Polyhydroxyalkanoate (PHA), a biodegradable polymer obtained from microorganisms and plants, have been widely used in biomedical applications and devices, such as sutures, cardiac valves, bone scaffold, and drug delivery of compounds with pharmaceutical interests, as well as in food packaging. This review focuses on the use of polyhydroxyalkanoates beyond the most common uses, aiming to inform about the potential uses of the biopolymer as a biosensor, cosmetics, drug delivery, flame retardancy, and electrospinning, among other interesting uses. The novel applications are based on the production and composition of the polymer, which can be modified by genetic engineering, a semi-synthetic approach, by changing feeding carbon sources and/or supplement addition, among others. The future of PHA is promising, and despite its production costs being higher than petroleum-based plastics, tools given by synthetic biology, bioinformatics, and machine learning, among others, have allowed for great production yields, monomer and polymer functionalization, stability, and versatility, a key feature to increase the uses of this interesting family of polymers.

Background: Endolichenic fungi represent an emerging source of bioactive secondary metabolites; however, the genomic basis of their chemical diversity remains largely poorly characterized. Specifically, the metabolic capabilities of Cladosporium limoniforme have not been explored at the genomic level. Objectives: This study aimed to characterize the biosynthetic potential of C. limoniforme by presenting its first whole-genome sequence and conducting a comparative analysis of its biosynthetic gene clusters (BGCs), with a specific focus on the evolutionary conservation of the DHN-melanin pathway. Methods: Genome mining was performed using antiSMASH and fungiSMASH tools. Comparative genomics involved heatmap-based distribution analysis across the Cladosporium genus, synteny profiling using Clinker to assess gene order conservation, and Maximum Likelihood phylogenetic analysis of the polyketide synthase (T1PKS) domain. Results: We identified 26 putative BGCs, revealing a largely untapped metabolic repertoire. Comparative analysis demonstrated a high degree of conservation for the metachelin C (siderophore) and 1,3,6,8-tetrahydroxynaphthalene (T4HN) clusters across the genus. Notably, synteny and phylogenetic analyses showed that while C. limoniforme retains a conserved, ancestral T1PKS core essential for stress survival, it exhibits a significant reduction in accessory genes compared to plant-pathogenic congeners. Conclusions: These findings support a “metabolic streamlining” hypothesis driven by the endolichenic lifestyle, where the fungus retains essential protective machinery while shedding costly accessory genes unnecessary in the buffered lichen niche. This study establishes C. limoniforme as a valuable genomic resource for future biotechnological research.

High-altitude ecosystems in the Andes present diverse extreme environmental conditions, yet the fungal biodiversity associated with crustose lichens remains largely unexplored. This study investigated the culturable fraction of the Endolichenic Fungi (ELF) community associated with the lichen Acarospora schleicheri (Ach.) A. Massal, collected from the Chilean Altiplano. Using culture-dependent techniques, fungal strains were isolated and identified through macro- and micro-morphological characterization combined with molecular phylogenetics of the Internal Transcribed Spacer (ITS) region. To ensure taxonomic robustness, phylogenetic analyses were performed separately for each identified genus. The results revealed a diverse assemblage dominated by the classes Dothideomycetes and Eurotiomycetes, with Cladosporium and Alternaria being the most representative. Remarkably, we report the presence of Monascus sp. and the basidiomycetous yeast Sporobolomyces reniformis within the lichen thallus, representing a novel record for this host as an ELF. The prevalence of pigmented genera suggests that the ELF community in A. schleicheri may possess specific adaptations to withstand high UV radiation and desiccation. These findings expand the known biogeography of lichen-associated fungi and highlight the Andean lichenosphere as a reservoir of stress-tolerant microbial lineages.