| Title : A Thermostable Lipase Isolated from Brevibacillus thermoruber Strain 7 Degrades -Polycaprolactone - Atanasova_2023_BioTech.(Basel)_12_ |
| Author(s) : Atanasova N , Paunova-Krasteva T , Kambourova M , Boyadzhieva I |
| Ref : BioTech (Basel) , 12 : , 2023 |
| Abstract : The tremendous problem with plastic waste accumulation has determined an interest in biodegradation by effective degraders and their enzymes, such as thermophilic enzymes, which are characterized by high catalytic rates, thermostability, and optimum temperatures close to the melting points of some plastics. In the present work, we report on the ability of a thermophilic lipase, by Brevibacillus thermoruber strain 7, to degrade -polycaprolactone (PCL), as well as the enzyme purification, the characterization of its physicochemical properties, the product degradation, and its disruptive effect on the PCL surface. The pure enzyme showed the highest reported optimum temperature at 55 degreesC and a pH of 7.5, while its half-life at 60 degreesC was more than five hours. Its substrate specificity referred the enzyme to the subgroup of lipases in the esterase group. A strong inhibitory effect was observed by detergents, inhibitors, and Fe(3+) while Ca(2+) enhanced its activity. The monomer -caprolactone was a main product of the enzyme degradation. Similar elution profiles of the products received after treatment with ultra-concentrate and pure enzyme were observed. The significant changes in PCL appearance comprising the formation of shallower or deeper in-folds were observed after a week of incubation. The valuable enzyme properties of the lipase from Brevibacillus thermoruber strain 7, which caused a comparatively quick degradation of PCL, suggests further possible exploration of the enzyme for effective and environment-friendly degradation of PCL wastes in the area of thermal basins, or in thermophilic remediation processes. |
| ESTHER : Atanasova_2023_BioTech.(Basel)_12_ |
| PubMedSearch : Atanasova_2023_BioTech.(Basel)_12_ |
| PubMedID: 36975313 |
| Title : Plastic Degradation by Extremophilic Bacteria - Atanasova_2021_Int.J.Mol.Sci_22_ |
| Author(s) : Atanasova N , Stoitsova S , Paunova-Krasteva T , Kambourova M |
| Ref : Int J Mol Sci , 22 : , 2021 |
| Abstract : Intensive exploitation, poor recycling, low repeatable use, and unusual resistance of plastics to environmental and microbiological action result in accumulation of huge waste amounts in terrestrial and marine environments, causing enormous hazard for human and animal life. In the last decades, much scientific interest has been focused on plastic biodegradation. Due to the comparatively short evolutionary period of their appearance in nature, sufficiently effective enzymes for their biodegradation are not available. Plastics are designed for use in conditions typical for human activity, and their physicochemical properties roughly change at extreme environmental parameters like low temperatures, salt, or low or high pH that are typical for the life of extremophilic microorganisms and the activity of their enzymes. This review represents a first attempt to summarize the extraordinarily limited information on biodegradation of conventional synthetic plastics by thermophilic, alkaliphilic, halophilic, and psychrophilic bacteria in natural environments and laboratory conditions. Most of the available data was reported in the last several years and concerns moderate extremophiles. Two main questions are highlighted in it: which extremophilic bacteria and their enzymes are reported to be involved in the degradation of different synthetic plastics, and what could be the impact of extremophiles in future technologies for resolving of pollution problems. |
| ESTHER : Atanasova_2021_Int.J.Mol.Sci_22_ |
| PubMedSearch : Atanasova_2021_Int.J.Mol.Sci_22_ |
| PubMedID: 34070607 |