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1.
Molecules ; 27(7)2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35408598

RESUMO

Naturally occurring phospholipids, such as phosphatidyl glycerol (PG), are gaining interest due to the roles they play in disease mechanisms. To elucidate the metabolism of PG, an optically pure material is required, but this is unfortunately not commercially available. Our previous PG synthesis route utilized phosphoramidite methodology that addressed issues surrounding fatty acid substrate scope and glycerol backbone modifications prior to headgroup phosphorylation, but faltered in the reproducibility of the overall pathway due to purification challenges. Herein, we present a robust pathway to optically pure PG in fewer steps, utilizing H-phosphonates that features a chromatographically friendly and stable triethyl ammonium H-phosphonate salt. Our route is also amendable to the simultaneous installation of different acyl chains, either saturated or unsaturated, on the glycerol backbone.


Assuntos
Organofosfonatos , Fosfatidilgliceróis , Ácidos Graxos/metabolismo , Glicerol/metabolismo , Fosfolipídeos/metabolismo , Reprodutibilidade dos Testes
2.
BMC Genomics ; 23(1): 308, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35428174

RESUMO

BACKGROUND: Chicken intramuscular fat (IMF) content is closely related to meat quality and performance, such as tenderness and flavor. Abdominal fat (AF) in chickens is one of the main waste products at slaughter. Excessive AF reduces feed efficiency and carcass quality. RESULTS: To analyze the differential deposition of IMF and AF in chickens, gene expression profiles in the breast muscle (BM) and AF tissues of 18 animals were analyzed by differential expression analysis and weighted co-expression network analysis. The results showed that IMF deposition in BM was associated with pyruvate and citric acid metabolism through GAPDH, LDHA, GPX1, GBE1, and other genes. In contrast, AF deposition was related to acetyl CoA and glycerol metabolism through FABP1, ELOVL6, SCD, ADIPOQ, and other genes. Carbohydrate metabolism plays an essential role in IMF deposition, and fatty acid and glycerol metabolism regulate AF deposition. CONCLUSION: This study elucidated the molecular mechanism governing IMF and AF deposition through crucial genes and signaling pathways and provided a theoretical basis for producing high-quality broilers.


Assuntos
Galinhas , Glicerol , Gordura Abdominal/metabolismo , Tecido Adiposo/metabolismo , Animais , Galinhas/genética , Galinhas/metabolismo , Glicerol/metabolismo , Metabolismo dos Lipídeos/genética , Músculo Esquelético/metabolismo
3.
Appl Microbiol Biotechnol ; 106(8): 2937-2951, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35416488

RESUMO

Glycerol dehydratase (gdrAB-dhaB123) operon from Klebsiella pneumoniae and NADPH-dependent 1,3-propanediol oxidoreductase (yqhD) from Escherichia coli were stably integrated on the chromosomal DNA of E. coli under the control of the native-host ldhA and pflB constitutive promoters, respectively. The developed E. coli NSK015 (∆ldhA::gdrAB-dhaB123 ∆ackA::FRT ∆pflB::yqhD ∆frdABCD::cat-sacB) produced 1,3-propanediol (1,3-PDO) at the level of 36.8 g/L with a yield of 0.99 mol/mol of glycerol consumed when glucose was used as a co-substrate with glycerol. Co-substrate of glycerol and cassava starch was also utilized for 1,3-PDO production with the concentration and yield of 31.9 g/L and 0.84 mol/mol of glycerol respectively. This represents a work for efficient 1,3-PDO production in which the overexpression of heterologous genes on the E. coli host genome devoid of plasmid expression systems. Plasmids, antibiotics, IPTG, and rich nutrients were omitted during 1,3-PDO production. This may allow a further application of E. coli NSK015 for the efficient 1,3-PDO production in an economically industrial scale. KEY POINTS:  â€¢ gdrAB-dhaB123 and yqhD were overexpressed in E. coli devoid of a plasmid system • E. coli NSK015 produced a high yield of 1,3-PDO at 99% theoretical maximum • Cassava starch was alternatively used as substrate for economical 1,3-PDO production.


Assuntos
Escherichia coli , Glicerol , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentação , Deleção de Genes , Glicerol/metabolismo , Propilenoglicol/metabolismo , Propilenoglicóis/metabolismo , Amido/metabolismo
4.
Transfusion ; 62(5): 954-960, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35403731

RESUMO

BACKGROUND: A 2-year-old, 10.8 kg male pediatric patient with X-linked chronic granulomatous disease (CGD) with McLeod syndrome (MLS) was scheduled for a hematopoietic stem cell transplant (HSCT). Identification of allogenic red blood cells (RBC) for post-transplant support was unsuccessful prompting the development of a customized method to collect and freeze rare autologous pediatric cells. STUDY DESIGN AND METHODS: A protocol was developed for the collection of small volume pediatric whole blood (WB) via peripheral venipuncture with collection into 10 ml syringes containing anticoagulants. Additionally, a closed system RBC glycerolization and deglycerolization instrument was adapted to process small volume, non-leukoreduced WB. Both collection and WB processes were validated. In total 4 approximately 100 ml autologous units were collected and frozen. Two units were thawed, deglycerolized, and used for clinical transfusion support. To appreciate processing impacts on RBC rigidity, ektacytometry was performed on pre-processed and post-deglycerolization samples. RESULTS: Free hemoglobin (HGB) of validation units after thawing/deglycerolization was <150 mg/dL with an average red cell recovery of 85%. These units also showed little difference between pre-and post-processing Lorrca deformability curves or membrane rigidity. Two pediatric units were thawed and deglycerolized for transfusion. Free HGB was 70 mg/dL and 50 mg/dL post-thaw, and these RBCs had a slight decrease in deformability and increased membrane rigidity. DISCUSSION: Customized WB collection, glycerolization, freezing, and deglycerolization processes were developed to successfully support a pediatric patient with CGD and MLS after autologous HSCT. Both pediatric units showed increased membrane rigidity post-deglycerolization which may be a consequence of the CGD and MLS genetic background.


Assuntos
Preservação de Sangue , Transplante de Medula Óssea , Preservação de Sangue/métodos , Criança , Pré-Escolar , Criopreservação/métodos , Eritrócitos/metabolismo , Glicerol/metabolismo , Hemoglobinas/metabolismo , Humanos , Masculino
5.
Sci Rep ; 12(1): 6612, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35459786

RESUMO

Human brown fat is a potential therapeutic target for preventing obesity and related metabolic diseases by dissipating energy as heat through uncoupling protein 1 (UCP1). We have previously reported a method to obtain chemical compound-induced brown adipocytes (ciBAs) converted from human dermal fibroblasts under serum-free conditions. However, pharmacological responses to bioactive molecules have been poorly characterised in ciBAs. This study showed that the treatment with Capsaicin, an agonist of transient receptor potential vanilloid 1, directly activated adipocyte browning such as UCP1 expression, mitochondrial biogenesis, energy consumption rates, and glycerol recycling in ciBAs. Furthermore, genome-wide transcriptome analysis indicated that Capsaicin activated a broad range of metabolic genes including glycerol kinase and glycerol 3-phosphate dehydrogenase 1, which could be associated with the activation of glycerol recycling and triglyceride synthesis. Capsaicin also activated UCP1 expression in immortalised human brown adipocytes but inhibited its expression in mesenchymal stem cell-derived adipocytes. Altogether, ciBAs successfully reflected the direct effects of Capsaicin on adipocyte browning. These findings suggested that ciBAs could serve as a promising cell model for screening of small molecules and dietary bioactive compounds targeting human brown adipocytes.


Assuntos
Adipócitos Marrons , Capsaicina , Adipócitos Marrons/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo Marrom/metabolismo , Capsaicina/metabolismo , Capsaicina/farmacologia , Fibroblastos/metabolismo , Glicerol/metabolismo , Humanos , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
6.
PLoS Pathog ; 18(3): e1010385, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35255112

RESUMO

We have identified GpsA, a predicted glycerol-3-phosphate dehydrogenase, as a virulence factor in the Lyme disease spirochete Borrelia (Borreliella) burgdorferi: GpsA is essential for murine infection and crucial for persistence of the spirochete in the tick. B. burgdorferi has a limited biosynthetic and metabolic capacity; the linchpin connecting central carbohydrate and lipid metabolism is at the interconversion of glycerol-3-phosphate and dihydroxyacetone phosphate, catalyzed by GpsA and another glycerol-3-phosphate dehydrogenase, GlpD. Using a broad metabolomics approach, we found that GpsA serves as a dominant regulator of NADH and glycerol-3-phosphate levels in vitro, metabolic intermediates that reflect the cellular redox potential and serve as a precursor for lipid and lipoprotein biosynthesis, respectively. Additionally, GpsA was required for survival under nutrient stress, regulated overall reductase activity and controlled B. burgdorferi morphology in vitro. Furthermore, during in vitro nutrient stress, both glycerol and N-acetylglucosamine were bactericidal to B. burgdorferi in a GlpD-dependent manner. This study is also the first to identify a suppressor mutation in B. burgdorferi: a glpD deletion restored the wild-type phenotype to the pleiotropic gpsA mutant, including murine infectivity by needle inoculation at high doses, survival under nutrient stress, morphological changes and the metabolic imbalance of NADH and glycerol-3-phosphate. These results illustrate how basic metabolic functions that are dispensable for in vitro growth can be essential for in vivo infectivity of B. burgdorferi and may serve as attractive therapeutic targets.


Assuntos
Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Doença de Lyme , Carrapatos , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Glicerol/metabolismo , Glicerolfosfato Desidrogenase/genética , Glicerolfosfato Desidrogenase/metabolismo , Camundongos , NAD/metabolismo , Oxirredução , Fosfatos/metabolismo
7.
Sci Rep ; 12(1): 4129, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260770

RESUMO

The fall armyworm (FAW), Spodoptera frugiperda, is native to the tropical and subtropical areas of the American continent and is one of the world's most destructive insect pests and invaded Africa and spread to most of Asia in two years. Glycerol is generally used as a cryoprotectant for overwintering insects in cold areas. In many studies, the increase in glycerol as a main rapid cold hardening (RCH) factor and enhancing the supercooling point was revealed at low temperatures. There are two genes, including glycerol-3-phosphate dehydrogenase (GPDH) and glycerol kinase (GK), that were identified as being associated with the glycerol synthesis pathway. In this study, one GPDH and two GK sequences (GK1 and GK2) were extracted from FAW transcriptome analysis. RNA interference (RNAi) specific to GPDH or GK1 and GK2 exhibited a significant down-regulation at the mRNA level as well as a reduction in survival rate when the RNAi-treated of FAW larvae post a RCH treatment. Following a cold period, an increase in glycerol accumulation was detected utilizing high-pressure liquid chromatography and colorimetric analysis of glycerol quantity in RCH treated hemolymph of FAW larvae. This research suggests that GPDH and GK isozymes are linked to the production of a high quantity of glycerol as an RCH factor, and glycerol as main cryoprotectant plays an important role in survival throughout the cold period in this quarantine pest studied.


Assuntos
Glicerol , Mariposas , Animais , Crioprotetores , Glicerol/metabolismo , Glicerol Quinase/genética , Glicerolfosfato Desidrogenase/metabolismo , Larva/fisiologia , Mariposas/metabolismo , Spodoptera/genética , Spodoptera/metabolismo
8.
FEMS Yeast Res ; 22(1)2022 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-35254447

RESUMO

Cells coordinate intracellular activities in response to changes in the extracellular environment to maximize their probability of survival and proliferation. Eukaryotic cells need to adapt to constant changes in the osmolarity of their environment. In yeast, the high-osmolarity glycerol (HOG) pathway is responsible for the response to high osmolarity. Activation of the Hog1 stress-activated protein kinase (SAPK) induces a complex program required for cellular adaptation that includes temporary arrest of cell cycle progression, adjustment of transcription and translation patterns, and the regulation of metabolism, including the synthesis and retention of the compatible osmolyte glycerol. Hog1 is a member of the family of p38 SAPKs, which are present across eukaryotes. Many of the properties of the HOG pathway and downstream-regulated proteins are conserved from yeast to mammals. This review addresses the global view of this signaling pathway in yeast, as well as the contribution of Dr Hohmann's group to its understanding.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Animais , Glicerol/metabolismo , Mamíferos/metabolismo , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Concentração Osmolar , Pressão Osmótica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
9.
J Am Chem Soc ; 144(17): 7720-7730, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35352954

RESUMO

Photoelectrocatalytic (PEC) glycerol oxidation offers a sustainable approach to produce dihydroxyacetone (DHA) as a valuable chemical, which can find use in cosmetic, pharmaceutical industries, etc. However, it still suffers from the low selectivity (≤60%) that substantially limits the application. Here, we report the PEC oxidation of glycerol to DHA with a selectivity of 75.4% over a heterogeneous photoanode of Bi2O3 nanoparticles on TiO2 nanorod arrays (Bi2O3/TiO2). The selectivity of DHA can be maintained at ∼65% under a relatively high conversion of glycerol (∼50%). The existing p-n junction between Bi2O3 and TiO2 promotes charge transfer and thus guarantees high photocurrent density. Experimental combined with theoretical studies reveal that Bi2O3 prefers to interact with the middle hydroxyl of glycerol that facilitates the selective oxidation of glycerol to DHA. Comprehensive reaction mechanism studies suggest that the reaction follows two parallel pathways, including electrophilic OH* (major) and lattice oxygen (minor) oxidations. Finally, we designed a self-powered PEC system, achieving a DHA productivity of 1.04 mg cm-2 h-1 with >70% selectivity and a H2 productivity of 0.32 mL cm-2 h-1. This work may shed light on the potential of PEC strategy for biomass valorization toward value-added products via PEC anode surface engineering.


Assuntos
Di-Hidroxiacetona , Glicerol , Adsorção , Catálise , Di-Hidroxiacetona/metabolismo , Glicerol/metabolismo , Radical Hidroxila , Oxirredução
10.
Nat Commun ; 13(1): 1545, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318330

RESUMO

Glycerol dibiphytanyl glycerol tetraethers (GDGTs) are archaeal monolayer membrane lipids that can provide a competitive advantage in extreme environments. Here, we identify a radical SAM protein, tetraether synthase (Tes), that participates in the synthesis of GDGTs. Attempts to generate a tes-deleted mutant in Sulfolobus acidocaldarius were unsuccessful, suggesting that the gene is essential in this organism. Heterologous expression of tes homologues leads to production of GDGT and structurally related lipids in the methanogen Methanococcus maripaludis (which otherwise does not synthesize GDGTs and lacks a tes homolog, but produces a putative GDGT precursor, archaeol). Tes homologues are encoded in the genomes of many archaea, as well as in some bacteria, in which they might be involved in the synthesis of bacterial branched glycerol dialkyl glycerol tetraethers.


Assuntos
Archaea , Sulfolobus acidocaldarius , Archaea/genética , Archaea/metabolismo , Bactérias/metabolismo , Glicerol/metabolismo , Lipídeos de Membrana/metabolismo , Sulfolobus acidocaldarius/genética , Sulfolobus acidocaldarius/metabolismo
11.
J Bacteriol ; 204(4): e0062321, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35254103

RESUMO

Exploration is a recently discovered mode of growth and behavior exhibited by some Streptomyces species that is distinct from their classical sporulating life cycle. While much has been uncovered regarding initiating environmental conditions and phenotypic outcomes of exploratory growth, how this process is coordinated at a genetic level remains unclear. We used RNA sequencing to survey global changes in the transcriptional profile of exploring cultures over time in the model organism Streptomyces venezuelae. Transcriptomic analyses revealed widespread changes in gene expression impacting diverse cellular functions. Investigations into differentially expressed regulatory elements revealed specific groups of regulatory factors to be impacted, including the expression of several extracytoplasmic function (ECF) sigma factors, second messenger signaling pathways, and members of the whiB-like (wbl) family of transcription factors. Dramatic changes were observed among primary metabolic pathways, especially among respiration-associated genes and the oxidative stress response; enzyme assays confirmed that exploring cultures exhibit an enhanced oxidative stress response compared with classically growing cultures. Changes in the expression of the glycerol catabolic genes in S. venezuelae led to the discovery that glycerol supplementation of the growth medium promotes a dramatic acceleration of exploration. This effect appears to be unique to glycerol as an alternative carbon source, and this response is broadly conserved across other exploration-competent species. IMPORTANCE Exploration represents an alternative growth strategy for Streptomyces bacteria and is initiated in response to other microbes or specific environmental conditions. Here, we show that entry into exploration involves comprehensive transcriptional reprogramming, with an emphasis on changes in primary metabolism and regulatory/signaling functions. Intriguingly, a number of transcription factor classes were downregulated upon entry into exploration. In contrast, respiration-associated genes were strongly induced, and this was accompanied by an enhanced oxidative stress response. Notably, our transcriptional analyses suggested that glycerol may play a role in exploration, and we found that glycerol supplementation dramatically enhanced the exploration response in many streptomycetes. This work sheds new light on the regulatory and metabolic cues that influence a fascinating new microbial behavior.


Assuntos
Glicerol , Streptomyces , Aceleração , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Glicerol/metabolismo , Estresse Oxidativo , Streptomyces/genética , Streptomyces/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
12.
Proc Natl Acad Sci U S A ; 119(10): e2122287119, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35238637

RESUMO

SignificanceMetformin is the most commonly prescribed drug for the treatment of type 2 diabetes mellitus, yet the mechanism by which it lowers plasma glucose concentrations has remained elusive. Most studies to date have attributed metformin's glucose-lowering effects to inhibition of complex I activity. Contrary to this hypothesis, we show that inhibition of complex I activity in vitro and in vivo does not reduce plasma glucose concentrations or inhibit hepatic gluconeogenesis. We go on to show that metformin, and the related guanides/biguanides, phenformin and galegine, inhibit complex IV activity at clinically relevant concentrations, which, in turn, results in inhibition of glycerol-3-phosphate dehydrogenase activity, increased cytosolic redox, and selective inhibition of glycerol-derived hepatic gluconeogenesis both in vitro and in vivo.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Gluconeogênese , Guanidinas/farmacologia , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Fenformin/farmacologia , Animais , Glucose/metabolismo , Glicerol/metabolismo , Glicerolfosfato Desidrogenase/antagonistas & inibidores , Fígado/efeitos dos fármacos , Fígado/metabolismo , Oxirredução , Piridinas/farmacologia
13.
Proc Natl Acad Sci U S A ; 119(10): e2117930119, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35239434

RESUMO

SignificanceWhile most small, regulatory RNAs are thought to be "noncoding," a few have been found to also encode a small protein. Here we describe a 164-nucleotide RNA that encodes a 28-amino acid, amphipathic protein, which interacts with aerobic glycerol-3-phosphate dehydrogenase and increases dehydrogenase activity but also base pairs with two mRNAs to reduce expression. The coding and base-pairing sequences overlap, and the two regulatory functions compete.


Assuntos
Carbono/metabolismo , Escherichia coli/metabolismo , RNA Bacteriano/fisiologia , Meios de Cultura , Escherichia coli/crescimento & desenvolvimento , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Galactose/metabolismo , Glicerol/metabolismo , Glicerolfosfato Desidrogenase/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Biossíntese de Proteínas , RNA Bacteriano/química , RNA Bacteriano/metabolismo , RNA Mensageiro/metabolismo
14.
Enzyme Microb Technol ; 157: 110021, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35231673

RESUMO

The dha operon of Klebsiella pneumoniae is responsible for glycerol catabolism and 1,3-propanediol formation. Subunits of glycerol dehydratase and the large subunit of glycerol dehydratase reactivating factor are encoded by dhaBCE and dhaF, respectively. Proteins of pdu operon form a microcompartment (bacteria organelle) and responsible for 1,2-propanediol catabolism. In this operon, pduCDE and pduG encode subunits of diol dehydratase and its reactivating factor. Diol dehydratase is an isofunctional enzyme of glycerol dehydratase, but its role in glycerol catabolism was not entirely clear. In this study, dhaBCE, pduCDE, dhaF, and pduG in K. pneumoniae were knocked out individually or combinedly. These strains were cultured with glycerol as a substrate, and dehydratase activities in the cytoplasm and microcompartment were detected. Results showed that glycerol dehydratase and diol dehydratase were simultaneously responsible for glycerol catabolism in K. pneumoniae. Besides being packaged in microcompartment, large amounts of diol dehydratase was also presented in the cytoplasm. However, the Pdu microcompartment reduced the accumulation of 3-hydroxypropionaldehyde in the fermentation broth. PduG can cross reactivate glycerol dehydratase instead of DhaF. However, DhaF is not involved in reactivation of diol dehydratase. In conclusion, diol dehydratase and Pdu microcompartment play important roles in glycerol catabolism in K. pneumoniae.


Assuntos
Propanodiol Desidratase , Cobamidas/metabolismo , Glicerol/metabolismo , Hidroliases/genética , Hidroliases/metabolismo , Klebsiella pneumoniae/genética , Óperon , Propanodiol Desidratase/genética , Propanodiol Desidratase/metabolismo
15.
Appl Microbiol Biotechnol ; 106(7): 2541-2555, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35325274

RESUMO

While crude glycerol is a cheap carbon source for industrial-scale cultivation of microorganisms, its application relies on fast growth and conversion. The biopolymer producing Cupriavidus necator H16 (synonym: Ralstonia eutropha H16) grows poorly on glycerol. The heterologous expression of glycerol facilitator glpF, glycerol kinase glpK, and glycerol dehydrogenase glpD from E. coli accelerated the growth considerably. The naturally occurring glycerol utilization is inhibited by low glycerol kinase activity. A limited heterotrophic growth promotes the dependency on autotrophic growth by carbon dioxide (CO2) fixation and refixation. As mixotrophic growth occurs in the wildtype due to low consumption rates of glycerol, CO2 fixation by the Calvin-Benson-Bassham (CBB) cycle is essential. The deletion of both cbbX copies encoding putative RuBisCO-activases (AAA + ATPase) resulted in a sharp slowdown of growth and glycerol consumption. Activase activity is necessary for functioning carboxylation by RuBisCO. Each of the two copies compensates for the loss of the other, as suggested by observed expression levels. The strong tendency towards autotrophy supports previous investigations of glycerol growth and emphasizes the versatility of the metabolism of C. necator H16. Mixotrophy with glycerol-utilization and CO2 fixation with a high dependence on the CBB is automatically occurring unless transportation and degradation of glycerol are optimized. Parallel engineering of CO2 fixation and glycerol degradation is suggested towards application for value-added production from crude glycerol. KEY POINTS: • Growth on glycerol is highly dependent on efficient carbon fixation via CBB cycle. • CbbX is essential for the efficiency of RuBisCO in C. necator H16. • Expression of glycerol degradation pathway enzymes accelerates glycerol utilization.


Assuntos
Aquaporinas , Cupriavidus necator , Proteínas de Escherichia coli , Aquaporinas/metabolismo , Dióxido de Carbono/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Glicerol/metabolismo , Glicerol Quinase/genética , Glicerol Quinase/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo
16.
FEMS Yeast Res ; 22(1)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35137036

RESUMO

While thermotolerance is an attractive trait for yeasts used in industrial ethanol production, oxygen requirements of known thermotolerant species are incompatible with process requirements. Analysis of oxygen-sufficient and oxygen-limited chemostat cultures of the facultatively fermentative, thermotolerant species Ogataea parapolymorpha showed its minimum oxygen requirements to be an order of magnitude larger than those reported for the thermotolerant yeast Kluyveromyces marxianus. High oxygen requirements of O. parapolymorpha coincided with a near absence of glycerol, a key NADH/NAD+ redox-cofactor-balancing product in many other yeasts, in oxygen-limited cultures. Genome analysis indicated absence of orthologs of the Saccharomyces cerevisiae glycerol-3-phosphate-phosphatase genes GPP1 and GPP2. Co-feeding of acetoin, whose conversion to 2,3-butanediol enables reoxidation of cytosolic NADH, supported a 2.5-fold increase of the biomass concentration in oxygen-limited cultures. An O. parapolymorpha strain in which key genes involved in mitochondrial reoxidation of NADH were inactivated did produce glycerol, but transcriptome analysis did not reveal a clear candidate for a responsible phosphatase. Expression of S. cerevisiae GPD2, which encodes NAD+-dependent glycerol-3-phosphate dehydrogenase, and GPP1 supported increased glycerol production by oxygen-limited chemostat cultures of O. parapolymorpha. These results identify dependence on respiration for NADH reoxidation as a key contributor to unexpectedly high oxygen requirements of O. parapolymorpha.


Assuntos
NAD , Saccharomyces cerevisiae , Glicerol/metabolismo , NAD/metabolismo , Oxigênio/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Saccharomyces cerevisiae/genética , Saccharomycetales
17.
J Biomech Eng ; 144(8)2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35147159

RESUMO

Changes in synovial fluid viscosity may be used to detect joint disease; however, methods to evaluate these changes at the point-of-care are currently rudimentary. Previously, we demonstrated that magnetic particle translation through static synovial fluid could serve as a surrogate marker of synovial fluid mechanics. In this work, we examine the magnetic deflection of a stream of particles flowing through a stream of synovial fluid and relate this deflection to changes in fluid mechanics. First, a flow device was designed, where a stream of magnetic particles flows along with synovial fluid. As the particle stream approaches and passes a fixed permanent magnet, the particle stream deflects. Conceptually, as the synovial fluid viscosity decreases, the deflection of the particle stream should increase due to a decreased drag force opposing the force magnetization. To assess this concept, particle deflection was first measured in Newtonian glycerol solutions of known varying viscosity under different flow conditions. Next, the device was used to test bovine synovial fluid viscosity, which had been progressively degraded using ultrasonication. A strong correlation was observed between the deflection of the magnetic particles and the viscosity of the glycerol solutions (R2 = 0.987) and the amount of ultrasonic degradation of synovial fluid (R2 = 0.7045). In the future, the principle of particle deflection may be used to design point-of-care quantification of synovial fluid mechanics, as the assessment does not require particles to be separated from the fluid for quantification and could be conducted under simple flow conditions.


Assuntos
Glicerol , Líquido Sinovial , Animais , Bovinos , Glicerol/metabolismo , Fenômenos Magnéticos , Imãs , Líquido Sinovial/metabolismo , Viscosidade
18.
Mar Drugs ; 20(2)2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35200644

RESUMO

Docosahexaenoic acid (DHA) is one of the most important long-chain polyunsaturated fatty acids (LC-PUFAs), with numerous health benefits. Crypthecodinium cohnii, a marine heterotrophic dinoflagellate, is successfully used for the industrial production of DHA because it can accumulate DHA at high concentrations within the cells. Glycerol is an interesting renewable substrate for DHA production since it is a by-product of biodiesel production and other industries, and is globally generated in large quantities. The DHA production potential from glycerol, ethanol and glucose is compared by combining fermentation experiments with the pathway-scale kinetic modeling and constraint-based stoichiometric modeling of C. cohnii metabolism. Glycerol has the slowest biomass growth rate among the tested substrates. This is partially compensated by the highest PUFAs fraction, where DHA is dominant. Mathematical modeling reveals that glycerol has the best experimentally observed carbon transformation rate into biomass, reaching the closest values to the theoretical upper limit. In addition to our observations, the published experimental evidence indicates that crude glycerol is readily consumed by C. cohnii, making glycerol an attractive substrate for DHA production.


Assuntos
Dinoflagelados/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo , Modelos Teóricos , Biomassa , Etanol/metabolismo , Fermentação , Glucose/metabolismo , Glicerol/metabolismo
19.
J Mater Chem B ; 10(7): 1042-1054, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35080234

RESUMO

Currently, glycerol is a conventional cryoprotectant of human red blood cells (hRBCs), but the time-consuming thawing and deglycerolization processes are essential before transfusion. Much of the research up to now has been conducted on the delivery of impermeable trehalose to hRBCs at 37 °C, but the cryoprotective effect of trehalose and deterioration of cells still remain challenging. Encouraged by the interaction of hydrophobic or cationic groups on cell membranes and osmotic stabilization, herein, we propose a novel cryopreservation system to facilitate trehalose entry into hRBCs at 4 °C and pH 7.4. High intracellular trehalose contents and cryosurvival of hRBCs were achieved with small function variations via the assistance of self-assembled nanoparticles of alkylated ε-poly(L-lysine) (ε-PL) along with poly(vinyl pyrrolidone) (PVP). The effect of amphipathic alkylated ε-PL with various alkyl chains and grafting ratios on membrane perturbation with protection of PVP was systematically investigated. Overall, by the combination of alkylated ε-PL and PVP, the intracellular trehalose could be enhanced to 109.7 ± 6.1 mM and subsequently hRBC cryosurvival reached 91.7 ± 5.5%, significantly higher than those containing trehalose only, 11.9 ± 1.1 mM and 50.0 ± 2.1%, respectively. It was observed that the biocompatible trehalose-loading system could benefit glycerol-free cryopreservation of hRBCs and also provide a feasible way for impermeable biomacromolecule delivery.


Assuntos
Glicerol , Trealose , Criopreservação , Crioprotetores/química , Crioprotetores/metabolismo , Crioprotetores/farmacologia , Eritrócitos , Glicerol/metabolismo , Humanos , Polilisina/metabolismo , Trealose/química
20.
J Appl Microbiol ; 132(4): 2883-2893, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35025114

RESUMO

AIMS: Enhancing biosurfactant production from indigenous Lactobacillus plantarum MGL-8 using mango waste substrate, and evaluating its characteristics as food sanitizer. METHODS AND RESULTS: Mango juice (a mixture of mango paste, sucrose, glycerol and deionized water) was used for batch fermentation with L. plantarum MGL-8 (L-MJ) and uninoculated (MC-MJ). Agitation, aeration and temperature were controlled. Maximum lactic acid bacteria (LAB) growth was observed in MC-MJ and L-MJ at 48 h, and the L-MJ fermentation provided the highest biosurfactant yield of 4.22 g L-1 at 120 h. The dried crude biosurfactant (BSF) provided surface tension 36.6 mN m-1 , a maximum emulsification index (E24%) of 41% and zone of inhibition of 15.53 mm. Preliminary characterization by Gas chromatography-Mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) indicated a multi-component glycolipoprotein BSF associated with fatty dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, proteins and polysaccharides. The BSF also displayed bactericidal activity against Listeria monocytogenes at 400 µg ml-1 . CONCLUSIONS: Mango waste substrate enhanced biosurfactant production by indigenous L. plantarum MGL-8. SIGNIFICANCE AND IMPACT OF THE STUDY: The study identifies a production process and characteristics of the biosurfactant, which can be employed as a food sanitizer.


Assuntos
Lactobacillus plantarum , Mangifera , Glicerol/metabolismo , Lactobacillus plantarum/metabolismo , Tensão Superficial , Tensoativos/metabolismo
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