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Journal of Hazardous Materials Jul 2023Phosphorus-rich biochar (PBC) has been extensively studied due to its significant adsorption effect on U(VI). However, the release of phosphorus from PBC into solution...
Phosphorus-rich biochar (PBC) has been extensively studied due to its significant adsorption effect on U(VI). However, the release of phosphorus from PBC into solution decreases its adsorption performance and reusability and causes phosphorus pollution of water. In this study, Alcaligenes faecalis (A. faecalis) was loaded on PBC to produce a novel biocomposite (A/PBC). After adsorption equilibrium, phosphorus released into solution from PBC was 2.32 mg/L, while it decreased to 0.34 mg/L from A/PBC (p < 0.05). The U(VI) removal ratio of A/PBC reached nearly 100%, which is 13.08% higher than that of PBC (p < 0.05), and it decreased only by 1.98% after 5 cycles. When preparing A/PBC, A. faecalis converted soluble phosphate into insoluble metaphosphate minerals and extracellular polymeric substances (EPS). And A. faecalis cells accumulated through these metabolites and formed biofilm attached to the PBC surface. The adsorption of metal cations on phosphate further contributed to phosphorus fixation in the biofilm. During U(VI) adsorption by A/PBC, A. faecalis synthesize EPS and metaphosphate minerals by using the internal components of PBC, thus increasing the abundance of acidic functional groups and promoting U(VI) adsorption. Hence, A/PBC can be a green and sustainable material for U(VI) removal from wastewater.
Topics: Phosphorus; Wastewater; Alcaligenes faecalis; Adsorption; Minerals; Charcoal; Phosphates; Uranium; Kinetics
PubMed: 37156195
DOI: 10.1016/j.jhazmat.2023.131484 -
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 -
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 -
Biotechnology Journal Dec 2023Poly(ethylene terephthalate) (PET) is one of the world's most widely used polyester plastics. Due to its chemical stability, PET is extremely difficult to hydrolyze in a...
Poly(ethylene terephthalate) (PET) is one of the world's most widely used polyester plastics. Due to its chemical stability, PET is extremely difficult to hydrolyze in a natural environment. Recent discoveries in new polyester hydrolases and breakthroughs in enzyme engineering strategies have inspired enormous research on biorecycling of PET. This study summarizes our research efforts toward large-scale, efficient, and economical biodegradation of post-consumer waste PET, including PET hydrolase selection and optimization, high-yield enzyme production, and high-capacity enzymatic degradation of post-consumer waste PET. First, genes encoding PETase and MHETase from Ideonella sakaiensis and the ICCG variant of leaf-branch compost cutinase (LCC ) were codon-optimized and expressed in Escherichia coli BL21(DE3) for high-yield production. To further lower the enzyme production cost, a pelB leader sequence was fused to LCC so that the enzyme can be secreted into the medium to facilitate recovery. To help bind the enzyme on the hydrophobic surface of PET, a substrate-binding module in a polyhydroxyalkanoate depolymerase from Alcaligenes faecalis (PBM) was fused to the C-terminus of LCC . The resulting four different LCC variants (LCC, PelB-LCC, LCC-PBM, and PelB-LCC-PBM), together with PETase and MHETase, were compared for PET degradation efficiency. A fed-batch fermentation process was developed to produce the target enzymes up to 1.2 g L . Finally, the best enzyme, PelB-LCC, was selected and used for the efficient degradation of 200 g L recycled PET in a well-controlled, stirred-tank reactor. The results will help develop an economical and scalable biorecycling process toward a circular PET economy.
Topics: Polyethylene Terephthalates; Hydrolases; Phthalic Acids; Ethylenes
PubMed: 37594123
DOI: 10.1002/biot.202300119 -
Journal of Microbiology (Seoul, Korea) Jun 2024Alcaligenes faecalis is one of the most important and clinically significant environmental pathogens, increasing in importance due to its isolation from soil and...
Alcaligenes faecalis is one of the most important and clinically significant environmental pathogens, increasing in importance due to its isolation from soil and nosocomial environments. The Gram-negative soil bacterium is associated with skin endocarditis, bacteremia, dysentery, meningitis, endophthalmitis, urinary tract infections, and pneumonia in patients. With emerging antibiotic resistance in A. faecalis, it has become crucial to understand the origin of such resistance genes within this clinically significant environmental and gut bacterium. In this research, we studied the impact of antibiotic overuse in poultry and its effect on developing resistance in A. faecalis. We sampled soil and faecal materials from five poultry farms, performed whole genome sequencing & analysis and identified four strains of A. faecalis. Furthermore, we characterized the genes in the genomic islands of A. faecalis isolates. We found four multidrug-resistant A. faecalis strains that showed resistance against vancomycin (MIC >1000 μg/ml), ceftazidime (50 μg/ml), colistin (50 μg/ml) and ciprofloxacin (50 μg/ml). From whole genome comparative analysis, we found more than 180 resistance genes compared to the reference sequence. Parts of our assembled contigs were found to be similar to different bacteria which included pbp1A and pbp2 imparting resistance to amoxicillin originally a part of Helicobacter and Bordetella pertussis. We also found the Mycobacterial insertion element IS6110 in the genomic islands of all four genomes. This prominent insertion element can be transferred and induce resistance to other bacterial genomes. The results thus are crucial in understanding the transfer of resistance genes in the environment and can help in developing regimes for antibiotic use in the food and poultry industry.
PubMed: 38904697
DOI: 10.1007/s12275-024-00129-w -
The Pediatric Infectious Disease Journal Sep 2023
Topics: Humans; Alcaligenes faecalis; Osteomyelitis
PubMed: 37310887
DOI: 10.1097/INF.0000000000003993 -
African Journal of Infectious Diseases 2024Infectious diseases due to antibiotic resistant pathogens are a global public health problem. This study aimed at determining the potential effect of bacterial-fungal...
BACKGROUND
Infectious diseases due to antibiotic resistant pathogens are a global public health problem. This study aimed at determining the potential effect of bacterial-fungal interaction on the antibiotic susceptibility profile of
MATERIALS AND METHODS
was isolated from water samples. The isolate was identified using the conventional biochemical tests and the 16S rRNA molecular sequencing technique. Additionally, species was isolated and identified based on colony morphological characteristics and microscopic features. Standardized isolates were co-cultured in broth medium. Antibiotic susceptibility evaluation of the from the co-culture and the original was carried out using the Kirby bauer disk diffusion method.
RESULTS
The antibiotic susceptibility profile of before and after co-culture remained largely unchanged except in the case of chloramphenicol, where the isolate showed reduced susceptibility. Molecular analysis of resistance gene revealed the absence of tested gene encoding antibiotic resistance, including the streptomycin resistance (str) genes ( and ) and the erythromycin resistance methylase () gene.
CONCLUSION
The result of this study showed that there is a minimal influence of cultures on the susceptibility of . Further research involving a wide spectrum of microorganisms and their interactions should be conducted to acquire a thorough understanding of the influence of microbial interactions on antibiotic susceptibility profiles in order to pave way for novel strategies to combat antimicrobial resistance.
PubMed: 38606189
DOI: 10.21010/Ajidv18i2.2 -
Biochemical and Biophysical Research... Aug 2024The emergence of drug-resistant bacteria, facilitated by metallo-beta-lactamases (MBLs), presents a significant obstacle to the effective use of antibiotics in the...
The emergence of drug-resistant bacteria, facilitated by metallo-beta-lactamases (MBLs), presents a significant obstacle to the effective use of antibiotics in the management of clinical drug-resistant bacterial infections. AFM-1 is a MBL derived from Alcaligenes faecalis and shares 86% homology with the NDM-1 family. Both AFM-1 and NDM-1 demonstrate the ability to hydrolyze ampicillin and other β-lactam antibiotics, however, their substrate affinities vary, and the specific reason for this variation remains unknown. We present the high-resolution structure of AFM-1. The active center of AFM-1 binds two zinc ions, and the conformation of the key amino acid residues in the active center is in accordance with that of NDM-1. However, the substrate-binding pocket of AFM-1 is considerably smaller than that of NDM-1. Additionally, the mutation of amino acid residues in the Loop3 region, as compared to NDM-1, results in the formation of a dense hydrophobic patch comprised of hydrophobic amino acid residues in this area, which facilitates substrate binding. Our findings lay the foundation for understanding the molecular mechanism of AFM-1 with a high affinity for substrates and provide a novel theoretical foundation for addressing the issue of drug resistance caused by B1 MBLs.
Topics: beta-Lactamases; Models, Molecular; Alcaligenes faecalis; Protein Conformation; Zinc; Crystallography, X-Ray; Catalytic Domain; Bacterial Proteins; Amino Acid Sequence; Binding Sites
PubMed: 38759302
DOI: 10.1016/j.bbrc.2024.150102 -
Applied Biochemistry and Biotechnology Sep 2023The development of microbial biofilm occurs with the adherence of the microbial cells on biotic and abiotic surfaces with the help of pili and with extracellular...
The development of microbial biofilm occurs with the adherence of the microbial cells on biotic and abiotic surfaces with the help of pili and with extracellular polymeric substances. The surfaces on which biofilm formation take place can be inert, abiotic, or biotic. The sessile microbial cells behave differently from their planktonic counterpart. The biofilm developed by Alcaligenes faecalis is responsible for the development of skin and soft-tissue infection. It was observed that green-synthesized carbon nanoparticles (NPs) from Ocimum sanctum showed a prolonged stability and activity. It showed a marked reduction in the viability of sessile microbial species with least revival in comparison to the plant extract and amoxicillin. It was observed that carbon NP was able to maximally reduce the quorum sensing (QS) activity of A. faecalis. Thus, the use of green-synthesized NPs would be an alternative in the treatment of the biofilm-associated chronic wound infections.
PubMed: 37715894
DOI: 10.1007/s12010-023-04695-4