Effective in situ harvest of microalgae with bacterial cellulose produced by Gluconacetobacter xylinus

A new biological approach was explored to harvest microalgae in situ with bacterial cellulose produced by Gluconacetobacter xylinus grown in microalgal culture by adding different proportions of glucose/yeast extract (GY) media. This study attempted to optimize this process in terms of GY media concentration, process time, microalgae cell concentration, and oscillation speed. Bacterial cellulose successfully harvested nearly 90% of Scenedesmus obliqnus and Chlamydomonas reinhardtii after only 8 h, and 92% of Chlorella vulgaris after 48 h, with supplementation of 30% (v/v) GY media to the microalgae culture. This method allows harvested media to be recycled instead of GY media, and can be used for a variety of cell densities. Scanning electron microscopy revealed that microalgae cells were harvested after being embedded in a network of bacterial cellulose. These results suggest this effective and simple operation has the potential for developing a cost-effective harvest method for microalgae production.