来源于海洋宏基因组塑料降解酶Ple629的耐热性提升改造

石化来源的聚酯类塑料如聚对苯二甲酸乙二醇酯(polyethylene terephthalate,PET)以及聚己二酸/对苯二甲酸丁二醇酯(polybutylene adipate terephthalate,PBAT)等已被广泛使用,但由于它们在自然界中难以降解或生物降解周期较长导致了严重的环境污染,因此对这些塑料废弃物的处理是亟待解决的问题之一。从循环经济的角度考虑,利用生物酶法对聚酯类塑料如PET或PBAT等的废弃物进行解聚,再将解聚产物进行循环利用,是一个很有潜力的研究方向。探究近年来关于聚酯塑料降解酶的报道发现,高活性且耐高温的降解酶会有更大的潜在优势。来自海洋微生物宏基因组的中温塑料降解酶Ple629,在常温下对聚酯类塑料PET和PBAT均有较好的降解活力,但由于不耐受高温,限制了其潜在应用。在前期获得Ple629三维结构的基础上,本研究基于结构比对及能量设计,找到了一些潜在提升其热稳定性的位点进行改造设计,并对突变体进行了表达纯化和热稳定性测定。突变体V80C和D226C/S281C的熔点温度(Tm)值分别提升了5.2℃和6.9℃,突变体D226C/S281C的活性也比野生型酶提高了1.5倍,为后续对Ple629的进一步改造提供了思路和依据。     

Thermophilic whole-cell degradation of polyethylene terephthalate using engineered Clostridium thermocellum

Polyethylene terephthalate (PET) is a mass-produced synthetic polyester contributing remarkably to the accumulation of solid plastics waste and plastics pollution in the natural environments. Recently, bioremediation of plastics waste using engineered enzymes has emerged as an eco-friendly alternative approach for the future plastic circular economy. Here we genetically engineered a thermophilic anaerobic bacterium, Clostridium thermocellum, to enable the secretory expression of a thermophilic cutinase (LCC), which was originally isolated from a plant compost metagenome and can degrade PET at up to 70°C. This engineered whole-cell biocatalyst allowed a simultaneous high-level expression of LCC and conspicuous degradation of commercial PET films at 60°C. After 14 days incubation of a batch culture, more than 60% of the initial mass of a PET film (approximately 50 mg) was converted into soluble monomer feedstocks, indicating a markedly higher degradation performance than previously reported whole-cell-based PET biodegradation systems using mesophilic bacteria or microalgae. Our findings provide clear evidence that, compared to mesophilic species, thermophilic microbes are a more promising synthetic microbial chassis for developing future biodegradation processes of PET waste.     

Investigation of the halophilic PET hydrolase PET6 from Vibrio gazogenes

The handling of plastic waste and the associated ubiquitous occurrence of microplastic poses one of the biggest challenges of our time. Recent investigations of plastic degrading enzymes have opened new prospects for biological microplastic decomposition as well as recycling applications. For polyethylene terephthalate, in particular, several natural and engineered enzymes are known to have such promising properties. From a previous study that identified new PETase candidates by homology search, we chose the candidate PET6 from the globally distributed, halophilic organism Vibrio gazogenes for further investigation. By mapping the occurrence of Vibrios containing PET6 homologs we demonstrated their ubiquitous prevalence in the pangenome of several Vibrio strains. The biochemical characterization of PET6 showed that PET6 has a comparatively lower activity than other enzymes but also revealed a superior turnover at very high salt concentrations. The crystal structure of PET6 provides structural insights into this adaptation to saline environments. By grafting only a few beneficial mutations from other PET degrading enzymes onto PET6, we increased the activity up to three‐fold, demonstrating the evolutionary potential of the enzyme. MD simulations of the variant helped rationalize the mutational effects of those mutants and elucidate the interaction of the enzyme with a PET substrate. With tremendous amounts of plastic waste in the Ocean and the prevalence of Vibrio gazogenes in marine biofilms and estuarine marshes, our findings suggest that Vibrio and the PET6 enzyme are worthy subjects to study the PET degradation in marine environments.     

Thermostability enhancement of polyethylene terephthalate degrading PETase using self- and nonself-ligating protein scaffolding approaches

Polyethylene terephthalate (PET) hydrolase enzymes show promise for enzymatic PET degradation and green recycling of single-use PET vessels representing a major source of global pollution. Their full potential can be unlocked with enzyme engineering to render activities on recalcitrant PET substrates commensurate with cost-effective recycling at scale. Thermostability is a highly desirable property in industrial enzymes, often imparting increased robustness and significantly reducing quantities required. To date, most engineered PET hydrolases show improved thermostability over their parental enzymes. Here, we report engineered thermostable variants of Ideonella sakaiensis PET hydrolase enzyme (IsPETase) developed using two scaffolding strategies. The first employed SpyCatcher-SpyTag technology to covalently cyclize IsPETase, resulting in increased thermostability that was concomitant with reduced turnover of PET substrates compared to native IsPETase. The second approach using a GFP-nanobody fusion protein (vGFP) as a scaffold yielded a construct with a melting temperature of 80°C. This was further increased to 85°C when a thermostable PETase variant (FAST PETase) was scaffolded into vGFP, the highest reported so far for an engineered PET hydrolase derived from IsPETase. Thermostability enhancement using the vGFP scaffold did not compromise activity on PET compared to IsPETase. These contrasting results highlight potential topological and dynamic constraints imposed by scaffold choice as determinants of enzyme activity.     

Active Site Flexibility as a Hallmark for Efficient PET Degradation by I. sakaiensis PETase

Polyethylene terephthalate (PET) is one of the most-consumed synthetic polymers, with an annual production of 50 million tons. Unfortunately, PET accumulates as waste and is highly resistant to biodegradation. Recently, fungal and bacterial thermophilic hydrolases were found to catalyze PET hydrolysis with optimal activities at high temperatures. Strikingly, an enzyme from Ideonella sakaiensis, termed PETase, was described to efficiently degrade PET at room temperature, but the molecular basis of its activity is not currently understood. Here, a crystal structure of PETase was determined at 2.02 Å resolution and employed in molecular dynamics simulations showing that the active site of PETase has higher flexibility at room temperature than its thermophilic counterparts. This flexibility is controlled by a novel disulfide bond in its active site, with its removal leading to destabilization of the catalytic triad and reduction of the hydrolase activity. Molecular docking of a model substrate predicts that PET binds to PETase in a unique and energetically favorable conformation facilitated by several residue substitutions within its active site when compared to other enzymes. These computational predictions are in excellent agreement with recent mutagenesis and PET film degradation analyses. Finally, we rationalize the increased catalytic activity of PETase at room temperature through molecular dynamics simulations of enzyme-ligand complexes for PETase and other thermophilic PET-degrading enzymes at 298, 323, and 353 K. Our results reveal that both the binding pose and residue substitutions within PETase favor proximity between the catalytic residues and the labile carbonyl of the substrate at room temperature, suggesting a more favorable hydrolytic reaction. These results are valuable for enabling detailed evolutionary analysis of PET-degrading enzymes and for rational design endeavors aiming at increasing the efficiency of PETase and similar enzymes toward plastic degradation.     

Quantification of lignin–carbohydrate linkages with high-resolution NMR spectroscopy

A quantitative approach to characterize lignin–carbohydrate complex (LCC) linkages using a combination of quantitative ¹³C NMR and HSQC 2D NMR techniques has been developed. Crude milled wood lignin (MWLc), LCC extracted from MWLc with acetic acid (LCC-AcOH) and cellulolytic enzyme lignin (CEL) preparations were isolated from loblolly pine (Pinus taeda) and white birch (Betula pendula) woods and characterized using this methodology on a routine 300 MHz NMR spectrometer and on a 950 MHz spectrometer equipped with a cryogenic probe. Structural variations in the pine and birch LCC preparations of different types (MWL, CEL and LCC-AcOH) were elucidated. The use of the high field NMR spectrometer equipped with the cryogenic probe resulted in a remarkable improvement in the resolution of the LCC signals and, therefore, is of primary importance for an accurate quantification of LCC linkages. The preparations investigated showed the presence of different amounts of benzyl ether, γ-ester and phenyl glycoside LCC bonds. Benzyl ester moieties were not detected. Pine LCC-AcOH and birch MWLc preparations were preferable for the analysis of phenyl glycoside and ester LCC linkages in pine and birch, correspondingly, whereas CEL preparations were the best to study benzyl ether LCC structures. The data obtained indicate that pinewood contains higher amounts of benzyl ether LCC linkages, but lower amounts of phenyl glycoside and γ-ester LCC moieties as compared to birch wood.     

Inhibition of cellulase, xylanase and beta-glucosidase activities by softwood lignin preparations

The conversion of lignocellulosic biomass to fuel ethanol typically involves a disruptive pretreatment process followed by enzyme-catalyzed hydrolysis of the cellulose and hemicellulose components to fermentable sugars. Attempts to improve process economics include protein engineering of cellulases, xylanases and related hydrolases to improve their specific activity or stability. However, it is recognized that enzyme performance is reduced during lignocellulose hydrolysis by interaction with lignin or lignin-carbohydrate complex (LCC), so the selection or engineering of enzymes with reduced lignin interaction offers an alternative means of enzyme improvement. This study examines the inhibition of seven cellulase preparations, three xylanase preparations and a beta-glucosidase preparation by two purified, particulate lignin preparations derived from softwood using an organosolv pretreatment process followed by enzymatic hydrolysis. The two lignin preparations had similar particle sizes and surface areas but differed significantly in other physical properties and in their chemical compositions determined by a 2D correlation HSQC NMR technique and quantitative 13C NMR spectroscopy. The various cellulases differed by up to 3.5-fold in their inhibition by lignin, while the xylanases showed less variability (< or = 1.7-fold). Of all the enzymes tested, beta-glucosidase was least affected by lignin.     

来源于嗜热氢化杆菌的新型对苯二甲酸双(羟乙)酯水解酶的表达纯化与酶学性质

石化来源的聚对苯二甲酸乙二酯(polyethylene terephthalate,PET)被广泛用于矿泉水瓶、食品包装和纺织品等领域,因其在自然界中不易分解,大量使用后的PET废弃物造成了严重的环境污染与资源浪费。使用生物酶法对PET废弃物进行解聚,并对解聚产物进行升级循环利用是进行塑料污染治理的重要方向之一,其中关键的是PET水解酶的解聚效率。对苯二甲酸双(羟乙基)酯(bis(hydroxyethyl)terephthalate,BHET)是PET生物酶解的中间产物,其累积是限制PET水解酶催化效率的一个重要因素,BHET水解酶和PET水解酶的联用能提升PET的整体水解效率。来源于嗜热氢化杆菌(Hydrogenobacter thermophilus)的双烯内酯酶(HtBHETase)对BHET有显著水解效果,将该酶在大肠杆菌(Escherichia coli)中进行重组表达并纯化后,对其酶学性质进行了研究。结果显示,HtBHETase对短碳链的酯类如对硝基苯酚乙酸酯催化活性较高,HtBHETase以BHET为底物时的最适反应pH值和最适反应温度分别为5.0和55℃;该酶有较好的热稳定性,经80℃的条件处理1 h仍能保持80%以上活性,显示出了良好的热稳定性,HtBHETase有在PET塑料生物解聚中使用的潜力,本研究为推动生物酶法降解PET提供了新的参考。     

聚氨酯塑料的微生物降解

未被合理处置的废塑料污染已成为全球性的环境问题,探索塑料废弃物的无害化处理技术势在必行。近来,研究证实了自然界中存在可以降解塑料的微生物及酶。利用微生物或酶对废塑料进行生物处理成为可能。聚氨酯塑料(Polyurethane,PUR)是广泛应用的通用塑料之一,其废弃物量已占到所有废塑料总体积的30%。文中将PUR塑料发明应用70年来有关微生物降解的研究进行了全面综述,对PUR塑料降解真菌、细菌、降解基因与酶、降解产物及相关的生物处理技术系统等进行了总结与分析,并对实现PUR废塑料高效生物处理需解决的关键科学问题进行了展望。     

A simple and general approach to generate photoactivatable DNA processing enzymes

DNA processing enzymes, such as DNA polymerases and endonucleases, have found many applications in biotechnology, molecular diagnostics, and synthetic biology, among others. The development of enzymes with controllable activity, such as hot-start or light-activatable versions, has boosted their applications and improved the sensitivity and specificity of the existing ones. However, current approaches to produce controllable enzymes are experimentally demanding to develop and case-specific. Here, we introduce a simple and general method to design light-start DNA processing enzymes. In order to prove its versatility, we applied our method to three DNA polymerases commonly used in biotechnology, including the Phi29 (mesophilic), Taq, and Pfu polymerases, and one restriction enzyme. Light-start enzymes showed suppressed polymerase, exonuclease, and endonuclease activity until they were re-activated by an UV pulse. Finally, we applied our enzymes to common molecular biology assays and showed comparable performance to commercial hot-start enzymes.     

饲料用酶制剂的研究进展与趋势

饲料用酶目前已成为世界工业酶产业中增长速度最快、势头最强劲的一部分。畜牧业开发应用饲料用酶制剂有着重大意义:可缓解饲料资源短缺、人畜争粮的局面,有利于保障粮食安全;提供更为安全、优质的动物产品,有利于保障食品安全;减轻环境污染,保障养殖业的可持续发展。饲料用酶的应用效果已在世界范围内得到公认,但酶的使用量还较低,其主要原因在于饲料用酶的性质难以满足饲料工业的要求,以及饲料用酶表达量低,生产成本较高。因此,目前的研发趋势主要体现在:1)饲料用酶基因资源的高通量筛选技术,尤其是特殊环境微生物和未培养微生物中的基因资源;2)酶蛋白的分子改良技术,利用蛋白质工程技术定向改良,创造具有优良特性的酶蛋白质分子,进一步提高饲料用酶的应用性能;3)饲料用酶高效表达和生产技术;4)饲料用酶的应用效果快速评估技术和配套应用技术体系。     

Review and perspective on the use of mixed-function oxygenase enzymes in biological monitoring

It is often suggested that changes in simple biochemical/physiological responses may be useful for predicting the impacts of pollutants at population and community levels of biological organization. There are serious conceptual constraints to such a thesis and its seems likely that such simple responses can go no further than serving as early warning systems for delineating potential areas of pollutant impact--areas which (if shown to be significant in size) can then be subjected to more detailed population and community type studies. Environmental testing is a prerequisite for any response suggested to have value as a biological monitoring index and the induction of mixed-function oxygenase (MFO) enzymes has now been validated in a large number of field studies worldwide. Investigations have progressed from documenting induction near localized sources of hydrocarbon contamination to more diffuse sources of mixed organic pollution originating from industrial and domestic sources. Studies in the Great Lakes and Europe have demonstrated that the induction of MFO enzymes is a biological response of sufficient sensitivity to discriminate water quality differences over broad geographical areas. We suggest that as an early warning system, the induction of these enzymes can fulfill the requirement of "most sensitive biological response" for assessing a variety of organic pollution conditions. Given the high level of sensitivity of the MFO enzyme response, negative as well as positive field trials can be of value in addressing concerns about the toxicological significance of "high-profile" chemicals (and potent inducers) such as polycyclic aromatic hydrocarbons and organochlorines. MFO enzyme induction can also be an economical tool for environmental managers for reacting to real or perceived concerns about pollution such as effects on commercial fish stocks at sites of petroleum hydrocarbon development in the oceans.     

Pyridoxal phosphate binding sites are similar in human heme-dependent and yeast heme-independent cystathionine beta-synthases. Evidence from 31P NMR and pulsed EPR spectroscopy that heme and PLP cofactors are not proximal in the human enzyme

Two classes of cystathionine beta-synthases have been identified in eukaryotes, the heme-independent enzyme found in yeast and the heme-dependent form found in mammals. Both classes of enzymes catalyze a pyridoxal phosphate (PLP)-dependent condensation of serine and homocysteine to produce cystathionine. The role of the heme in the human enzyme and its location relative to the PLP in the active site are unknown. (31)P NMR spectroscopy revealed that spin-lattice relaxation rates of the phosphorus nucleus in PLP are similar in both the paramagnetic ferric (T(1) = 6.34 +/- 0.01 s) and the diamagnetic ferrous (T(1) = 5.04 +/- 0.06 s) enzyme, suggesting that the two cofactors are not proximal to each other. This is also supported by pulsed EPR studies that do not provide any evidence for strong or weak coupling between the phosphorus nucleus and the ferric iron. However, the (31)P signal in the reduced enzyme moved from 5.4 to 2.2 ppm, and the line width decreased from 73 to 16 Hz, providing the first structural evidence for transmission to the active site of an oxidation state change in the heme pocket. These results are consistent with a regulatory role for the heme as suggested by previous biochemical studies from our laboratory. The (31)P chemical shifts of the resting forms of the yeast and human enzymes are similar, suggesting that despite the difference in their heme content, the microenvironment of the PLP is similar in the two enzymes. The addition of the substrate, serine, resulted in an upfield shift of the phosphorus resonance in both enzymes, signaling formation of reaction intermediates. The resting enzyme spectra were recovered following addition of excess homocysteine, indicating that both enzymes retained catalytic activity during the course of the NMR experiment.     

Biochemical markers of oxidative stress in Perna viridis exposed to mercury and temperature

Oxidative damage and antioxidant properties have been studied in Perna viridis subjected to short-term exposure to Hg along with temperature (72h) and long-term temperature exposures (14 days) as pollution biomarkers. The elevated thiobarbituric acid reactive substances (TBA-RS) levels observed in gills and digestive gland under exposure to Hg, individually and combined with temperature, as also long-term temperature stress have been assigned to the oxidative damage resulting in lipid peroxidation (LPX). Increased activities of antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) both in gills and digestive glands under long-term exposures to temperatures are more prominent to heat rather than cold stress suggesting activation of physiological mechanism to scavenge the ROS produced during heat stress. Also decreased values of reduced glutathione (GSH) on long exposures to temperature stress indicate utilisation of this antioxidant, either to scavenge oxiradicals or act in combination with other enzymes, was more than its production capacity under heat stress. The results suggest that temperature variation does alter the active oxygen metabolism by modulating antioxidant enzyme activities, which can be used as biomarker to detect sublethal effects of pollution.     

评论：塑料结合模块促进聚对苯二甲酸乙二醇酯的酶法降解

塑料的大量生产和无节制的使用已造成严重的环境污染。为了减少塑料废物对环境的影响,近年来塑料酶法降解已成为国内外研究者关注的热点。例如,通过蛋白质工程策略提高塑料降解酶催化活性和热稳定性,进一步提高酶法降解的效率。另外,通过融合酶策略将塑料结合模块与塑料降解酶融合,也可以促进塑料降解。近期发表在期刊Chem Catalysis的一项研究表明,采用碳水化合物结合模块融合策略可以在低浓度(<10 wt%)的底物聚对苯二甲酸乙二醇酯[poly(ethylene terephthalate),PET]中提高塑料降解酶的活性。但是在高浓度底物(10 wt%−20 wt%)中,该策略无法提高PET的酶法降解。该项研究对于采用塑料结合模块促进酶法降解塑料具有重要的指导意义。     

Biocatalytic modification of polyethylene terephthalate fibres by esterases from actinomycete isolates

The modification of polyethylene terephthalate (PET) fibres by extracellular enzymes produced by actinomycetes was investigated. Cultivation of isolates in media containing PET yarn and suberin, a plant polyester composed of aliphatic and aromatic moieties, induced the production of p-nitrophenyl butyrate hydrolyzing enzymes. Incubation of enzyme preparations from the isolates M5, M9 and Thermomonospora fusca KW3b with PET yarn resulted in an increase in the absorbance of the reaction mixtures at 240 nm indicating the release of terephthalic acid or its esters catalyzed by the enzymes. The results of dyeing of enzyme-treated PET fabrics with a reactive dye (CI Reactive Red 2) indicated an increase in hydroxyl groups at the fibre surfaces as a result of the enzyme treatment.     

Towards a physiological response of fishes under variable environmental conditions: An approach through neural network

Present study aims to explore the effectiveness of environmental factors as predictive markers for assessing their impact on stress and endocrine physiology in selected five ecologically important fish species of Sundarban mangrove estuarine area, India. Our goal was to develop a realistic integrated conceptual model to analyze and envisage the consequence of fluctuating environmental parameters on the stress physiology of these fishes and their adaptive responses to thrive in such environment. Fishes were collected monthly throughout the year from 3 different study sites and various anti-oxidant (enzymatic and non-enzymatic) and detoxification enzymes were measured. Levels of the stress hormone cortisol and reproductive hormone 17β-estradiol were also measured as indicators of stress accumulation and reproductive status of the selected fish species. The study sites showed variations in physical factors such as pH, dissolved oxygen, temperature and salinity, which may be related to environmental fluctuation and/or pollution level. Such panel of multiple enzyme and hormone biomarkers in fish might be a useful tool to develop an assessment model. This study demonstrated a sharp indication of variation in the antioxidant enzyme profiles depending on the physical environment but the changes is exclusively site as well as species specific. To justify our assumptions cluster and non-metric multidimensional scaling (NMDS) analysis have been done to investigate the ordination of physiological parameters and water quality parameters; if it varies for each species or not. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidise (GPx), malondialdehyde (MDA) and glutathione (GSH) showed variations depending on the physical environment but the changes is exclusively site as well as species specific. Finally, the prediction model and NMDS scaling confirmed MDA, GST and GSH as decisive factor to envisage steroid hormone, whereas organic carbon, temperature, ammonia and alkalinity as the major contributor of its prediction.     

Biocatalytic modification of polyethylene terephthalate fibres by esterases from actinomycete isolates

The modification of polyethylene terephthalate (PET) fibres by extracellular enzymes produced by actinomycetes was investigated. Cultivation of isolates in media containing PET yarn and suberin, a plant polyester composed of aliphatic and aromatic moieties, induced the production of p-nitrophenyl butyrate hydrolyzing enzymes. Incubation of enzyme preparations from the isolates M5, M9 and Thermomonospora fusca KW3b with PET yarn resulted in an increase in the absorbance of the reaction mixtures at 240 nm indicating the release of terephthalic acid or its esters catalyzed by the enzymes. The results of dyeing of enzyme-treated PET fabrics with a reactive dye (CI Reactive Red 2) indicated an increase in hydroxyl groups at the fibre surfaces as a result of the enzyme treatment.     

Noncovalent interaction between ubiquitin and the human DNA repair protein Mms2 is required for Ubc13-mediated polyubiquitination

Ubiquitin-conjugating enzyme variants share significant sequence similarity with typical E2 (ubiquitin-conjugating) enzymes of the protein ubiquitination pathway but lack their characteristic active site cysteine residue. The MMS2 gene of Saccharomyces cerevisiae encodes one such ubiquitin-conjugating enzyme variant that is involved in the error-free DNA postreplicative repair pathway through its association with Ubc13, an E2. The Mms2-Ubc13 heterodimer is capable of linking ubiquitin molecules to one another through an isopeptide bond between the C terminus and Lys-63. Using highly purified components, we show here that the human forms of Mms2 and Ubc13 associate into a heterodimer that is stable over a range of conditions. The ubiquitin-thiol ester form of the heterodimer can be produced by the direct activation of its Ubc13 subunit with E1 (ubiquitin-activating enzyme) or by the association of Mms2 with the Ubc13-ubiquitin thiol ester. The activated heterodimer is capable of transferring its covalently bound ubiquitin to Lys-63 of an untethered ubiquitin molecule, resulting in diubiquitin as the predominant species. In (1)H (15)N HSQC ((1)H (15)N heteronuclear single quantum coherence) NMR experiments, we have mapped the surface determinants of tethered and untethered ubiquitin that interact with Mms2 and Ubc13 in both their monomeric and dimeric forms. These results have identified a surface of untethered ubiquitin that interacts with Mms2 in the monomeric and heterodimeric form. Furthermore, the C-terminal tail of ubiquitin does not participate in this interaction. These results suggest that the role of Mms2 is to correctly orient either a target-bound or untethered ubiquitin molecule such that its Lys-63 is placed proximally to the C terminus of the ubiquitin molecule that is linked to the active site of Ubc13.     

Call for biotechnological approach to degrade plastic in the era of COVID-19 pandemic

Plastic pollution is a global issue and has become a major concern since Coronavirus disease (COVID)-19. In developing nations, landfilling and illegal waste disposal are typical ways to dispose of COVID-19-infected material. These technologies worsen plastic pollution and other human and animal health problems. Plastic degrades in light and heat, generating hazardous primary and secondary micro-plastic. Certain bacteria can degrade artificial polymers using genes, enzymes, and metabolic pathways. Microorganisms including bacteria degrade petrochemical plastics slowly. High molecular weight, strong chemical bonds, and excessive hydrophobicity reduce plastic biodegradation. There is not enough study on genes, enzymes, and bacteria-plastic interactions. Synthetic biology, metabolic engineering, and bioinformatics methods have been created to biodegrade synthetic polymers. This review will focus on how microorganisms' degrading capacity can be increased using recent biotechnological techniques.