-
Journal of Innate Immunity 2023Epigenetic reprogramming of innate immune cells by β-glucan in a process called trained immunity leads to an enhanced host response to a secondary infection. β-Glucans...
Epigenetic reprogramming of innate immune cells by β-glucan in a process called trained immunity leads to an enhanced host response to a secondary infection. β-Glucans are structural components of plants, algae, fungi, and bacteria and thus recognized as non-self by human macrophages. We selected the β-glucan curdlan from Alcaligenes faecalis, WGP dispersible from Saccharomyces cerevisiae, and β-glucan-rich culture supernatant of Alternaria and investigated whether they could produce trained immunity effects leading to an increased control of virulent Mycobacterium tuberculosis. We observed a significant M. tuberculosis growth reduction in macrophages trained with curdlan and Alternaria, which also correlated with increased IL-6 and IL-1β release. WGP dispersible-trained macrophages were stratified into "non-responders" and "responders," according to their ability to control M. tuberculosis, with "responders" producing higher IL-6 levels. The addition of neutrophils to infected macrophage cultures further enhanced macrophage control of virulent M. tuberculosis, but not in a stimuli-dependent manner. Pathway enrichment analysis of DNA methylome data also highlighted hypomethylation of genes in pathways associated with signaling and cellular reorganization and motility, and "responders" to WGP training were enriched in the interferon-gamma signaling pathway. This study adds evidence that certain β-glucans show promise as immune-training agents.
Topics: Humans; Pilot Projects; Interleukin-6; Macrophages; beta-Glucans; Immunity, Innate; Mycobacterium tuberculosis; Saccharomyces cerevisiae; Tuberculosis
PubMed: 37734337
DOI: 10.1159/000533873 -
Scientific Reports Nov 2021Alcaligenes faecalis is a heterotrophic nitrifying bacterium that oxidizes ammonia and generates nitrite and nitrate. When A. faecalis was cultivated in a medium...
Alcaligenes faecalis is a heterotrophic nitrifying bacterium that oxidizes ammonia and generates nitrite and nitrate. When A. faecalis was cultivated in a medium containing pyruvate and ammonia as the sole carbon and nitrogen sources, respectively, high concentrations of nitrite accumulated in the medium whose carbon/nitrogen (C/N) ratio was lower than 10 during the exponential growth phase, while the accumulation was not observed in the medium whose C/N ratio was higher than 15. Comparative transcriptome analysis was performed using nitrifying and non-nitrifying cells of A. faecalis cultivated in media whose C/N ratios were 5 and 20, respectively, to evaluate the fluctuations of gene expression during induction of heterotrophic nitrification. Expression levels of genes involved in primary metabolism did not change significantly in the cells at the exponential growth phase under both conditions. We observed a significant increase in the expression levels of four gene clusters: pod cluster containing the gene encoding pyruvic oxime dioxygenase (POD), podh cluster containing the gene encoding a POD homolog (PODh), suf cluster involved in an iron-sulfur cluster biogenesis, and dnf cluster involved in a novel hydroxylamine oxidation pathway in the nitrifying cells. Our results provide valuable insight into the biochemical mechanism of heterotrophic nitrification.
Topics: Alcaligenes faecalis; Ammonia; Cluster Analysis; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Heterotrophic Processes; Hydroxylamine; Multigene Family; Nitrates; Nitrification; Nitrites; Nitrogen; Propionates; Transcriptome
PubMed: 34845321
DOI: 10.1038/s41598-021-02579-3 -
Science Advances Jun 2024Chronic wounds are a common and costly complication of diabetes, where multifactorial defects contribute to dysregulated skin repair, inflammation, tissue damage, and...
Chronic wounds are a common and costly complication of diabetes, where multifactorial defects contribute to dysregulated skin repair, inflammation, tissue damage, and infection. We previously showed that aspects of the diabetic foot ulcer microbiota were correlated with poor healing outcomes, but many microbial species recovered remain uninvestigated with respect to wound healing. Here, we focused on , a Gram-negative bacterium that is frequently recovered from chronic wounds but rarely causes infection. Treatment of diabetic wounds with accelerated healing during early stages. We investigated the underlying mechanisms and found that treatment promotes reepithelialization of diabetic keratinocytes, a process that is necessary for healing but deficient in chronic wounds. Overexpression of matrix metalloproteinases in diabetes contributes to failed epithelialization, and we found that treatment balances this overexpression to allow proper healing. This work uncovers a mechanism of bacterial-driven wound repair and provides a foundation for the development of microbiota-based wound interventions.
Topics: Alcaligenes faecalis; Wound Healing; Animals; Keratinocytes; Humans; Matrix Metalloproteinases; Diabetic Foot; Mice; Re-Epithelialization; Male
PubMed: 38924411
DOI: 10.1126/sciadv.adj2020 -
Frontiers in Microbiology 2019Controlling aflatoxigenic and aflatoxins (AFs) in grains and food during storage is a great challenge to humans worldwide. N1-4 isolated from tea rhizosphere soil can...
Controlling aflatoxigenic and aflatoxins (AFs) in grains and food during storage is a great challenge to humans worldwide. N1-4 isolated from tea rhizosphere soil can produce abundant antifungal volatiles, and greatly inhibited the growth of in un-contacted face-to-face dual culture testing. Gas chromatography tandem mass spectrometry revealed that dimethyl disulfide (DMDS) and methyl isovalerate (MI) were two abundant compounds in the volatile profiles of N1-4. DMDS was found to have the highest relative abundance (69.90%, to the total peak area) in N1-4, which prevented the conidia germination and mycelial growth of at 50 and 100 μL/L, respectively. The effective concentration for MI against is 200 μL/L. Additionally, Real-time quantitative PCR analysis proved that the expression of 12 important genes in aflatoxin biosynthesis pathway was reduced by these volatiles, and eight genes were down regulated by 4.39 to 32.25-folds compared to control treatment with significant differences. And the infection and AFs contamination in groundnut, maize, rice and soybean of high water activity were completely inhibited by volatiles from N1-4 in storage. Scanning electron microscope further proved that conidia inoculated on peanuts surface were severely damaged by volatiles from N1-4. Furthermore, strain N1-4 showed broad and antifungal activity to other six important plant pathogens including , and Thus, N1-4 and volatile DMDS and MI may have potential to be used as biocontrol agents to control and AFs during storage.
PubMed: 31293550
DOI: 10.3389/fmicb.2019.01419 -
Bioprocess and Biosystems Engineering Oct 2021A new heterotrophic nitrifying bacterium was isolated from the compost of swine manure and rice husk and identified as Alcaligenes faecalis SDU20. Strain SDU20 had...
A new heterotrophic nitrifying bacterium was isolated from the compost of swine manure and rice husk and identified as Alcaligenes faecalis SDU20. Strain SDU20 had heterotrophic nitrification potential and could remove 99.7% of the initial NH-N. Nitrogen balance analysis revealed that 15.9 and 12.3% of the NH-N were converted into biological nitrogen and nitrate nitrogen, respectively. The remaining 71.44% could be converted into N or NO. Single-factor experiments showed that the optimal conditions for ammonium removal were the carbon source of sodium succinate, C/N ratio 10, initial pH 8.0, and temperature 30 °C. Nitrification genes were determined to be upregulated when sodium succinate was used as the carbon source analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Strain SDU20 could tolerate 4% salinity and show resistance to some heavy metal ions. Strain SDU20 removed 72.6% high concentrated NH-N of 2000 mg/L within 216 h. In a batch experiment, the highest NH-N removal efficiency of 98.7% and COD removal efficiency of 93.7% were obtained in the treatment of unsterilized swine wastewater. Strain SDU20 is promising in high-ammonium wastewater treatment.
Topics: Alcaligenes faecalis; Ammonium Compounds; Animals; Gene Expression; Genes, Bacterial; Hydrogen-Ion Concentration; Manure; Metals, Heavy; Nitrification; Phylogeny; Real-Time Polymerase Chain Reaction; Salinity; Swine; Temperature; Wastewater; Water Purification
PubMed: 33978835
DOI: 10.1007/s00449-021-02581-z -
Angewandte Chemie (International Ed. in... Apr 2021Alcaligenes faecalis is the predominant Gram-negative bacterium inhabiting gut-associated lymphoid tissues, Peyer's patches. We previously reported that an A. faecalis...
Alcaligenes faecalis is the predominant Gram-negative bacterium inhabiting gut-associated lymphoid tissues, Peyer's patches. We previously reported that an A. faecalis lipopolysaccharide (LPS) acted as a weak agonist for Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD-2) receptor as well as a potent inducer of IgA without excessive inflammation, thus suggesting that A. faecalis LPS might be used as a safe adjuvant. In this study, we characterized the structure of both the lipooligosaccharide (LOS) and LPS from A. faecalis. We synthesized three lipid A molecules with different degrees of acylation by an efficient route involving the simultaneous introduction of 1- and 4'-phosphates. Hexaacylated A. faecalis lipid A showed moderate agonistic activity towards TLR4-mediated signaling and the ability to elicit a discrete interleukin-6 release in human cell lines and mice. It was thus found to be the active principle of the LOS/LPS and a promising vaccine adjuvant candidate.
Topics: Alcaligenes faecalis; Animals; Carbohydrate Conformation; Cell Line; Humans; Interleukin-6; Lipid A; Lipopolysaccharides; Mice; Toll-Like Receptor 4
PubMed: 33522128
DOI: 10.1002/anie.202012374 -
Polymers Jun 2022Polyethylene and Polyester materials are resistant to degradation and a significant source of microplastics pollution, which is an emerging concern. In the present...
Polyethylene and Polyester materials are resistant to degradation and a significant source of microplastics pollution, which is an emerging concern. In the present study, the potential of a dumped site bacterial community was evaluated. After primary screening, it was observed that 68.5% were linear low-density polyethylene, 33.3% were high-density, and 12.9% were Polyester degraders. Five strains were chosen for secondary screening, in which they were monitored by FTIR, SEM and weight loss degradation trials. Major results were observed for (MK517568) and (MK517567), as they showed the highest degradation activity. (MK517568) degrades LLDPE by 3.5%, HDPE by 5.8% and Polyester by 17.3%. (MK517567) is better tolerated at 30 °C and degrades Polyester by 29%. Changes in infrared spectra indicated degradation pathways of different strains depending on the types of plastics targeted. Through SEM analysis, groves, piths and holes were observed on the surface. These findings suggest that soil bacteria develop an effective mechanism for degradation of microplastics and beads that enables them to utilize plastics as a source of energy without the need for pre-treatments, which highlights the importance of these soil bacteria for the future of effective plastic waste management in a soil environment.
PubMed: 35683947
DOI: 10.3390/polym14112275 -
3 Biotech Jun 2024Despite their widespread applications in sectors such as pulp and paper, textile, food and beverage, pharmaceuticals, and biofuel production, laccases encounter... (Review)
Review
UNLABELLED
Despite their widespread applications in sectors such as pulp and paper, textile, food and beverage, pharmaceuticals, and biofuel production, laccases encounter challenges related to their activity and stability under varying reaction conditions. This review accumulates data on the complex interplay between laccase characteristics and reaction conditions for maximizing their efficacy in diverse biotechnological processes. Benefits of organic media such as improved substrate selectivity and reaction control, and their risks such as enzyme denaturation and reduced activity are reported. Additionally, the effect of reaction conditions such as pH and temperature on laccase activity and stability are gathered and reported. Sources like are producing laccases that are both thermo-active and alkali-active. Additionally, changes induced by the presence of various substances within reaction media such as metals, inhibitors, and organic solvents are also reported. and produce the most resistant laccases in this case. Finally, the remarkable laccases have been highlighted and the proper laccase source for each industrial application is suggested.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-024-04015-5.
PubMed: 38817737
DOI: 10.1007/s13205-024-04015-5 -
Applied Microbiology and Biotechnology Dec 2024Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate (ODHP) was extracted in a previous study from the culture broth of soil isolate Alcaligenes faecalis MT332429...
Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate (ODHP) was extracted in a previous study from the culture broth of soil isolate Alcaligenes faecalis MT332429 and showed a promising antimycotic activity. This study was aimed to formulate ODHP loaded β-cyclodextrins (CD) nanosponge (NS) hydrogel (HG) to control skin fungal ailments since nanosponges augment the retention of tested agents in the skin. Box-Behnken design was used to produce the optimized NS formulation, where entrapment efficiency percent (EE%), polydispersity index (PDI), and particle size (PS) were assigned as dependent parameters, while the independent process parameters were polyvinyl alcohol % (w/v %), polymer-linker ratio, homogenization time, and speed. The carbopol 940 hydrogel was then created by incorporating the nanosponges. The hydrogel fit Higuchi's kinetic release model the best, according to in vitro drug release. Stability and photodegradation studies revealed that the NS-HG remained stable under tested conditions. The formulation also showed higher in vitro antifungal activity against Candida albicans compared to the control fluconazole. In vivo study showed that ODHP-NS-HG increased survival rates, wound contraction, and healing of wound gap and inhibited the inflammation process compared to the other control groups. The histopathological examinations and Masson's trichrome staining showed improved healing and higher records of collagen deposition. Moreover, the permeability of ODHP-NS-HG was higher through rats' skin by 1.5-folds compared to the control isoconazole 1%. Therefore, based on these results, NS-HG formulation is a potential carrier for enhanced and improved topical delivery of ODHP. Our study is a pioneering research on the development of a formulation for ODHP produced naturally from soil bacteria. KEY POINTS: • Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propanoate was successfully formulated as a nanosponge hydrogel and statistically optimized. • The new formula exhibited in vitro good stability, drug release, and higher antifungal activity against C. albicans as compared to the fluconazole. • Ex vivo showed enhanced skin permeability, and in vivo analysis showed high antifungal activity as evidenced by measurement of various biochemical parameters and histopathological examination.
Topics: Rats; Animals; Hydrogels; Antifungal Agents; Fluconazole; Propionates; Alcaligenes faecalis; Candida albicans; Soil; Particle Size; Butanes
PubMed: 38217256
DOI: 10.1007/s00253-023-12819-3 -
Biosensors & Bioelectronics May 2018Bioelectrochemical systems use microbes as catalysts for current production or consumption. Up to now only a few microbes have been demonstrated to be capable of both...
Bioelectrochemical systems use microbes as catalysts for current production or consumption. Up to now only a few microbes have been demonstrated to be capable of both outward and inward extracellular electron transfer (EET) (i.e. bidirectional electron transfer). However, the mechanisms of electron exchange between microbes and extracellular solids remain uncertain. Here, we showed that Alcaligenes faecalis catalyzed an outward EET and generated electricity at a poised potential of +0.3V vs. SHE, whereas it conducted an inward EET for autotrophic denitrification at -0.5V vs. SHE. Both cyclic voltammetry and in situ electrochemical FTIR spectroscopy revealed that different redox components were utilized during the outward and inward EET. Electron transport inhibitor experiments indicated for the first time that complex I, II, III, and the quinone pool on the plasma membrane were involved in the bidirectional EET. Comparative proteomics showed that the protein expression profile of outward-EET biofilms differed greatly from those of inward-EET biofilms, implying that the pili and outer membrane proteins might be responsible for the interfacial outward and inward EET, respectively. These results suggest different electron transport conduits of A. faecalis biofilms could be used for bidirectional EET.
Topics: Alcaligenes faecalis; Bioelectric Energy Sources; Biofilms; Biosensing Techniques; Electron Transport; Electrons; Proteomics; Quinones
PubMed: 29414084
DOI: 10.1016/j.bios.2018.01.032