Metagenome-assembled genomes reveal carbohydrate degradation and element metabolism of microorganisms inhabiting Tengchong hot springs, China

Metagenome-Assembled Genomes (MAGs): Advances, Challenges, and Ecological Insights

Metagenome-assembled genomes (MAGs) have revolutionized microbial ecology by enabling the genome-resolved study of uncultured microorganisms directly from environmental samples. By leveraging high-throughput sequencing, advanced assembly algorithms, and genome binning techniques, researchers can reconstruct microbial genomes without the need for cultivation. These methodological advances have expanded the known microbial diversity, revealing novel taxa and metabolic pathways involved in key biogeochemical cycles, including carbon, nitrogen, and sulfur transformations. MAG-based studies have identified microbial lineages form Archaea and Bacteria responsible for methane oxidation, carbon sequestration in marine sediments, ammonia oxidation, and sulfur metabolism, highlighting their critical roles in ecosystem stability. From a sustainability perspective, MAGs provide essential insights for climate change mitigation, sustainable agriculture, and bioremediation. The ability to characterize microbial communities in diverse environments, including soil, aquatic ecosystems, and extreme habitats, enhances biodiversity conservation and supports the development of microbial-based environmental management strategies. Despite these advancements, challenges such as assembly biases, incomplete metabolic reconstructions, and taxonomic uncertainties persist. Continued improvements in sequencing technologies, hybrid assembly approaches, and multi-omics integration will further refine MAG-based analyses. As methodologies advance, MAGs will remain a cornerstone for understanding microbial contributions to global biogeochemical processes and developing sustainable interventions for environmental resilience.

MIL-88-NH2(Fe) conjugated pectin through a post-modification Ugi four-component reaction: A robust bio-based catalyst for the synthesis of cyclic carbonate via CO2 fixation reaction

The functionalization of materials via multicomponent reactions (MCRs) led to a recent surge in the interest of researchers, owing to the creation of exceptional properties in materials. Herein, a novel robust porous catalyst was prepared via the conjugation of MIL-88-NH2(Fe) and pectin (DAP/MIL-88-NH2(Fe)) through the post-modification Ugi four-component reaction (Ugi-4CR) for the first time. To achieve this aim, pectin was oxidized using sodium periodate as an oxidant agent to produce dialdehyde pectin (DAP). Next, the generated carbonyl functional groups participated in the Ugi-4CR of MIL-88-NH2(Fe), 4-methyl carboxylic acid, and cyclohexyl (c-hex) isocyanide to produce DAP/MIL-88-NH2(Fe) catalyst. The catalytic activity of the prepared bio-based catalyst was examined in producing cyclic carbonates through the chemical fixation of CO2 with epoxides in the presence of TBAB as a co-catalyst. Interestingly, catalytic experiments revealed that the prepared bio-based catalyst could be remarkably active regarding the CO2 fixation reaction and performed it in the shortest reaction time (1 h) via high CO2 adsorbent capacity. The outstanding benefits of the prepared bio-based catalyst include its non-hazardous nature, inexpensive, green and gentle reaction conditions, and ability to be reusable in several runs with slight loss of catalytic activity due to a more durable framework with high chemical and thermal stability.

Integrating multi-platform assembly to recover MAGs from hot spring biofilms: insights into microbial diversity, biofilm formation, and carbohydrate degradation

BACKGROUND

Hot spring biofilms provide a window into the survival strategies of microbial communities in extreme environments and offer potential for biotechnological applications. This study focused on green and brown biofilms thriving on submerged plant litter within the Sungai Klah hot spring in Malaysia, characterised by temperatures of 58-74 °C. Using Illumina shotgun metagenomics and Nanopore ligation sequencing, we investigated the microbial diversity and functional potential of metagenome-assembled genomes (MAGs) with specific focus on biofilm formation, heat stress response, and carbohydrate catabolism.

RESULTS

Leveraging the power of both Illumina short-reads and Nanopore long-reads, we employed an Illumina-Nanopore hybrid assembly approach to construct MAGs with enhanced quality. The dereplication process, facilitated by the dRep tool, validated the efficiency of the hybrid assembly, yielding MAGs that reflected the intricate microbial diversity of these extreme ecosystems. The comprehensive analysis of these MAGs uncovered intriguing insights into the survival strategies of thermophilic taxa in the hot spring biofilms. Moreover, we examined the plant litter degradation potential within the biofilms, shedding light on the participation of diverse microbial taxa in the breakdown of starch, cellulose, and hemicellulose. We highlight that Chloroflexota and Armatimonadota MAGs exhibited a wide array of glycosyl hydrolases targeting various carbohydrate substrates, underscoring their metabolic versatility in utilisation of carbohydrates at elevated temperatures.

CONCLUSIONS

This study advances understanding of microbial ecology on plant litter under elevated temperature by revealing the functional adaptation of MAGs from hot spring biofilms. In addition, our findings highlight potential for biotechnology application through identification of thermophilic lignocellulose-degrading enzymes. By demonstrating the efficiency of hybrid assembly utilising Illumina-Nanopore reads, we highlight the value of combining multiple sequencing methods for a more thorough exploration of complex microbial communities.