Experimental, Genomic, and Structural Evidence Supporting Putative PET‐Hydrolases in Thermophilic Bacteria Isolated From Hot Springs in Cajamarca, Peru

Diverse thermophilic anaerobes from Indian hot springs show potential for bioenergy production from lignocellulosic biomass

Genomic insights into the bioremediation potential of Paenibacillus taichungensis strain 53b: a multi-resistant plant growth-promoting bacterium

Whole genome sequencing and molecular characterization of two Bacillus licheniformis strains isolated from hot springs in yellowstone ational park

Bacillus licheniformis is a Gram-positive, endospore-forming bacterium with broad biotechnological applications. Thermophilic environments such as hot springs may harbor strains with unique biosynthetic capabilities relevant to drug discovery. In this study, we isolated two B. licheniformis strains (S3 and S4) from the Five Sisters hot spring in Yellowstone National Park (68 °C and 65 °C, pH 8) and performed whole-genome sequencing using both the Oxford Nanopore long read and Illumina platforms. Hybrid de novo assembly using Unicycler yielded genome sizes of 4.80 Mbp (S3, 14 contigs) and 4.79 Mbp (S4, 22 contigs); GC contents were 45.12% and 45.10%, and N50 values were 4,546,802 bp and 2,415,736 bp, for S3 and S4, respectively. Both strains were assigned to Multi-Locus Sequence Typing sequence type ST-42. Pangenome comparison with 61 complete B. licheniformis genomes revealed an open pangenome of 10,374 genes, with 3,272 core genes, 430 soft core, 1,250 shell, and 5,422 cloud genes. AMRFinderPlus identified the blaP, encoding a class A beta-lactamase and its regulatory elements (blaI and blaR1); erm(D), encoding a 23S rRNA methyltransferase conferring macrolide–lincosamide–streptogramin B resistance; and catA, encoding a chloramphenicol O-acetyltransferase that inactivates chloramphenicol through acetylation in both strains. A chromosomal arsBC locus was identified in both B. licheniformis S3 and S4, consistent with the arsenic-rich geothermal environment of Five Sisters hot spring. These findings highlight the biosynthetic potential of B. licheniformis strains isolated from extreme environments and provide a genomic foundation for future exploration of novel bioactive compounds with potential applications in drug discovery, agriculture, and biotechnology.

Metagenomic insights into potential PET hydrolases from Antarctic soils and rhizospheres

A metagenomic analysis of soil and rhizosphere samples from the Antarctic vascular plants Deschampsia antarctica and Colobanthus quitensis is conducted, as sources of microbial enzymes with potential PET-hydrolytic activity, demonstrating the diversity of PET-hydrolase-like genes within Antarctic rhizosphere and soil microbiomes.

Genomic and structural insights into the high-efficiency poly(3-hydroxybutyrate) biodegradation in Terrabacter sp. AAH1

The freshwater isolate Terrabacter sp. AAH1 exhibits highly efficient poly(3-hydroxybutyrate) (PHB) biodegradation, achieving 98.02 ± 0.08% weight loss within 12 days. Scanning electron microscopy and Fourier-transform infrared spectroscopy demonstrated that this rapid disintegration is driven by extensive surface erosion and the hydrolytic cleavage of ester bonds. Comparative genomic analysis across related taxa revealed that while putative PHB depolymerase genes are present in a subset of Terrabacter and allied genera, strain AAH1 is distinguished by its candidate degradation phenotype. The strain’s genomic architecture is predicted to integrate a secreted putative PHB depolymerase with a predict metabolic suite for the degradation of PHB via 3-HB oxidation, SCOT-mediated acetoacetate activation, and β-oxidation-like pathway converging on the TCA cycle. In silico structural modeling and molecular docking further supported a hypothetical compartmentalized degradation system, in which the Sec-type secreted putative depolymerase Te_EPD is proposed to initiate extracellular PHB hydrolysis, while Te_YbfF, Te_AES1, and Te_AES2 predicted to lack signal peptides are tentatively assigned putative intracellular roles. Among the four candidates, Te_EPD exhibited a predicted binding affinity of –4.9 kcal/mol for the PHB trimer via a conserved Ser–Asp–His (S–D–H) catalytic triad, and was uniquely classified within the extracellular short-chain-length PHA depolymerase type 1 (e_dPHAscl_type1) family based on domain annotation and sequence motif analysis. By proposing a putative association between specific genomic features and macroscopic polymer degradation, this study suggests that Terrabacter sp. AAH1 may represent a candidate biocatalyst warranting further investigation for potential applications in bioplastic waste management.

Genomic insights from a long-read assembly of a deep-sea Chromohalobacter israelensis strain from Santos Basin pockmarks field

Continental slopes, particularly the pockmark and salt diapir regions of the Santos Basin, represent extreme environments characterized by high hydrostatic pressure, low temperatures, elevated salinity, and limited organic matter, fostering unique bacterial communities. This study aimed to elucidate the metabolic strategies enabling survival in these conditions by exploring the genome of a Chromohalobacter israelensis strain isolated from such sediments, utilizing long-read sequencing. The genome, assembled into a single 3.8 Mb contig with 98.9% completeness, confirmed the strain’s taxonomic identity. Analysis revealed genes for metabolizing diverse carbohydrate sources, a complete ectoine synthesis cluster essential for halophily, and genes conferring tolerance to osmotic stress, low temperatures, and pH, underscoring its polyextremophilic capacity. Pangenome analysis identified a substantial core genome with essential metabolic functions, including a species-exclusive sulfur metabolism reaction. These findings highlight the strain’s biotechnological potential and contribute to understanding the genus’s adaptation to diverse hypersaline habitats and the strain’s potential role in the sampled environment.