Allelopathy as a potential strategy to improve microalgae cultivation

Abstract

One of the main obstacles for continuous productivity in microalgae cultivation is the presence of biological contaminants capable of eliminating large numbers of cells in a matter of days or even hours. However, a number of strategies are being used to combat and prevent contamination in microalgae cultivation. These strategies include the use of extreme conditions in the culture media such as high salinity and high pH to create an unfavorable environment for the competitive organisms or predators of the microalgae. Numerous studies have explored the potential of naturally occurring bioactive secondary metabolites, which are natural products from plants and microorganisms, as a source of such compounds. Some of these compounds are herbicides, and marine and freshwater microalgae are a source of these compounds. Microalgae produce a remarkable diversity of biologically active metabolites. Results based on the allelopathic potential of algae have only been described for laboratory-scale production and not for algae cultivation on a pilot scale. The adoption of allelopathy on microalgal strains is an unexplored field and may be a novel solution to improve algae production. Here we present information showing the diversity of allelochemicals from microalgae and the use of an allelopathic approach to control microalgae cultivation on a pilot scale based on R&D activities being carried out in Brazil for biodiesel production.

Low algal diversity systems are a promising method for biodiesel production in wastewater fed open reactors

“…In fact, allelopathic interactions are an important factor in determining species presence and abundance within planktonic communities. Microalgal allelopathy in certain groups of algae like the diatoms and cyanobacteria may negatively affect the performance of each other while existing as a mixed community in the same environment (Bacellar Mendes and Vermelho 2013). This is consistent with our study in which Chlorella has the highest growth rate as a monoculture but not when present as a part of the mixed culture which has members of the diatoms and cyanobacteria (Fig.…”

Algicidal microorganisms and secreted algicides: New tools to induce microalgal cell disruption

“…Furthermore, mutualistic and allelopathic interaction between bacteria and microalgae have recently been highlighted for applications in biofuels production processes as a potential strategy to control culture contamination during algal cultivation (Bacellar Mendes and Vermelho 2013), to fast-sedimentation of microalgae by bacterial aggregation and to disrupt microalgae biomass using algicidal microorganisms Cheng et al 2013;Lenneman et al 2014;Lü et al 2013;Muñoz et al 2014;Wang and Yuan 2014).…”

Extracellular Metabolites from Industrial Microalgae and Their Biotechnological Potential

“…Several species of microalgae can excrete remarkable biologically active metabolites into the medium, some of which are allelochemicals [130]. A better understanding of them will help to seek out a promising strategy to achieve the goal of producing bulk volumes of microalgae in large-scale cultivation [131]. The major types of allelochemicals from the medium of valuable microalgae are summarized briefly in Table 4.…”