Aldehyde Ketone Research Articles

Jianpi-Yangxue-Jiedu decoction improves the energy metabolism of psoriasis mice by regulating the electron transfer of oxidative phosphorylation

Ethnopharmacological relevanceThe inflammatory skin condition psoriasis is immune-related. The decoction of Jianpi-Yangxue-Jiiedu (JPYX) is a useful medication for psoriasis. However, the underlying mechanics of JPYX have not yet been clarified. Aim of the studyThe objective of this study was to investigate the mechanism underlying the efficacy of JPYX in the treatment of psoriasis in the context of a high-fat diet. Materials and methodsThis work generated a high-fat feeding model of imiquimod (IMQ)-induced psoriasis-like lesion mice. The blood composition of JPYX was examined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The mechanism of JPYX decoction for treating psoriasis was predicted using methods of network pharmacology, metabolomics, and transcriptomics. ResultsJPYX prevented the release of inflammatory cytokines, decreased keratinocyte proliferation, enhanced the percentage of Treg cells in the skin, lymph nodes, and thymus, and greatly alleviated psoriatic lesions. Network pharmacology predicted that IL-1β, TNF, STAT3, and EGFR may be potential targets, and KEGG results showed that PI3K-AKT-mTOR may be a potential mechanism of action. Verification of experimental data demonstrated that the JPYX decoction dramatically decreased mTOR and AKT phosphorylation. According to metabolomics analysis, amino acids and their metabolites, benzene and its substitutes, aldehyde ketone esters, heterocyclic compounds, etc. were the primary metabolites regulated by JPYX. KEGG enrichment analysis of differential metabolites was performed. Fatty acid biosynthesis, Type I polyketide structures, Steroid hormone biosynthesis, Biosynthesis of unsaturated fatty acid, etc. Transcriptomic results showed that JPYX significantly regulated skin development, keratinocyte differentiation, and oxidative phosphorylation. Further experimental data verification showed that JPYX decoction significantly reduced the mRNA levels of mt-Nd4, mt-Nd5, mt-Nd1, Ifi205, Ifi211, and mt-Atp8. ConclusionsJPYX may improve psoriasis by regulating the metabolic pathways of fatty acids and electron transport of oxidative phosphorylation.

Emission characteristics and probabilistic health risk of volatile organic compounds from leather sofa

Furniture is identified as a vital volatile organic compound (VOC) emission source in the indoor environment. Leather has become the most common raw and auxiliary fabric material for upholstered furniture, particularly with extensive consumption in sofas, due to its abundant resources and efficient functions. Despite being widely traded across the world, little research has been conducted on the VOCs released by leather materials and their health risk assessment in the indoor environment. Accordingly, this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure. Based on the ultra-fast gas phase electronic nose (EN) and GC-FID/Qtof, the substantial emissions of aliphatic aldehyde ketones (Aks), particularly hexanal, appear to be the cause of off-flavor in medium and low grade (MG and LG) sofa leathers. The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents. Given the abundance of VOC sources and the accumulation of health risks in the indoor environment, more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.

Enzyme-Compatible Core-Shell Nanoreactor for in Situ H2 -Driven NAD(P)H Regeneration.

The regeneration of the reduced form cofactor NAD(P)H is essential for the extra-cellular application of bio-reduction, which necessitates not only the development of efficient artificial NAD(P)H regeneration catalytic system but also its well compatibility with the cascade enzymatic reduction system. In this work, we reported the preparation of a metal nanoparticle (NP) and metal complex integrated core-shell nanoreactor for H2 -driven NAD(P)H regeneration through the immobilization of a Rh complex on Ni/TiO2 surface via a bipyridine contained 3D porous organic polymer (POP). In comparison with the corresponding single component metal NPs and the immobilized Rh complex, the integrated catalyst presented simultaneously enhanced activity and selectivity in NAD(P)H regeneration thanks to the rapid spillover of activated H species from metal NPs to Rh complex. In addition, the size-sieving effect of POP precluded the direct interaction of enzyme and Rh complex confined in the pores, enabling the success coupling of core-shell nanoreactor and aldehyde ketone reductase (AKR) for chemoenzymatic reduction of acetophenone to (R)-1-phenylethan-1-ol. This work provides a strategy for the rational manipulation of multicomponent cooperation catalysis.

Enzyme‐Compatible Core‐Shell Nanoreactor for in Situ H2‐Driven NAD(P)H Regeneration

AbstractThe regeneration of the reduced form cofactor NAD(P)H is essential for the extra‐cellular application of bio‐reduction, which necessitates not only the development of efficient artificial NAD(P)H regeneration catalytic system but also its well compatibility with the cascade enzymatic reduction system. In this work, we reported the preparation of a metal nanoparticle (NP) and metal complex integrated core‐shell nanoreactor for H2‐driven NAD(P)H regeneration through the immobilization of a Rh complex on Ni/TiO2 surface via a bipyridine contained 3D porous organic polymer (POP). In comparison with the corresponding single component metal NPs and the immobilized Rh complex, the integrated catalyst presented simultaneously enhanced activity and selectivity in NAD(P)H regeneration thanks to the rapid spillover of activated H species from metal NPs to Rh complex. In addition, the size‐sieving effect of POP precluded the direct interaction of enzyme and Rh complex confined in the pores, enabling the success coupling of core‐shell nanoreactor and aldehyde ketone reductase (AKR) for chemoenzymatic reduction of acetophenone to (R)‐1‐phenylethan‐1‐ol. This work provides a strategy for the rational manipulation of multicomponent cooperation catalysis.

Synthesis of biofuel precursors from benzaldehyde and cyclopentanone via aldehyde-ketone condensation in a deep eutectic solvent system.

Production of biofuel precursors from biomass-derived platform compounds (BDPC) has a profound influence on biofuel industries. Herein, an efficient catalytic system composed of the deep eutectic solvent (DES, i.e., ChCl/Fa) and SnCl4 (ChCl/Fa-SnCl4) was developed to produce biofuel precursors (C12 and C19) through aldehyde-ketone (A-K) condensation of benzaldehyde (BD) and cyclopentanone (CPO). ChCl/Fa-SnCl4 exhibited the prospective catalytic performance and given the high selectivity (SC12 = 49.20%, SC19 = 15.20%) and total yield (YC12+C19 = 64.37%) of C12 and C19, as well as 99.96% BD conversion under the optimized conditions (BD : CPO molar ratio of 1 : 6, ChCl : Fa molar ratio of 1 : 12, 4 mmol SnCl4, 80 °C for 120 min). Subsequently, the C12 and C19 precursors were successfully applied to generate cyclic alkanes (C12H14 and C19H18) by hydrodeoxygenation with selectivity of 37.61% and 24.10%, respectively. Finally, the potential catalytic mechanism was explored by density functional theory (DFT) calculations. The results unveiled that the formation of a stable structure for the ChCl/Fa-SnCl4 system was ascribed to the viable interactions among ChCl, Fa and SnCl4 by coordination bonds, electrostatic interactions and H-bonds, which decreased reaction energy barriers and drove the condensation of BD and CPO. In this case, the catalytic reactions between BD and CPO were enhanced to promote the synthesis of C12 and C19. This work provides a novel strategy for the applicability of different BDPC to synthesize fuel precursors for the development of liquid biofuels.

Analysis of Volatile Flavor Substances in the Enzymatic Hydrolysate of Lanmaoa asiatica Mushroom and Its Maillard Reaction Products Based on E-Nose and GC-IMS.

An electronic nose (E-Nose) and gas chromatography-ion mobility spectrometry (GC-IMS) were used to analyze the volatile flavor compounds (VFCs) of the enzymatic hydrolysate of Lanmaoa asiatica and its Maillard reaction products (MRPs). E-Nose sensors have strong response signals to sulfide, nitrogen oxides, alcohols, and aldehyde ketone, and the aroma profile was increased after the Maillard reaction (MR). According to GC-IMS, A total of 84 known compounds were identified. Aldehydes, ketones and alcohols are the main VFCs. After MR, the concentrations of some alcohols decreased, and the concentration of pyrazines and ketones increased. Principal component analysis (PCA) and similarity analysis showed that the enzymatic hydrolysate and MRPs were different and could be effectively distinguished. In conclusion, this study clarified the changes in VFCs before and after the MR. The results can provide a theoretical basis for the quality control and flavor changes during the processing of Lanmaoa asiatica and provide a new method for flavor analysis of edible mushrooms and their products.

Emission of odor pollutants and variation in microbial community during the initial decomposition stage of municipal biowaste

Odor pollution often occurs in the initial decomposition stage of municipal biowaste, including throwing/collection and transportation. However, this aspect of odor impact from municipal biowaste has not been well studied. In this study, a practical dustbin (120 L) equipped with flux chamber and filled with three types of municipal biowaste was used to simulate garbage storage conditions. The result indicated that the emission rate of odor pollutants for uncooked food waste (UFW) represented a nearly linear growth trend, reaching the maximum (3963 ± 149 μg kg−1 DM h−1) at 72 h. Cooked food waste (CFW) increased rapidly from 8 h to 24 h, and then remain fluctuated, reached the maximum (2026 ± 77 μg kg−1 DM h−1) at 72 h. Comparatively, household kitchen waste (HKW) reached the maximum emission rate (10,396 ± 363 μg kg−1 DM h−1) at 16 h. Sulfide and aldehydes ketones were identified as dominant odor contributor to UFW and CFW, respectively. While aldehydes ketones and sulfides were both dominant odor contributor to HKW. Moreover, the microbial diversity analysis suggests that Acinetobacter was the dominant genus in UFW, and Lactobacillus was the dominant genus in CFW and HKW. In addition, it was evident that each odorous pollutant was significantly associated with two or more bacterial genera, and most bacterial genera such as Acinetobacter, were also significantly associated with multiple odorous pollutants. The variation of odorants composition kept consistent with microbial composition. The present study could provide essential evidence for a comprehensive understanding of odorant generation in the initial decomposition stage of municipal biowaste. It could contribute to setting out strategies for odor control and abatement in municipal biowaste management systems.

Michael acceptor molecules in natural products and their mechanism of action.

Purpose: Michael receptor molecules derived from plants are biologically active due to electrophilic groups in their structure. They can target nucleophilic residues on disease-related proteins, with significant therapeutic effects and low toxicity for many diseases. They provide a good option for relevant disease treatment. The aim of this study is to summarize the existing MAMs and their applications, and lay a foundation for the application of Michael receptor molecules in life science in the future. Methods: This review summarizes the published studies on Michael receptor molecules isolated from plants in literature databases such as CNKI, Wanfang Data, PubMed, Web of Science, ScienceDirect, and Wiley. Latin names of plants were verified through https://www.iplant.cn/. All relevant compound structures were verified through PubChem and literature, and illustrated with ChemDraw 20.0. Result: A total of 50 Michael receptor molecules derived from various plants were discussed. It was found that these compounds have similar pharmacological potential, most of them play a role through the Keap1-Nrf2-ARE pathway and the NF-κB pathway, and have biological activities such as antioxidant and anti-inflammatory. They can be used to treat inflammatory diseases and tumors. Conclusion: The Michael receptor molecule has electrophilicity due to its unsaturated aldehyde ketone structure, which can combine with nucleophilic residues on the protein to form complexes and activate or inhibit the protein pathway to play a physiological role. Michael receptor molecules can regulate the Keap1-Nrf2-ARE pathway and the NF-κB pathway. Michael receptor molecules can be used to treat diseases such as inflammation, cancer, oxidative stress, etc.

Hydrogenation of biomass pyrolysis oil using enhanced reduction catalytic capacity cellular by expressing excavated carbonyl reductase

A biocatalytic method to achieve the hydromodification of biomass fast pyrolysis oil was implemented. Two carbonyl reductases SDR-1 and SDR-8 were excavated in the genome of Bacillus coagulans NL01, enhanced Escherichia coli ability to tolerate and reduce various toxic ketone aldehydes. 10 g/L furfural and 8 g/L acetoin as bio-oil model compounds could be transformed by the recombinant E. coli SDR-1 and E. coli SDR-8 respectively. The biphasic catalysis system was constructed to convert the keto-aldehyde compounds in bio-oil to the corresponding alcohol at 30 °C. Recombinant E. coli SDR-8 could completely consume 20 g/L glucose and consume 60% 20 g/L glucose in the diluted 50-fold and 30-fold bio-oil catalytic system, respectively. This provided a new pathway for the hydrogenation of bio-oil by biocatalytic method and laid the foundation for the low-temperature esterification in the later stage.

Construction and yield optimization of a cinnamylamine biosynthesis route in Escherichia coli

BackgroundWith the development of metabolic engineering and synthetic biology, the biosynthesis of aromatic compounds has attracted much attention. Cinnamylamine is an aromatic compound derived from l-phenylalanine, which is used in the synthesis of biologically active molecules, including drugs, and energetic materials. Cinnamylamine has been mainly synthesized by chemical methods to date, and few reports have focused on the biosynthesis of cinnamylamine. Therefore, it is desirable to establish an efficient biosynthesis method for cinnamylamine.ResultsThe ω-aminotransferase Cv-ωTA from Chromobacterium violaceum has been demonstrated to have high enzyme activity in the conversion of cinnamaldehyde to cinnamylamine. To prevent the preferable conversion of cinnamaldehyde to cinnamyl alcohol in wild-type Escherichia coli, the E. coli MG1655 strain with reduced aromatic aldehyde reduction (RARE) in which six aldehyde ketone reductase and alcohol dehydrogenase genes have been knocked out was employed. Then, the carboxylic acid reductase from Neurospora crassa (NcCAR) and phosphopantetheinyl transferase (PPTase) from E. coli were screened for a high conversion rate of cinnamic acid to cinnamaldehyde. To shift the equilibrium of the reaction toward cinnamylamine, saturation mutagenesis of Cv-ωTA at key amino acid residues was performed, and Cv-ωTA Y168G had the highest conversion rate with 88.56 mg/L cinnamylamine obtained after 4 h of fermentation. Finally, by optimizing the substrates and the supply of the cofactors, PLP and NADPH, in the fermentation, the yield of cinnamylamine in engineered E. coli reached 523.15 mg/L.ConclusionWe achieved the first biosynthesis of cinnamylamine using cinnamic acid as the precursor in E. coli using a combinatorial metabolic engineering strategy. This study provides a reference for the biosynthesis of other amine compounds and lays a foundation for the de novo synthesis of cinnamylamine.

The emission of volatile organic compounds during the initial decomposition stage of food waste and its relationship with the bacterial community

Volatile organic compounds (VOCs) generated from food waste are serious environmental problems. The characteristics of VOCs and the corresponding indigenous microorganisms in the initial decomposition stage of food waste are not well known. This study investigates the concentration and composition of VOCs emitted from food waste at different temperatures and the correlation with bacterial communities at a laboratory scale. A total of 110 VOCs in seven categories were detected, and alcohols, primarily ethanol, were the main VOCs, followed by esters. Moreover, the amounts of total VOCs increased with increasing temperature due to the accelerated microbial activities and volatilisation. The proportion of alcohols decreased from 94.5% to 56.7%, while esters significantly increased when the temperature rose from 10 °C to 35 °C. Esters became the dominant VOC during fermentation of 35 °C after 24 h, while alcohols were the most dominant VOC throughout the experiment at 10 °C. The temperature clearly affected the bacterial community structure and composition in food waste. Furthermore, Weissella, Lactococcus, Shewanella, Klebsiella, Corynebacterium, and Acetobacter showed close relationships with alcohols, alkanes, olefins, terpenes, sulfur compounds, and aldehydes–ketones during the initial decomposition stage of food waste. Overall, the temperature of fermentation was an essential factor affecting the VOCs emission and corresponding bacterial communities in the initial decomposition stage of food waste.

Characterization of the volatile flavor profiles of Zhenjiang aromatic vinegar combining a novel nanocomposite colorimetric sensor array with HS-SPME-GC/MS

In this work, the feasibility of combining headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS) with colorimetric sensor array (CSA) for flavor characterization of Zhenjiang aromatic vinegar (ZAV) from different grades was evaluated. Firstly, a new type of nanocomposite CSA that combines porous nanomaterials including hollow zeolitic imidazolate framework-8 (H-ZIF-8) and Universitetet i Oslo-66-NO2 (UiO-66-NO2) with chemically responsive dyes was successfully constructed. Then, the nanocomposite CSA was applied to effectively discriminate ZAV of different grades and further quantitively predict the characteristic aroma components by using multivariate data analysis. Compared with other pattern recognition methods, support vector machine (SVM) model achieved the highest recognition rate both for training set (100%) and prediction set (94.44%). Furthermore, a good performance of quantitative prediction of characteristic aroma components of ZAV including acetic acid, total volatile acids, furfural, aldehyde ketones, ethyl acetate and esters combining CSA with partial least square (PLS) regression was achieved with all the correlation coefficients being over 0.80 for training and prediction sets. Therefore, the nanocomposite CSA combined with chemometrics could be an effective tool for the rapid and nondestructive assessment of flavor and quality of vinegar.

Controllably crosslinked dual enzymes enabled by genetic-encoded non-standard amino acid for efficiently enantioselective hydrogenation.

In traditional method for preparing crosslinked enzymes aggregates using glutaraldehyde, random linkage is inevitable, which often destroys the enzyme active sites and severely decreases the activity. To address this issue, using genetic encode expanding, nonstandard amino acids (NSAAs) were inserted into enzyme proteins at the preselected sites for crosslinking. When aldehyde ketone reductase (AKR), alcohol dehydrogenase (ADH) and glucose dehydrogenase (GDH) were utilized as model enzymes, their mutants containing p-azido-L-phenylalanine were bio-orthogonally crosslinked with diyne to form crosslinked dual enzymes (CLDEs) acting as a cascade biological oxidation and reduction system. Then, the resultant self-purified CLDEs were characterized using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM), etc. In the asymmetric synthesis of (S)-1-(2,6-dichloro-3-fluorophenyl) ethanol using CLDEs, high product yield (76.08%), ee value (99.99%) and reuse stability were achieved. The yield and ee value were 12.05 times and 1.39 times higher than those using traditional crosslinked enzyme aggregates, respectively. Thus, controllable insertion NSAAs in number and location can engender reasonable linkage and metal-free self-purification for target enzyme proteins. This facile and sustainable method could be further expanded to other dual and multienzyme systems for cascade biocatalysis.

Field investigation of pollutant characteristics and targeted ventilation control strategies in high-ceiling aircraft spraying workshop

To achieve efficient ventilation and purification in the high-ceiling painting workshop is faced with the contradiction between effect and energy consumption. Understanding the characteristics of gaseous pollutants is of paramount importance for ventilation and purification system design. The composition and concentration of volatile organic compounds (VOCs) emitted from aircraft painting workshop were sampled by Tenax-TA tubes and analyzed with gas chromatography-mass spectrometry (GC-MS). Approximately 50 types of VOCs (detection rate>50%) were detected in the aircraft spraying workshop, with percentages of 36.3% for esters, 31.9% for aldehyde ketones, 28.5% for biphenylenes, 1.9% for alcohols and 1.4% for alkanes. The TVOC concentrations in the workshop were 48.6 mg/m3 and 132.4 mg/m3, during the varnish painting and the finish painting processes, respectively, and these are several times higher than those observed in other industries (automobile painting and wooden furniture painting). The field test data of spraying workshops from 197 spraying factories in five industry sectors were collected from field measurement and existing literature. Some VOCs components are the general pollutants in the painting workshops, such as Acetic acid, butyl ester, Toluene, and 2-Butanone. A novel ventilation model using multiple target purification units is proposed to eliminate the pollutants in an aircraft spraying workshop. Compared with the original trench exhaust system, the air volume of the proposed targeted ventilation system is reduced by 75%, and the energy consumption is reduced by 45,000 kW·h per aircraft.

Hydrothermal co-liquefaction of rice straw and waste cooking-oil model compound for bio-crude production

This study aims to investigate the hydrothermal co-liquefaction of rice straw (RS) and waste cooking-oil model compound (WCOM) under sub-critical conditions for the optimum bio-crude yield and conversion. Effects of temperature, catalyst (K2CO3), residence time and mass ratios of RS to WCOM on products’ distribution were examined and the reaction mechanism for co-liquefaction of RS and WCOM was also explored. The highest bio-crude yield (88.77%) was obtained when mass ratio of RS to WCOM was 1:3 at 300 ℃, 10 min and in absence of K2CO3. When the mass ratio was 3:1, 1:1 and 1:3, the synergistic effect approached 14.38%, 11.38% and 12.84%, respectively. WCOM could improve the overall conversion rate of RS during co-liquefaction. GC-MS analysis suggested that the bio-crude contained large amounts of fatty acids and smaller amounts of phenols and ketone aldehydes. Co-liquefaction was found effective to improve the qualitative and quantitate features of products from biomass.

3D-Printed Aldo-keto reductase within biocompatible polymers as catalyst for chiral drug intermediate

Aldo-keto reductases (AKRs) are an important class of enzymes that can catalyze the asymmetric reduction of the first-line antidepressant duloxetine intermediate. Although the aldehyde ketone reductase has great application potential, the free state of the enzyme is unstable and difficult to recover, which greatly limits its practical applications in industry. In this work, we used 3D printing technology to immobilize the aldehyde ketone reductase AKR-IA to improve its reusability. After optimizing the preparation conditions of the 3D printing AKR-IA ink, it was determined that the concentrations of sodium alginate and CaCl2 were 1 wt% and 3.28 wt%, and the crosslinking time was 2 min. And the ink is determined to be printable. Scanning electron microscopy showed that the 3D printed AKR-IA was uniformly loaded in calcium alginate. Importantly, the reusability of 3D printed AKR-IA was also studied, the 3D printed AKR-IA still remains more than 57% enzyme activities after 6 repeated uses. Finally, we 3D printed the AKR-IA catalytic substrate DKTP, and the results showed that the conversion rate of the 3D printed AKR-IA catalytic product S-DHTP reached 70% with 96% optical purity. This study shows that 3D printing AKR-IA has certain application potential in the industrial production of the antidepressant duloxetine.

Synthesis, Characterization and Evaluation of some newer Pyrimidine derivatives as Anti-inflammatory Agents

Pyrimidine is an important baseone of the base formed by hydrolysis of nucleosides. It is an interesting molecule in the medicinal chemistry because of its diversified biological activities. Alloxan which is an oxidation product of Uric acid is also a pyrimidine derivative of interest to a medicinal chemist. Several pyrimidines are reported as antimicrobial, analegesic, anti-inflammatory, antibacterial, and antiparasitic agents. Pyrimidine scaffold is considered as an interesting one due to its various pharmacological properties. In this scheme, an attempt is made to carry out synthesis of some new pyrimidine derivatives. The Starting material Chalcone is synthesized by condensation of various aromatic aldehyde and aromatic ketone. Chalcone is then treated with thiourea and KOH in presence of ethanol to yield pyrimidine derivatives. Then those pyrimidine derivatives were subjected to alkylation and acetylation. The synthesized compounds were characterized and confirmed by IR and 1HNMR spectroscopy and then evaluated for their anti-inflammatory activity. The anti-inflammatory activity of newly synthesized pyrimidine derivatives were carried out by the carrageenan induced rat hind paw edema method by taking Diclofenac sodium as standard.

Research progress of serum biomarkers for early screening of hepatocellular carcinoma

The latest research data shows that the cause of death of liver cancer patients ranks third among malignant tumors. The global situation of early detection, early diagnosis and early treatment of liver cancer is severe. Therefore, how to achieve early diagnosis of liver cancer has important clinical significance. At present, alpha-fetoprotein, alpha-fetoprotein-L3 and des-gamma-carboxythrombin are commonly used in the clinical detection of hepatocellular carcinoma; however, their sensitivity cannot meet the diagnostic needs of patients with early liver cancer. With the development of molecular biology techniques such as serum oligosaccharide chains detection, B10, a member of the aldehyde ketone reductase family, microRNAs, circulating tumor cells, DNA methylation, and other novel serum biomarkers, a new option for the early screening and diagnosis of hepatocellular carcinoma patients will be offered.

Combined adaptive evolution and transcriptomic profiles reveal aromatic aldehydes tolerance mechanisms in Yarrowia lipolytica

Yarrowia lipolytica is an efficient oleaginous yeast, whereas its activity is typically reduced by inhibitors present in lignocellulosic hydrolysate. Understanding the response mechanism of Y. lipolytica to hydrolysate inhibitors and developing inhibitor tolerant strains are vital to lignocellulose valorization by this promising species. In this study, through adaptive laboratory evolution on three representative aromatic aldehyde inhibitors, evolved strains were obtained. Fermentation phenotype suggested that aromatic aldehydes conversion was one main reason for high tolerance of adapted strains. Transcriptome profiling analysis and reverse metabolic engineering confirmed that overexpressing the aldehyde ketone reductase gene YALI0_B07117g and aldehyde dehydrogenase gene YALI0_B01298g effectively converted aromatic aldehyde to corresponding alcohols and acids. The potential degradation pathways for aromatic aldehyde inhibitors in Y. lipolytica XYL+ were then discussed. This study provided insights to the aromatic aldehyde degradation in Y. lipolytica and a reliable basis for the development of aromatic aldehyde tolerant strains.

Catalytic co-liquefaction of sugarcane bagasse and polyethylene for bio-oil production under supercritical conditions: Effect of catalysts

Catalytic co-liquefaction of high-density polyethylene and sugarcane bagasse over metal salt and oxide catalysts in ethanol solvent was investigated. The obtained bio-oil samples were analyzed and characterized by gas chromatography–mass spectroscopy (GC–MS), nuclear magnetic resonance (NMR), ultimate analysis (CHNS/O), Fourier transform infrared spectroscopy (FTIR) and different solid products characterized by x-ray fluorescence (XRF) and Scanning Electron Microscope (SEM) analysis. The results suggested that adding ZnSO4 gives the highest HHV (34.61 MJ/kg), while CuSO4 gives the highest bio-oil yield (38.42 %) and conversion (69.54 %). GC–MS analysis suggested that the bio-oils contained large amounts of hydrocarbons, phenols, ketone aldehydes, alcohols and esters. The 1H and 13C NMR spectra were integrated over spectral regions to quantify classes of carbon and hydrogen atoms in each bio-oil and suggested that bio-oils largely contain alkanes, aliphatics and alcohols. The liquid products are promising bio-fuel precursors for further utilization.