Yeasts are microscopic fungi inhabiting all Earth environments, including those inhospitable for most life forms, considered extreme environments. According to their habitats, yeasts could be extremotolerant or extremophiles. Some are polyextremophiles, depending on their growth capacity, tolerance, and survival in the face of their habitat’s physical and chemical constitution. The extreme yeasts are relevant for the industrial production of value-added compounds, such as biofuels, lipids, carotenoids, recombinant proteins, enzymes, among others. This review calls attention to the importance of yeasts inhabiting extreme environments, including metabolic and adaptive aspects to tolerate conditions of cold, heat, water availability, pH, salinity, osmolarity, UV radiation, and metal toxicity, which are relevant for biotechnological applications. We explore the habitats of extreme yeasts, highlighting key species, physiology, adaptations, and molecular identification. Finally, we summarize several findings related to the industrially-important extremophilic yeasts and describe current trends in biotechnological applications that will impact the bioeconomy.

Several populations of a non-tapering and tapering, fasciculated, single and geminate false branching heterocytous cyanobacterium were collected from rocky shores in the Pacific Ocean and Gulf of Mexico. The populations were provisionally plac...

This paper is a contribution to the morphological and molecular characterization of the cyanobacterium Brasilonema roberti-lamii from populations found in Central Mexico. The general growth form and the morphological, morphometric and ecological characteristics of the populations studied clearly correspond to those described for Brasilonema roberti-lamii (basionym: Tolypothrix roberti-lamii) from the French Antilles. Based on molecular data from DNA sequencing of the16S rRNA gene and the IGS of the cpcB-cpcA phycocyanin operon (cpcBA-IGS), we propose that the populations that we studied are closely related to those of other Brasilonema species, including B. octagenarum UFV-OR1, UFV-E1 and HA4187-MV1-p1F, Brasilonema sennae CENA 114, B. tolantongensis, B. terrestre CENA 116, B. angustatum HA4187-MV1-B2+p1F and HA4187-MV1-B2+p1H and B. bromeliae SPC951. Our findings support the transference of Tolypothrix roberti-lamii, which was made based exclusively on morphological criteria, to Brasilonema. The use of molecular analyses in addition to traditional morphological and ecological criteria, known as polyphasic approach, is a good alternative to describe taxa of cyanobacteria, mainly at the genus and species levels.