Photobioreactors for cultivation and synthesis: Specifications, challenges, and perspectives

Abstract

Due to their versatility and the high biomass yield produced, cultivation of phototrophic organisms is an increasingly important field. In general, open ponds are chosen to do it because of economic reasons; however, this strategy has several drawbacks such as poor control of culture conditions and a considerable risk of contamination. On the other hand, photobioreactors are an attractive choice to perform cultivation of phototrophic organisms, many times in a large scale and an efficient way. Furthermore, photobioreactors are being increasingly used in bioprocesses to obtain valuable chemical products. In this review, we briefly describe different photobioreactor set‐ups, including some of the recent designs, and their characteristics. Additionally, we discuss the current challenges and advantages that each different type of photobioreactor presents, their applicability in biocatalysis and some modern modeling tools that can be applied to further enhance a certain process.

Influence of Different Light-Emitting Diode Colors on Growth and Phycobiliprotein Generation of Arthrospira platensis

“…Studies on optimizing the production yield of AP show that, among other factors, the light color (and of course intensity [ 28 ]) can influence the build-up of biomass but also of various ingredients [ 29 , 30 , 31 ]. On a molecular level, pigments and phycobiliproteins play a pivotal role for these processes.…”

Photobiocatalysis in Continuous Flow

“…The most common way to grow microorganisms for photobiotransformations is using open photobioreactor (PBR) systems, which are economical in terms of construction, operation and maintenance, but have a poor control on growth conditions, which makes them inadequate for the production of fine chemicals (Chisti, 2007;Chanquia et al, 2021). These PBRs are usually raceway-shaped shallow pools.…”

“…They demand a higher initial investment, and also the costs related to their operation and maintenance are higher than those of open systems; however, they offer an excellent control over cultivation conditions, which usually results in better productivities (Zhu et al, 2018). Closed PBRs can have many different configurations and shapes, being horizontal or vertical tubular vessels, flat panels or even plastic bags, just to mention some of the most common (Chanquia et al, 2020;Chanquia et al, 2021).…”

“…Amongst these reviews we want to highlight the publications made by Schmermund et al (2019), that gives an overview on the different possible strategies for using light in biocatalysis, and Meyer et al (2021), which covers the most recent advances regarding in vitro photobiocatalysis. Additionally, Chanquia et al (2021) describes different photobioreactors setups, as well as challenges and perspectives related to them. On the other hand, we also believe that is important to mention the publications by Özgen et al (2021), that focuses on how to overcome challenges when dealing with photo(chemo) enzymatic reactions, and Seel and Gulder (2019) who reviewed several different relevant photocatalyzed transformations.…”

Exploitation of Hetero- and Phototrophic Metabolic Modules for Redox-Intensive Whole-Cell Biocatalysis

“…Conventional photobioreactor systems are often limited by low cell densities ( Chanquia et al, 2021 ). Therefore, innovative approaches to overcome light limitation have been developed recently ( Johnson et al, 2018 ; Kirnev et al, 2020 ; Chanquia et al, 2021 ), including bioreactors with internal illumination ( Heining et al, 2015 ; Hobisch et al, 2021 ), biofilm-based concepts ( Li et al, 2017 ), and cell immobilization approaches ( Léonard et al, 2010 ; Polakovič et al, 2017 ). Biofilm bioreactors enable high surface to volume ratios and thus high biomass concentrations and high light utilization efficiency.…”