An integrated cofactor and co-substrate recycling pathway for the biosynthesis of 1,5-pentanediol.

BACKGROUND: 1,5-pentanediol (1,5-PDO) is a linear diol with an odd number of methylene groups, which is an important raw material for polyurethane production. In recent years, the chemical methods have been predominantly employed for synthesizing 1,5-PDO. However, with the increasing emphasis on environmentally friendly production, it has been a growing interest in the biosynthesis of 1,5-PDO. Due to the limited availability of only three reported feasible biosynthesis pathways, we developed a new biosynthetic pathway to form a cell factory in Escherichia coli to produce 1,5-PDO. RESULTS: In this study, we reported an artificial pathway for the synthesis of 1,5-PDO from lysine with an integrated cofactor and co-substrate recycling and also evaluated its feasibility in E.coli. To get through the pathway, we first screened aminotransferases originated from different organisms to identify the enzyme that could successfully transfer two amines from cadaverine, and thus GabT from E. coli was characterized. It was then cascaded with lysine decarboxylase and alcohol dehydrogenase from E. coli to achieve the whole-cell production of 1,5-PDO from lysine. To improve the whole-cell activity for 1,5-PDO production, we employed a protein scaffold of EutM for GabT assembly and glutamate dehydrogenase was also validated for the recycling of NADPH and α-ketoglutaric acid (α-KG). After optimizing the cultivation and bioconversion conditions, the titer of 1,5-PDO reached 4.03 mM. CONCLUSION: We established a novel pathway for 1,5-PDO production through two consecutive transamination reaction from cadaverine, and also integrated cofactor and co-substrate recycling system, which provided an alternative option for the biosynthesis of 1,5-PDO.

Amelioration of inflammation through reduction of oxidative stress in rheumatoid arthritis by treating fibroblast-like synoviocytes (FLS) with DMF-loaded PLGA nanoparticles.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory condition, and Dimethyl fumarate (DMF) is known for inducing antioxidant enzymes and reducing reactive oxygen species (ROS). Fibroblast-like synoviocytes (FLS) contribute to joint damage by releasing interleukins (IL-1ß, IL-6, and IL-8) in response to ROS. Given ROS's impact on FLS acquiring an invasive phenotype, our study explored the effects of poly lactic-co-glycolic acid (PLGA) nanoparticles containing DMF on the expression of the HO-1 enzyme and the inflammatory cytokines IL-1ß, IL-6, and IL-8 in FLS cells. METHODS: In this study, we evaluated and compared the impact of Free-DMF and PLGA-DMF, on the gene expression of the HO-1 and inflammatory cytokines (IL-1ß, IL-6, and IL-8) in FLS cells derived from 13 patients with rheumatoid arthritis. qRT-PCR method was used to quantify the gene expression levels. RESULTS: PLGA-DMF nanoparticles demonstrated a significant increase in HO-1 expression and a significant decrease in IL-1ß gene expression. Also, a significant decrease in IL-6 gene expression was seen under the effect of Free-DMF. These results indicate the potential effectiveness of PLGA-DMF nanoparticles in reducing inflammation and improving rheumatoid arthritis symptoms. DISCUSSION: According to the findings, PLGA-DMF nanoparticles are expected to be effective in reducing inflammation and improving the symptoms of rheumatoid arthritis. Also, further studies on other factors affected by oxidative stress such as cell invasion factors and survival factors after the effect of PLGA-DMF nanoparticle are recommended.

Glycols: The ubiquitous solvent for dermal formulations.

Glycols stand out as one of the most commonly employed safe and effective excipients for pharmaceutical and cosmeceutical products. Their widespread adoption can be attributed to their exceptional solvency characteristics and their ability to interact effectively with skin lipids and keratin for permeation enhancement. Notably, propylene glycol enjoys significant popularity in this regard. Ongoing research endeavours have been dedicated to scrutinising the impact of glycols on dermal drug delivery and shedding light on the intricate mechanisms by which glycols enhance skin permeation. This review aims to mitigate the discordance within the existing literature, assemble a holistic understanding of the impact of glycols on the percutaneous absorption of active compounds and furnish the reader with a profound comprehension of the foundational facets pertaining to their skin permeation enhancement mechanisms, while simultaneously delving deeper into the intricacies of these processes.

Assessing the efficacy and mechanisms of glycol-contaminated water treatment through floating treatment wetlands.

The growing concerns surrounding water pollution and the degradation of ecosystems worldwide have led to an increased use of nature-based solutions (NbSs). This study assessed the feasibility of using floating treatment wetlands (FTWs) as an NbS to treat propylene glycol-contaminated water and quantitatively investigated different removal pathways. With an environmentally relevant concentration of propylene glycol (1,250 mg/L), FTWs containing Acorus calamus and mixed species demonstrated the highest average glycol mass removal efficacy (99%), followed by Carex acutiformis (98%), Juncus effusus (93%), and the control group without plants (10%) after 1 week. Additional mesocosm-scale experiments with varying FTW configurations, including surface coverage to reduce evaporation and photodegradation processes, and the addition of antibiotics to inhibit microbial activity, were conducted to quantify glycol removal pathways. Mass balance analysis results revealed that microbial biodegradation (33.3-39.7%) and plant uptake (37.9-45.2%) were the primary pathways for glycol removal. Only 15.5-19.5% of the glycol removal via evaporation and photodegradation was accounted in this study, which may be attributed to the mesocosm experimental setup (static water and no wind). Aligned with the broader discussion regarding biodiversity improvements and carbon storage capacity, this study demonstrated that FTWs are an environmentally friendly and effective NbS for addressing glycol-contaminated water.

Influence of Phosphoric, Glycolic, and Ferulic Acids on Dentin Enzymatic Degradation, Ultimate Tensile Strength, and Permeability.

This study evaluated dentin enzymatic degradation based on the total matrix metalloproteinase (MMP) activity of demineralized dentin matrices before and after exposure to phosphoric acid (PA), glycolic acid (GA), and ferulic acid (FA). The release of hydroxyproline (HP), ultimate tensile strength (UTS), and dentin permeability (DP) were also evaluated. Dentin collagen matrices were assessed according to total MMP activity before and after treatment with the tested acids (n=10) for 15 seconds and compared with the control (GM6001 inhibitor). Dentin beams were analyzed for HP release and UTS after the treatments. Dentin discs were tested for DP at a pressure of 5 psi before and after treatment with the acids (n=10). The FA group had a lower percentage of enzymatic inhibition than the PA and GA groups (p<0.0001). No significant difference in UTS was found among the acids (p=0.6824), but HP release was significantly higher in the FA group than in the PA and GA groups (p<0.0001). No significant difference in DP was found for the acids (p=0.0535). GA led to less activation of MMPs and less release of HP, whereas the UTS and DP for GA were like those found for PA. In contrast, FA promoted greater enzymatic activity and greater release of HP, while having similar results to GA and PA regarding mechanical properties.

Recent progress in PLGA-based microneedle-mediated transdermal drug and vaccine delivery.

Microneedles (MNs) have recently been found to have applications in drug, vitamin, protein and vaccine delivery. Polymeric MN arrays continue to attract increasing attention due to their capability to bypass the skin's stratum corneum (SC) barrier with minimal invasiveness. These carriers can achieve the targeted intradermal delivery of drugs and vaccines and improve their transdermal delivery level. As a nontoxic FDA-approved copolymer, polylactic glycolic acid (PLGA) has good biocompatibility and biodegradability. Currently, PLGA-based MNs have a noticeable tendency to be utilized as a delivery system. This study focuses on the most recent advances in PLGA-based MNs. Both PLGA nanoparticle-based MNs and PLGA matrix-based MNs, created for the delivery of vaccines, drugs, proteins and other therapeutic agents, are discussed. The paper also discusses the various types of MNs and their potential applications. Finally, the prospects and challenges of PLGA-based MNs are reviewed.

Preparation of a Klebsiella pneumoniae conjugate nanovaccine using glycol-engineered Escherichia coli.

BACKGROUND: Engineered strains of Escherichia coli have been used to produce bioconjugate vaccines using Protein Glycan Coupling Technology (PGCT). Nanovaccines have also entered the vaccine development arena with advances in nanotechnology and have been significantly developed, but chassis cells for conjugate nanovaccines have not been reported. RESULTS: To facilitate nanovaccine preparation, a generic recombinant protein (SpyCather4573) was used as the acceptor protein for O-linked glycosyltransferase PglL, and a glycol-engineered Escherichia coli strain with these two key components (SC4573 and PglL) integrated in its genome was developed in this study. The targeted glycoproteins with antigenic polysaccharides produced by our bacterial chassis can be spontaneously bound to proteinous nanocarriers with surface exposed SpyTag in vitro to form conjugate nanovaccines. To improve the yields of the targeted glycoprotein, a series of gene cluster deletion experiments was carried out, and the results showed that the deletion of the yfdGHI gene cluster increased the expression of glycoproteins. Using the updated system, to the best of our knowledge, we report for the first time the successful preparation of an effective Klebsiella pneumoniae O1 conjugate nanovaccine (KPO1-VLP), with antibody titers between 4 and 5 (Log10) after triple immunization and up to 100% protection against virulent strain challenge. CONCLUSIONS: Our results define a convenient and reliable framework for bacterial glycoprotein vaccine preparation that is flexible and versatile, and the genomic stability of the engineered chassis cells promises a wide range of applications for biosynthetic glycobiology research.

Optimizing Concentration of Polyethelene Glycol for Exosome Isolation from Plasma for Downstream Application.

BACKGROUND: Exosomes are ubiquitous extracellular nanovesicles secreted from almost all living cells that are thought to be involved in several important cellular processes, including cell-cell communication and signaling. Exosomes serve as a liquid biopsy tool for clinical and translational research. Although many techniques have been used to isolate exosomes, including ultracentrigation, size-exclusion chromatography, and immunocapturing-based techniques, these techniques are not convenient, they require expensive instrumentation, and they are unhandy for clinical samples. Precipitation techniques from available commercial kits that contain polyethelene glycol (PEG) are now widely used, but these kits are expensive, especially if a large number of biological samples are to be processed. OBJECTIVE: the purpose of this study is to compare and optimize the efficacy of different concentrations of PEG with two commercial kits ExoQuick (SBI) and Total Exosome Isolation (TEI) from Invitrogen in human plasma. METHODS AND MATERIALS: we determined exosome quantity, size distribution, marker expression, and downstream application. RESULTS: among the precipitation methods, we found the size of particles and concentrations with 10-20% PEG are similar to ExoQuick and better than TEI. Interestingly, we detected cfDNA with ExoQuick and 10-20% PEG but not TEI and 5% PEG. Moreover, 10% PEG detection of miR-122 and miR-16 expression was superior to ExoQuick and TEI. Furthermore, in proteomics results it also found the identified proteins better than commercial kits but there was a high level of contamination of other proteins in serum. CONCLUSIONS: together, these findings show that an optimal concentration of 10% PEG serves as a guide for use with clinical samples in exosome isolation for downstream applications.

Hydrogel-Embedded Poly(Lactic-co-Glycolic Acid) Microspheres for the Delivery of hMSC-Derived Exosomes to Promote Bioactive Annulus Fibrosus Repair.

OBJECTIVE: Intervertebral disk degeneration is a prevalent postoperative complication after discectomy, underscoring the need to develop preventative and bioactive treatment strategies that decelerate degeneration and seal annulus fibrosus (AF) defects. Human mesenchymal stem cell-derived exosomes (MSC-Exos) hold promise for cell-free bioactive repair; however, their ability to promote AF repair is poorly understood. The objective of this study was to evaluate the ability of MSC-Exos to promote endogenous AF repair processes and integrate MSC-Exos within a biomaterial delivery system. DESIGN: We characterize biophysical and biochemical properties of normoxic (Nx) and hypoxic (Hx) preconditioned MSC-Exos from young, healthy donors and examine their effects on AF cell proliferation, migration, and gene expression. We then integrate a poly(lactic-co-glycolic acid) microsphere (PLGA µSphere) delivery platform within an interpenetrating network hydrogel to facilitate sustained MSC-Exo delivery. RESULTS: Hx MSC-Exos led to a more robust response in AF cell proliferation and migration than Nx MSC-Exos and was selected for a downstream protection experiment. Hx MSC-Exos maintained a healthy AF cell phenotype under a TNFα challenge in vitro and attenuated catabolic responses. In all functional assays, AF cell responses were more sensitive to Hx MSC-Exos than Nx MSC-Exos. PLGA µSpheres released MSC-Exos over a clinically relevant timescale without affecting hydrogel modulus or pH upon initial embedment and µSphere degradation. CONCLUSIONS: This MSC-Exo treatment strategy may offer benefits of stem cell therapy without the need for exogenous stem cell transplantation by stimulating cell proliferation, promoting cell migration, and protecting cells from the degenerative proinflammatory microenvironment.

Glycol/glycerol-fed electrically conductive aggregates suggest a mechanism of stimulating direct interspecies electron transfer in methanogenic digesters.

The possibility of stimulating direct interspecies electron transfer (DIET) within aggregates of methanogenic digesters respectively with ethanol, glycol, and glycerol as a primary substrate was investigated to better understand the mechanisms of alcohol compounds stimulating DIET. Aggregates fed with ethanol, glycol, and glycerol were electrically conductive (10.4-19.4 uS/cm), with a temperature dependence of metallic-like conductivity. Close examination of transmission electron microscope images observed the potential interspecies connected networks assembled by filaments within these aggregates. Further investigations via metatranscriptomics found that, genes for electrically conductive pili (e-pili) (Log2FPKM, 9.39-10.96) and c-type cytochromes (8.90-9.64) were highly expressed within aggregates. Glycerol-fed aggregates exhibited the highest gene expression for e-pili, while glycol-fed aggregates exhibited the highest gene expression for c-type cytochromes. Methanothrix species were dominant and metabolically active within aggregates. Genes encoding the enzymes involved in carbon dioxide reduction were highly expressed in Methanothrix species, suggesting that they participated in DIET. In addition, transcript abundance of genes encoding alcohol dehydrogenase and NADH-quinone oxidoreductase in alcohol dehydrogenation closely associated with NADH/NAD+ transformation within glycol- and glycerol-fed aggregates was generally higher than that within ethanol-fed aggregates. These results, and the fact that NADH/NAD+ transformation was very linked to the ATP synthesis complex that further supported the formation of extracellular electrical connection components, e-pili and membrane-bound multi-heme c-type cytochromes (MHCs), provided a possibility that alcohol compounds comprised of hydroxy groups could stimulate DIET and more hydroxy groups comprised were better for this stimulation.

The effects of glycols on molecular mobility, structure, and permeability in stratum corneum.

The skin provides an attractive alternative to the conventional drug administration routes. Still, it comes with challenges as the upper layer of the skin, the stratum corneum (SC), provides an efficient barrier against permeation of most compounds. One way to overcome the skin barrier is to apply chemical permeation enhancers, which can modify the SC structure. In this paper, we investigated the molecular effect of three different types of glycols in SC: dipropylene glycol (diPG), propylene glycol (PG), and butylene glycol (BG). The aim is to understand how these molecules influence the molecular mobility and structure of the SC components, and to relate the molecular effects to the efficiency of these molecules as permeation enhancers. We used complementary experimental techniques, including natural abundance 13C NMR spectroscopy and wide-angle X-ray diffraction to characterize the molecular consequences of these compounds at different doses in SC at 97% RH humidity and 32 °C. In addition, we study the permeation enhancing effects of the same glycols in comparable conditions using Raman spectroscopy. Based on the results from NMR, we conclude that all three glycols cause increased mobility in SC lipids, and that the addition of glycols has an effect on the keratin filaments in similar manner as Natural Moisturizing Factor (NMF). The highest mobility of both lipids and amino acids can be reached with BG, which is followed by PG. It is also shown that one reaches an apparent saturation level for all three chemicals in SC, after which increased addition of the compound does not lead to further increase in the mobility of SC lipids or protein components. The examination with Raman mapping show that BG and PG give a significant permeation enhancement as compared to SC without any added glycol at corresponding conditions. Finally, we observe a non-monotonic response in permeation enhancement with respect to the concentration of glycols, where the highest concentration does not give the highest permeation. This is explained by the dehydration effects at highest glycol concentrations. In summary, we find a good correlation between the molecular effects of glycols on the SC lipid and protein mobility, and macroscopic permeation enhances of the same molecules.

On-tissue boronic acid derivatization for the analysis of vicinal diol metabolites in maize with MALDI-MS imaging.

Derivatization reactions are commonly used in mass spectrometry to improve analyte signals, specifically by enhancing the ionization efficiency of those compounds. Vicinal diols are one group of biologically important compounds that have been commonly derivatized using boronic acid. In this study, a boronic acid with a tertiary amine was adapted for the derivatization of vicinal diol metabolites in B73 maize tissue cross-sections for mass spectrometry imaging analysis. Using this method, dozens of vicinal diol metabolites were derivatized, effectively improving the signal of those metabolites. Many of these metabolites were tentatively assigned using high-resolution accurate mass measurements. In addition, reaction interference and cross-reactivity with various other functional groups were systematically studied to verify data interpretation.

Development and application of a high throughput assay system for the detection of Rieske dioxygenase activity.

Herein we report the development of a new periodate-based reactive assay system for the fluorescent detection of the cis-diol metabolites produced by Rieske dioxygenases. This sensitive and diastereoselective assay system successfully evaluates the substrate scope of Rieske dioxygenases and determines the relative activity of a rationally designed Rieske dioxygenase variant library. The high throughput capacity of the assay system enables rapid and efficient substrate scope investigations and screening of large dioxygenase variant libraries.

Metabolic Engineering of Escherichia coli for De Novo Production of 1,5-Pentanediol from Glucose.

1,5-Pentanediol (1,5-PDO) is an important C5 building block for the synthesis of different value-added polyurethanes and polyesters. However, no natural metabolic pathway exists for the biosynthesis of 1,5-PDO. Herein we designed and constructed a promising nonnatural pathway for de novo production of 1,5-PDO from cheap carbohydrates. This biosynthesis route expands natural lysine pathways and employs two artificial metabolic modules to sequentially convert lysine into 5-hydroxyvalerate (5-HV) and 1,5-PDO via 5-hydroxyvaleryl-CoA. Theoretically, the 5-hydroxyvaleryl-CoA-based pathway is more energy-efficient than a recently published carboxylic acid reductase-based pathway for 1,5-PDO production. By combining strategies of systematic enzyme screening, pathway balancing, and transporter engineering, we successfully constructed a minimally engineered Escherichia coli strain capable of producing 3.19 g/L of 5-HV and 0.35 g/L of 1,5-PDO in a medium containing 20 g/L of glucose and 5 g/L lysine. Introducing the synthetic modules into a lysine producer and enhancing NADPH supply enabled the strain to accumulate 1.04 g/L of 5-HV and 0.12 g/L of 1,5-PDO using glucose as the main carbon source. This work lays the basis for the development of a biological route for 1,5-PDO production from renewable bioresources.

Bacterial synthesis of C3-C5 diols via extending amino acid catabolism.

Amino acids are naturally occurring and structurally diverse metabolites in biological system, whose potentials for chemical expansion, however, have not been fully explored. Here, we devise a metabolic platform capable of producing industrially important C3-C5 diols from amino acids. The presented platform combines the natural catabolism of charged amino acids with a catalytically efficient and thermodynamically favorable diol formation pathway, created by expanding the substrate scope of the carboxylic acid reductase toward noncognate ω-hydroxylic acids. Using the established platform as gateways, seven different diol-convertible amino acids are converted to diols including 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol. Particularly, we afford to optimize the production of 1,4-butanediol and demonstrate the de novo production of 1,5-pentanediol from glucose, with titers reaching 1.41 and 0.97 g l-1, respectively. Our work presents a metabolic platform that enriches the pathway repertoire for nonnatural diols with feedstock flexibility to both sugar and protein hydrolysates.

Engineering Carboxylic Acid Reductase (CAR) through a Whole-Cell Growth-Coupled NADPH Recycling Strategy.

Rapid evolution of enzyme activities is often hindered by the lack of efficient and affordable methods to identify beneficial mutants. We report the development of a new growth-coupled selection method for evolving NADPH-consuming enzymes based on the recycling of this redox cofactor. The method relies on a genetically modified Escherichia coli strain, which overaccumulates NADPH. This method was applied to the engineering of a carboxylic acid reductase (CAR) for improved catalytic activities on 2-methoxybenzoate and adipate. Mutant enzymes with up to 17-fold improvement in catalytic efficiency were identified from single-site saturated mutagenesis libraries. Obtained mutants were successfully applied to whole-cell conversions of adipate into 1,6-hexanediol, a C6 monomer commonly used in polymer industry.

Molecular Aspects of Heparanase Interaction with Heparan Sulfate, Heparin and Glycol Split Heparin.

Heparanase is the principal enzyme that degrades heparan sulfate (HS) in both physiological (HS turnover) and pathological (tumor metastasis, inflammation) cell conditions, catalysing the hydrolysis of the ß-1-4 glycosidic bond in -GlcUA-ß(1-4)-GlcNX-. Despite efforts to define the minimum trisaccharide sequence that allows glycans to be recognized by heparanase, a rigorous "molecular code" by which the enzyme reads and degrades HS chains has not been identified. The X-ray diffraction model of heparanase, resolved by Wu et al (2015), revealed a complex between the trisaccharide GlcNS6S-GlcUA-GlcNS6S and heparanase. Efforts are ongoing to better understand how HS mimetics longer than three residues are recognized by heparanase before being hydrolyzed or inhibit the enzyme. It is also important to consider the flexibility of the enzyme active site, a feature that opens up the development of heparanase inhibitors with structures significantly different from HS or heparin. This chapter reviews the state-of-the-art knowledge about structural aspects of heparanase activities in terms of substrate recognition, mechanism of hydrolysis, and inhibition.

Reaction strategies for the enzymatic synthesis of neopentyl glycol diheptanoate.

This work describes for the first time the green synthesis of neopentyl glycol diheptanoate in a solvent-free medium via an enzymatic pathway. The process has been carried out in an open-air reactor in order to ease water removal through evaporation and shift the chemical equilibrium towards product formation. The inhibiting effect of high concentrations of heptanoic acid has been put into evidence by a reduction of initial reaction rate when esterification was performed with stoichiometric amounts of substrates. Therefore, in this work different strategies for the stepwise addition of heptanoic acid are proposed, and best results were obtained when stoichiometric quantities of acid were divided in four equal amounts and added when previous batch was consumed. Biocatalyst Novozym® 435 concentration and temperature were optimised, giving yields of 90% in neopentyl glycol diheptanoate when 7.5% (w/w) and 70 °C were used. With a remaining 7% of heptanoic acid (probably caused by the alcohol evaporation) the addition of neopentyl glycol led to a conversion of 95%. Thus, product can be used in cosmetics without further purification and can be labelled as environmentally-friendly synthesized because of its enzymatic origin.

MMOD-induced structural changes of hydroxylase in soluble methane monooxygenase.

Soluble methane monooxygenase in methanotrophs converts methane to methanol under ambient conditions. The maximum catalytic activity of hydroxylase (MMOH) is achieved through the interplay of its regulatory protein (MMOB) and reductase. An additional auxiliary protein, MMOD, functions as an inhibitor of MMOH; however, its inhibitory mechanism remains unknown. Here, we report the crystal structure of the MMOH-MMOD complex from Methylosinus sporium strain 5 (2.6 Å). Its structure illustrates that MMOD associates with the canyon region of MMOH where MMOB binds. Although MMOD and MMOB recognize the same binding site, each binding component triggers different conformational changes toward MMOH, which then respectively lead to the inhibition and activation of MMOH. Particularly, MMOD binding perturbs the di-iron geometry by inducing two major MMOH conformational changes, i.e., MMOH ß subunit disorganization and subsequent His147 dissociation with Fe1 coordination. Furthermore, 1,6-hexanediol, a mimic of the products of sMMO, reveals the substrate access route.

In situ transformation of ethoxylate and glycol surfactants by shale-colonizing microorganisms during hydraulic fracturing.

In the last decade, extensive application of hydraulic fracturing technologies to unconventional low-permeability hydrocarbon-rich formations has significantly increased natural-gas production in the United States and abroad. The injection of surface-sourced fluids to generate fractures in the deep subsurface introduces microbial cells and substrates to low-permeability rock. A subset of injected organic additives has been investigated for their ability to support biological growth in shale microbial community members; however, to date, little is known on how complex xenobiotic organic compounds undergo biotransformations in this deep rock ecosystem. Here, high-resolution chemical, metagenomic, and proteomic analyses reveal that widely-used surfactants are degraded by the shale-associated taxa Halanaerobium, both in situ and under laboratory conditions. These halotolerant bacteria exhibit surfactant substrate specificities, preferring polymeric propoxylated glycols (PPGs) and longer alkyl polyethoxylates (AEOs) over polyethylene glycols (PEGs) and shorter AEOs. Enzymatic transformation occurs through repeated terminal-end polyglycol chain shortening during co-metabolic growth through the methylglyoxal bypass. This work provides the first evidence that shale microorganisms can transform xenobiotic surfactants in fracture fluid formulations, potentially affecting the efficiency of hydrocarbon recovery, and demonstrating an important association between injected substrates and microbial growth in an engineered subsurface ecosystem.