Stress leads to the development of adaptive mechanisms that enable survival and increase the evolutionary fitness of microorganisms. The green alga Chlamydomonas reinhardtii is a common member of wet soils and is hence subject to biotic and abiotic stress ( 2, 4, 5). As photosynthetic microorganisms, algae convert CO 2 to energy-rich organic carbon sources and thereby refuel the carbon cycle. Green algae are often overlooked when soil ecosystems are discussed despite their pivotal role as primary producers of organic carbohydrates fixing roughly 39 g carbon per square meter of soil per year ( 2, 3). Soil is an extremely densely populated habitat, and hence, microbial interactions are nearly inevitable ( 1). Additionally, it underlines the importance of natural products as microbial cues, which initiate interesting ecological scenarios of attack and counter defense. Our finding suggests that multicellularity may have evolved to endure the presence of harmful competing bacteria. Their structure and polysaccharide matrix may be ancestral to the complex mucilage formed by multicellular members of the Chlamydomonadales such as Eudorina and Volvox. reinhardtii at alkaline pH and otherwise lethal concentrations of azalomycin F. Furthermore, gloeocapsoids allow for the survival of C. The presence of marginolactone biosynthesis gene clusters in numerous streptomycetes, their ubiquity in soil, and our observation that other marginolactones such as desertomycin A and monazomycin also trigger the formation of gloeocapsoids suggests a cross-kingdom competition with ecological relevance. After azalomycin F removal, gloeocapsoid aggregates readily disassemble, and single cells are released. Gloeocapsoids contain several cells which share multiple cell membranes and cell walls and are surrounded by a spacious matrix consisting of acidic polysaccharides. reinhardtii, which we named gloeocapsoid. Here, we report that sublethal concentrations of azalomycin F trigger the formation of a protective multicellular structure by C. Whether the alga senses and reacts to azalomycin F remained unknown. We previously discovered such an interaction between Streptomyces iranensis releasing the marginolactone azalomycin F in the presence of C. Terrestrial habitats are densely populated, and hence, microbial interactions mediated by natural products are inevitable. Photosynthetic microorganisms including the green alga Chlamydomonas reinhardtii are essential to terrestrial habitats as they start the carbon cycle by conversion of CO 2 to energy-rich organic carbohydrates.

7 days to die farming alpha 15