Overcoming the Biological Contamination in Microalgae and Cyanobacteria Mass Cultivations for Photosynthetic Biofuel Production

Abstract

Microalgae and cyanobacteria have shown significant potential for the development of the next biofuels innovation because of their own characteristics as photosynthetic microorganisms. However, it is confronted with a lot of severe challenges on the economic scaling-up of the microalgae- and cyanobacteria-based biofuels production. One of these major challenges is the lack of a reliable preventing and controlling culture system of biological contamination, which can attack the cell growth or product accumulation causing crashing effects. To increase the commercial viability of microalgae- and cyanobacteria-based biofuels production, overcoming the biological contaminations should be at the top of the priority list. Here, we highlight the importance of two categories of biological contaminations and their controlling strategies in the mass cultivations of microalgae and cyanobacteria, and outline the directions that should be exploited in the future.

Anaerobic digestion and agronomic applications of microalgae for its sustainable valorization

“…59 Also, the capacity of Brachionus calyciorus to consume more than 500 cells of Chlamydomonas reinhardtii per hour and per rotifer was reported. 58 Grazers prevention can be carried out by sterilizing the medium before introduction in photobioreactors. 60 However, the risk of contamination is high in open ponds compared to photobioreactors.…”

“…Biological contaminants affecting the growth of microalgae are classified into 4 categories: zooplankton, microorganisms (bacteria, fungi and protozoa), other microalgae species and viruses. 58 Contaminants can also be distinguished according to their contamination mechanisms. Microalgae grazers are found in all-natural aquatic environments.…”

Biological Contamination: A Serious Constraint in Large Scale Microalgae Biomass Production

“…Thus, early detection of biological contaminants is an imperative step during the large-scale microalgae and cyanobacteria cultivation in outdoor conditions. Staining and microscopy is one of the traditional morphological observation methods that can be used in early and routine detection methods [4]. Gerphagnon et al [5] devised a modified staining approach for the detection of chitinous fluorochrome and nucleic acid stain in combination with epifluorescence microscopy and characterization of chytrid prolificacy in Anabaena macrospora, a cyanobacterium [4].…”

“…Staining and microscopy is one of the traditional morphological observation methods that can be used in early and routine detection methods [4]. Gerphagnon et al [5] devised a modified staining approach for the detection of chitinous fluorochrome and nucleic acid stain in combination with epifluorescence microscopy and characterization of chytrid prolificacy in Anabaena macrospora, a cyanobacterium [4]. However, in large-scale industrial applications, automated detection systems would be perfect for the identification of biological pollutants at the beginning stage.…”

Improvement of Photoautotrophic Algal Biomass Production after Interrupted CO2 Supply by Urea and KH2PO4 Injection

“…However, the supply of CO 2 is not only interrupted at night but depending on the situation of the power plant such as emergency stop and over-haul thereby causing pH change in unexpected times. Thus, if the supply of flue gas containing a high concentration of CO 2 is halted during this period, a rapid change in the pH of the culture medium occurs, resulting in a decrease in cell growth or cell death [49]. Cultivating microalgae after cell death is expensive and time consuming, due to the need to wash photobioreactors (PBR), creating a culture medium, and preparing microalgal seeds [50].…”