Chlamydomonas reinhardtii, a Reference Organism to Study Algal–Microbial Interactions: Why Can’t They Be Friends?

Abstract

The stability and harmony of ecological niches rely on intricate interactions between their members. During evolution, organisms have developed the ability to thrive in different environments, taking advantage of each other. Among these organisms, microalgae are a highly diverse and widely distributed group of major primary producers whose interactions with other organisms play essential roles in their habitats. Understanding the basis of these interactions is crucial to control and exploit these communities for ecological and biotechnological applications. The green microalga Chlamydomonas reinhardtii, a well-established model, is emerging as a model organism for studying a wide variety of microbial interactions with ecological and economic significance. In this review, we unite and discuss current knowledge that points to C. reinhardtii as a model organism for studying microbial interactions.

Species interactions and food-web context drive temperature-dependent prey evolution

“…ciliate protists) and metazoans (e.g., rotifers, cladocerans) alike (Calatrava et al 2023). Our focal prey species, the unicellular green algae Chlamydomonas reinhardtii, is a well-established model organism with known mutations linked to functional traits (Sasso et al 2018;Calatrava et al 2023). Here we used two genetically and phenotypically distinct strains of C. reinhardtii: wild type (wt) and vfl1-1 (i.e., 'variable flagellar number1-1') as our prey population, and kept track of their abundances, phenotypes, and shifts in genetic frequencies over time as means to quantify evolution by clonal sorting.…”

Microalgal and Nitrogen-Fixing Bacterial Consortia: From Interaction to Biotechnological Potential

“…In this regard, it has been shown that H 2 production by Chlamydomonas can be improved in the presence of certain diazotrophic bacteria. These bacteria include, among others, the soil bacteria Pseudomonas stutzeri, Rhizobium etli, Pseudomonas fluorescens, Azotobacter chroococcum, Mesorhizobium sangaii, Bradyrhizobium japonicum, see reviews [9,167]. However, until now, it has not been studied in detail whether this increased production of H 2 is related to N fixation.…”

“…Symbiosis is a phenomenon widely utilized in nature, taking on multiple forms and serving various objectives that can be beneficial for only one of the organisms (commensalism, parasitism) or for both (mutualism) [7]. It has been observed that microalgae are capable of establishing symbiotic interactions with a diverse range of organisms, including plants, animals, fungi, and bacteria [8,9]. The term "phycosphere" refers to the area beyond Plants 2023, 12, 2476 2 of 21 the microalgal cell membrane, including the extracellular aqueous zone where bacteria interact with the microalgae.…”

Exchange or Eliminate: The Secrets of Algal-Bacterial Relationships

“…The number of algal species has been estimated to exceed one million, with most of them being microalgae [ 8 , 9 ]. Algae are prominent in bodies of water, such as oceans, rivers, and lakes [ 7 , 10 ], and are also common in terrestrial environments [ 11 , 12 ]. Algae can be found on snow and ice [ 13 ], and even in the desert [ 14 ].…”

“…Partners of algae include viruses [ 72 , 73 , 74 , 75 ] and bacteria [ 12 , 25 , 76 ], as well as eukaryotic organisms such as fungi [ 77 , 78 , 79 , 80 ] or even sloths [ 81 ]. For this review, we will focus on the bacterial partners of algae.…”