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FEMS Yeast Research Jan 2024Pretreatment of lignocellulose yields a complex sugar mixture that potentially can be converted into bioethanol and other chemicals by engineered yeast. One approach to...
Pretreatment of lignocellulose yields a complex sugar mixture that potentially can be converted into bioethanol and other chemicals by engineered yeast. One approach to overcome competition between sugars for uptake and metabolism is the use of a consortium of specialist strains capable of efficient conversion of single sugars. Here, we show that maltose inhibits cell growth of a xylose-fermenting specialist strain IMX730.1 that is unable to utilize glucose because of the deletion of all hexokinase genes. The growth inhibition cannot be attributed to a competition between maltose and xylose for uptake. The inhibition is enhanced in a strain lacking maltase enzymes (dMalX2) and completely eliminated when all maltose transporters are deleted. High-level accumulation of maltose in the dMalX2 strain is accompanied by a hypotonic-like transcriptional response, while cells are rescued from maltose-induced cell death by the inclusion of an extracellular osmolyte such as sorbitol. These data suggest that maltose-induced cell death is due to high levels of maltose uptake causing hypotonic-like stress conditions and can be prevented through engineering of the maltose transporters. Transporter engineering should be included in the development of stable microbial consortia for the efficient conversion of lignocellulosic feedstocks.
Topics: Saccharomyces cerevisiae; Maltose; Microbial Viability; Gene Deletion; Sorbitol; Xylose; Monosaccharide Transport Proteins; Saccharomyces cerevisiae Proteins; Glucose
PubMed: 38565313
DOI: 10.1093/femsyr/foae012 -
BioRxiv : the Preprint Server For... Mar 2024Interspecies hybridization is prevalent in various eukaryotic lineages and plays important roles in phenotypic diversification, adaption, and speciation. To better...
Interspecies hybridization is prevalent in various eukaryotic lineages and plays important roles in phenotypic diversification, adaption, and speciation. To better understand the changes that occurred in the different subgenomes of a hybrid species and how they facilitated adaptation, we completed chromosome-level assemblies of all 16 pairs chromosomes for a recently formed hybrid yeast, strain CBS380 (IFO11022), using Nanopore MinION long-read sequencing. Characterization of subgenomes and comparative analysis with the genomes of its parent species, and provide several new insights into understanding genome evolution after a relatively recent hybridization. For instance, multiple recombination events between the two subgenomes have been observed in each chromosome, followed by loss of heterozygosity (LOH) in most chromosomes in nine chromosome pairs. In addition to maintaining nearly all gene content and synteny from its parental genomes, has acquired many genes from other yeast species, primarily through the introgression of , such as those involved in the maltose metabolism. In addition, the patterns of recombination and LOH suggest an allotetraploid origin of . The gene acquisition and rapid LOH in the hybrid genome probably facilitated its adaption to maltose brewing environments and mitigated the maladaptive effect of hybridization.
PubMed: 38562692
DOI: 10.1101/2024.03.17.585453 -
Animals : An Open Access Journal From... Mar 2024Biological invasion is a primary direct driver of biodiversity loss. Recently, owing to exploitation competition with an invasive mussel, (Hanley, 1843), there has been...
Biological invasion is a primary direct driver of biodiversity loss. Recently, owing to exploitation competition with an invasive mussel, (Hanley, 1843), there has been a drastic decrease in the population of native (Linnaeus, 1758) in several western Pacific regions. In the present study, intestinal microbiota, metabolome, and key digestive enzyme activities were compared between the two competing mussels, and , to elucidate the differences in intestinal microbiota and metabolic points. We observed that , , and were the three predominant bacterial phyla in the two species. The relative abundance of related to carbohydrate-degrading ability was significantly higher in than in . Compared to , different metabolites including maltose and trehalose were enriched in . Lastly, higher carbohydrases activities of alpha-amylase, cellulase, and xylanase were observed in than in . These differences might play an important role in the adaptation process of to the new environment. This study provides important basic knowledge for investigating the competition between and in terms of food resources utilization.
PubMed: 38540015
DOI: 10.3390/ani14060918 -
Biochimica Et Biophysica Acta.... Apr 2024S. cerevisiae (or budding yeast) is an important micro-organism for sucrose-based fermentation in biotechnology. Yet, it is largely unknown how budding yeast adapts to...
S. cerevisiae (or budding yeast) is an important micro-organism for sucrose-based fermentation in biotechnology. Yet, it is largely unknown how budding yeast adapts to sucrose transitions. Sucrose can only be metabolized when the invertase or the maltose machinery are expressed and we propose that the Gpr1p receptor signals extracellular sucrose availability via the cAMP peak to adapt cells accordingly. A transition to sucrose or glucose gave a transient cAMP peak which was maximally induced for sucrose. When transitioned to sucrose, cAMP signalling mutants showed an impaired cAMP peak together with a lower growth rate, a longer lag phase and a higher final OD compared to a glucose transition. These effects were not caused by altered activity or expression of enzymes involved in sucrose metabolism and imply a more general metabolic adaptation defect. Basal cAMP levels were comparable among the mutant strains, suggesting that the transient cAMP peak is required to adapt cells correctly to sucrose. We propose that the short-term dynamics of the cAMP signalling cascade detects long-term extracellular sucrose availability and speculate that its function is to maintain a fermentative phenotype at continuously low glucose and fructose concentrations.
Topics: Saccharomyces cerevisiae; Saccharomycetales; Saccharomyces cerevisiae Proteins; Glucose; Sucrose
PubMed: 38521467
DOI: 10.1016/j.bbamcr.2024.119706 -
Poultry Science May 2024Eggs, as a crucial source of essential nutrients for consumers, possess a high nutritional value owing to their rich composition of vital components essential for human... (Comparative Study)
Comparative Study
Eggs, as a crucial source of essential nutrients for consumers, possess a high nutritional value owing to their rich composition of vital components essential for human health. While previous research has extensively investigated genetic factors influencing egg quality, there has been a limited focus on exploring the impact of specific strains, particularly within the African context, on the polar metabolite profile of eggs. In this extensive study, we conducted an untargeted analysis of the chemical composition of both albumen and yolk from 3 distinct strains of hens-Blue Holland, Sasso, and Wassache-raised under identical feeding conditions. Utilizing gas chromatography coupled with mass spectrometry (GC-MS), we meticulously examined amino acids, carbohydrates, fatty acids, and other small polar metabolites. In total, 38 and 44 metabolites were identified in the whites and yolk, respectively, of the 3 studied strains. The application of chemometric analysis revealed notable differences in metabolite profiles with 8 relevant metabolites in each egg part. These metabolites include amino acids (N-α-Acetyl-L-lysine, lysine, L-valine, L-Tryptophan), fatty acids (oleic acid, linoleic acid, palmitic acid and stearic acid), and carbohydrates (d-glucose, maltose, lactose). These findings shed light on strain-specific metabolic nuances within eggs, emphasizing potential nutritional implications. The ensuing discussion delves into the diverse metabolic pathways influenced by the identified metabolites, offering insights that contribute to a broader understanding of egg composition and its significance in tailoring nutritional strategies for diverse populations.
Topics: Animals; Chickens; Gas Chromatography-Mass Spectrometry; Metabolomics; Eggs; Metabolome; Egg Yolk; Female; Fatty Acids; Amino Acids; Ovum
PubMed: 38503138
DOI: 10.1016/j.psj.2024.103616 -
Research Square Mar 2024Patients with COVID-19 under invasive mechanical ventilation are at higher risk of developing ventilator-associated pneumonia (VAP), associated with increased healthcare...
BACKGROUND
Patients with COVID-19 under invasive mechanical ventilation are at higher risk of developing ventilator-associated pneumonia (VAP), associated with increased healthcare costs, and unfavorable prognosis. The underlying mechanisms of this phenomenon have not been thoroughly dissected. Therefore, this study attempted to bridge this gap by performing a lung microbiota analysis and evaluating the host immune responses that could drive the development of VAP.
MATERIALS AND METHODS
In this prospective cohort study, mechanically ventilated patients with confirmed SARS-CoV-2 infection were enrolled. Nasal swabs (NS), endotracheal aspirates (ETA), and blood samples were collected initially within 12 hours of intubation and again at 72 hours post-intubation. Plasma samples underwent cytokine and metabolomic analyses, while NS and ETA samples were sequenced for lung microbiome examination. The cohort was categorized based on the development of VAP. Data analysis was conducted using RStudio version 4.3.1.
RESULTS
In a study of 36 COVID-19 patients on mechanical ventilation, significant differences were found in the nasal and pulmonary microbiome, notably in and , linked to VAP. Patients with VAP showed a higher SARS-CoV-2 viral load, elevated neutralizing antibodies, and reduced inflammatory cytokines, including IFN-δ, IL-1β, IL-12p70, IL-18, IL-6, TNF-α, and CCL4. Metabolomic analysis revealed changes in 22 metabolites in non-VAP patients and 27 in VAP patients, highlighting D-Maltose-Lactose, Histidinyl-Glycine, and various phosphatidylcholines, indicating a metabolic predisposition to VAP.
CONCLUSIONS
This study reveals a critical link between respiratory microbiome alterations and ventilator-associated pneumonia in COVID-19 patients, with elevated SARS-CoV-2 levels and metabolic changes, providing novel insights into the underlying mechanisms of VAP with potential management and prevention implications.
PubMed: 38496464
DOI: 10.21203/rs.3.rs-3952944/v1 -
BMC Plant Biology Mar 2024Chalkiness is a common phenotype induced by various reasons, such as abiotic stress or the imbalance of starch synthesis and metabolism during the development period....
BACKGROUND
Chalkiness is a common phenotype induced by various reasons, such as abiotic stress or the imbalance of starch synthesis and metabolism during the development period. However, the reason mainly for one gene losing its function such as NAC (TFs has a large family in rice) which may cause premature is rarely known to us.
RESULTS
The Ko-Osnac02 mutant demonstrated an obviously early maturation stage compared to the wild type (WT) with 15 days earlier. The result showed that the mature endosperm of Ko-Osnac02 mutant exhibited chalkiness, characterized by white-core and white-belly in mature endosperm. As grain filling rate is a crucial factor in determining the yield and quality of rice (Oryza sativa, ssp. japonica), it's significant that mutant has a lower amylose content (AC) and higher soluble sugar content in the mature endosperm. Interestingly among the top DEGs in the RNA sequencing of N2 (3DAP) and WT seeds revealed that the OsBAM2 (LOC_Os10g32810) expressed significantly high in N2 mutant, which involved in Maltose up-regulated by the starch degradation. As Prediction of Protein interaction showed in the chalky endosperm formation in N2 seeds (3 DAP), seven genes were expressed at a lower-level which should be verified by a heatmap diagrams based on DEGs of N2 versus WT. The Tubulin genes controlling cell cycle are downregulated together with the MCM family genes MCM4 ( ↓), MCM7 ( ↑), which may cause white-core in the early endosperm development. In conclusion, the developing period drastically decreased in the Ko-Osnac02 mutants, which might cause the chalkiness in seeds during the early endosperm development.
CONCLUSIONS
The gene OsNAC02 which controls a great genetic co-network for cell cycle regulation in early development, and KO-Osnac02 mutant shows prematurity and white-core in endosperm.
Topics: Endosperm; Starch; Seeds; Edible Grain; Homeostasis; Oryza; Gene Expression Regulation, Plant
PubMed: 38494545
DOI: 10.1186/s12870-024-04845-8 -
ACS Infectious Diseases Apr 2024Tuberculosis (TB), caused by (Mtb), is the leading cause of death worldwide by infectious disease. Treatment of Mtb infection requires a six-month course of multiple...
Tuberculosis (TB), caused by (Mtb), is the leading cause of death worldwide by infectious disease. Treatment of Mtb infection requires a six-month course of multiple antibiotics, an extremely challenging regimen necessitated by Mtb's ability to form drug-tolerant persister cells. Mtb persister formation is dependent on the trehalose catalytic shift, a stress-responsive metabolic remodeling mechanism in which the disaccharide trehalose is liberated from cell surface glycolipids and repurposed as an internal carbon source to meet energy and redox demands. Here, using a biofilm-persister model, metabolomics, and cryo-electron microscopy (EM), we found that azidodeoxy- and aminodeoxy-d-trehalose analogues block the Mtb trehalose catalytic shift through inhibition of trehalose synthase TreS (Rv0126), which catalyzes the isomerization of trehalose to maltose. Out of a focused eight-member compound panel constructed by chemoenzymatic synthesis, the natural product 2-trehalosamine exhibited the highest potency and significantly potentiated first- and second-line TB drugs in broth culture and macrophage infection assays. We also report the first structure of TreS bound to a substrate analogue inhibitor, obtained via cryo-EM, which revealed conformational changes likely essential for catalysis and inhibitor binding that can potentially be exploited for future therapeutic development. Our results demonstrate that inhibition of the trehalose catalytic shift is a viable strategy to target Mtb persisters and advance trehalose analogues as tools and potential adjunctive therapeutics for investigating and targeting mycobacterial persistence.
Topics: Humans; Mycobacterium tuberculosis; Trehalose; Cryoelectron Microscopy; Tuberculosis; Catalysis
PubMed: 38485491
DOI: 10.1021/acsinfecdis.4c00138 -
STAR Protocols Jun 2024Polyphosphate exhibits a unique post-translational modification-like function, known as histidine polyphosphate modification (HPM), marked by a robust non-covalent...
Polyphosphate exhibits a unique post-translational modification-like function, known as histidine polyphosphate modification (HPM), marked by a robust non-covalent interaction with histidine repeat proteins. Here, we present a protocol for detecting HPM of human proteins via maltose-binding protein-tagged expression in E. coli. We describe steps for detecting HPM by observing electrophoretic mobility shifts on NuPAGE gels followed by western blot. We then detail procedures for analyzing the influence of ionic strength and pH on HPM. For complete details on the use and execution of this protocol, please refer to Neville et al..
Topics: Escherichia coli; Humans; Polyphosphates; Maltose-Binding Proteins; Histidine; Protein Processing, Post-Translational; Blotting, Western
PubMed: 38470910
DOI: 10.1016/j.xpro.2024.102947 -
Veterinary Research Forum : An... 2024The non-structural protein (nsp) 8 of the porcine epidemic diarrhea virus (PEDV) is highly stable across different PEDV strains and plays an important role in PEDV...
The non-structural protein (nsp) 8 of the porcine epidemic diarrhea virus (PEDV) is highly stable across different PEDV strains and plays an important role in PEDV virulence. In current study, nsp8 prokaryotic expression vectors were constructed based on parental vectors pMAL-c2x-maltose binding protein (MBP) and pET-28a (+). Subsequently, the optimization of expression conditions in , including induced temperature, time and isopropyl β-D-thiogalactopyranoside concentration were performed to obtain a stable expression of MBP-nsp8 and nsp8. The nsp8 fused with MBP increased the water solubility of the expressed products. Target proteins were further purified from culture and their immunogenicities were evaluated by mice. The antibody titers of serum from nsp8 immunized mice were up to 1:7,750,000 when measured by indirect enzyme-linked immunosorbent assay; meanwhile, the mice immunized with MBP-nsp8 gave an antibody titer reaching 1:1,000,000. In all, the expression and purification system of PEDV nsp8 and MBP-nsp8 were successfully established in this work and a strong immune response was elicited in mice by both purified nsp8 and MBP-nsp8, providing a basis for the study of the structure and function of PEDV nsp8.
PubMed: 38465319
DOI: 10.30466/vrf.2023.2009322.3977