor photocurrent originated from light-gated ion channels (channelrhodopsins) in microalgae population upon light illumination. We demonstrate growth phase monitoring by showing that the temporal dynamics of photocurrent over a microalga culture period is highly correlated with cell growth. Also, we observe that the temporal dynamics of photocurrent is highly correlated with dynamics of the high-value metabolite accumulation in microalgae cells, which can be useful as a strategic index for algal cultivation. We believe online optical control and photocurrent sensor holds great potentials for in-situ, real-time monitoring in large-scale microalgal farming for harvesting energy and environmental surveillance.
Project end date: 08/12/19