Genomic Analysis and Characterization of Phenotypic Traits of Hydrocarbon-Degrading Actinobacterial Strains Isolated from a Sierozem Soil of Southern Kazakhstan

Isolation, Molecular Characterization, and Screening for Hydrocarbon-degrading Potential of an Indigenous Enterobacter sp. from Petroleum-contaminated Soil for Bioremediation Applications

The results indicate that indigenous bacteria from chronically hydrocarbon-contaminated soils can show differing relative activities under the screening conditions, with K2 displaying the strongest response among the isolates tested.

Isolation, Genomic Characterization and Biotechnological Potential of Culturable Bacteria from Metal-Rich and Organic Soils of La Soledad Dam, Guanajuato, Mexico

Findings highlight the potential biotechnological relevance of culturable bacterial isolates recovered from historically mining-impacted soils and provide genomic resources for future studies on environmental remediation, sustainable agriculture, and industrial biotechnology.

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

ABSTRACT Polyethylene terephthalate (PET) waste represents a major environmental challenge due to limited recycling solutions. Thermophilic bacteria from geothermal environments harbor diverse enzymatic machinery adapted to extreme conditions, offering promising biocatalysts for plastic degradation; however, biological resources from Peru and other South American countries remain scarce. We characterized four bacterial strains isolated from two geothermal sites in Cajamarca, Peru, screened for PET hydrolysis at 50°C. Whole‐genome sequencing using hybrid assembly achieved near‐complete circular genomes. GTDB‐Tk classification identified three species: Neobacillus thermocopriae (strain 19A), Bacillus licheniformis (strains 16P and BI2), and Brevibacillus agri (strain BI8). Quantitative assays revealed that strain 16P achieved the highest mass loss (0.598%), followed by strain BI8 (0.449%). ATR‐FTIR analysis of the incubated sheets showed a significant reduction of the ester carbonyl index in strains 16P, 19A, and BI8 relative to both non‐incubated PET and an abiotic control, whereas strain BI2 did not differ from the controls, indicating preferential modification of ester bonds at the sheet surface. Genome mining and structure‐based homology searches identified multiple candidate enzymes similar to validated PETases and carboxylesterases, including PETase46‐like homologs in strains BI8 and 16P and a terephthalate‐active carboxylesterase homolog in strain 16P. Molecular docking supported the conservation of catalytic geometry and substrate‐binding sites in these candidates. This work represents one of the first systematic genomic and structural characterizations of putative PET‐hydrolases in Peruvian geothermal bacteria, expanding knowledge of extremophile diversity and advancing thermostable enzymes for sustainable plastic waste management.

Production of Some Extracellular Hydrolases by Halophilic Bacteria Isolated from Mangrove Soil in Sumberkima Village, Bali, Indonesia

Hydrolases are enzymes with broad industrial applications across the food, pharmaceutical, textile, detergent, and paper sectors. For commercial use, these enzymes are primarily sourced from microorganisms. Halophilic bacteria, which thrive in high-salinity environments, represent a promising yet underutilized source of novel hydrolases. This study aimed to isolate and screen halophilic bacteria from mangrove soil in Sumberkima Village, Buleleng Regency, Bali Province, Indonesia, for their ability to produce extracellular hydrolases. Soil samples were cultivated on Luria-Bertani (LB) media supplemented with 5% and 10% (w/v) NaCl. Putative colonies were isolated and screened for amylase, cellulase, and lipase production using starch, carboxymethyl cellulose, and rhodamine-olive oil agar, respectively. Enzymatic activities were quantified via spectrophotometry, and the most proficient isolates were identified through 16S rRNA gene phylogenetic analysis. The screening yielded several halophilic bacteria with significant extracellular hydrolase activity. The most proficient isolates identified were: amylase-producing Vibrio xiamenensis SKMG1(4) (0.44 U/mL), cellulase-producing Vibrio hepatarius SKMG1(3) (0.36 U/mL), and lipase-producing Salinivibrio kushneri SKMG2(5) (21.6 U/mL). Phylogenetic analysis confirmed the close taxonomic relationship of these isolates to their respective type strains. This study represents the first report of extracellular hydrolase production from these three halophilic bacterial species, highlighting their potential for specialized industrial applications.

Culturable bacterial diversity and genome-encoded metabolic potential in Al Wahbah Crater’s volcanic soils, Saudi Arabia

The growing demand for sustainable biotechnological solutions has intensified interest in microorganisms inhabiting understudied and environmentally constrained ecosystems. Volcanic systems create ecological niches shaped by geochemical and physicochemical stressors, yet the culturable bacteria in many remain poorly characterized. Here, we investigated the culturable bacterial fraction in the soils of Al Wahbah Crater (Saudi Arabia), an underexplored volcanic ecosystem, and evaluated its members’ hydrolytic enzyme production and the genome-encoded metabolic potential of the most-promising isolates. Using multiple media and incubation conditions, we isolated bacterial strains from three crater soil types, identifying 65 representative isolates through 16S rRNA gene sequencing. The culture collection was dominated by Bacillota, particularly Bacillus spp., reflecting selective pressures typical of mineral-rich, saline soils. All isolates were screened for six hydrolases: cellulase, xylanase, amylase, protease, lipase, and gelatinase. Twenty-three strains exhibited activities for all six, while only one (Paenibacillus sp. AWC54) showed no detectable enzymatic activity. Cellulase activity was most prevalent (61/65 isolates), followed by xylanase (59/65), amylase (57/65), protease (48/65), lipase (35/65), and gelatinase (31/65). Five high-performing strains, Bacillus spizizenii AWC2, B. cereus AWC16, B. vallismortis AWC57 and AWC81, and B. haynesii AWS14, were selected for whole-genome sequencing and genome mining. Genome annotations revealed diverse carbohydrate-active enzyme repertoires including glycoside hydrolases, glycosyl transferases, and polysaccharide lyases, as well as multiple biosynthetic gene clusters predicted to encode antimicrobial and antifungal metabolites. Together, these findings establish Al Wahbah Crater as a cultivable regional reservoir of metabolically versatile bacteria and provide a curated strain collection and genomic framework for future ecological, evolutionary, and biotechnological investigations of volcanic microbiomes in the Arabian Peninsula.

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