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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 -
Zhonghua Er Bi Yan Hou Tou Jing Wai Ke... Sep 2023To investigate the characteristics of nasal flora and the pathogenic role of differential microbiome in patients with allergic rhinitis (AR) and non-allergic rhinitis...
To investigate the characteristics of nasal flora and the pathogenic role of differential microbiome in patients with allergic rhinitis (AR) and non-allergic rhinitis (nAR). Thirty-five patients with AR who attended the rhinology outpatient clinic of the Second Hospital of Harbin Medical University from February to July 2022 were selected. A total of 35 nAR patients were selected as the test group, and 20 cases of healthy people with physical examination at the same period were selected as the control group, including 39 males and 51 females, aged 8 to 55 years. 16SrDNA High-throughput sequencing was used to analyze the relative abundance from nasal flora in the three groups of subjects. Alpha diversity index analysis was conducted with R software, and differences between groups were analyzed with LEfSe, Metastats, and tests. At the same time, the role of microbiome and its relationship with environmental factors were analyzed with R software. There was a significant difference in the bacterial composition of the samples from the three groups, with the relative abundance of Staphylococcus aureus (=0.032) and Corynebacterium proinquum (=0.032) within the AR group being significantly higher than that of the nAR group, and that of Lactobacillus murinus, Lactobacillus kunkeei, and Alcaligenes faecalis ( value was 0.016, 0.005, and 0.001, respectively) being significantly lower than that of the nAR group. The relative abundance of Ackermannia muciniphila within the nAR group was higher than that of the control group (=0.009). Correlation analysis of environmental factors showed a negative correlation between Lactobacillus kunkeei and IgE (=0.044), and a positive correlation between Lactobacillus murinus and age (=0.019). AR and nAR random forest prediction models were constructed for the five genera, respectively, and the area under the curve (AUC) of the models of Streptococcus-SP-FF10, Pseudoalteromonas luteoviolacea, Pseudomonas parafulva, Acinetobacter ursingii, and Azotobacter chroococcum in the AR group was 100% (95%CI: 100% to 100%). The AUC for the Pseudomonas parafulva, Azotobacter chroococcum, Closoridium baratii, Turicibacter-SP-H121, and Streptococcus lutetiensis models in the nAR group was 98.4% (95%CI: 94.9% to 100%). The distribution of nasal flora in AR patients, nAR patients and healthy subjects is significantly different, and the changes of bacterial flora abundance are significantly related to the occurrence of AR and nAR. Combined detection of microbiota has the potential to diagnose AR and nAR patients.
Topics: Female; Male; Humans; Rhinitis; Rhinitis, Allergic
PubMed: 37675527
DOI: 10.3760/cma.j.cn115330-20221012-00605 -
Antonie Van Leeuwenhoek Oct 2023Some heterotrophic microorganisms carry out nitrification to produce nitrite and nitrate from pyruvic oxime. Pyruvic oxime dioxygenase (POD) is an enzyme that catalyzes...
Some heterotrophic microorganisms carry out nitrification to produce nitrite and nitrate from pyruvic oxime. Pyruvic oxime dioxygenase (POD) is an enzyme that catalyzes the degradation of pyruvic oxime to pyruvate and nitrite from the heterotrophic nitrifying bacterium Alcaligenes faecalis. Sequence similarity searches revealed the presence of genes encoding proteins homologous to A. faecalis POD in bacteria of the phyla Proteobacteria and Actinobacteria and in fungi of the phylum Ascomycota, and their gene products were confirmed to have POD activity in recombinant experiments. Phylogenetic analysis further classified these POD homologs into three groups. Group 1 POD is mainly found in heterotrophic nitrifying Betaproteobacteria and fungi, and is assumed to be involved in heterotrophic nitrification. It is not clear whether group 2 POD, found mainly in species of the Gammaproteobacteria and Actinobacteria, and group 3 POD, found simultaneously with group 1 POD, are involved in heterotrophic nitrification. The genes of bacterial group 1 POD comprised a single transcription unit with the genes related to the metabolism of aromatic compounds, and many of the genes group 2 POD consisted of a single transcription unit with the gene encoding the protein homologous to 4-hydroxy-tetrahydrodipicolinate synthase (DapA). LysR- or Cro/CI-type regulatory genes were present adjacent to or in the vicinity of these POD gene clusters. POD may be involved not only in nitrification, but also in certain metabolic processes whose functions are currently unknown, in coordination with members of gene clusters.
Topics: Dioxygenases; Phylogeny; Nitrites; Nitrification; Actinobacteria
PubMed: 37596503
DOI: 10.1007/s10482-023-01862-9 -
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 Nanobiotechnology Aug 2023In recent years, crop production has expanded due to the variety of commercially available species. This increase in production has led to global competition and the...
BACKGROUND
In recent years, crop production has expanded due to the variety of commercially available species. This increase in production has led to global competition and the search for biostimulant products that improve crop quality and yield. At the same time, agricultural products that protect against diseases caused by phytopathogenic microorganisms are needed. Thus, the green synthesis of selenium nanoparticles (SeNPs) is a proposal for achieving these needs. In this research, SeNPs were synthesized from methanolic extract of Amphipterygium glaucum leaves, and chemically and biologically characterized.
RESULTS
The characterization of SeNPs was conducted by ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM), electron microscopy transmission (TEM), Dynamic Light Scattering (DLS), energy dispersion X-ray spectroscopy (EDX), and infrared spectrophotometry (FTIR) techniques. SeNPs with an average size of 40-60 nm and spherical and needle-shaped morphologies were obtained. The antibacterial activity of SeNPs against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis was evaluated. The results indicate that the methanolic extracts of A. glaucum and SeNPs presented a high antioxidant activity. The biostimulant effect of SeNPs (10, 20, 50, and 100 µM) was evaluated in vinca (Catharanthus roseus), and calendula (Calendula officinalis) plants under greenhouse conditions, and they improved growth parameters such as the height, the fresh and dry weight of roots, stems, and leaves; and the number of flowers of vinca and calendula.
CONCLUSIONS
The antibacterial, antioxidant, and biostimulant properties of SeNPs synthesized from A. glaucum extract demonstrated in this study support their use as a promising tool in crop production.
Topics: Antioxidants; Selenium; Nanoparticles; Anti-Bacterial Agents; Plant Extracts
PubMed: 37537575
DOI: 10.1186/s12951-023-02027-6 -
PeerJ 2023has a well-established negative impact on rice yield in transplanted and direct-seeded rice, resulting in yield losses of up to 20 to 90 percent. Studies were...
has a well-established negative impact on rice yield in transplanted and direct-seeded rice, resulting in yield losses of up to 20 to 90 percent. Studies were undertaken to isolate potential native strains of bio-control agents to manage the devastating Rice Root Knot Nematode (). Eighteen bacterial strains and eleven fungal strains were isolated from the rhizosphere of crops like rice, okra, ash gourd, chili, beans and cucumber, enveloping diverse soil types from the Upper Brahmaputra Valley region of Assam. Six bacterial strains were gram-positive according to morphological results, while twelve others stained negatively. Fifteen bacteria were rod-shaped, two were coccus and one was diplococcus, and all the bacterial isolates showed signs of movement. All the bacterial strains exhibited positivity for gelatin hydrolysis and catalase test. Seven bacteria showed positive, while eleven showed negative reactions to possess the ability to deduce carbon and energy from citrate. The study of the efficacy of the twenty-nine bacterial and fungal isolates tested against second-stage juveniles (J) of revealed that all the bacterial and fungal isolates potentially inhibited the test organism and caused significant mortality over sterile water treatment. The promising bacterial and fungal isolates that exhibited mortality above 50% were identified as BSH8, BTS4, BTS5, BJA15, FJB 11 and FSH5. The strain BSH8 exhibited the best result of mortality, with 80.79% mortality against J of . The strain BTS4 and BTS5 expressed mortality of 71.29% and 68.75% under conditions and were significant. The effective and promising bioagents were identified using the 16 S rRNA sequencing as (BSH8), (BTS4), (BTS5), (BJA15), (FSH5) and (FJB11). These results indicated the microorganism's potential against and its potential for successful biological implementation. Further, the native strains could be tested against various nematode pests of rice in field conditions. Its compatibility with various pesticides and the implication of the potential strains in integrated pest management can be assessed.
Topics: Animals; Tylenchoidea; Oryza; Soil; Pest Control; Pesticides
PubMed: 37529212
DOI: 10.7717/peerj.15779 -
BioRxiv : the Preprint Server For... Jun 2023Chronic 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 re-epithelialization of diabetic keratinocytes, a process which 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.
PubMed: 37425836
DOI: 10.1101/2023.06.30.547263 -
Protein Expression and Purification Oct 2023Penicillin G acylase (PGA) is a strategic enzyme in the production processes of beta-lactam antibiotics. High demand for β-lactam semisynthetic antibiotics explain the...
Penicillin G acylase (PGA) is a strategic enzyme in the production processes of beta-lactam antibiotics. High demand for β-lactam semisynthetic antibiotics explain the genetic and biochemical engineering strategies devoted towards novel ways for PGA production and application. This work presents a fermentation process for the heterologous production of PGA from Alcaligenes faecalis in Bacillus megaterium with optimization. The thermal stability from A. faecalis PGA is considerably higher than other described PGA and the recombinant enzyme is secreted to the culture medium by B. megaterium, which facilitates the separation and purification steps. Media optimization using fractional factorial design experiments was used to identify factors related to PGA activity detection in supernatant and cell lysates. The optimized medium resulted in almost 6-fold increased activity in the supernatant samples when compared with the basal medium. Maximum enzyme activity in optimized medium composition achieves values between 135 and 140 IU/ml. The results suggest a promising model for recombinant production of PGA in B. megaterium with possible extracellular expression of the active enzyme.
Topics: Alcaligenes faecalis; Bacillus megaterium; Penicillin Amidase; Anti-Bacterial Agents; beta-Lactams
PubMed: 37348663
DOI: 10.1016/j.pep.2023.106327 -
Chemistry (Weinheim An Der Bergstrasse,... Aug 2023The immobilization of copper-containing nitrite reductase (NiR) from Alcaligenes faecalis on functionalised multi-walled carbon nanotube (MWCNT) electrodes is reported....
The immobilization of copper-containing nitrite reductase (NiR) from Alcaligenes faecalis on functionalised multi-walled carbon nanotube (MWCNT) electrodes is reported. It is demonstrated that this immobilization is mainly driven by hydrophobic interactions, promoted by the modification of MWCNTs with adamantyl groups. Direct electrochemistry shows high bioelectrochemical reduction of nitrite at the redox potential of NiR with high current density of 1.41 mA cm . Furthermore, the desymmetrization of the trimer upon immobilization induces an independent electrocatalytic behavior for each of the three enzyme subunits, corroborated by an electron-tunneling distance dependence.
PubMed: 37310888
DOI: 10.1002/chem.202301351 -
The Pediatric Infectious Disease Journal Sep 2023
Topics: Humans; Alcaligenes faecalis; Osteomyelitis
PubMed: 37310887
DOI: 10.1097/INF.0000000000003993