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Food Chemistry Aug 2024The unique high isoelectric point of lysozyme (LYZ) restricts its application in composite antibacterial coating due to the unfavorable liability to electrostatic...
The unique high isoelectric point of lysozyme (LYZ) restricts its application in composite antibacterial coating due to the unfavorable liability to electrostatic interaction with other components. In this work, the antibacterial activity of a dispersible LYZ-carboxymethyl konjac glucomannan (CMKGM) polyelectrolyte complex was evaluated. Kinetic analysis revealed that, compared with free LYZ, the complexed enzyme exhibited decreased affinity (K) but markedly increased V against Micrococcus lysodeikticus, and QCM and dynamic light scattering analysis confirmed that the complex could bind with the substrate but in a much lower ratio. The complexation with CMKGM did not alter the antibacterial spectrum of LYZ, and the complex exerted antibacterial function by delaying the logarithmic growth phase and impairing the cell integrity of Staphylococcus aureus. Since the LYZ-CMKGM complex is dispersible in water and could be assembled easily, it has great potential as an edible coating in food preservation.
Topics: Mannans; Muramidase; Anti-Bacterial Agents; Staphylococcus aureus; Kinetics; Micrococcus
PubMed: 38581793
DOI: 10.1016/j.foodchem.2024.139229 -
Journal of Biophotonics Jun 2024Mid-infrared laser spectroscopy was used to investigate common bacteria encountered in biopharmaceutical industries. The study involved the detection of bacteria using...
Mid-infrared laser spectroscopy was used to investigate common bacteria encountered in biopharmaceutical industries. The study involved the detection of bacteria using quantum cascade laser spectroscopy coupled to a grazing angle probe (QCL-GAP). Substrates similar to surfaces commonly used in biopharmaceutical industries were used as support media for the samples. Reflectance measurements were assisted by Multivariate Analysis (MVA) to assemble a powerful spectroscopic technique with classification and identification resources. The species analyzed, Staphylococcus aureus, Staphylococcus epidermidis, and Micrococcus luteus, were used to challenge the technique's capability to discriminate from microorganisms of the same family. Principal Components Analysis and Partial Least Squares-Discriminant Analysis differentiated between the bacterial species, using QCL-GAP-MVA as the reference. Spectral differences in the bacterial membrane were used to determine if these microorganisms were present in the samples analyzed. Results herein provided effective discrimination for the bacteria under study with high sensitivity and specificity.
Topics: Multivariate Analysis; Lasers; Principal Component Analysis; Staphylococcus epidermidis; Staphylococcus aureus; Micrococcus luteus; Industrial Microbiology; Spectrum Analysis; Discriminant Analysis
PubMed: 38581192
DOI: 10.1002/jbio.202300391 -
Bioscience, Biotechnology, and... May 2024N-Methylisothiazolinone (MIT) is a thiol group modifier and antimicrobial agent. Arthrobacter sarcosine oxidase (SoxA), a diagnostic enzyme for assaying creatinine,...
N-Methylisothiazolinone (MIT) is a thiol group modifier and antimicrobial agent. Arthrobacter sarcosine oxidase (SoxA), a diagnostic enzyme for assaying creatinine, loses its activity upon the addition of MIT, and its inactivation mechanism remains unclear. In this study, SoxA was chemically modified using MIT (mo-SoxA), and its structural and chemical properties were characterized. Spectral analysis data, oxygen consumption rates, and reactions were compared between intact SoxA and mo-SoxA. These demonstrate that the oxidative half-reaction toward oxygen is inhibited by MIT modification. The oxidase activity of mo-SoxA was approximately 2.1% of that of intact SoxA, and its dehydrogenase activity was approximately 4.2 times higher. The C-to-S mutants revealed that cooperative modification of 2 specific cysteine residues caused a drastic change in the enzyme reaction mode. Based on the modeled tertiary structures, the putative entrance for oxygen uptake is predicted to be blocked by the chemical modification of the 2 cysteine residues.
Topics: Arthrobacter; Oxygen; Sarcosine Oxidase; Thiazoles; Oxidation-Reduction; Cysteine; Models, Molecular; Kinetics
PubMed: 38553959
DOI: 10.1093/bbb/zbae039 -
Marine Drugs Feb 2024Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control...
Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control the degree of sulfation, are being more extensively researched. In this work, a novel sulfatase (SulA1) encoded by the gene was characterized. The -gene is located upstream of a chondroitin lyase encoding gene in the genome of the marine Arthrobacter strain (MAT3885). The sulfatase was produced in . Based on the primary sequence, the enzyme is classified under sulfatase family 1 and the two catalytic residues typical of the sulfatase 1 family-Cys57 (post-translationally modified to formyl glycine for function) and His190-were conserved. The enzyme showed increased activity, but not improved stability, in the presence of Ca, and conserved residues for Ca binding were identified (Asp17, Asp18, Asp277, and Asn278) in a structural model of the enzyme. The temperature and pH activity profiles (screened using -nitrocatechol sulfate) were narrow, with an activity optimum at 40-50 °C and a pH optimum at pH 5.5. The was significantly higher (67 °C) than the activity optimum. Desulfation activity was not detected on polymeric substrates, but was found on GalNAc4S, which is a sulfated monomer in the repeated disaccharide unit (GlcA-GalNAc4S) of, e.g., chondroitin sulfate A. The position of the sulA1 gene upstream of a chondroitin lyase gene and combined with the activity on GalNAc4S suggests that there is an involvement of the enzyme in the chondroitin-degrading cascade reaction, which specifically removes sulfate from monomeric GalNAc4S from chondroitin sulfate degradation products.
Topics: Sulfates; Acetylgalactosamine; Arthrobacter; Sulfatases; Escherichia coli; Galactosamine; Chondroitin Lyases; Cloning, Molecular
PubMed: 38535445
DOI: 10.3390/md22030104 -
Brazilian Journal of Microbiology :... Jun 2024Microbial pigments are considered as one of the main sources of natural types, and the attention to them is increasing in the food and pharmaceutical industries. This...
Microbial pigments are considered as one of the main sources of natural types, and the attention to them is increasing in the food and pharmaceutical industries. This study aimed to investigate the effects of pigments extracted from Micrococcus roseus (PEM) on the gene expression of a and b staphylococcal enterotoxins (sea and seb) and their acute toxicity. Real-time PCR was used to study the anti-enterotoxigenic activity of PEM against Staphylococcus aureus at sub-inhibitory concentrations. In addition, the acute toxicity of PEM was evaluated on albino mice through alkaline phosphatase (ALP), aspartate aminotransferas (AST), and alanine aminotransferase (ALT) of liver and its histopathological changes. Based on the results, the expression of sea and seb was decreased in the presence of PEM at sub-inhibitory concentrations. The 2 was measured 0.02 and 0.01 for the expression of sea and seb of S. aureus grown in the MHB containing 16 mg/ml PEM. The results showed that the expression of seb is more sensitive to PEM compared to the expression of sea. After treatment of mice with PEM for two weeks, the condition of mice was normal, and the results of liver enzymatic activities and histopathological changes showed insignificant difference compared to the control sample.
Topics: Animals; Mice; Staphylococcus aureus; Pigments, Biological; Liver; Enterotoxins; Micrococcus; Anti-Bacterial Agents; Staphylococcal Infections; Male; Alkaline Phosphatase; Microbial Sensitivity Tests; Alanine Transaminase
PubMed: 38532186
DOI: 10.1007/s42770-024-01316-y -
Journal of Environmental Sciences... Aug 2024The degradation of tilmicosin (TLM), a semi-synthetic 16-membered macrolide antibiotic, has been receiving increasing attention. Conventionally, there are three...
The degradation of tilmicosin (TLM), a semi-synthetic 16-membered macrolide antibiotic, has been receiving increasing attention. Conventionally, there are three tilmicosin degradation methods, and among them microbial degradation is considered the best due to its high efficiency, eco-friendliness, and low cost. Coincidently, we found a new strain, Glutamicibacter nicotianae sp. AT6, capable of degrading high-concentration TLM at 100 mg/L with a 97% removal efficiency. The role of tryptone was as well investigated, and the results revealed that the loading of tryptone had a significant influence on TLM removals. The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances. Based on the identified intermediates, the degradation of TLM by AT6 processing through two distinct pathways was then proposed.
Topics: Wastewater; Tylosin; Anti-Bacterial Agents; Biodegradation, Environmental; Micrococcaceae
PubMed: 38527883
DOI: 10.1016/j.jes.2023.07.009 -
Journal of Hazardous Materials May 2024Pesticides and fertilisers are frequently used and may co-exist on farmlands. The overfertilisation of soil may have a profound influence on pesticide residues, but the...
Pesticides and fertilisers are frequently used and may co-exist on farmlands. The overfertilisation of soil may have a profound influence on pesticide residues, but the mechanism remains unclear. The effects of chemical fertilisers on the environmental behaviour of atrazine and their underlying mechanisms were investigated. The present outcomes indicated that the degradation of atrazine was inhibited and the half-life was prolonged 6.0 and 7.6 times by urea and compound fertilisers (NPK) at 1.0 mg/g (nitrogen content), respectively. This result, which was confirmed in both sterilised and transfected soils, was attributed to the inhibitory effect of nitrogen fertilisers on soil microorganisms. The abundance of soil bacteria was inhibited by nitrogen fertilisers, and five families of potential atrazine degraders (Micrococcaceae, Rhizobiaceae, Bryobacteraceae, Chitinophagaceae, and Sphingomonadaceae) were strongly and positively (R > 0.8, sig < 0.05) related to the decreased functional genes (atzA and trzN), which inhibited hydroxylation metabolism and ultimately increased the half-life of atrazine. In addition, nitrogen fertilisers decreased the sorption and vertical migration behaviour of atrazine in sandy loam might increase the in-situ residual and ecological risk. Our findings verified the weakened atrazine degradation with nitrogen fertilisers, providing new insights into the potential risks and mechanisms of atrazine in the context of overfertilisation.
Topics: Atrazine; Soil; Fertilizers; Nitrogen; Metabolome; Soil Microbiology; Soil Pollutants; Herbicides; Biodegradation, Environmental
PubMed: 38518695
DOI: 10.1016/j.jhazmat.2024.133974 -
The Pediatric Infectious Disease Journal Jul 2024
Topics: Humans; Adolescent; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Anti-Bacterial Agents; Micrococcaceae; Male; Treatment Outcome; Central Nervous System Bacterial Infections; Actinomycetales Infections; Female
PubMed: 38502880
DOI: 10.1097/INF.0000000000004322 -
Developmental and Comparative Immunology Jul 2024Renibacterium salmoninarum causes Bacterial Kidney Disease (BKD) in several fish species. Atlantic lumpfish, a cleaner fish, is susceptible to R. salmoninarum. To...
Renibacterium salmoninarum causes Bacterial Kidney Disease (BKD) in several fish species. Atlantic lumpfish, a cleaner fish, is susceptible to R. salmoninarum. To profile the transcriptome response of lumpfish to R. salmoninarum at early and chronic infection stages, fish were intraperitoneally injected with either a high dose of R. salmoninarum (1 × 10 cells dose) or PBS (control). Head kidney tissue samples were collected at 28- and 98-days post-infection (dpi) for RNA sequencing. Transcriptomic profiling identified 1971 and 139 differentially expressed genes (DEGs) in infected compared with control samples at 28 and 98 dpi, respectively. At 28 dpi, R. salmoninarum-induced genes (n = 434) mainly involved in innate and adaptive immune response-related pathways, whereas R. salmoninarum-suppressed genes (n = 1537) were largely connected to amino acid metabolism and cellular processes. Cell-mediated immunity-related genes showed dysregulation at 98 dpi. Several immune-signalling pathways were dysregulated in response to R. salmoninarum, including apoptosis, alternative complement, JAK-STAT signalling, and MHC-I dependent pathways. In summary, R. salmoninarum causes immune suppression at early infection, whereas lumpfish induce a cell-mediated immune response at chronic infection. This study provides a complete depiction of diverse immune mechanisms dysregulated by R. salmoninarum in lumpfish and opens new avenues to develop immune prophylactic tools to prevent BKD.
Topics: Animals; Head Kidney; Fish Diseases; Renibacterium; Gene Expression Profiling; Transcriptome; Immunity, Innate; Fish Proteins; Adaptive Immunity; Fishes; Chronic Disease; Perciformes; Gram-Negative Bacterial Infections; Kidney Diseases; Micrococcaceae
PubMed: 38499166
DOI: 10.1016/j.dci.2024.105165 -
Archives of Microbiology Mar 2024This article reports the results of quantitative intra- and intergeneric taxonomic relationships among Micrococcaceae strains and a novel endophytic bacterium (SG)...
Quantitative intra- and intergeneric taxonomic relationships among Micrococcaceae strains reveal contradictions in the historical assignments of the strains and indicate the need for species reclassification.
This article reports the results of quantitative intra- and intergeneric taxonomic relationships among Micrococcaceae strains and a novel endophytic bacterium (SG) isolated from a suspension culture of Arabidopsis thaliana (L.) Heynh in our laboratory. The known strain Rothia sp. ND6WE1A was used as a reference one for SG. Whole-genome sequencing and phylogenetic analysis were based on the 16S rRNA test. Quantitative analysis for the nucleotide identity (ANI) and calculation of evolutionary distances were based on the identified amino acids (AAI) test indicating the generic assignment of the reference strain within and between the identified monophyletic groups of Micrococcaceae. The amino acid data structure of Rothia sp. ND6WE1A was compared against the UniProt database (250 million records) of close lineage of Micrococcaceae, including other Rothia spp. These data presented unique and evolutionary amino acid alignments, eventually expected in the new SG isolate as well. The metagenomic entries of the respective genome and proteome, characterized at the genus and species levels, could be considered for evolutionary taxonomic reclassification of the isolated and the reference strain (SG + Rothia sp. ND6WE1A). Therefore, our results warrant further investigations on the isolated SG strain.
Topics: Micrococcaceae; Phylogeny; Fatty Acids; RNA, Ribosomal, 16S; Sequence Analysis, DNA; DNA, Bacterial; Base Composition; Amino Acids; Bacterial Typing Techniques; Nucleic Acid Hybridization
PubMed: 38485793
DOI: 10.1007/s00203-024-03896-7