Genomics Insights into Pseudomonas sp. CG01: An Antarctic Cadmium-Resistant Strain Capable of Biosynthesizing CdS Nanoparticles Using Methionine as S-Source

Abstract

Here, we present the draft genome sequence of Pseudomonas sp. GC01, a cadmium-resistant Antarctic bacterium capable of biosynthesizing CdS fluorescent nanoparticles (quantum dots, QDs) employing a unique mechanism involving the production of methanethiol (MeSH) from methionine (Met). To explore the molecular/metabolic components involved in QDs biosynthesis, we conducted a comparative genomic analysis, searching for the genes related to cadmium resistance and sulfur metabolic pathways. The genome of Pseudomonas sp. GC01 has a 4,706,645 bp size with a 58.61% G+C content. Pseudomonas sp. GC01 possesses five genes related to cadmium transport/resistance, with three P-type ATPases (cadA, zntA, and pbrA) involved in Cd-secretion that could contribute to the extracellular biosynthesis of CdS QDs. Furthermore, it exhibits genes involved in sulfate assimilation, cysteine/methionine synthesis, and volatile sulfur compounds catabolic pathways. Regarding MeSH production from Met, Pseudomonas sp. GC01 lacks the genes E4.4.1.11 and megL for MeSH generation. Interestingly, despite the absence of these genes, Pseudomonas sp. GC01 produces high levels of MeSH. This is probably associated with the metC gene that also produces MeSH from Met in bacteria. This work is the first report of the potential genes involved in Cd resistance, sulfur metabolism, and the process of MeSH-dependent CdS QDs bioproduction in Pseudomonas spp. strains.

Comparative Genomic Analysis of Antarctic Pseudomonas Isolates with 2,4,6-Trinitrotoluene Transformation Capabilities Reveals Their Unique Features for Xenobiotics Degradation

“…analyzed; Figure S7: Metabolic functions encoded by unique genes in TNT isolates; Figure S8: Average nucleotide identity heat map based on MUMmer algorithm (ANIm) among the 24 pseudomonads considered in this study; Figure S9: Genomic islands (GIs) predicted in the genomes of TNT isolates; Figure S10: Putative gene cluster for production of xanthoferrin in TNT19 isolate; Figure S11: Multiple sequence alignment of putative nitroreductases in some pseudomonads; Figure S12: Multiple sequence alignment of putative xenobiotic reductases in some pseudomonads; Figure S13: Multiple sequence alignment of putative azoreductases in some pseudomonads; Figure S14: Neighbor-ioining (NJ) cladogram depicting phylogenetic relationships among TNT-degrading enzymes; Table S1: Characteristics of the pseudomonads used for comparative genomic analysis in this study; Table S2: Enzymes encoded by genes of the “trinitrotoluene degradation” pathway found by PATRIC/RASTtk in TNT isolates genomes; Table S3: The pangenome of the 24 pseudomonads used in this study and groups of sub-pangenomes constructed with Roary; Table S4: Prophage regions found in the genomes of TNT-transforming bacteria; Table S5: Putative TNT-degrading enzymes found in TNT isolates. References [ 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 ] are cited in the Supplementary Materials.…”