Lately, "Insights into differences between spore-assisted and pellet-assisted microalgae harvesting using a research paper by Professor Yu Hong of the School of Environmental Science and Engineering highly efficient fungus: efficiency, high-value substances and mechanisms" from the School of Environmental Science and Engineering is published in TOP journal in environment circle Science of the Total Environment (Q1, IF=10.753).
Microalgae have been recognized as a promising third-generation biofuel feedstock owing their fast reproduction rate, high lipid content, and CO2-fixing properties. Although microalgae cells can be processed into broad-spectrum biofuels, but several challenges hinder the development of algal biofuel technology for commercial practicality. The high price is the greatest setback limiting the commercialization of microalgae.
Recently, bio-flocculation by adding auto-flocculation microalgae, bacteria, fungi, or flocculent substances extracted from microorganisms has been considered a promising method for low-cost microalgal capture. Under certain conditions, harvesting microalgae with fungal pellets have many advantages, such as relatively low specific surface area, high loading, better stability, and promotion of the metabolic activity of the algal system. Additionally, the larger fungi-algae pellets formed after capture (>2.0 mm on average) enabled easier filtration from the culture medium.
In this study, fungi that can form stable pellets were screened from domestic sewage, and the harvesting efficiency and content of high-value substances were investigated by harvesting microalgae via FSH and FPH. Aspergillus niger HW8-1 was selected to harvest the microalgae and the microalgae preculture time, glucose content and initial algal density were optimized to increase the high-value substances contents of the fungus-alga pellets. Finally, the mechanical differences between FSH and FPH were explored based on the microstructure, the change in surface charge, extracellular polymeric substances (EPS), and respiration-photosynthesis rate. This study investigated fungi-based microalgae harvesting to determine the best mode for future use.
The first author is Wang Qianru, a graduate student from the Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Sciences and Engineering. Beijing Forestry University is the signature unit of the first author.
This research is funded by the National Key Research and Development Program of China (No. 2021YFC3200602) and the National Natural Science Foundation of China (No. 52270021).
Paper link: https://doi.org/10.1016/j.scitotenv.2023.162945