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Microbial Cell Factories Jan 2022Cyanobacteria are engineered via heterologous biosynthetic pathways to produce value-added chemicals via photosynthesis. Various chemicals have been successfully...
BACKGROUND
Cyanobacteria are engineered via heterologous biosynthetic pathways to produce value-added chemicals via photosynthesis. Various chemicals have been successfully produced in engineered cyanobacteria. Chemical inducer-dependent promoters are used to induce the expression of target biosynthetic pathway genes. A chemical inducer is not ideal for large-scale reactions owing to its high cost; therefore, it is important to develop scaling-up methods to avoid their use. In this study, we designed a green light-inducible alcohol production system using the CcaS/CcaR green light gene expression system in the cyanobacterium Synechocystis sp. PCC 6803 (PCC 6803).
RESULTS
To establish the green light-inducible production of isobutanol and 3-methyl-1-butanol (3MB) in PCC 6803, keto-acid decarboxylase (kdc) and alcohol dehydrogenase (adh) were expressed under the control of the CcaS/CcaR system. Increases in the transcription level were induced by irradiation with red and green light without severe effects on host cell growth. We found that the production of isobutanol and 3MB from carbon dioxide (CO) was induced under red and green light illumination and was substantially repressed under red light illumination alone. Finally, production titers of isobutanol and 3MB reached 238 mg L and 75 mg L, respectively, in 5 days under red and green light illumination, and these values are comparable to those reported in previous studies using chemical inducers.
CONCLUSION
A green light-induced alcohol production system was successfully integrated into cyanobacteria to produce value-added chemicals without using expensive chemical inducers. The green light-regulated production of isobutanol and 3MB from CO is eco-friendly and cost-effective. This study demonstrates that light regulation is a potential tool for producing chemicals and increases the feasibility of cyanobacterial bioprocesses.
Topics: Bacterial Proteins; Butanols; Light; Metabolic Engineering; Pentanols; Photoreceptors, Microbial; Photosynthesis; Promoter Regions, Genetic; Synechocystis
PubMed: 34991586
DOI: 10.1186/s12934-021-01732-x -
Angewandte Chemie (International Ed. in... Apr 2022D-Luciferin (D-LH ), a substrate of firefly luciferase (Fluc), is important for a wide range of bioluminescence applications. This work reports a new and green method...
D-Luciferin (D-LH ), a substrate of firefly luciferase (Fluc), is important for a wide range of bioluminescence applications. This work reports a new and green method using enzymatic reactions (HELP, HadA Enzyme for Luciferin Preparation) to convert 19 phenolic derivatives to 8 D-LH analogues with ≈51 % yield. The method can synthesize the novel 5'-methyl-D-LH and 4',5'-dimethyl-D-LH , which have never been synthesized or found in nature. 5'-Methyl-D-LH emits brighter and longer wavelength light than the D-LH . Using HELP, we further developed LUMOS (Luminescence Measurement of Organophosphate and Derivatives) technology for in situ detection of organophosphate pesticides (OPs) including parathion, methyl parathion, EPN, profenofos, and fenitrothion by coupling the reactions of OPs hydrolase and Fluc. The LUMOS technology can detect these OPs at parts per trillion (ppt) levels. The method can directly detect OPs in food and biological samples without requiring sample pretreatment.
Topics: Firefly Luciferin; Luciferases, Firefly; Luciferins; Luminescence; Luminescent Measurements; Pesticides
PubMed: 35138676
DOI: 10.1002/anie.202116908 -
Food Research International (Ottawa,... Sep 2022This study aimed to evaluate the volatile compounds of chocolates made of Brazilian cocoas and statistically track them according to the products' sensorial profile in...
This study aimed to evaluate the volatile compounds of chocolates made of Brazilian cocoas and statistically track them according to the products' sensorial profile in order to relate them to consumers' acceptance by preference map methodology. The intensity of the chocolate, acidity, woody, smoked, green, floral, burned, musty, and cocoa notes from chocolates produced with cocoa from different Brazilian states were analyzed by a trained panel and by 128 consumers. Samples from Côte d'Ivoire, which is known for its high-quality chocolate, were evaluated for comparison. Solid-phase microextraction headspace sampling/gas chromatography-mass spectrometry was employed to evaluate the samples' volatile compounds. One hundred volatile compounds were identified within the samples. The results from the preference maps showed that the maximum preference was found for chocolate made of cocoa from Rondônia, Bahia, and Espírito Santo and Côte d'Ivoire and organic samples from Pará. The ideal sample point was characterized by intense chocolate, floral, and woody notes and mild green and burned notes. The presence of furfural, 3-methyl butanal, phenethyl acetate, 2-phenyl-5-methyl-2-hexenal, methyl pyrazine, phenethyl acetate, 2-phenyl-5-methyl-2-hexenal, and tetramethyl pyrazine were shown to be important for consumer acceptance in the ideal product, whereas the presence of (Z)-2-heptenal and 2-pentyl furan may increase consumer rejection. 2,3-Methyl pyrazine, methyl pyrazine, and 2,3-butanediol, which are important volatile compounds previously reported in the literature, were statistically tracked to both positive and negative sample attributes and must be better explored concerning consumers' acceptance of chocolates.
Topics: Brazil; Cacao; Chocolate; Pyrazines; Taste; Volatile Organic Compounds
PubMed: 35940809
DOI: 10.1016/j.foodres.2022.111618 -
Journal of Asian Natural Products... Apr 2023Erysolin and its two metabolites which were found in blood, ERY-GSH and ERY-NAC, were synthesized by alkylation, amination, isothiocyanation and oxidation reactions from...
Erysolin and its two metabolites which were found in blood, ERY-GSH and ERY-NAC, were synthesized by alkylation, amination, isothiocyanation and oxidation reactions from 1-bromo-4-chlorobutane and sodium methyl mercaptide. The reaction temperature, time, feed ratios and purification method were also optimized. The synthesis method was simple, green, safe and low-cost. Erysolin, ERY-GSH and ERY-NAC showed good antitumor activities against MCF-7, HeLa, HepG2, A549 and SW480 cells, which suggested that the antitumor mechanism of erysolin can also be clarified from its metabolites in addition to itself.
Topics: Humans; Thiocyanates; HeLa Cells; Sulfones; Drug Screening Assays, Antitumor; Antineoplastic Agents; Cell Proliferation
PubMed: 35763370
DOI: 10.1080/10286020.2022.2091989 -
The Science of the Total Environment Apr 2021To avoid potential risks of biofuels on the environment and human, ecotoxicity investigation should be integrated into the early design stage for promising biofuel...
To avoid potential risks of biofuels on the environment and human, ecotoxicity investigation should be integrated into the early design stage for promising biofuel candidates. In the present study, a green toxicology testing strategy combining experimental bioassays with in silico tools was established to investigate the potential ecotoxicity of biofuel candidates. Experimental results obtained from the acute immobilisation test, the fish embryo acute toxicity test and the in vitro micronucleus assay (Chinese hamster lung fibroblast cell line V79) were compared with model prediction results by ECOSAR and OECD QSAR Toolbox. Both our experimental and model prediction results showed that 1-Octanol (1-Oct) and Di-n-butyl ether (DNBE) were the most toxic to Daphnia magna and zebrafish among all the biofuel candidates we investigated, while Methyl ethyl ketone (MEK), Dimethoxymethane (DMM) and Diethoxymethane (DEM) were the least toxic. Moreover, both in vitro micronucleus assay and OECD QSAR Toolbox evaluation suggested that the metabolites present higher genotoxicity than biofuel candidates themselves. Overall, our results proved that this green toxicology testing strategy is a useful tool for assessing ecotoxicity of biofuel candidates.
Topics: Animals; Biofuels; Cell Line; Cricetinae; Daphnia; Humans; Toxicity Tests, Acute; Water Pollutants, Chemical; Zebrafish
PubMed: 33757253
DOI: 10.1016/j.scitotenv.2020.142902 -
Environmental Science and Pollution... Aug 2023The United Nations Sustainable Development Goals (SDGs) are imperative from the point of view of protecting the environment by employing sustainable options....
The United Nations Sustainable Development Goals (SDGs) are imperative from the point of view of protecting the environment by employing sustainable options. Considerable research has been carried out in the transportation sector to meet this objective. Here, the influence is assessed of epoxidised gingelly oil methyl ester biolubricant with alumina (AlO) nanoparticles on the performance and emissions of a single cylinder 0.66-L capacity direct injection compression ignition engine driven by gingelly B20 biodiesel. Engine tests are carried out with gingelly B20 biodiesel as a fuel, and gingelly methyl ester (B100), epoxidised gingelly methyl ester (B100E), and epoxidised gingelly methyl ester (B100E) mixed with 0.5%, 1.0%, and 1.5% w/w alumina (AlO) nanoparticles as the lubricant combinations. The results are compared with baseline B20 biodiesel fuel-mineral lubricant operation. The findings indicate that brake thermal efficiency increases by 8.64% for epoxidised gingelly methyl ester (B100E) with 1.0% w/w alumina (AlO) nanoparticle biolubricant in comparison to baseline operation. Considerable reductions in emissions are detected; specifically, reductions of 52.4%, 22.0%, 20.0%, and 34.9%, respectively, are observed for CO, NO, and HC concentrations and smoke opacity for the abovementioned combination as compared to baseline operation. The present work suggests that further research is merited on green fuel-green lubricant combinations. The findings of this study address the United Nations Sustainable Development Goals (SDGs) 7 and 13.
Topics: Gasoline; Smoke; Biofuels; Vehicle Emissions; Metal Nanoparticles; Esters; Aluminum Oxide
PubMed: 37477812
DOI: 10.1007/s11356-023-28645-z -
Chemosphere Nov 2023Microplastics (MPs) and dye pollutants are widespread in aquatic environments. Here, the adsorption characteristics of anionic dye methyl orange (MO) and cationic dye...
Microplastics (MPs) and dye pollutants are widespread in aquatic environments. Here, the adsorption characteristics of anionic dye methyl orange (MO) and cationic dye malachite green (MG) on polyamide 6 (PA6) and polyamide 66 (PA66) MPs were investigated, including kinetics, isotherm equilibrium and thermodynamics. The co-adsorption of MO and MG under different pH was also evaluated. The results reveal that the adsorption process of MO and MG is suitably expounded by a pseudo-second-order kinetic model. The process can be characterized by two stages: internal diffusion and external diffusion. The isothermal adsorption equilibrium of MO and MG can be effectively described using the Langmuir model, signifying monolayer adsorption. Furthermore, the thermodynamic results indicated that the adsorption was spontaneous with exothermic and endothermic properties, respectively. The results of binary systems reveal that MO dominates the adsorption at low pH (2-5), while MG dominates at high pH (8-10). Strong competitive adsorption was observed between MO and MG in neutral conditions (pH 6-8). The desorption experiments confirm that PA6 and PA66 could serve as potential carriers of MO and MG. The interaction between dyes and polyamide MPs is primarily mediated through hydrogen bonds and electrostatic attraction. The results reveal that PA6 formed more hydrogen bonds with the dyes, resulting in higher adsorption capacity than that of PA66. This difference can be attributed to the disparities in the synthesis process and polymerization method. Our study uncovered the adsorption mechanism of dye pollutants on PA6 and PA66, and provided a more comprehensive theoretical basis for the risk assessment concerning different types of polyamide MPs in aquatic environments.
Topics: Microplastics; Nylons; Plastics; Adsorption; Hydrogen Bonding; Hydrogen-Ion Concentration; Thermodynamics; Coloring Agents; Kinetics; Water Pollutants, Chemical
PubMed: 37574090
DOI: 10.1016/j.chemosphere.2023.139806 -
Food Science & Nutrition Dec 2023Jasmine tea is loved by most people who drink flower tea owing to its unique aroma, and it is known as the top of flower teas. In our study, the quantitative evaluation...
Jasmine tea is loved by most people who drink flower tea owing to its unique aroma, and it is known as the top of flower teas. In our study, the quantitative evaluation of the quality of jasmine tea and detection of aroma components were carried out. First, the flavor quality of 92 kinds of jasmine tea was evaluated using multiple sub-factor quality evaluation methods. According to the evaluation results, jasmine tea was divided into three types: "fresh and lovely" (FL), "heavy and thick" (HT), and "fresh and heavy" (FH). Gas chromatography-mass spectrometry (GC-MS) was used to detect the aroma components of the three types of jasmine tea samples. α-Farnesene, cis-3-hexenyl benzoate, acid phenylmethyl ester, linalool, methyl anthranilate, and indole were the main substances that constituted the basic aroma quality characteristics of jasmine tea. Compared to the FL type, the HT and FH types were weaker in the diversification of the characteristic aroma and accumulation of green, herb, sweet, and roast aroma substances. Green and herb aromas play crucial roles in the fresh and persistent qualities of the three types of jasmine tea, which are the key quality factors research focus of jasmine tea.
PubMed: 38107141
DOI: 10.1002/fsn3.3701 -
Materials (Basel, Switzerland) Nov 2022The solubilization and thermodynamic analysis of isotretinoin (ITN) in eleven distinct green solvents, such as water, methyl alcohol (MeOH), ethyl alcohol (EtOH),...
The solubilization and thermodynamic analysis of isotretinoin (ITN) in eleven distinct green solvents, such as water, methyl alcohol (MeOH), ethyl alcohol (EtOH), 1-butyl alcohol (1-BuOH), 2-butyl alcohol (2-BuOH), ethane-1,2-diol (EG), propane-1,2-diol (PG), polyethylene glycol-400 (PEG-400), ethyl acetate (EA), Transcutol-HP (THP), and dimethyl sulfoxide (DMSO) was studied at several temperatures and a fixed atmospheric pressure. The equilibrium approach was used to measure the solubility of ITN, and the Apelblat, van’t Hoff, and Buchowski−Ksiazczak λh models were used to correlate the results. The overall uncertainties were less than 5.0% for all the models examined. The highest ITN mole fraction solubility was achieved as 1.01 × 10−1 in DMSO at 318.2 K; however, the least was achieved as 3.16 × 10−7 in water at 298.2 K. ITN solubility was found to be enhanced with an increase in temperature and the order in which it was soluble in several green solvents at 318.2 K was as follows: DMSO (1.01 × 10−1) > EA (1.73 × 10−2) > PEG-400 (1.66 × 10−2) > THP (1.59 × 10−2) > 2-BuOH (6.32 × 10−3) > 1-BuOH (5.88 × 10−3) > PG (4.83 × 10−3) > EtOH (3.51 × 10−3) > EG (3.49 × 10−3) > MeOH (2.10 × 10−3) > water (1.38 × 10−6). ITN−DMSO showed the strongest solute−solvent interactions when compared to the other ITN and green solvent combinations. According to thermodynamic studies, ITN dissolution was endothermic and entropy-driven in all of the green solvents tested. The obtained outcomes suggested that DMSO appears to be the best green solvent for ITN solubilization.
PubMed: 36431759
DOI: 10.3390/ma15228274 -
Foods (Basel, Switzerland) May 2022Fatty acids (FAs) are important precursors of oolong tea volatile substances, and their famous derivatives have been shown to be the key aroma components. However, the...
Fatty acids (FAs) are important precursors of oolong tea volatile substances, and their famous derivatives have been shown to be the key aroma components. However, the relationship between fatty acids and their derivatives during oolong tea production remains unclear. In this study, fresh Tieguanyin leaves were manufactured into oolong tea and green tea (control), and fatty acids and fatty acid-derived volatiles (FADV) were extracted from processed samples by the sulfuric acid-methanol method and solvent-assisted flavor evaporation (SAFE), respectively. The results showed that unsaturated fatty acids were more abundant than saturated fatty acids in fresh leaves and decreased significantly during tea making. Relative to that in green tea, fatty acids showed larger variations in oolong tea, especially at the green-making stage. Unlike fatty acids, the FADV content first increased and then decreased. During oolong tea manufacture, FADV contents were significantly and negatively correlated with total fatty acids; during the green-making stage, methyl jasmonate (MeJA) content was significantly and negatively correlated with abundant fatty acids except steric acid. Our data suggest that the aroma quality of oolong tea can be improved by manipulating fatty acid transformation.
PubMed: 35681313
DOI: 10.3390/foods11111563