Search Results (7)

Land-use change strongly affects soil microbiota, yet the role of agroecological systems in shaping soil fungal communities remains poorly understood in tropical soils. We evaluated the diversity, trophic modes, community composition, and co-occurrence networks of culturable soil fungal taxa across a land-use gradient in the Colombian Andes–Amazon transition zone. Agroecological systems—including improved pasture (IP), cacao and copoazu agroforestry systems (CaAS and CoAS), secondary forest with agroforestry enrichment (SFAE), and a moriche palm swamp ecosystem (MPSE)—were compared with dominant land-uses (degraded pasture, DP and old-growth forest, OF). Fungi were isolated using the soil dilution plate method and identified based on morphological and molecular characteristics, and soil physicochemical properties were measured to evaluate their relationships with fungal community patterns. A total of 420 isolates were assigned to 93 fungal species. Alpha-diversity metrics revealed significantly higher fungal richness in OF and MPSE, and higher Shannon diversity in agroforestry and forest-based systems, whereas DP exhibited the lowest values. Ordination analyses showed clear differences in fungal community composition, with CoAS displaying the most distinct assemblage. Agroecological and forest-based systems favored saprotrophic and symbiotrophic modes. Co-occurrence network analyses indicated that MPSE, OF, and IP supported more complex and modular fungal networks. Soil pH and total phosphorus (TP) were key drivers of fungal community composition, whereas exchangeable calcium, TP, soil organic carbon, and base saturation were associated with network attributes. Overall, our findings highlight the importance of agroecological management for soil fungal diversity and network organization in Amazonian transition landscapes. Full article

This study evaluated the seasonal variability of soil–atmosphere greenhouse gas (GHG) fluxes—carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O)—across a land-use gradient in the Andean–Amazon transition zone of Colombia. The gradient included five land-use types incorporating at least one innovative climate-smart practice—improved pasture (IP), cacao agroforestry system (CaAS), copoazu agroforestry system (CoAS), secondary forest with agroforestry enrichment (SFAE), and moriche palm swamp ecosystem (MPSE)—alongside the dominant regional land uses, old-growth forest (OF) and degraded pasture (DP). Soil GHG fluxes varied markedly among land-use types and between seasons. CO₂ fluxes were consistently higher during the dry season, whereas CH₄ and N₂O fluxes peaked in the rainy season. Agroecological and restoration systems exhibited substantially lower CO₂ emissions (7.34–9.74 Mg CO₂-C ha⁻¹ yr⁻¹) compared with DP (18.85 Mg CO₂-C ha⁻¹ yr⁻¹) during the rainy season, and lower N₂O fluxes (0.21–1.04 Mg CO₂-C ha⁻¹ yr⁻¹) during the dry season. In contrast, the MPSE presented high CH₄ emissions in the rainy season (300.45 kg CH₄-C ha⁻¹ yr⁻¹). Across all land uses, CO₂ was the dominant contributor to the total GWP (>95% of emissions). The highest global warming potential (GWP) occurred in DP, whereas CaAS, CoAS and MPSE exhibited the lowest values. Soil temperature, pH, exchangeable acidity, texture, and bulk density play a decisive role in regulating GHG fluxes, whereas climatic factors, such as air temperature and relative humidity, influence fluxes indirectly by modulating soil conditions. These findings underscore the role of diversified agroforestry and restoration systems in mitigating GHG emissions and the need to integrate soil and climate drivers into regional climate models. Full article

Amazonian fruits are a source of bioactive compounds, among which phenolic compounds, flavonoids, and carotenes stand out. These compounds play a crucial role in restoring oxidative balance, consequently reducing the proliferation of cancer cells. However, the content of these metabolites and their biological properties may vary significantly depending on the geographical location and the environmental conditions where plants grow. This research assessed the content of metabolites, free radical scavenging capacity, and hemolytic and antiproliferative effects of the hydro-methanolic extracts of the Amazonian fruits Theobroma grandiflorum and Mauritia flexuosa. The results revealed that the extracts derived from the seeds of Theobroma grandiflorum sourced from the Balcanes experimental farm and the pulp of Mauritia flexuosa harvested in Florencia exhibited higher contents compared to other analyzed sites: Total phenolic content (TPC) (619.41 ± 12.05 and 285.75 ± 10.06 mg GAE/100 g FW), Total flavonoid content (TFC) (569.09 ± 4.51 and 223.21 ± 3.92 mg CAT/100 g FW), and Total carotenoid content (TCC) (25.12 ± 0.16 and 48.00 ± 0.28 mg eq β-carotene/100 g FW), respectively. Also, these samples demonstrated superior scavenging capacities for the ABTS and DPPH radicals, while the peel of Mauritia flexuosa exhibited the highest scavenging capacity for the oxygen radical (526.23 ± 2.08 µmol Trolox.g⁻¹). The hemolytic effect shows dose-dependent responses with IC50 values of 27.73 μg/mL for the Balcanes seeds and 1.27 μg/mL for the Florencia pulp. Furthermore, it was observed that treatment with the fruit-derived extracts effectively reduced the number of viable human colorectal cancer cells, using SW480 ATCC cell line, demonstrating a non-dose-dependent behavior compared to the control cells. Full article

Theobroma grandiflorum (copoazu) is a plant native to South America, widely cultivated in countries within the Amazon region. Its unique phytochemical composition imparts distinctive organoleptic properties, making it an exotic fruit. In this study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC-MS) was used to identify the volatile organic compounds (VOCs) produced by copoazu. The optimal conditions for sample pretreatment were first determined using a Design of Experiments (DoE) approach. Analysis of the volatile profiles enabled the identification of 96 copoazu VOCs across three ripening stages. Of these, 79 VOCs were classified into chemical compound families using spectral correlation analysis across various libraries and databases, as well as molecular network analysis. Additionally, a volatilomic analysis was conducted to examine the changes in VOCs throughout the ripening process. Molecular network analysis showed that the VOCs emitted by the fruit are linked to the interconversion of compounds, which can be observed through the study of the metabolic pathways. These findings provide a comprehensive analysis of the copoazu volatilome, providing valuable insights into the organoleptic characteristics of this Amazonian fruit. Esters and terpenes such as α-terpineol, trans-4-methoxythujane, linalool, 2-methylbutyl butanoate, 3-methylbut-2-enoic acid, 2-methylpentyl ester, and 2-methylpropyl hexanoate were identified as potential biomarkers associated with the copoazu ripening process. Full article

The Copoazú is a Theobroma species of Amazonian origin, and its derived products have a high content of lipids valuable for both the cosmetic and food industries. The composition of the butter extracted from its seeds can vary depending on the postharvest process and the diverse extraction techniques employed. In this study, the composition of this butter processed with and without seed fermentation was analyzed using two extraction techniques: expeller pressing and hydraulic pressing. Parameters such as lipid profile, quality indexes, melting point, and the content of phytosterols and glyceric compounds were compared with a highly sought-after commercial raw material assessed through standardized volumetric and spectroscopic methodologies. The results showed that non-fermentation and cold-pressing conditions preserved the properties of the butter. This analysis is the first step in a standardized process for developing high-quality cosmetic ingredients derived from Copoazú butter. Full article

Studies on polyphenols and flavonoids in natural products reveal benefits in the prevention of multiple diseases. Proper extraction, treatment of extracts, and quantification of polyphenols and flavonoids demand attention from the scientific community in order to report more specific biological action. Total polyphenol content (TPC) and total flavonoid content (TFC) (measured at three different times) of ethanol, methanol and acetone extracts of Mauritia flexuosa (aguaje) and Theobroma grandiflorum (copoazú) fresh pulp, from the Colombian Amazon region, were evaluated with the purpose of focusing in the polyphenol/flavonoid proportion and its effective antioxidant activity. This objective could help to explain specific flavonoid biological action based on higher flavonoid proportion rather than higher total polyphenol content. Differences in extracting solvents resulted in statistically significant different yields; the highest TPC was observed with acetone 70% in Mauritia flexuosa and ethanol 80% for T. grandiflorum. The best flavonoid/polyphenol ratio in M. flexuosa was about 1:2.4 and 1:12.8 in T. grandiflorum and the antioxidant efficacy was proportionally higher for flavonoids extracted from T. grandiflorum. HPLC analysis revealed 54 µg/g of the flavonoid kaempferol in M. Flexuosa and 29 µg/g in T. grandiflorum. Further studies evaluating this proportionality, in seeds or peel of fruits, as well as, other specific biological activities, could help to understand the detailed flavonoid action without focusing on the high total polyphenol content. Full article

The genome characterization of the Lactiplantibacillus plantarum strain UTNGt2, isolated from wild copoazu or white cacao (Theobroma grandiflorum), is described. A total of 31 contigs is assembled with a total length of 3,264,448 bases, with all contigs matching the core genome of different groups in the database. The genome size is 3,540,752 bases with GC content of 44.53% and the genome repeat sequences constitute around 457,386 bases of the assembly. The UTNGt2 matches the Lactiplantibacillus plantarum genome with 99% identity. The genome contains 3115 genes, 3052 protein-coding genes, assigned with the EggNOG database. On the basis of the results, 745 proteins are classified with an unknown function, from which 128 proteins have no match in the BLASTN database. It also contains 57 tRNAs, 5 copies of 5S rRNA, and 1 copy of tmRNA. Based on gene prediction and annotation results, 9.4% of proteins are involved in carbohydrate transport and metabolism and 8.46% in transcription, 2.36% are responsible for defense mechanisms, 0.5% are responsible for the biosynthesis of secondary metabolites, transport, and catabolism, while 25.11% have an unknown function. The genome revealed the presence of genes involved in riboflavin and folate production, the presence of CRISPR/Cas genes, phage sequences, the absence of acquired antibiotics resistance genes, virulence, and pathogenic factors, suggesting that UTNGt2 is a safe strain. Its highly antimicrobial capacity is related to the presence of two bacteriocin clusters (class IIc) of the sactipeptide class (contig 4) and plantaricin E class (contig 22), as detected by the BAGEL 4 webserver. Several RiPP-like peptides (non-bactericidal ribosomally produced and post-translationally modified peptides), polyketides (PKs), and terpenes were predicted. Whole-genome sequencing analysis revealed that the UTNGt2 strain has diverse bacteriocins with a high inhibitory capacity, thus it is a bacteriocinogenic strain. Considering the safety profile, UTNGt2 is a nonpathogenic, nonvirulent strain with valuable biotechnological traits and can be further exploited for its probiotic and antimicrobial potential in the food industry or as a potential producer strain of antimicrobial peptides as an alternative to conventional antibiotics. Full article