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2.
J Org Chem ; 89(9): 6230-6237, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38629386

ABSTRACT

A concise synthesis of pareitropone by oxidative cyclization of a phenolic nitronate is delineated. The use of TMSOTf as an additive to promote the facile formation of a strained norcaradiene intermediate provides convenient access to highly condensed multicyclic tropones in high yields. This synthesis is modular, efficient, and scalable, highlighting the synthetic utility of radical anion coupling reactions in annulation reactions. This work is discussed in the context of total syntheses of the tropoloisoquinoline alkaloids. Also included are the preparation of several congeners and a brief description of their biological activities.


Subject(s)
Antineoplastic Agents , Humans , Molecular Structure , Cyclization , Cell Line, Tumor , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Drug Screening Assays, Antitumor , Oxidation-Reduction
3.
Polymers (Basel) ; 16(5)2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38475335

ABSTRACT

Polybutylene succinate (PBS) stands out as a promising biodegradable polymer, drawing attention for its potential as an eco-friendly alternative to traditional plastics due to its biodegradability and reduced environmental impact. In this study, we aimed to enhance PBS degradation by examining artificial consortia composed of bacterial strains. Specifically, Terribacillus sp. JY49, Bacillus sp. JY35, and Bacillus sp. NR4 were assessed for their capabilities and synergistic effects in PBS degradation. When only two types of strains, Bacillus sp. JY35 and Bacillus sp. NR4, were co-cultured as a consortium, a notable increase in degradation activity toward PBS was observed compared to their activities alone. The consortium of Bacillus sp. JY35 and Bacillus sp. NR4 demonstrated a remarkable degradation yield of 76.5% in PBS after 10 days. The degradation of PBS by the consortium was validated and our findings underscore the potential for enhancing PBS degradation and the possibility of fast degradation by forming artificial consortia, leveraging the synergy between strains with limited PBS degradation activity. Furthermore, this study demonstrated that utilizing only two types of strains in the consortium facilitates easy control and provides reproducible results. This approach mitigates the risk of losing activity and reproducibility issues often associated with natural consortia.

4.
iScience ; 27(1): 108699, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38299026

ABSTRACT

N,N-diethyl-meta-toluamide (DEET) is a commonly used synthetic insect repellent. Although the neurological effects of DEET have been widely investigated, its effects on the germline are less understood. Here, we show that exposure of the nematode Caenorhabditis elegans, which is highly predictive of mammalian reprotoxicity, resulting in internal DEET levels within the range detected in human biological samples, causes activation of p53/CEP-1-dependent germ cell apoptosis, altered meiotic recombination, chromosome abnormalities, and missegregation. RNA-sequencing analysis links DEET-induced alterations in the expression of genes related to redox processes and chromatin structure to reduced mitochondrial function, impaired DNA double-strand break repair progression, and defects during early embryogenesis. We propose that Caenorhabditis elegans exposure to DEET interferes with gene expression, leading to increased oxidative stress and altered chromatin structure, resulting in germline effects that pose a risk to reproductive health.

5.
J Chest Surg ; 57(2): 184-194, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38360679

ABSTRACT

Background: Left ventricular assist devices (LVADs) are widely employed as a therapeutic option for end-stage heart failure. We evaluated the outcomes associated with centrifugal-flow LVAD implantation, comparing 2 device models: the Heartmate 3 (HM3) and the Heartware Ventricular Assist Device (HVAD). Methods: Data were collected from patients who underwent LVAD implantation between June 1, 2015 and December 31, 2022. We analyzed overall survival, first rehospitalization, and early, late, and LVAD-related complications. Results: In total, 74 patients underwent LVAD implantation, with 42 receiving the HM3 and 32 the HVAD. A mild Interagency Registry for Mechanically Assisted Circulatory Support score was more common among HM3 than HVAD recipients (p=0.006), and patients receiving the HM3 exhibited lower rates of preoperative ventilator use (p=0.010) and extracorporeal membrane oxygenation (p=0.039). The overall early mortality rate was 5.4% (4 of 74 patients), with no significant difference between groups. Regarding early right ventricular (RV) failure, HM3 implantation was associated with a lower rate (13 of 42 [31.0%]) than HVAD implantation (18 of 32 [56.2%], p=0.051). The median rehospitalization-free period was longer for HM3 recipients (16.9 months) than HVAD recipients (5.3 months, p=0.013). Furthermore, HM3 recipients displayed a lower incidence of late hemorrhagic stroke (p=0.016). In the multivariable analysis, preoperative use of continuous renal replacement therapy (odds ratio, 22.31; p=0.002) was the only significant predictor of postoperative RV failure. Conclusion: The LVAD models (HM3 and HVAD) demonstrated comparable overall survival rates. However, the HM3 was associated with a lower risk of late hemorrhagic stroke.

6.
J Microbiol Biotechnol ; 34(4): 969-977, 2024 Apr 28.
Article in English | MEDLINE | ID: mdl-38213292

ABSTRACT

Indigo is a valuable, natural blue dye that has been used for centuries in the textile industry. The large-scale commercial production of indigo relies on its extraction from plants and chemical synthesis. Studies are being conducted to develop methods for environment-friendly and sustainable production of indigo using genetically engineered microbes. Here, to enhance the yield of bioindigo from an E. coli whole-cell system containing tryptophanase (TnaA) and flavin-containing monooxygenase (FMO), we evaluated tryptophan transporters to improve the transport of aromatic compounds, such as indole and tryptophan, which are not easily soluble and passable through cell walls. Among the three transporters, Mtr, AroP, and TnaB, AroP enhanced indigo production the most. The combination of each transporter with AroP was also evaluated, and the combination of AroP and TnaB showed the best performance compared to the single transporters and two transporters. Bioindigo production was then optimized by examining the culture medium, temperature, isopropyl ß-D-1-thiogalactopyranoside concentration, shaking speed (rpm), and pH. The novel strain containing aroP and tnaB plasmid with tnaA and FMO produced 8.77 mM (2.3 g/l) of bioindigo after 66 h of culture. The produced bioindigo was further recovered using a simple method and used as a watercolor dye, showing good mixing with other colors and color retention for a relatively long time. This study presents an effective strategy for enhancing indigo production using a combination of transporters.


Subject(s)
Escherichia coli , Indigo Carmine , Indoles , Tryptophan , Tryptophan/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Indoles/metabolism , Indigo Carmine/metabolism , Tryptophanase/genetics , Tryptophanase/metabolism , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Culture Media/chemistry , Oxygenases/genetics , Oxygenases/metabolism , Amino Acid Transport Systems/genetics , Amino Acid Transport Systems/metabolism , Plasmids/genetics , Metabolic Engineering/methods , Fermentation , Hydrogen-Ion Concentration , Coloring Agents/metabolism , Temperature
7.
Gastroenterology ; 166(5): 859-871.e3, 2024 May.
Article in English | MEDLINE | ID: mdl-38280684

ABSTRACT

BACKGROUND & AIMS: The complex tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) has hindered the development of reliable predictive biomarkers for targeted therapy and immunomodulatory strategies. A comprehensive characterization of the TME is necessary to advance precision therapeutics in PDAC. METHODS: A transcriptomic profiling platform for TME classification based on functional gene signatures was applied to 14 publicly available PDAC datasets (n = 1657) and validated in a clinically annotated independent cohort of patients with PDAC (n = 79). Four distinct subtypes were identified using unsupervised clustering and assessed to evaluate predictive and prognostic utility. RESULTS: TME classification using transcriptomic profiling identified 4 biologically distinct subtypes based on their TME immune composition: immune enriched (IE); immune enriched, fibrotic (IE/F); fibrotic (F); and immune depleted (D). The IE and IE/F subtypes demonstrated a more favorable prognosis and potential for response to immunotherapy compared with the F and D subtypes. Most lung metastases and liver metastases were subtypes IE and D, respectively, indicating the role of clonal phenotype and immune milieu in developing personalized therapeutic strategies. In addition, distinct TMEs with potential therapeutic implications were identified in treatment-naive primary tumors compared with tumors that underwent neoadjuvant therapy. CONCLUSIONS: This novel approach defines a distinct subgroup of PADC patients that may benefit from immunotherapeutic strategies based on their TME subtype and provides a framework to select patients for prospective clinical trials investigating precision immunotherapy in PDAC. Further, the predictive utility and real-world clinical applicability espoused by this transcriptomic-based TME classification approach will accelerate the advancement of precision medicine in PDAC.


Subject(s)
Biomarkers, Tumor , Carcinoma, Pancreatic Ductal , Gene Expression Profiling , Pancreatic Neoplasms , Precision Medicine , Transcriptome , Tumor Microenvironment , Humans , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/immunology , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/therapy , Tumor Microenvironment/immunology , Tumor Microenvironment/genetics , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/immunology , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/therapy , Biomarkers, Tumor/genetics , Male , Female , Middle Aged , Aged , Gene Expression Regulation, Neoplastic , Immunotherapy/methods , Prognosis , Neoadjuvant Therapy , Liver Neoplasms/genetics , Liver Neoplasms/immunology , Liver Neoplasms/pathology , Liver Neoplasms/therapy , Predictive Value of Tests , Lung Neoplasms/genetics , Lung Neoplasms/immunology , Lung Neoplasms/pathology , Databases, Genetic
8.
Oral Oncol ; 149: 106688, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38219706

ABSTRACT

Head and neck squamous cell carcinoma (HNSCC) is a highly prevalent malignancy worldwide, with a significant proportion of patients developing recurrent and/or metastatic (R/M) disease. Despite recent advances in therapy, the prognosis for patients with advanced HNSCC remains poor. Here, we present the case of a patient with recurrent metastatic HNSCC harboring an HRAS G12S mutation who achieved a durable response to treatment with tipifarnib, a selective inhibitor of farnesyltransferase. The patient was a 48-year-old woman who had previously received multiple lines of therapy with no significant clinical response. However, treatment with tipifarnib resulted in a durable partial response that lasted 8 months. Serial genomic and transcriptomic analyses demonstrated upregulation of YAP1 and AXL in metastatic lesions compared with the primary tumor, the evolution of the tumor microenvironment from an immune-enriched to a fibrotic subtype with increased angiogenesis, and activation of the PI3K/AKT/mTOR pathway in tipifarnib treatment. Lastly, in HRAS-mutated PDXs and in the syngeneic HRAS model, we demonstrated that tipifarnib efficacy is limited by activation of the AKT pathway, and dual treatment with tipifarnib and the PI3K inhibitor, BYL719, resulted in enhanced anti-tumor efficacy. Our case study highlights the potential of targeting HRAS mutations with tipifarnib in R/M HNSCC and identifies potential mechanisms of acquired resistance to tipifarnib, along with immuno-, chemo-, and radiation therapy. Preclinical results provide a firm foundation for further investigation of drug combinations of HRAS-and PI3K -targeting therapeutics in R/M HRAS-driven HNSCC.


Subject(s)
Head and Neck Neoplasms , Proto-Oncogene Proteins c-akt , Quinolones , Female , Humans , Middle Aged , Squamous Cell Carcinoma of Head and Neck/drug therapy , Squamous Cell Carcinoma of Head and Neck/genetics , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Neoplasm Recurrence, Local/drug therapy , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/genetics , Cell Line, Tumor , Tumor Microenvironment , Proto-Oncogene Proteins p21(ras)/genetics
9.
Transl Res ; 263: 53-72, 2024 01.
Article in English | MEDLINE | ID: mdl-37678757

ABSTRACT

Neuropathic pain is caused by injury or disease of the somatosensory system, and its course is usually chronic. Several studies have been dedicated to investigating neuropathic pain-related targets; however, little attention has been paid to the persistent alterations that these targets, some of which may be crucial to the pathophysiology of neuropathic pain. The present study aimed to identify potential targets that may play a crucial role in neuropathic pain and validate their long-term impact. Through bioinformatics analysis of RNA sequencing results, we identified Slc9a1 and validated the reduced expression of sodium-hydrogen exchanger 1 (NHE1), the protein that Slc9a1 encodes, in the spinal nerve ligation (SNL) model. Colocalization analysis revealed that NHE1 is primarily co-localized with vesicular glutamate transporter 2-positive neurons. In vitro experiments confirmed that poly(lactic-co-glycolic acid) nanoparticles loaded with siRNA successfully inhibited NHE1 in SH-SY5Y cells, lowered intracellular pH, and increased intracellular calcium concentrations. In vivo experiments showed that sustained suppression of spinal NHE1 expression by siRNA-loaded nanoparticles resulted in delayed hyperalgesia in naïve and SNL model rats, whereas amiloride-induced transient suppression of NHE1 expression yielded no significant changes in pain sensitivity. We identified Slc9a1, which encodes NHE1, as a key gene in neuropathic pain. Utilizing the sustained release properties of nanoparticles enabled us to elucidate the chronic role of decreased NHE1 expression, establishing its significance in the mechanisms of neuropathic pain.


Subject(s)
Neuralgia , Neuroblastoma , Rats , Humans , Animals , Sodium-Hydrogen Exchanger 1/genetics , Sodium-Hydrogen Exchanger 1/metabolism , Polylactic Acid-Polyglycolic Acid Copolymer , Glycols , Delayed-Action Preparations , RNA, Small Interfering/genetics
10.
J Microbiol Biotechnol ; 34(3): 700-709, 2024 Mar 28.
Article in English | MEDLINE | ID: mdl-37919866

ABSTRACT

Polyhydroxybutyrate (PHB) production from lignocellulosic biomass is economically beneficial. Because lignocellulosic biomass is a mixture rich in glucose and xylose, Escherichia coli, which prefers glucose, needs to overcome glucose repression for efficient biosugar use. To avoid glucose repression, here, we overexpressed a xylose regulator (xylR) in an E. coli strain expressing bktB, phaB, and phaC from Cupriavidus necator and evaluated the effect of xylR on PHB production. XylR overexpression increased xylose consumption from 0% to 46.53% and produced 4.45-fold more PHB than the control strain without xylR in a 1% sugar mixture of glucose and xylose (1:1). When the xylR-overexpressed strain was applied to sugars from lignocellulosic biomass, cell growth and PHB production of the strain showed a 4.7-fold increase from the control strain, yielding 2.58 ± 0.02 g/l PHB and 4.43 ± 0.28 g/l dry cell weight in a 1% hydrolysate mixture. XylR overexpression increased the expression of xylose operon genes by up to 1.7-fold. Moreover, the effect of xylR was substantially different in various E. coli strains. Overall, the results showed the effect of xylR overexpression on PHB production in a non-native PHB producer and the possible application of xylR for xylose utilization in E. coli.


Subject(s)
Escherichia coli Proteins , Sugars , Sugars/metabolism , Escherichia coli/metabolism , Xylose/metabolism , Biomass , Polyhydroxybutyrates , Glucose/metabolism , Transcription Factors/genetics , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism
11.
Int J Biol Macromol ; 256(Pt 2): 128376, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38007029

ABSTRACT

As polyhydroxybutyrate (P(3HB)) was struggling with mechanical properties, efforts have been directed towards increasing mole fraction of 3-hydroxyhexanoate (3HHx) in P(3HB-co-3HHx) to improve the properties of polyhydroxyalkanoates (PHAs). Although genetic modification had significant results, there were several issues related to cell growth and PHA production by deletion of PHA synthetic genes. To find out easier strategy for high 3HHx mole fraction without gene deletion, Cupriavidus necator H16 containing phaC2Ra-phaACn-phaJ1Pa was examined with various oils resulting that coconut oil gave the highest 3HHx mole fraction. When fatty acid composition analysis with GC-MS was applied, coconut oil was found to have very different composition from other vegetable oil containing very high lauric acid (C12) content. To find out specific fatty acid affecting 3HHx fraction, different fatty acids from caproic acid (C6) to stearic acid (C18) was evaluated and the 3HHx mole fraction was increased to 26.5 ± 1.6 % using lauric acid. Moreover, the 3HHx mole fraction could be controlled from 9 % to 31.1 % by mixing bean oil and lauric acid with different ratios. Produced P(3HB-co-3HHx) exhibited higher molecular than P(3HB-co-3HHx) from phaB-deletion mutant. This study proposes another strategy to increase 3HHx mole fraction with easier way by modifying substrate composition without applying deletion tools.


Subject(s)
Cupriavidus necator , Polyhydroxyalkanoates , Polyhydroxybutyrates , Caproates/chemistry , 3-Hydroxybutyric Acid/chemistry , Cupriavidus necator/genetics , Coconut Oil , Hydroxybutyrates , Polyhydroxyalkanoates/chemistry , Lauric Acids
12.
Anal Biochem ; 685: 115390, 2024 01 15.
Article in English | MEDLINE | ID: mdl-37951454

ABSTRACT

To alleviate environmental problems caused by using conventional plastics, bioplastics have garnered significant interest as alternatives to petroleum-based plastics. Despite possessing better degradability traits compared to traditional plastics, the degradation of bioplastics still demands a longer duration than initially anticipated. This necessitates the utilization of degradation strains or enzymes to enhance degradation efficiency, ensuring timely degradation. In this study, a novel screening method to identify bioplastic degraders faster was suggested to circumvent the time-consuming and laborious characteristics of solid-based plate assays. This liquid-based colorimetric method confirmed the extracellular esterase activity with p-nitrophenyl esters. It eliminated the needs to prepare plastic emulsion plates at the initial screening system, shortening the time for the overall screening process and providing more quantitative data. p-nitrophenyl hexanoate (C6) was considered the best substrate among the various p-nitrophenyl esters as substrates. The screening was performed in liquid-based 96-well plates, resulting in the discovery of a novel strain, Bacillus sp. SH09, with a similarity of 97.4% with Bacillus licheniformis. Furthermore, clear zone assays, degradation investigations, scanning electron microscopy, and gel permeation chromatography were conducted to characterize the biodegradation capabilities of the new strain, the liquid-based approach offered a swift and less labor-intensive option during the initial stages.


Subject(s)
Esterases , Plastics , Plastics/chemistry , Esterases/chemistry , High-Throughput Screening Assays , Colorimetry , Biopolymers
13.
Nature ; 623(7985): 157-166, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37853118

ABSTRACT

Immunotherapy failures can result from the highly suppressive tumour microenvironment that characterizes aggressive forms of cancer such as recurrent glioblastoma (rGBM)1,2. Here we report the results of a first-in-human phase I trial in 41 patients with rGBM who were injected with CAN-3110-an oncolytic herpes virus (oHSV)3. In contrast to other clinical oHSVs, CAN-3110 retains the viral neurovirulence ICP34.5 gene transcribed by a nestin promoter; nestin is overexpressed in GBM and other invasive tumours, but not in the adult brain or healthy differentiated tissue4. These modifications confer CAN-3110 with preferential tumour replication. No dose-limiting toxicities were encountered. Positive HSV1 serology was significantly associated with both improved survival and clearance of CAN-3110 from injected tumours. Survival after treatment, particularly in individuals seropositive for HSV1, was significantly associated with (1) changes in tumour/PBMC T cell counts and clonal diversity, (2) peripheral expansion/contraction of specific T cell clonotypes; and (3) tumour transcriptomic signatures of immune activation. These results provide human validation that intralesional oHSV treatment enhances anticancer immune responses even in immunosuppressive tumour microenvironments, particularly in individuals with cognate serology to the injected virus. This provides a biological rationale for use of this oncolytic modality in cancers that are otherwise unresponsive to immunotherapy (ClinicalTrials.gov: NCT03152318 ).


Subject(s)
Brain Neoplasms , Glioblastoma , Herpesvirus 1, Human , Oncolytic Virotherapy , Oncolytic Viruses , Humans , Brain Neoplasms/immunology , Brain Neoplasms/pathology , Glioblastoma/immunology , Glioblastoma/pathology , Nestin/genetics , Oncolytic Virotherapy/adverse effects , Oncolytic Viruses/genetics , Oncolytic Viruses/immunology , Oncolytic Viruses/physiology , Reproducibility of Results , Survival Analysis , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Treatment Outcome , Tumor Microenvironment/immunology , Herpesvirus 1, Human/genetics , Herpesvirus 1, Human/immunology , Herpesvirus 1, Human/physiology
14.
Blood ; 142(26): 2282-2295, 2023 12 28.
Article in English | MEDLINE | ID: mdl-37774374

ABSTRACT

ABSTRACT: The spatial anatomy of hematopoiesis in the bone marrow (BM) has been extensively studied in mice and other preclinical models, but technical challenges have precluded a commensurate exploration in humans. Institutional pathology archives contain thousands of paraffinized BM core biopsy tissue specimens, providing a rich resource for studying the intact human BM topography in a variety of physiologic states. Thus, we developed an end-to-end pipeline involving multiparameter whole tissue staining, in situ imaging at single-cell resolution, and artificial intelligence-based digital whole slide image analysis and then applied it to a cohort of disease-free samples to survey alterations in the hematopoietic topography associated with aging. Our data indicate heterogeneity in marrow adipose tissue (MAT) content within each age group and an inverse correlation between MAT content and proportions of early myeloid and erythroid precursors, irrespective of age. We identify consistent endosteal and perivascular positioning of hematopoietic stem and progenitor cells (HSPCs) with medullary localization of more differentiated elements and, importantly, uncover new evidence of aging-associated changes in cellular and vascular morphologies, microarchitectural alterations suggestive of foci with increased lymphocytes, and diminution of a potentially active megakaryocytic niche. Overall, our findings suggest that there is topographic remodeling of human hematopoiesis associated with aging. More generally, we demonstrate the potential to deeply unravel the spatial biology of normal and pathologic human BM states using intact archival tissue specimens.


Subject(s)
Artificial Intelligence , Hematopoietic Stem Cells , Humans , Mice , Animals , Hematopoietic Stem Cells/pathology , Bone Marrow/pathology , Hematopoiesis/physiology , Aging
15.
Microb Cell Fact ; 22(1): 184, 2023 Sep 15.
Article in English | MEDLINE | ID: mdl-37715205

ABSTRACT

BACKGROUND: Bioplastics are attracting considerable attention, owing to the increase in non-degradable waste. Using microorganisms to degrade bioplastics is a promising strategy for reducing non-degradable plastic waste. However, maintaining bacterial viability and activity during culture and storage remains challenging. With the use of conventional methods, cell viability and activity was lost; therefore, these conditions need to be optimized for the practical application of microorganisms in bioplastic degradation. Therefore, we aimed to optimize the feasibility of the lyophilization method for convenient storage and direct use. In addition, we incoporated protective reagents to increase the viability and activity of lyophilized microorganisms. By selecting and applying the best protective reagents for the lyophilization process and the effects of additives on the growth and PHB-degrading activity of strains were analyzed after lyophilization. For developing the lyophilization method for protecting degradation activity, it may promote practical applications of bioplastic-degrading bacteria. RESULTS: In this study, the polyhydroxybutyrate (PHB)-degrading strain, Bacillus sp. JY14 was lyophilized with the use of various sugars as protective reagents. Among the carbon sources tested, raffinose was associated with the highest cell survival rate (12.1%). Moreover, 7% of raffionose showed the highest PHB degradation yield (92.1%). Therefore, raffinose was selected as the most effective protective reagent. Also, bacterial activity was successfully maintained, with raffinose, under different storage temperatures and period. CONCLUSIONS: This study highlights lyophilization as an efficient microorganism storage method to enhance the applicability of bioplastic-degrading bacterial strains. The approach developed herein can be further studied and used to promote the application of microorganisms in bioplastic degradation.


Subject(s)
Bacillus , Raffinose , Carbon , Freeze Drying
16.
Enzyme Microb Technol ; 170: 110305, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37595400

ABSTRACT

One of the key intermediates, 5-hydroxyvaleric acid (5-HV), is used in the synthesis of polyhydroxyalkanoate monomer, δ-valerolactone, 1,5-pentanediol (1,5-PDO), and many other substances. Due to global environmental problems, eco-friendly bio-based synthesis of various platform chemicals and key intermediates are socially required, but few previous studies on 5-HV biosynthesis have been conducted. To establish a sustainable bioprocess for 5-HV production, we introduced gabT encoding 4-aminobutyrate aminotransferase and yqhD encoding alcohol dehydrogenase to produce 5-HV from 5-aminovaleric acid (5-AVA), through glutarate semialdehyde in Escherichia coli whole-cell reaction. As, high reducing power is required to produce high concentrations of 5-HV, we newly introduced glucose dehydrogenase (GDH) for NADPH regeneration system from Bacillus subtilis 168. By applying GDH with D-glucose and optimizing the parameters, 5-HV conversion rate from 5-AVA increased from 47% (w/o GDH) to 82% when using 200 mM (23.4 g/L) of 5-AVA. Also, it reached 56% conversion in 2 h, showing 56 mM/h (6.547 g/L/h) productivity from 200 mM 5-AVA, finally reaching 350 mM (41 g/L) and 14.6 mM/h (1.708 g/L/h) productivity at 24 h when 1 M (117.15 g/L) 5-AVA was used. When the whole-cell system with GDH was expanded to produce 1,5-PDO, its production was also increased 5-fold. Considering that 5-HV and 1,5-PDO production depends heavily on the reducing power of the cells, we successfully achieved a significant increase in 5-HV and 1,5-PDO production using GDH.


Subject(s)
Escherichia coli , Industrial Microbiology , Valerates , Valerates/chemical synthesis , Escherichia coli/genetics , Escherichia coli/metabolism , Transaminases/genetics , Alcohol Dehydrogenase/genetics , NADP/metabolism , Biotransformation
17.
Int J Biol Macromol ; 250: 126152, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37558031

ABSTRACT

The production cost of biodegradable polymer like polyhydroxybutyrate (PHB) is still higher than that of petroleum-based plastics. A potential solution for reducing its production cost is using a cheap carbon source and avoiding a process of sterilization. In this study, a novel PHB-producing microbial strain, Priestia sp. YH4 was screened from the marine environment using sugarcane molasses as the carbon source without sterilization. Culture conditions, such as carbon, NaCl, temperature, pH, inoculum size, and cultivation time, were optimized for obtaining the highest PHB production by YH4 resulting in 5.94 g/L of dry cell weight (DCW) and 61.7 % of PHB content in the 5 mL culture. In addition, it showed similar PHB production between the cultures with or without sterilization in Marine Broth media. When cultured using only tap water, sugarcane molasses, and NaCl in a 5 L fermenter, 24.8 g/L DCW was produced at 41 h yielding 13.9 g/L PHB. Finally, DSC (Differential Scanning Calorimetry) and GPC (Gel Permeation Chromatography) were used to analyze thermal properties and molecular weights resulting in Tm = 167.2 °C, Tc = 67.3 °C, Mw = 2.85 × 105, Mn = 1.05 × 105, and PDI = 2.7, respectively. Therefore, we showed the feasibility of more economical process for PHB production by finding novel strain, utilizing molasses with minimal media components and avoiding sterilization.

19.
Bioresour Technol ; 384: 129290, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37290712

ABSTRACT

Macroalgae (seaweed) is considered a favorable feedstock for polyhydroxyalkanoates (PHAs) production owing to its high productivity, low land and freshwater requirement, and renewable nature. Among different microbes Halomonas sp. YLGW01 can utilize algal biomass-derived sugars (galactose and glucose) for growth and PHAs production. Biomass-derived byproducts furfural, hydroxymethylfurfural (HMF), and acetate affects Halomonas sp. YLGW01 growth and poly(3-hydroxybutyrate) (PHB) production i.e., furfural > HMF > acetate. Eucheuma spinosum biomass-derived biochar was able to remove 87.9 % of phenolic compounds from its hydrolysate without affecting sugar concentration. Halomonas sp. YLGW01 grows and accumulates a high amount of PHB at 4 % NaCl. The use of detoxified unsterilized media resulted in high biomass (6.32 ± 0.16 g cdm/L) and PHB production (3.88 ± 0.04 g/L) compared to undetoxified media (3.97 ± 0.24 g cdm/L, 2.58 ± 0.1 g/L). The finding suggests that Halomonas sp. YLGW01 has the potential to valorize macroalgal biomass into PHAs and open a new avenue for renewable bioplastic production.


Subject(s)
Halomonas , Polyhydroxyalkanoates , Seaweed , Sugars , Furaldehyde
20.
Enzyme Microb Technol ; 168: 110244, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37196383

ABSTRACT

In the dark fermentation of hydrogen, development of production host is crucial as bacteria act on substrates and produce hydrogen. The present study aimed to improve hydrogen production through the development of Clostridium acetobutylicum as a superior biohydrogen producer. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which produces NADH/NADPH for metabolites and energy in primary pathways, was introduced to enhance hydrogen production. The strain CAC824-G containing gapC that encodes GAPDH showed a 66.3 % higher hydrogen production than the wild-type strain, with increased NADH and NADPH pools. Glucose consumption and other byproducts, such as acetone, butanol, and ethanol, were also high in CAC824-G. Overexpression of gapC resulted in increased hydrogen production with sugars obtained from different biomass, even in the presence of inhibitors such as vanillin, 5-hydroxymethylfufural, acetic acid, and formic acid. Our results imply that overexpression of gapC in Clostridium is possible to expand the production of the reported biochemicals to produce hydrogen.


Subject(s)
Clostridium acetobutylicum , Clostridium acetobutylicum/genetics , Clostridium acetobutylicum/metabolism , NADP/metabolism , NAD/metabolism , Butanols/metabolism , Fermentation , Hydrogen/metabolism
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