Dataset Information

Degradation Products of Polychlorinated Biphenyls and Their In Vitro Transformation by Ligninolytic Fungi.

ABSTRACT: Metabolites of polychlorinated biphenyls (PCBs)-hydroxylated PCBs (OH-PCBs), chlorobenzyl alcohols (CB-OHs), and chlorobenzaldehydes (CB-CHOs)-were incubated in vitro with the extracellular liquid of Pleurotus ostreatus, which contains mainly laccase and low manganese-dependent peroxidase (MnP) activity. The enzymes were able to decrease the amount of most of the tested OH-PCBs by > 80% within 1 h; the removal of more recalcitrant OH-PCBs was greatly enhanced by the addition of the laccase mediator syringaldehyde. Conversely, glutathione substantially hindered the reaction, suggesting that it acted as a laccase inhibitor. Hydroxylated dibenzofuran and chlorobenzoic acid were identified as transformation products of OH-PCBs. The extracellular enzymes also oxidized the CB-OHs to the corresponding CB-CHOs on the order of hours to days; however, the mediated and nonmediated setups exhibited only slight differences, and the participating enzymes could not be determined. When CB-CHOs were used as the substrates, only partial transformation was observed. In an additional experiment, the extracellular liquid of Irpex lacteus, which contains predominantly MnP, was able to efficiently transform CB-CHOs with the aid of glutathione; mono- and di-chloroacetophenones were detected as transformation products. These results demonstrate that extracellular enzymes of ligninolytic fungi can act on a wide range of PCB metabolites, emphasizing their potential for bioremediation.

SUBMITTER: Sredlova K

PROVIDER: S-EPMC8070434 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundMany fungi grow as saprobic organisms and obtain nutrients from a wide range of dead organic materials. Among saprobes, fungal species that grow on wood or in polluted environments have evolved prolific mechanisms for the production of degrading compounds, such as ligninolytic enzymes. These enzymes include arrays of intense redox-potential oxidoreductase, such as laccase, catalase, and peroxidases. The ability to produce ligninolytic enzymes makes a variety of fungal species suitable for application in many industries, including the production of biofuels and antibiotics, bioremediation, and biomedical application as biosensors. However, fungal ligninolytic enzymes are produced naturally in small quantities that may not meet the industrial or market demands. Over the last decade, combined synthetic biology and computational designs have yielded significant results in enhancing the synthesis of natural compounds in fungi. In this review, we gave insights into different protein engineering methods, including rational, semi-rational, and directed evolution approaches that have been employed to enhance the production of some important ligninolytic enzymes in fungi. We described the role of metabolic pathway engineering to optimize the synthesis of chemical compounds of interest in various fields. We highlighted synthetic biology novel techniques for biosynthetic gene cluster (BGC) activation in fungo and heterologous reconstruction of BGC in microbial cells. We also discussed in detail some recombinant ligninolytic enzymes that have been successfully enhanced and expressed in different heterologous hosts. Finally, we described recent advance in CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas (CRISPR associated) protein systems as the most promising biotechnology for large-scale production of ligninolytic enzymes.Short conclusionAggregation, expression, and regulation of ligninolytic enzymes in fungi require very complex procedures with many interfering factors. Synthetic and computational biology strategies, as explained in this review, are powerful tools that can be combined to solve these puzzles. These integrated strategies can lead to the production of enzymes with special abilities, such as wide substrate specifications, thermo-stability, tolerance to long time storage, and stability in different substrate conditions, such as pH and nutrients.

Project description:Soils are sorbents for many organic compounds and children consume relatively large amounts of soil. To improve the estimated health risks from this exposure pathway, we examined the role of co-ingested foods in determining the post-ingestion bioaccessibility (mobilization) of 18 polychlorinated biphenyls (PCBs) sorbed to 10 characterized soils. The bioaccessibility test system (DIN 19738, 2004) was an in vitro, 3-compartment, digestive tract containing salts, protein, and bile. Each soil was fortified with PCBs, then, digestive fluids appropriate to each compartment, were added sequentially. Next, digestive fluid and soil were seperated and PCB concentrations in both media were measured. This complete test system was then reduced to assess contributions of individual endogenous digestive fluid constituents (water, salts, pancreatin, bile, and mucin) and representative foods: protein (bovine serum albumin (BSA)), sugar (glucose), and fat (oleic acid). Then, the influence of increasing concentrations of BSA, glucose, and oleic acid was evaluated (individually) complete test systems. In a subset of the samples, solid phase microextraction (SPME) was used to measure freely dissolved PCBs. Across all treatments, percent soil organic carbon was the most influential bioaccessibility determinant, accounting for ?87% of the explained variation. When evaluated individually, pancreatin, mucin, BSA, bile, and oleic acid each effectively increased PCB bioaccessibility and reduced freely dissolved PCB concentrations. This suggests competitive sorption of PCBs by organic constituents of the digestive constituents. Without sink material, intra-PCB mobilization differences were observed as freely dissolved PCB concentrations inversely correlated (p < 0.05) with their respective log Kow's. When added to the complete digestive fluid, increasing oleic acid mass increased PCB bioaccessibility (p < 0.05), while adding more BSA or glucose did not (p > 0.05). This indicates that fat intake may be the sole consideration needed when modeling dietary contributions to bioaccessibility of soil sorbed PCBs.

Dataset Information

Degradation Products of Polychlorinated Biphenyls and Their In Vitro Transformation by Ligninolytic Fungi.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets