An Open-Source Modular Bioreactor Platform for Cultivation of Synechocystis sp. PCC 6803 and Extraction of Intracellular Glucose.

Abstract

Rising carbon emissions have intensified the demand for sustainable biomanufacturing systems. Algae like Synechocystis sp. PCC 6803 lend themselves as a promising photosynthetic machine for high carbon-capture while generating valuable bioproducts like glucose, which can serve as a feedstock for downstream biofuel applications. However, current cultivation technologies remain expensive, closed-source, and poorly suited for integrated downstream processing. This study presents a low-cost, open-source bioreactor platform with integrated modules for cultivation, chemical lysis, and glucose extraction from Synechocystis biomass. The system incorporates a photobioreactor illuminated by a programmable Godox LED, a lysis module for acid and ultrasound-based cell disruption, and a pressure-driven filtration setup for lysis clarification. Optical density was continuously monitored using a custom-built light attenuation module, and glucose concentration was quantified using HPLC. Under an incident light intensity of approximately 400 μ mol photons m ^-2 s ^-1 , cultures reached a peak biomass productivity of 90 mg L ^-1 day ^-1 , with a specific growth rate of 0.166 day ^-1 over 7 days of culture. A random forest model was successfully developed to characterize the system, enabling prediction of the culture's optical density growth curve based on all measured environmental parameters. The model achieved a mean absolute error of 0.0009 with a variance of 0.0003 across a 10-fold cross-validation, demonstrating strong predictive accuracy. Post-lysis, glucose concentrations of up to 5.08 mg L ^-1 were obtained. The system demonstrated an approximate 65% reduction in cost compared to commercial alternatives. This modular platform provides a scalable, accessible solution for biomanufacturing research and education, and serves as a template for sustainable glucose bioproduction from cyanobacteria.