Pseudomonas sp. Produce Bioflocculants for Microalgae Harvest

Bioflocculation has been developed as an effective method to harvest microalgae. However, the high production cost of bioflocculants makes it difficult to scale up. Haipeng Guo of Lakehead University in China aimed to develop low-cost bioflocculants using untreated corn stover and a biomass-degrading bacterium, Pseudomonas sp. GO2.

Pseudomonas sp. GO2 showed excellent production of bioflocculants by directly hydrolyzing various biomasses. The untreated corn stover was selected as carbon source for bioflocculants' production due to its high flocculating efficiency. Biochemical analysis showed that bioflocculants contained 59.0% polysaccharides with uronic acid (34.2%), 32.1% protein, and 6.1% nucleic acid. In addition, the bioflocculants showed the highest flocculating efficiency and were stable over broad ranges of pH and temperature.

These results indicate that Pseudomonas sp. GO2 can directly use various untreated biomasses to produce low-cost bioflocculants. The produced bioflocculants showed high efficiency to harvest two green microalgae in a low GO2 fermentation broth/algal culture ratio.