From nature to industry: Harnessing enzymes for biocatalysis

Science, Journal Year: 2023, Volume and Issue: 382(6673)

Published: Nov. 23, 2023

Biocatalysis harnesses enzymes to make valuable products. This green technology is used in countless applications from bench scale industrial production and allows practitioners access complex organic molecules, often with fewer synthetic steps reduced waste. The last decade has seen an explosion the development of experimental computational tools tailor enzymatic properties, equipping enzyme engineers ability create biocatalysts that perform reactions not present nature. By using (chemo)-enzymatic synthesis routes or orchestrating intricate cascades, scientists can synthesize elaborate targets ranging DNA pharmaceuticals starch made vitro CO2-derived methanol. In addition, new chemistries have emerged through combination biocatalysis transition metal catalysis, photocatalysis, electrocatalysis. review highlights recent key developments, identifies current limitations, provides a future prospect for this rapidly developing technology.

Language: Английский

---

Recyclable and (Bio)degradable Polyesters in a Circular Plastics Economy

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(7), P. 4393 - 4478

Published: March 22, 2024

Polyesters carrying polar main-chain ester linkages exhibit distinct material properties for diverse applications and thus play an important role in today's plastics economy. It is anticipated that they will even greater tomorrow's circular economy focuses on sustainability, thanks to the abundant availability of their biosourced building blocks presence bonds can be chemically or biologically cleaved demand by multiple methods bring about more desired end-of-life plastic waste management options. Because this potential promise, there have been intense research activities directed at addressing recycling, upcycling biodegradation existing legacy polyesters, designing biorenewable alternatives, redesigning future polyesters with intrinsic chemical recyclability tailored performance rival commodity are either petroleum based and/or hard recycle. This review captures these exciting recent developments outlines challenges opportunities. Case studies poly(lactic acid), poly(3-hydroxyalkanoate)s, poly(ethylene terephthalate), poly(butylene succinate), poly(butylene-adipate presented, emerging recyclable comprehensively reviewed.

Language: Английский

---

Assessment of Four Engineered PET Degrading Enzymes Considering Large-Scale Industrial Applications

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(20), P. 13156 - 13166

Published: Sept. 26, 2023

In recent years, enzymatic recycling of the widely used polyester polyethylene terephthalate (PET) has become a complementary solution to current thermomechanical for colored, opaque, and mixed PET. A large set promising hydrolases that depolymerize PET have been found enhanced by worldwide initiatives using various methods protein engineering. Despite achievements made in these works, it remains difficult compare enzymes' performance their applicability large-scale reactions due lack homogeneity between experimental protocols used. Here, we pave way standardized hydrolysis protocol reaction conditions relevant larger scale apply parameters four recently reported (LCCICCG, FAST-PETase, HotPETase, PES-H1L92F/Q94Y). We show FAST-PETase HotPETase intrinsic limitations may not permit application on scales, mainly relatively low depolymerization rates. With 80% depolymerization, PES-H1L92F/Q94Y be suitable candidate industrial scales upon further rounds enzyme evolution. LCCICCG outperforms other enzymes, converting 98% into monomeric products terephthalic acid (TPA) ethylene glycol (EG) 24 h. addition, optimized toward economic viability, reducing required amount factor 3 temperature from 72 68 °C. anticipate our findings advance coherent assessment enzymes materialize feasibility at scales.

Language: Английский

---

Sustainable production and degradation of plastics using microbes

Nature Microbiology, Journal Year: 2023, Volume and Issue: 8(12), P. 2253 - 2276

Published: Nov. 29, 2023

Language: Английский

---

Significance of poly(ethylene terephthalate) (PET) substrate crystallinity on enzymatic degradation

New Biotechnology, Journal Year: 2023, Volume and Issue: 78, P. 162 - 172

Published: Nov. 6, 2023

Poly(ethylene terephthalate) (PET) is a semi-crystalline plastic polyester material with global production volume of 83 Mt/year. PET mainly used in textiles, but also widely for packaging materials, notably bottles, and major contributor to environmental waste accumulation. Now that enzymes have been demonstrated catalyze degradation, new options sustainable bio-recycling materials via enzymatic catalysis emerged. The degradation rate strongly influenced by the properties PET, degree crystallinity, XC. higher XC material, slower rate. Crystallization resulting increased XC, induced thermally (via heating) and/or mechanically stretching), most bottles microplastics exceeds what currently known can readily degrade. action occurs at surface insoluble improves when chain mobility increases. increases drastically temperature glass transition temperature, Tg, which ∼40 °C layer PET. Since crystallization starts 70 °C, ideal just below balance high reaction activation without inducing crystal formation. This paper reviews current understanding on as an enzyme substrate summarizes recent knowledge how crystalline amorphous regions form, Tg impact efficiency degradation.

Language: Английский

---

Natural diversity screening, assay development, and characterization of nylon-6 enzymatic depolymerization

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Feb. 9, 2024

Abstract Successes in biocatalytic polyester recycling have raised the possibility of deconstructing alternative polymers enzymatically, with polyamide (PA) being a logical target due to array amide-cleaving enzymes present nature. Here, we screen 40 potential natural and engineered nylon-hydrolyzing (nylonases), using mass spectrometry quantify eight compounds resulting from enzymatic nylon-6 (PA6) hydrolysis. Comparative time-course reactions incubated at 40-70 °C showcase enzyme-dependent variations product distributions extent PA6 film depolymerization, significant nylon deconstruction activity appearing rare. The most active nylonase, NylC K variant rationally thermostabilized (an N-terminal nucleophile (Ntn) hydrolase, -TS, T m = 87.4 °C, 16.4 higher than wild-type), hydrolyzes 0.67 wt% film. Reactions fail restart after fresh enzyme addition, indicating that substrate-based limitations, such as restricted access hydrolysable bonds, prohibit more extensive deconstruction. Overall, this study expands our understanding nylonase distribution, indicates Ntn hydrolases may greatest for further development, identifies key targets progressing including improving activity, selectivity, enhancing polymer accessibility.

Language: Английский

---

Ring-Opening Polymerization of Lactones to Prepare Closed-Loop Recyclable Polyesters

Macromolecules, Journal Year: 2024, Volume and Issue: 57(5), P. 1919 - 1940

Published: Feb. 22, 2024

The large production and indiscriminate disposal of plastics have resulted in serious resource global environmental crises, which has raised a demand to develop more sustainable circular economy. An ideal strategy address the end-of-life issue is next-generation polymers with closed-loop life cycles, can be selectively depolymerized back monomers at end their service life. Aliphatic polyesters prepared by ring-opening polymerization (ROP) moderately strained lactones shown great potential recyclable polymers. This Perspective highlights recent achievements for that are derived from four-, five-, six-, seven-membered focusing on discussion thermodynamic kinetic considerations, monomer design principles polymer preparations, material properties, chemical recyclability. Finally, current challenges possible directions also discussed.

Language: Английский

---

Plastic Waste Recycling─A Chemical Recycling Perspective

ACS Sustainable Chemistry & Engineering, Journal Year: 2024, Volume and Issue: 12(33), P. 12270 - 12288

Published: July 1, 2024

This article provides an overview of plastic recycling development since the 1970s. It discusses three common options: mechanical recycling, chemical and energetic recycling. Additionally, it considers challenges waste cleaning sorting. The describes processes in detail for main constituents waste, such as polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), terephthalate (PET). current rates indicate that only is economically viable, which insufficient a sustainable circular economy. Chemical methods are often too energy-intensive require complex presorting making them unattractive. To become competitive, requirements have been derived this article. In context, splitting polymer chains using low-temperature atmospheric pressure plasma proposed novel technology. date, technology has used surface treatment plastic. However, shows potential processing unsorted, low-value especially PE, PP, mixed would otherwise be sent incineration or to landfills. Mechanical unsuitable these streams, competitive not yet established on industrial scale.

Language: Английский

---

Dynamic Docking-Assisted Engineering of Hydrolases for Efficient PET Depolymerization

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 3627 - 3639

Published: Feb. 21, 2024

Poly(ethylene terephthalate) (PET) is the most abundant polyester plastic and causing serious environmental pollution. Rapid biological depolymerization of PET waste at a large scale requires powerful engineered enzymes with excellent performance. Here, we designed computational strategy to analyze ligand affinity energy chains by molecular docking dynamic protein conformations, named analysis based on (ADD). After three rounds engineering assisted ADD, drastically enhanced PET-depolymerizing activity leaf-branch-compost cutinase (LCC). The best variant LCC-A2 depolymerized >90% pretreated, postconsumer into corresponding monomers within 3.3 h 78 °C, over 99% products was terminal (terephthalic acid ethylene glycol), representing fastest rate reported date in bioreactor under optimal condition. Structural revealed interesting features that improved catalytic In conclusion, proposed variants represent substantial advancement circular economy for PET.

Language: Английский

---

Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation

Chemosphere, Journal Year: 2024, Volume and Issue: 355, P. 141749 - 141749

Published: March 21, 2024

Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient cause great damage to ecosystems. The development biodegradable offers promising solution waste management. These designed break down under various conditions, opening up new possibilities mitigate negative impact traditional plastics. Microbes, including bacteria fungi, play crucial role in bioplastics by producing secreting extracellular enzymes, such as cutinase, lipases, proteases. However, these microbial enzymes sensitive extreme environmental temperature acidity, affecting their functions stability. To address challenges, scientists have employed protein engineering immobilization techniques enhance enzyme stability predict structures. Strategies improving substrate interaction, increasing thermostability, reinforcing bonding between active site substrate, refining activity being utilized boost functionality. Recently, bioengineering through gene cloning expression potential microorganisms, revolutionized biodegradation bioplastics. This review aimed discuss most recent strategies modifying bioplastic-degrading terms functionality, thermostability enhancement, binding site, with other improvement surface action. Additionally, discovered exoenzymes metagenomics were emphasized.

Language: Английский

---