Pigments of fungal origin have aroused increasing interest in the food dye and cosmetic industries since the global demand for natural dyes has grown. Endophytic microorganisms are a source of bioactive compounds, and Amazonian plant species can harbor fungi with a wide range of biotechnological applications. Popularly known in Brazil as crajiru, Fridericia chica is a medicinal plant that produces a red pigment. In this study, a total of 121 fungi were isolated in potato dextrose agar from three plants. We identified nine pigment-producing endophytic fungi isolated from branches and leaves of F. chica. The isolates that showed pigment production in solid media were molecularly identified via multilocus analysis as Aspergillus welwitschiae, A. sydowii, Curvularia sp., Diaporthe cerradensis (two strains), Hypoxylon investiens, Neoscytalidium sp. (two strains) and Penicillium rubens. These isolates were subjected to submerged fermentation in two culture media to obtain metabolic extracts. The extracts obtained were analyzed in terms of their absorbance between 400 and 700 nm. The pigmented extract produced by H. investiens in medium containing yeast extract showed maximum absorbance in the red absorption range (UA₇₀₀ = 0.550) and significant antioxidant and antimicrobial activity. This isolate can thus be considered a new source of extracellular pigment.

The Yanomami are one of the oldest indigenous tribes in the Amazon and are direct descendants of the first people to colonize South America 12,000 years ago. They are located on the border between Venezuela and Brazil, with the Venezuelan side remaining uncontacted. While they maintain a hunter-gatherer society, they are currently experiencing contact with urbanized populations in Brazil. The human gut microbiota of traditional communities has become the subject of recent studies due to the Westernization of their diet and the introduction of antibiotics and other chemicals, which have affected microbial diversity in indigenous populations, thereby threatening their existence. In this study, we preliminarily characterized the diversity of the gut microbiota of the Yanomami, a hunter-gatherer society from the Amazon, experiencing contact with urbanized populations. Similarly, we compared their diversity with the population in Manaus, Amazonas. A metabarcoding approach of the 16 S rRNA gene was carried out on fecal samples. Differences were found between the two populations, particularly regarding the abundance of genera (e.g., Prevotella and Bacteroides) and the higher values of the phyla Bacteroidetes over Firmicutes, which were significant only in the Yanomami. Some bacteria were found exclusively in the Yanomami (Treponema and Succinivibrio). However, diversity was statistically equal between them. In conclusion, the composition of the Yanomami gut microbiota still maintains the profile characteristic of a community with a traditional lifestyle. However, our results suggest an underlying Westernization process of the Yanomami microbiota when compared with that of Manaus, which must be carefully monitored by authorities, as the loss of diversity can be a sign of growing danger to the health of the Yanomami.

Pimelodus grosskopfii and Pimelodus yuma, two species endemic to the Magdalena-Cauca basin in Colombia, overlap in the ranges of some of their diagnostic characters, which hampers their correct morphological identification. Aiming to help discriminate these species, this study conducted an integrative analysis using traditional and geometric morphometrics, phylogenetic analysis based on partial sequences of the mitochondrial cytochrome c oxidase subunit 1 gene (COI, cox1) and the identification of diagnostic Single Nucleotide Polymorphism markers (SNP). The species differ significantly in body geometry, allowing 100% discrimination, which was reinforced by a phylogenetic analysis that recovered well-supported monophyly of each species (posterior probability > 0.95). Additionally, the traditional morphometric results corroborated some previously reported diagnostic traits for both species and let us describe one non-overlapping ratio related to the adipose fin length. Three of five SNP markers had reciprocally exclusive alleles suitable for identifying each species. The morphometric and molecular methods conducted in this study constitute alternative tools for the correct discrimination of P. grosskopfii and P. yuma in the wild and in captive populations used for aquaculture.

The Balbina hydroelectric dam was built in the 1980s on the Uatumã River to supply electricity to Manaus, capital of the state of Amazonas, Brazil. Its construction caused a drastic change to the alluvial landscape, forming a large, lentic, artificial reservoir rather than a previously dynamic river system. The objective of our research was to evaluate the impact of the hydroelectric dam on the microevolutionary processes of fish, taking as a model Cichla temensis, an iconic non-migratory fish from the Amazon, abundant in this ecosystem. We collected double digest restriction site-associated DNA sequencing data and extracted single nucleotide polymorphisms, which we identified at neutral and adaptive loci, for subsequent analyses. The results showed that the connectivity of the population was affected historically by natural physical barriers, before the construction of the hydroelectric dam, recognizing two independent population units. We detected that the hydroelectric dam increased the differentiation between populations and affected the genetic diversity and effective population sizes, in addition to promoting a recent population expansion upstream of the dam, as a consequence of adaptation to the new environment. This study provides the first evidence that hydroelectric dams can promote local adaptation in some fish, such as non-migratory ones.

Varieties represent a defined group with differentiated characteristics derived through natural selection and/or selective breeding from within a species. In the Central-Andean region of Colombia (Urrao) there are three endemic varieties of the species Coffea arabica L [“Caturra Chiroso” (CCH), “Bourbon Chiroso” (BCH), and “Chiroso” (CHCH)], known as “Chiroso” group, globally renowned for their high quality and distinctive cup profile. Despite its significance, there is a lack of reported genomic resources or basic biological information for these. In this study, we conducted the first assembly and characterization of the complete chloroplast (Cp) genomes of these varieties and reconstructed their ancestry relationships. The Cp genomes were 155,188 bp in length (A = 30.93%; C = 19.06%; G = 18.37%; T = 31.64%); containing 131 genes, comprising 86 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. They consisted of four subregions: the large single-copy (LSC) region (85,159 bp; 83 genes), the short single-copy (SSC) region (18,136 bp; 12 genes), and the inverted repeats IRA (25,944 bp; 18 genes) and IRB (25,945 bp; 18 genes). Likewise, among 26 intraspecific varieties analyzed, CCH + BCH formed a unique haplotype, and CHCH + Bourbon + Caturra formed another. CCH and BCH featured an exclusive Cytosine mutation (SNP: C/A), position 47,413 bp (intergenic spacer region trnT(UGU)-trnL(UAA)]. Likewise, a total of 445 short tandem repeats were found in the Cp genomes (dinucleotides: 370; trinucleotides: 71; tetranucleotides: 1). Finally, the three formed a well-supported monophyletic group with conspecific varieties, being more closely related to Eastern Ethiopian-origin varieties [e.g. Berbere region], as well as with traditional ones like Typica, Bourbon, and Caturra. These coffee varieties are a valuable new genetic resource for use as a gene source for genetic improvement, biotechnology, direct exploitation and cultivation worldwide.