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Metabolic pathways for the production of 1,2-PDO from glucose (Methylglyoxal pathway). The genes in Fig. 2 are all from E. coli. ALDO: fructose–bisphosphate aldolase; tpi: triose-phosphate isomerase; mgsA: methylglyoxal synthase; gldA: glycerol dehydrogenase; yqhD: alcohol dehydrogenase; fucO: propanediol oxidoreductase; Glyoxalase system: glyoxalase I (lactoylglutathione lyase), glyoxalase II (hydroxyacylglutathione hydrolase)
Source publication
1,2-Propanediol is an important building block as a component used in the manufacture of unsaturated polyester resin, antifreeze, biofuel, nonionic detergent, etc. Commercial production of 1,2-propanediol through microbial biosynthesis is limited by low efficiency, and chemical production of 1,2-propanediol requires petrochemically derived routes i...
Citations
... Consequently, this is a new report that describes various phytocompounds using GC-MS characterization. 1,2 propanediol,2-acetate (CAS-110806) is used as a starting material for some drugs and food additives, antimicrobial and anti-inflammatory [45]; cyclohexanone,2acetyl (CAS-13400) acts as anti-microbial and anti-inflammatory [46]; 2,3 anhydro-d-galactosan (CAS-91691622) acts as anti-coagulant and anti-viral [47]; diethyl phthalate (CAS-6781) is used as anti-microbial agent ( [48,49], benzoic acid,4-hydroxy-3,5 dimethoxy (CAS-10742) is an anti-inflammatory, anti-microbial and analgesic [50,51]; N-hexadecanoic acid (CAS-985) is an anti-inflammatory and anti-oxidant [52,53]; 9,12 octadecadienoic acid (CAS-5280450) is an anti-cancerous and anti-inflammatory [53]; Eicosane,2-methyl (CAS-519146) acts as anti-inflammatory, anti-oxidative and anti-fungal [54] and Content courtesy of Springer Nature, terms of use apply. Rights reserved. ...
Biopolymers are a great option for biomedical and other applications because of their versatile properties. Although numerous research studies are documented on biopolymer-producing bacterial isolates in the literature, the potential of Enterococcus gallinarum in biopolymer production remains unexplored and presents many opportunities for further investigation. This research mainly focuses on the isolation and characterization of biopolymer-producing bacterial isolates from floral waste samples collected from Vellore and Ujjain, India. Furthermore, in silico docking studies were performed in this study to investigate the binding of ligand-protein interaction for biomedical applications. The utilization of floral waste for biopolymer production is not broadly explored in the literature and therefore is the novelty of this research study. Enterococcus gallinarum produced 36.06 g l⁻¹ of melanin-free exopolysaccharide (EPS) in 120 h at 30 °C in 5% sucrose-containing medium. Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed that the chemical structure and nature of the exopolysaccharide produced by Enterococcus gallinarum and standard pullulan were identical. Further, gas chromatography-mass spectrometry was performed to identify the compounds or substances in the pullulan sample and to perform in silico docking studies. This is the first report of pullulan production at 15% (w/v) sucrose concentration by a bacterial isolate Enterococcus gallinarum. As a result, this study presents a novel strategy for sustainable development by combining the synthesis of microbial biopolymers with the valorisation of floral waste that could potentially aid in the economical manufacturing of biopolymers by utilizing inexpensive floral waste as a raw material in the near future.
Graphical abstract
... Then, acetolactate is further decarboxylated to acetoin (C 4 H 8 O 2 ) and the carbonyl function of acetoin is finally reduced to give 2,3-butanediol [29]. 1,2-propanediol is, analogously to 2,3-butanediol, another diol with high industrial demand [30]. As can be seen from Fig. 6B, 1,2-propanediol (propylene glycol) is the only metabolite which is upregulated in class 3Ca-Treatment250 with respect to class 2Ca-Treatment125. ...
... Closely similar to the production of 1,2-propanediol by K. pneumoniae, production of 2,3-butanediol by C. albicans in presence of an excess of dyplopirone C stressor provides a way to increase the availability of NAD + . In fact, an interesting metabolic pathway, based on methylglyoxal, has been proposed for the biosynthesis of 1,2-propanediol in which two NAD + molecules are made available for each molecule of 1, 2-propanediol produced [30]. Methylglyoxal (C 3 H 4 O 2 ), released from dihydroxyacetone phosphate (C 3 H 7 O 6 P, a glycolysis intermediate) by the action of methylglyoxal synthase, can be converted to 1,2-propanediol (C 3 H 8 O 2 ) via two alternative routes. ...
Seen initially as wonder drugs, the widespread and often inappropriate use of antibiotics led to the development
of microbial resistances. As a result, a true emergency has arisen, and a significant need has emerged to discover
and develop new safe and valuable antibiotics. The captivating chemical structure of the fungal metabolite
diplopyrone C has caught our attention as an excellent candidate for a circumstantial study aimed at revealing its
antimicrobial and antibiofilm activities. In this work, we describe the full analytical strategy from the isolation/
identification to the evaluation of the metabolomics effect on target microorganisms of this fungal metabolite.
Our results show interesting antimicrobial and antibiofilm activities of diplopyrone C against two frequently
isolated nosocomial pathogens (i.e., the fungus Candida albicans and the gram-negative bacterium Klebsiella
pneumoniae). Moreover, a GC-MS based metabolomics footprinting approach gave an insight into the uptake and
excretion of metabolites from and into the culture medium as a response to the presence of this active substance.
The workflow employed in this study is suitable to exploit natural resources for the search of lead compounds for
drug development
... The C3-diols 1,2-and 1,3-propanediol (PDO) are important building blocks and are widely used in the polymer, food, cosmetic and drug industry [1,2]. For 1,3-PDO and 1,2-PDO a global market size of around 1.4 billion and 0.4 billion US dollars is expected in the next years [2,3]. ...
... The C3-diols 1,2-and 1,3-propanediol (PDO) are important building blocks and are widely used in the polymer, food, cosmetic and drug industry [1,2]. For 1,3-PDO and 1,2-PDO a global market size of around 1.4 billion and 0.4 billion US dollars is expected in the next years [2,3]. Both diols are mainly produced from fossil fuels, but bio-based production processes, utilizing renewable resources, are favorable to tackle the concerns of climate change and the limited availability of fossil resources. ...
... Notably, first commercial microbial processes for 1,3-PDO production are readily available [4]. Although several natural 1,2-PDO producers are known and established microbial systems have been extensively engineered for its production, a sustainable process at the industrial level is still missing [2]. ...
Background
1,2-propanediol (1,2-PDO) is widely used in the cosmetic, food, and drug industries with a worldwide consumption of over 1.5 million metric tons per year. Although efforts have been made to engineer microbial hosts such as Corynebacterium glutamicum to produce 1,2-PDO from renewable resources, the performance of such strains is still improvable to be competitive with existing petrochemical production routes.
Results
In this study, we enabled 1,2-PDO production in the genome-reduced strain C. glutamicum PC2 by introducing previously described modifications. The resulting strain showed reduced product formation but secreted 50 ± 1 mM d-lactate as byproduct. C. glutamicum PC2 lacks the d-lactate dehydrogenase which pointed to a yet unknown pathway relevant for 1,2-PDO production. Further analysis indicated that in C. glutamicum methylglyoxal, the precursor for 1,2-PDO synthesis, is detoxified with the antioxidant native mycothiol (MSH) by a glyoxalase-like system to lactoylmycothiol and converted to d-lactate which is rerouted into the central carbon metabolism at the level of pyruvate. Metabolomics of cell extracts of the empty vector-carrying wildtype, a 1,2-PDO producer and its derivative with inactive d-lactate dehydrogenase identified major mass peaks characteristic for lactoylmycothiol and its precursors MSH and glucosaminyl-myo-inositol, whereas the respective mass peaks were absent in a production strain with inactivated MSH synthesis. Deletion of mshA, encoding MSH synthase, in the 1,2-PDO producing strain C. glutamicum ΔhdpAΔldh(pEKEx3-mgsA-yqhD-gldA) improved the product yield by 56% to 0.53 ± 0.01 mM1,2−PDO mMglucose⁻¹ which is the highest value for C. glutamicum reported so far.
Conclusions
Genome reduced-strains are a useful basis to unravel metabolic constraints for strain engineering and disclosed in this study the pathway to detoxify methylglyoxal which represents a precursor for 1,2-PDO production. Subsequent inactivation of the competing pathway significantly improved the 1,2-PDO yield.
... Some LAB strains were able to degrade lactic acid into acetic acid. It has been reported that each mole of lactic acid was converted into approximately 0.5 mol of acetic acid, 0.5 mol of 1,2-propanediol, and traces of ethanol by certain LAB strains [42,43]. This may be the reason for the high proportion of acetic acid (39.64%) in the chemical composition of CFS from S. thermophilus. ...
The bioactive properties of the combination of microencapsulated cell-free supernatant (CFS) from Streptococcus thermophilus and thyme extract on food-related bacteria (Photobacterium damselae, Proteus mirabilis, Vibrio vulnificus, Staphylococcus aureus ATCC29213, Enterococcus faecalis ATCC29212, and Salmonella Paratyphi A NCTC13) were investigated. The microencapsulated CFS of S. thermophilus, in combination with ethanolic thyme extract, had a particle size in the range of 1.11 to 11.39 µm. The microencapsulated CFS of S. thermophilus had a wrinkled, spherical form. In the supernatant, especially at 2% (v/w), the thyme extract additive caused a decrease in the wrinkled form and a completely spherical structure. A total of 11 compounds were determined in the cell-free supernatant of S. thermophilus, and acetic acid (39.64%) and methyl-d3 1-dideuterio-2-propenyl ether (10.87%) were the main components. Thyme extract contained seven components, the main component being carvacrol at 67.96% and 1,2,3-propanetriol at 25.77%. Significant differences (p < 0.05) were observed in the inhibition zones of the extracts on bacteria. The inhibitory effect of thyme extract on bacteria varied between 25.00 (P. damselae) and 41.67 mm (V. vulnificus). Less antibacterial activity was shown by the microencapsulated CFS from S. thermophilus compared to their pure form. (p < 0.05). As a result, it was found that microencapsulated forms of CFS from S. thermophilus, especially those prepared in combination with 2% (v/w) thyme extract, generally showed higher bioactive effects on bacteria.
... Moreover, it has been reported that its production by microorganisms is advantageous in comparison to chemical synthesis [54]. In addition, we also identified the genes involved in the conversion of dihydroxyacetone phosphate into methylglyoxal and the posterior synthesis of 1,2-PDO, which is also highly demanded in the industry due to its wide range of applications [55]. Complexes identified in the genomic analysis, which are involved in the production and consumption of hydrogen in Citrobacter sp. ...
... Moreover, it has been reported that its production by microorganisms is advantageous in comparison to chemical synthesis [54]. In addition, we also identified the genes involved in the conversion of dihydroxyacetone phosphate into methylglyoxal and the posterior synthesis of 1,2-PDO, which is also highly demanded in the industry due to its wide range of applications [55]. ...
Microbial diversity that thrives in the deep subsurface remains largely unknown. In this work, we present the characterization of Citrobacter sp. T1.2D-1, isolated from a 63.6 m-deep core sample extracted from the deep subsurface of the Iberian Pyrite Belt (IPB). A genomic analysis was performed to identify genes that could be ecologically significant in the IPB. We identified all the genes that encoded the formate–hydrogen lyase and hydrogenase-2 complexes, related to hydrogen production, as well as those involved in glycerol fermentation. This is particularly relevant as some of the substrates and byproducts of this process are of industrial interest. Additionally, we conducted a phylogenomic study, which led us to conclude that our isolate was classified within the Citrobacter telavivensis species. Experimentally, we verified the strain’s ability to produce hydrogen from glucose and glycerol and, thus, of performing dark fermentation. Moreover, we assessed the activity of the nitrate and tetrathionate reductase complexes and the isolate’s ability to tolerate high concentrations of heavy metals, especially Zn. These results suggest that C. telavivensis T1.2D-1 can play a role in the carbon, hydrogen, iron, nitrogen, and sulfur cycles that occur in the deep subsurface of the IPB, making it a candidate worthy of further study for possible biotechnological applications.
... 1,2-propanediol combined with choline chloride (30% aqueous solution) gives optimal NADES composition for the extraction of Q, naringenin, kaempferol and isorhamnetin from Typha angustifolia pollen [103]. Bio-based production of 1,2-propanediol is limited, but new, environmentally friendly possibilities are being researched [104]. ...
... Alumina and silica are commonly used as catalytic supports, but research is ongoing for new types of catalyst supports, such as polymer or carbon nanotubes (CNTs). 78,79 The addition of promoters or excipients, such as Ce and B, to the catalytic system is important for improving the selectivity of the hydrogenolysis process. Basic oxides such as MgO, CaO, or NaOH can also improve the catalytic properties, but their addition to the raw material can also result in excessive hydrolysis and difficulty in separating the final products. ...
... These methods have gained more industrial applications due to the wide range of biomass that can be used. 79,84 The reaction carried out by the microorganisms can be directed toward the R or S form of 1,2-propanediol, which is unique compared to the racemic mixture produced in other methods. This stereoselectivity increases the potential for use in the pharmaceutical industry as the R or S form of 1,2-propanediol is 200-fold more valuable than the racemic mixture. ...
The production of 1,2-propanediol is a significant challenge for the chemical industry due to the increasing demand for this versatile product and the pro-ecological regulatory actions. The traditional method of producing this compound through the hydrolysis of petroleum-derived 1,2-epoxypropane (propylene oxide) is energy intensive, and sustainable routes based on renewable raw materials are becoming more attractive. This perspective presents the current state of scientific and patent literature on the production of 1,2-propanediol and the implementation of new technologies by leading companies. This perspective also discusses alternative pathways, including glycerol hydrogenolysis and biotechnological methods, highlighting their potential to reduce energy consumption and lower the carbon footprint of the process. The focus is on modern methods, including chromium-free catalytic systems for glycerol hydrogenolysis, in situ hydrogen generation, and multifunctional catalysts for saccharides hydrolysis and hydrogenolysis. Biobased 1,2-propanediol produced from renewable alternative raw materials has great potential to replace traditional petroleum-derived 1,2-propanediol with substantial environmental and economic benefits.
... Propane-1,2-diol, commonly known as propylene glycol, is widely used as a food and cosmetic additive and represents a safer alternative to conventional ethylene glycol-based, anti-freezing, liquids. Furthermore, it can be produced through the chemical modification of glycerol [37,38] and its microbial synthesis [39] is currently a relevant object of study. The synthetic work on these molecules is the continuation of a first green approach to the synthesis of unsubstituted and alkyl-substituted phthalocyanines that we recently published [31], in which we were, however, unable to identify suitable reaction conditions for obtaining them with satisfactory yields. ...
Perovskite Solar Cells (PSCs) have attracted attention due to their low cost, easy solution processability, high efficiency, and scalability. However, the benchmark expensive hole transport material (HTM) 2,2′,7,7′-tetrakis[N, N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (Spiro-MeOTAD), which is traditionally solution-processed with toxic solvents such as chlorobenzene (CB), dichlorobenzene (DCB), or toluene, is a bottleneck. To address this issue, this work investigates the implementation of Zn(II), Cu(II), or Co(II) tetra-tert-butylphthalocyanines (TBU4-Cu, TBU4-Zn, TBU4-Co), established macrocyclic derivatives whose synthesis and processing inside the devices have been redesigned to be more environmentally sustainable and cost-effective by substituting conventional solvents with greener alternatives such as anisole, propane-1,2-diol, and their mixture, as dopant-free HTMs in planar n-i-p PSCs. The anisole-processed HTMs provided power conversion efficiencies (PCE) up to 12.27% for TBU4-Cu and 11.73% for TBU4-Zn, with better photovoltaic parameters than the corresponding cells made with chlorobenzene for which the best results obtained were, respectively, 12.22% and 10.81%.
... Lactobacillus buchneri was added in the LB and PB groups. It is more acid-tolerant and can grow normally in the late silage period, so the abundance of Lentilactobacillus was higher, which is consistent with the results of Tao et al. [60]. The genus composition of the CK group in the pre-silage period is more diverse, which is due to the slow process of lactic acid fermentation, resulting in the growth of more miscellaneous bacteria. ...
Silage of native grasses can alleviate seasonal forage supply imbalance in pastures and provide additional sources to meet forage demand. The study aimed to investigate the effects of Lactobacillus plantarum (LP), Lactobacillus buchneri (LB), and Lactobacillus plantarum in combination with Lactobacillus buchneri (PB) on the nutritional quality, fermentation quality, and microbial community of native grass silage at 2, 7, 15, and 60 days after ensiling and at 4 and 8 days after aerobic exposure. The results showed that dry matter content, crude protein content, the number of lactic acid bacteria, and lactic acid and acetic acid content increased and pH and ammonia nitrogen content decreased after lactic acid bacteria (LAB) inoculation compared with the control group (CK). LP had the lowest pH and highest lactic acid content but did not have greater aerobic stability. LB maintained a lower pH level and acetic acid remained at a higher level after aerobic exposure; aerobic bacteria, coliform bacteria, yeast, and molds all decreased in number, which effectively improved aerobic stability. The effect of the compound addition of LAB was in between the two other treatments, having higher crude protein content, lactic acid and acetic acid content, lower pH, and ammonia nitrogen content. At the phylum level, the dominant phylum changed from Proteobacteria to Firmicutes after ensiling, and at the genus level, Lactiplantibacillus and Lentilactobacillus were the dominant genera in both LAB added groups, while Limosilactobacillus was the dominant genus in the CK treatment. In conclusion, the addition of LAB can improve native grass silage quality by changing bacterial community structure. LP is beneficial to improve the fermentation quality in the ensiling stage, LB is beneficial to inhibit silage deterioration in the aerobic exposure stage, and compound LAB addition is more beneficial to be applied in native grass silage.
... Lactic acid (g/L) Acetic acid (g/L) Succinate (g/L) Ethanol (g/L) 1,3-PDO (g/L) 1,2-PDO production through the methylglyoxal pathway in engineered bacteria. Studies of 1,2-PDO production through the lactic acid pathway have only used glucose as a substrate, and only used genetically engineered E. coli [27]. To our knowledge, the present study is the first to report the biosynthesis of 1,2-PDO from lactic acid in K. pneumoniae with the use of glycerol as the substrate. ...
Background
To support the sustainability of biodiesel production, by-products, such as crude glycerol, should be converted into high-value chemical products. 1,2-propanediol (1,2-PDO) has been widely used as a building block in the chemical and pharmaceutical industries. Recently, the microbial bioconversion of lactic acid into 1,2-PDO is attracting attention to overcome limitations of previous biosynthetic pathways for production of 1,2-PDO. In this study, we examined the effect of genetic engineering, metabolic engineering, and control of bioprocess factors on the production of 1,2-PDO from lactic acid by K. pneumoniae GEM167 with flux enhancement of the oxidative pathway, using glycerol as carbon source.
Results
We developed K. pneumoniae GEM167ΔadhE/pBR-1,2PDO, a novel bacterial strain that has blockage of ethanol biosynthesis and biosynthesized 1,2-PDO from lactic acid when glycerol is carbon source. Increasing the agitation speed from 200 to 400 rpm not only increased 1,2-PDO production by 2.24-fold to 731.0 ± 24.7 mg/L at 48 h but also increased the amount of a by-product, 2,3-butanediol. We attempted to inhibit 2,3-butanediol biosynthesis using the approaches of pH control and metabolic engineering. Control of pH at 7.0 successfully increased 1,2-PDO production (1016.5 ± 37.3 mg/L at 48 h), but the metabolic engineering approach was not successful. The plasmid in this strain maintained 100% stability for 72 h.
Conclusions
This study is the first to report the biosynthesis of 1,2-PDO from lactic acid in K. pneumoniae when glycerol was carbon source. The 1,2-PDO production was enhanced by blocking the synthesis of 2,3-butanediol through pH control. Our results indicate that K. pneumoniae GEM167 has potential for the production of additional valuable chemical products from metabolites produced through oxidative pathways.
