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The Journal of Antibiotics Jul 2020Microbial-derived natural products provide unique bioactivities and serve as a unique source of drug leads. In the present study, we isolated one new...
Microbial-derived natural products provide unique bioactivities and serve as a unique source of drug leads. In the present study, we isolated one new chresdihydrochalcone (1), one new chresphenylacetone (2), and one known streptimidone (3) from Streptomyces chrestomyceticus BCC 24770 using antibacterial activity-guided isolation and purification procedures. We determined their molecular weights using MS and HRMS and elucidated their chemical structures from their 1D and 2D NMR and electronic circular dichroism (ECD) spectra. Compound 1 showed moderate inhibitory activities against the Gram-positive bacteria Methicillin-resistant Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteus. Cytotoxicity and hemolytic activity were not observed at a concentration of up to 100 μg ml. The specific antimicrobial activity and low toxicity of compound 1 indicate this compound to be a potential antibiotic candidate, especially as antibiotic resistance has become a significant public health threat.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Bacillus subtilis; Gram-Positive Bacteria; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Micrococcus luteus; Streptomyces
PubMed: 32203125
DOI: 10.1038/s41429-020-0298-1 -
Colloids and Surfaces. B, Biointerfaces Jun 2021In this study, mesoporous polyacrylonitrile (PAN)/thermoplastic polyurethane (TPU) blended nanofibers were prepared to immobilize Micrococcus luteus for enhancing the...
In this study, mesoporous polyacrylonitrile (PAN)/thermoplastic polyurethane (TPU) blended nanofibers were prepared to immobilize Micrococcus luteus for enhancing the conversion of trehalose. The images of SEM showed the cells were adsorbed on the surface and pores due to the unique pore structure. The results of contact angle, Zeta potential and water holding ratio exhibited the good hydrophilicity and stability of PAN/TPU-P2. Besides, it was indicated that the biomass and immobilization efficiency were increased to 0.633 g/L and 0.153 g/g, respectively. It was the most noteworthy that the trehalose yield could reach 23.46 g/L, which was 71.62 % higher than that of the control in the multi-batch fermentation. Moreover, the reactive oxygen species (ROS) level was decreased to 12.8 % while the enzyme concentration was increased to 11.176 mg/mL. Meanwhile, it was also found that PAN/TPU-P2 immobilization substantially increased the expression of target gene MtreY by 3.500 times. In other words, the mechanism by which immobilized cells increased trehalose yield was that PAN/TPU-P regulated gene expression of MtreY. Therefore, this research provided theoretical foundation for the metabolic regulation of sufficient trehalose production by immobilized cells.
Topics: Fermentation; Gene Expression; Micrococcus luteus; Nanofibers; Trehalose
PubMed: 33765627
DOI: 10.1016/j.colsurfb.2021.111714 -
Veterinary Research Feb 2021Tissue factor pathway inhibitors (TFPI), including TFPI-1 and TFPI-2, are Kunitz-type serine protease inhibitors that mainly inhibit the blood coagulation induced by...
Tissue factor pathway inhibitors (TFPI), including TFPI-1 and TFPI-2, are Kunitz-type serine protease inhibitors that mainly inhibit the blood coagulation induced by tissue factors. Previous reports on teleost proved TFPI play important roles in innate immunity. In this study, two TFPI (PoTFPI-1 and PoTFPI-2) molecules from Japanese flounder (Paralichthys olivaceus) were analyzed and characterized for their expression patterns, antibacterial and anticancer activities of the C-terminal derived peptides. Quantitative real time RT-PCR analysis shows that constitutive PoTFPI-1 expression occurred, in increasing order, in the brain, muscle, spleen, gills, head kidney, blood, intestine, heart, and liver; PoTFPI-2 was expressed, in increasing order, in the brain, gills, head kidney, muscle, intestine, spleen, liver, heart, and blood. Under the stimulation of fish pathogens, both PoTFPI-1 and PoTFPI-2 expressions increased significantly in a manner that depended on the pathogens, tissue type, and infection stage. Furthermore, C-terminal peptides TP25 and TP26, derived from PoTFPI-1 and PoTFPI-2, respectively, were synthesized and proved to be active against Micrococcus luteus (for TP25 and TP26) and Staphylococcus aureus (for TP25) via retardation effects on bacterial nucleic acids. In addition, TP25 and TP26 also displayed significant inhibitory effects on human colon cancer cell line HT-29. These results reveal that both PoTFPI-1 and PoTFPI-2 play important roles in host innate immunity. The antibacterial activity and anticancer cells function of TP25 and TP26 will add new insights into the roles of teleost TFPI.
Topics: Amino Acid Sequence; Animals; Anti-Bacterial Agents; Antineoplastic Agents; Fish Diseases; Fish Proteins; Flatfishes; Gene Expression Profiling; Gene Expression Regulation; Glycoproteins; Immunity, Innate; Lipoproteins; Micrococcus luteus; Phylogeny; Staphylococcus aureus
PubMed: 33632337
DOI: 10.1186/s13567-021-00908-y -
Journal of Dairy Science Oct 2020The objective of this work was to determine the effect of milk bactofugation on the counts and microbial diversity of mesophilic (MT), psychrotrophic (PT), and...
The objective of this work was to determine the effect of milk bactofugation on the counts and microbial diversity of mesophilic (MT), psychrotrophic (PT), and thermophilic (TT) thermoduric bacteria and its potential as a technological method to remove spoilage microorganisms resistant to pasteurization. Different batches of raw milk from 69 dairy farms divided into sets in 3 bulk tanks (A, B, C) were evaluated at different times during the technological process. As the raw milk was preheated (∼55°C) immediately before bactofugation (10,000 × g), the effect of bactofugation was estimated by comparing the counts in raw, preheated, and bactofuged milk. This centrifugation was sufficient to reduce the isolation of 88% of the MT in preheated milk. For PT, it was possible to verify a reduction of 72.5% in batch C. The TT were not recovered at higher detection limits (<5 cfu/mL). For diversity, 310 isolates were identified using a molecular approach; 15 species of contaminating thermoduric bacteria were identified from raw and preheated milk, and only 6 species were recovered in bactofuged milk. Only MT were recovered from the bactofuged milk, mainly the species Lysinibacillus fusiformis (61.7%) and Bacillus licheniformis (12.3%). Both species are known to be endospore-forming psychrotrophs and have proteolytic or lipolytic activity. The bactofugation of raw milk reduced the number of isolates of B. licheniformis, Bacillus toyonensis, Micrococcus aloeverae, and Aestuariimicrobium kwangyangense by 33, 43, 86, and 92%, respectively, and reduced the isolates of Macrococcus caseolyticus, Lysinibacillus varians, Carnobacterium divergens, Microbacterium hominis, Kocuria indica, Micrococcus yunnanensis, Gordonia paraffinivorans, Bacillus invictae, and Kocuria kristinae to undetectable levels. The results of this study indicate that bactofugation can be applied by the dairy industry to reduce pasteurization-resistant microorganisms in combination with prophylactic measures to prevent the contamination of raw milk by spores and vegetative forms of bacteria.
Topics: Actinobacteria; Animals; Bacillaceae; Bacillus; Bacteria, Thermoduric; Carnobacterium; Centrifugation; Micrococcaceae; Micrococcus; Milk; Propionibacteriaceae; Staphylococcaceae
PubMed: 32828509
DOI: 10.3168/jds.2020-18591 -
Nature Communications Aug 2020Here, we demonstrate the self-assembly of the antimicrobial human LL-37 active core (residues 17-29) into a protein fibril of densely packed helices. The surface of the...
Here, we demonstrate the self-assembly of the antimicrobial human LL-37 active core (residues 17-29) into a protein fibril of densely packed helices. The surface of the fibril encompasses alternating hydrophobic and positively charged zigzagged belts, which likely underlie interactions with and subsequent disruption of negatively charged lipid bilayers, such as bacterial membranes. LL-37 correspondingly forms wide, ribbon-like, thermostable fibrils in solution, which co-localize with bacterial cells. Structure-guided mutagenesis analyses supports the role of self-assembly in antibacterial activity. LL-37 resembles, in sequence and in the ability to form amphipathic helical fibrils, the bacterial cytotoxic PSMα3 peptide that assembles into cross-α amyloid fibrils. This argues helical, self-assembling, basic building blocks across kingdoms of life and points to potential structural mimicry mechanisms. The findings expose a protein fibril which performs a biological activity, and offer a scaffold for functional and durable biomaterials for a wide range of medical and technological applications.
Topics: Amyloid; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Bacteria; Benzothiazoles; Cathelicidins; Crystallography, X-Ray; Gorilla gorilla; Humans; Microbial Sensitivity Tests; Micrococcus luteus; Microscopy, Confocal; Microscopy, Electron, Transmission; Models, Molecular; Protein Conformation; Staphylococcus hominis; X-Ray Diffraction
PubMed: 32753597
DOI: 10.1038/s41467-020-17736-x -
Developmental and Comparative Immunology Dec 2017Leucine-rich repeat (LRR)-only proteins are involved in the innate immune responses as they mediate protein-ligand interactions. In the present study, three novel...
Leucine-rich repeat (LRR)-only proteins are involved in the innate immune responses as they mediate protein-ligand interactions. In the present study, three novel LRR-only proteins, CfLRRop-4, CfLRRop-5 and CfLRRop-6, were identified and characterized from Zhikong scallop Chlamys farreri. They all contained LRR motifs with consensus signature sequences of LxxLxLxxNxL or LxxLxLxxCxxL. All the mRNA transcripts of three CfLRRops were high abundant in hepatopancreas, gills and gonads, and their mRNA transcripts in hemocytes could respond to the stimulations of different microbes, including Vibrio anguillarum, Micrococcus luteus and Pichia pastoris. These three CfLRRops exhibited similar ligand binding and recognition characteristics as Toll-like receptors (TLRs) and NOD-like receptors (NLRs). The immune effectors, including tumor necrosis factor α, superoxide dismutase, catalase and lysozyme, varied significantly after the scallops were stimulated by recombinant LRR-only proteins. All these results indicated that LRR-only proteins are functionally differentiated and exhibit different immunomodulation activities on various downstream immune effectors.
Topics: Animals; Gram-Positive Bacterial Infections; Hepatopancreas; Immunity, Innate; Immunomodulation; Leucine; Micrococcus luteus; Mycoses; Pectinidae; Pichia; Protein Binding; Receptors, Pattern Recognition; Repressor Proteins; Tumor Necrosis Factor-alpha; Vibrio; Vibrio Infections
PubMed: 28807724
DOI: 10.1016/j.dci.2017.08.005 -
Macromolecular Bioscience Nov 2021Bioremediation of copper (Cu ) with immobilized Micrococcus luteus in polymer matrices has been broadly studied for a wide range of applications including wastewater...
Bioremediation of copper (Cu ) with immobilized Micrococcus luteus in polymer matrices has been broadly studied for a wide range of applications including wastewater treatment. Herein, the bioremediation efficiency based on modified immobilization techniques and by the addition of Cu is investigated. Porous composite nonwovens with living M. luteus (living polymer composites) are prepared by encapsulation of the bacterial cells in poly(vinyl alcohol) (PVA) microparticles (M. luteus/PVA microparticles) produced by spray drying method. The M. luteus/PVA microparticles are chemically cross-linked. The hydrogel microparticles with encapsulated M. luteus are embedded in a nonwoven of poly (lactic acid) (PLA) electrospun short fibers provided by wet-laid method. Two different models of composite nonwovens are reported, in which the place position of the hydrogel PVA microparticles with encapsulated M. luteus and PLA nonwoven can affect the bioremediation process.
Topics: Biodegradation, Environmental; Copper; Hydrogels; Micrococcus luteus; Microscopy, Electron, Scanning; Polyvinyl Alcohol
PubMed: 34414670
DOI: 10.1002/mabi.202100086 -
Acta Biologica Hungarica Dec 2016Five Iranian Trichoderma isolates from species T. viride, T. viridescens, T. asperellum, T. longibrachiatum and T. citrinoviride - selected from the Fungal Collection of...
Five Iranian Trichoderma isolates from species T. viride, T. viridescens, T. asperellum, T. longibrachiatum and T. citrinoviride - selected from the Fungal Collection of the Bu Ali Sina University, Hamedan, Iran - were investigated for their peptaibol production. All examined isolates showed remarkable antibacterial activities during the screening of their extracts for peptaibol content with a Micrococcus luteus test culture. HPLC-ESI-IT MS was used for identification and elucidation of the amino acid sequences of peptaibols. The detected peptaibol compounds contain 20 or 18 amino acid residues and belong to the trichobrachin and trichotoxin groups of peptaibols, respectively. T. longibrachiatum and T. citrinoviride produced trichobrachins, while trichotoxins could be detected in T. viride, T. viridescens and T. asperellum. Out of 37 sequences detetermined, 26 proved to be new, yet undescribed compounds, while others were identified as previously reported trichotoxins (trichotoxin A-50s and T5D2) and trichobrachins (longibrachins AI, AII, AIII, BII and BIII). Compounds within the two groups of detected peptaibols differed from each other only by a single or just a few amino acid changes.
Topics: Anti-Infective Agents; Antimicrobial Cationic Peptides; Chromatography, High Pressure Liquid; Iran; Micrococcus luteus; Peptaibols; Peptides; Spectrometry, Mass, Electrospray Ionization; Trichoderma
PubMed: 28000507
DOI: 10.1556/018.67.2016.4.9 -
Archives of Microbiology Dec 2023Due to their non-toxic and non-carcinogenic nature, biopigments have a phenomenal benefit over synthetic pigments, making them a desirable source for human utilization...
Due to their non-toxic and non-carcinogenic nature, biopigments have a phenomenal benefit over synthetic pigments, making them a desirable source for human utilization and a potential alternative to traditional synthetic pigments that are hazardous to the environment and public health. Endosymbiotic interactions between mangrove plants and bacteria could provide an alternate source for the synthesis of unique compounds with potent biomedical applications. Pigmented endophytic bacteria were screened from the explants of Avicennia marina, a mangrove plant, and identified as Micrococcus luteus by molecular characterization. The intracellular pigment was successfully extracted using the sonication-assisted solvent extraction method, and screening factors impacting the pigmentation bioprocess were determined using a one-factor-at-a-time approach. The endophyte produced yellow pigment in the liquid medium, with the maximum growth and pigment production recorded in nutrient broth at 37 ℃ and pH 7 after 96 h of incubation, while the maximum accumulation of pigment was observed in the media supplemented with glucose and tryptone as carbon and nitrogen sources, respectively. The extracted crude pigment was further characterized by ultraviolet, followed by Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry. The obtained crude pigment has been evaluated for its antioxidant and anticancer activity by various assays, such as DPPH radical scavenging activity, FRAP assay, superoxide anion and nitric oxide radical scavenging, metal chelating activity, phosphomolybdenum assay, and MTT assay, respectively, at varying concentrations. The results of our study revealed that the yellow pigment produced by the endophyte showed significant dose-dependent antioxidant and anticancer activity.
Topics: Humans; Antioxidants; Avicennia; Micrococcus luteus; Nutrients; Carbon; Endophytes
PubMed: 38108901
DOI: 10.1007/s00203-023-03751-1 -
Biochimica Et Biophysica Acta. Proteins... Feb 2022Bacteriophage endolysins are crucial for progeny release at the end of the lytic cycle. Mycobacteriophage's genomes carry a lysin A essential gene, whose product cleaves...
Bacteriophage endolysins are crucial for progeny release at the end of the lytic cycle. Mycobacteriophage's genomes carry a lysin A essential gene, whose product cleaves the peptidoglycan (PG) layer and a lysin B, coding for an esterase, that cleaves the linkage between the mycolic acids and the arabinogalactan-PG complex. Lysin A mycobacteriophage proteins are highly modular and in gp29 (LysA) of phage TM4 three distinctive domains were identified. By bioinformatics analysis the central module was previously found to be similar to an amidase-2 domain family with an N-acetylmuramoyl -L-alanine amidase activity. We demonstrated experimentally that purified LysA is able to lyse a suspension of Micrococcus lysodeikticus and can promote cell lysis when expressed in E. coli and Mycobacterium smegmatis. After incubation of LysA with MDP (Muramyl dipeptide, N-acetyl-muramyl-L-alanyl-D-isoglutamine) we detected the presence of N-acetylmuramic acid (NAcMur) and L-Ala- D- isoGlutamine (L-Ala-D-isoGln) corroborating the proposed muramidase activity of this enzyme. This protein was stabilized at acidic pH in the presence of Zn consistent with the increase of the enzymatic activity under these conditions. By homology modeling, we predicted that the Zn ion is coordinated by His 226, His 335, and Asp 347 and we also identified the amino acid Glu 290 as the catalytic residue. LysA activity was completely abolished in derived mutants on these key residues, suggesting that the PG hydrolysis solely relies on the central domain of the protein.
Topics: Computational Biology; Endopeptidases; Escherichia coli; Galactans; Hydrolysis; Mass Spectrometry; Micrococcus; Muramic Acids; Mycobacteriophages; Mycobacterium smegmatis; N-Acetylmuramoyl-L-alanine Amidase; Peptidoglycan; Viral Proteins
PubMed: 34906734
DOI: 10.1016/j.bbapap.2021.140745