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Archives of Microbiology Jul 2022Malathion is widely used as an agricultural insecticide, but its toxic nature makes it a serious environmental contaminant. To screen indigenous bacteria for malathion...
Malathion is widely used as an agricultural insecticide, but its toxic nature makes it a serious environmental contaminant. To screen indigenous bacteria for malathion degradation, a strain MAGK3 capable of utilizing malathion as its sole carbon and energy source was isolated from Pennisetum glaucum agricultural soil. Based on morphological and biochemical characteristics and 16S rDNA sequence analysis, strain MAGK3 was identified as Micrococcus aloeverae. The strain was cultured in the presence of malathion under aerobic and energy-restricting conditions, and it grew well in MSM containing malathion (1000 µl/L), showing the highest specific growth rate at 500 µl/L Reverse-phase UHPLC-DAD analysis indicated that 100%, 90.48%, 84.27%, 75.46%, 66.65%, and 31.96% of malathion were degraded within 15 days in liquid culture augmented with 50, 100, 200, 300, 500, and 1000 µl/L concentrations of commercial malathion, respectively. Confirmation of malathion degradation to malathion mono, diacids, and phosphorus moiety was performed by Q-TOF-MS analysis, and a pathway of biodegradation was proposed. The influence of co-substrates was also examined to optimize biodegradation further. Kinetic studies based on different models were conducted, and the results demonstrated good conformity with the first-order model. Malathion degradation process by Micrococcus aloeverae was characterized by R of 0.95, and the initial concentration was reduced by 50% i.e. (DT50) in 8.11 d at an initial concentration of 500 µl/L. This establishes the Micrococcus sp. as a potent candidate for active bioremediation of malathion in liquid cultures as it can withstand high malathion load and can possibly impact the development strategies of bioremediation for its elimination.
Topics: Biodegradation, Environmental; Kinetics; Malathion; Micrococcus; Soil Microbiology
PubMed: 35834020
DOI: 10.1007/s00203-022-03106-2 -
Materials Science & Engineering. C,... Jan 2019The objective of the present work was to develop immobilized lysozyme systems through adsorption on magnetic nanoparticles for potential usage in bacteria killing...
The objective of the present work was to develop immobilized lysozyme systems through adsorption on magnetic nanoparticles for potential usage in bacteria killing studies. For this, magnetic poly(HEMA-GMA) nanoparticles were prepared by surfactant free emulsion polymerization technique and functionalized with dye ligand Reactive Green 5. Synthesized magnetic nanoparticles were then characterized by FTIR, SEM, EDX and ESR studies. Particle size range of the polymers was found to be as 90-120 nm. Magnetic behavior was also demonstrated by ESR with the g value of 2.48. Maximum lysozyme loading was found to be as 1045.1 mg/g nanopolymer. Repeated usability of the magnetic nanoparticles was also studied. Immobilized form of lysozyme protected 85.85% of its initial activity at the end of the immobilization process. Bacteria killing capacity of the lysozyme immobilized magnetic nanoparticles were investigated by using Micrococcus lysodeikticus bacteria and it was demonstrated that all bacteria were successfully destroyed by the lysozyme immobilized magnetic nanoparticles within 5 min.
Topics: Adsorption; Coloring Agents; Enzymes, Immobilized; Kinetics; Magnetite Nanoparticles; Microbial Viability; Micrococcus; Muramidase; Osmolar Concentration; Spectroscopy, Fourier Transform Infrared
PubMed: 30423740
DOI: 10.1016/j.msec.2018.10.003 -
ACS Applied Materials & Interfaces May 2020Biofilm formation is most commonly combatted with antibiotics or biocides. However, proven toxicity and increasing resistance of bacteria increase the need for...
Biofilm formation is most commonly combatted with antibiotics or biocides. However, proven toxicity and increasing resistance of bacteria increase the need for alternative strategies to prevent adhesion of bacteria to surfaces. Chemical modification of the surfaces by tethering of functional polymer brushes or films provides a route toward antifouling coatings. Furthermore, nanorough or superhydrophobic surfaces can delay biofilm formation. Here we show that submicrometer-sized roughness can outweigh surface chemistry by testing the adhesion of to surfaces of different topography and wettability over long exposure times (>7 days). Gram-negative and positive bacterial strains are tested for comparison. We show that an irregular three-dimensional layer of silicone nanofilaments suppresses bacterial adhesion, both in the presence and absence of an air cushion. We hypothesize that a 3D topography can delay biofilm formation (i) if bacteria do not fit into the pores of the coating or (ii) if bending of the bacteria is required to adhere. Thus, such a 3D topography offers an underestimated possibility to design antibacterial surfaces that do not require biocides or antibiotics.
Topics: Bacterial Adhesion; Biofouling; Escherichia coli; Glass; Hydrocarbons, Fluorinated; Micrococcus luteus; Nanostructures; Pseudomonas fluorescens; Silicones; Wettability
PubMed: 32142252
DOI: 10.1021/acsami.9b22621 -
Journal of Fish Diseases Nov 2018Acute hepatopancreatic necrosis disease (AHPND) was first reported in China in 2009 and afterwards in Mexico in 2013. AHPND is caused by Vibrio parahaemolyticus and...
Acute hepatopancreatic necrosis disease (AHPND) was first reported in China in 2009 and afterwards in Mexico in 2013. AHPND is caused by Vibrio parahaemolyticus and affects Penaeus monodon and Litopenaeus vannamei shrimp cultures. The bacterium contains the pirA- and pirB-like genes in 69- to 70-Kb plasmids, which encode the toxins that produce the disease. The aim of this study was to determine whether pirA- and pirB-like genes existed in bacterial genera distinct from Vibrio before the first cases of AHPND were documented in Mexico. Two bacterial isolates were selected from shrimp farms in Nayarit in 2006 and analysed by nested-PCR to determine the presence of pirA- and pirB-like genes. The two isolates chosen did indeed show the presence of these genes, and those findings were confirmed by sequencing. Both strains matched to the bacterial species Micrococcus luteus. Results revealed two important situations: (a) the pirA- and pirB-like genes were present in a bacterial species that has not been reported previously (Micrococcus luteus); and (b) pirA- and pirB-like bacterial genes were present in Mexico before the first AHPND outbreak was reported in China.
Topics: Animals; Bacterial Proteins; Genes, Bacterial; Mexico; Micrococcus luteus; Penaeidae; Polymerase Chain Reaction
PubMed: 30051482
DOI: 10.1111/jfd.12874 -
Journal of Applied Microbiology Nov 2022To reveal the antibacterial mechanism of protocatechuic acid (PCA) against Micrococcus luteus.
AIM
To reveal the antibacterial mechanism of protocatechuic acid (PCA) against Micrococcus luteus.
METHODS AND RESULTS
M. luteus was exposed to PCA, and the antibacterial mechanism was revealed by measuring membrane potential, intracellular ATP and pH levels and transcriptome analysis. PCA induced the membrane potential depolarization of M. luteus, significantly decreased the intracellular ATP and pH levels of M. luteus and disrupted the integrity of the M. luteus cell membrane. Transcriptome analysis showed that PCA induced 782 differentially expressed genes (DEGs) of M. luteus. GO enrichment analysis revealed that the majority of DEGs are involved in pathways of metabolic process, cellular process, biological regulation and transport activity. In addition, PCA inhibited the growth of M. luteus in skimmed milk and extended the shelf life of skimmed milk.
CONCLUSION
PCA had good bactericidal activity against M. luteus through the mechanism of cell membrane disruption and metabolic process disorder.
SIGNIFICANCE AND IMPACT OF THE STUDY
PCA inhibits the growth of M. luteus in skimmed milk, suggesting that PCA is promising to be used as a novel preservative in food storage.
Topics: Micrococcus luteus; Gene Expression Profiling; Anti-Bacterial Agents; Adenosine Triphosphate; Micrococcus
PubMed: 35996816
DOI: 10.1111/jam.15743 -
Scientific Reports Oct 2021In recent years' synthesis of metal nanoparticle using plants has been extensively studied and recognized as a non-toxic and efficient method applicable in biomedical...
In recent years' synthesis of metal nanoparticle using plants has been extensively studied and recognized as a non-toxic and efficient method applicable in biomedical field. The aim of this study is to investigate the role of different parts of medical plant Carduus crispus on synthesizing silver nanoparticles and characterize the produced nanoparticle. Our study showed that silver nanoparticles (AgNP) synthesized via whole plant extract exhibited a blue shift in absorption spectra with increased optical density, which correlates to a high yield and small size. Also, the results of zeta potential, X-ray diffraction, photon cross-correlation spectroscopy analysis showed the surface charge of - 54.29 ± 4.96 mV (AgNP-S), - 42.64 ± 3.762 mV (AgNP-F), - 46.02 ± 4.17 mV (AgNP-W), the crystallite size of 36 nm (AgNP-S), 13 nm (AgNP-F), 14 nm (AgNP-W) with face-centered cubic structure and average grain sizes of 145.1 nm, 22.5 nm and 99.6 nm. Another important characteristic, such as elemental composition and constituent capping agent has been determined by energy-dispersive X-ray spectroscopy and Fourier transform infrared. The silver nanoparticles were composed of ~ 80% Ag, ~ 15% K, and ~ 7.5% Ca (or ~ 2.8% P) elements. Moreover, the results of the FTIR measurement suggested that the distinct functional groups present in both AgNP-S and AgNP-F were found in AgNP-W. The atomic force microscopy analysis revealed that AgNP-S, AgNP-F and AgNP-W had sizes of 131 nm, 33 nm and 70 nm respectively. In addition, the biosynthesized silver nanoparticles were evaluated for their cytotoxicity and antibacterial activity. At 17 µg/ml concentration, AgNP-S, AgNP-F and AgNP-W showed very low toxicity on HepG2 cell line but also high antibacterial activity. The silver nanoparticles showed antibacterial activity on both gram-negative bacterium Escherichia coli (5.5 ± 0.2 mm to 6.5 ± 0.3 mm) and gram-positive bacterium Micrococcus luteus (7 ± 0.4 mm to 7.7 ± 0.5 mm). Our study is meaningful as a first observation indicating the possibility of using special plant organs to control the characteristics of nanoparticles.
Topics: Anti-Bacterial Agents; Carduus; Escherichia coli; Hep G2 Cells; Humans; Metal Nanoparticles; Micrococcus luteus; Silver
PubMed: 34702916
DOI: 10.1038/s41598-021-00520-2 -
Brazilian Journal of Microbiology :... Jun 2024In recent years, some microorganisms have shown resistance to conventional treatments. Considering this increase in resistant pathogens, treatment alternatives are...
In recent years, some microorganisms have shown resistance to conventional treatments. Considering this increase in resistant pathogens, treatment alternatives are needed to promote greater treatment efficiency. In this sense, antimicrobial photodynamic therapy (aPDT) has been an alternative treatment. This technique uses a photosensitizer that is activated by light with a specific wavelength producing reactive species, leading to the death of pathogenic microorganisms. In this study, bacteriochlorophyll derivatives such as bacteriochlorin metoxi (Bchl-M) and bacteriochlorin trizma (Bchl-T) obtained from purple bacterium (Rhodopseudomonas faecalis), were evaluated as photosensitizers in the aPDT. Photodynamic inactivation (PDI) of the microorganisms Staphylococcus aureus, Micrococcus luteus, Candida albicans and Pseudomonas aeruginosa was investigated with both bacteriochlorins (Bchl-M and Bchl-T) at different concentrations (1, 15 and 30 µM for S. aureus; 1, 15, 30, 45, 60 and 75 µM for M. luteus; 30, 60, 90, 105, 120 and 150 µM for C. albicans; and 200 µM for P. aeruginosa) and different doses of light (20 and 30 J/cm for S. aureus and M. luteus; 30 and 45 J/cm for C. albicans; and 45 J/cm for P. aeruginosa) to inactivate them. Both photosensitizers showed good activation against S. aureus and for M. luteus, we observed the inactivation of these microorganisms at approximately 3 log, showing to be a good photosensitizers for these microorganisms.
Topics: Photosensitizing Agents; Candida albicans; Pseudomonas aeruginosa; Staphylococcus aureus; Light; Photochemotherapy; Porphyrins; Microbial Viability; Micrococcus luteus; Bacteria
PubMed: 38378880
DOI: 10.1007/s42770-024-01278-1 -
Food & Function Jul 2021Traditional fermented fish products are favored due to their unique flavors. The fermentation process of fish is accompanied by the formation of flavor substances... (Review)
Review
Traditional fermented fish products are favored due to their unique flavors. The fermentation process of fish is accompanied by the formation of flavor substances through a complex metabolic reaction of microorganisms, especially lipolysis and lipid oxidation. However, it is difficult to precisely control the reaction of microorganisms during the fermentation process in modern industrial production, and fermented fish products have lost their traditional characteristic flavors. The purpose of this review is to summarize the different kinds of fermented fish, core microorganisms in it, and flavor formation mechanisms, providing guidance for industrial cultural starters. Future research on the flavor formation mechanism is necessary to confirm the relationship between flavor formation, lipid metabolism, and microorganisms to ensure stable flavor and safety, and to elucidate the mechanism directly toward industrial application.
Topics: Animals; Bacillus; Bioreactors; Fermentation; Fish Products; Fishes; Food Microbiology; Humans; Lactobacillus; Lipid Metabolism; Lipolysis; Micrococcus; Oxidation-Reduction; Taste; Yeasts
PubMed: 34037049
DOI: 10.1039/d1fo00692d -
The Journal of Antibiotics Aug 2019A new catecholate-containing siderophore, labrenzbactin (1), was isolated from the fermentation broth of a coral-associated bacterium Labrenzia sp. The structure and...
A new catecholate-containing siderophore, labrenzbactin (1), was isolated from the fermentation broth of a coral-associated bacterium Labrenzia sp. The structure and absolute configuration of 1 was determined by spectroscopic methods and Marfey's analysis. Overall, 1 showed antimicrobial activity against Ralstonia solanacearum SUPP1541 and Micrococcus luteus ATCC9341 with MIC values of 25 and 50 µg ml, respectively, and cytotoxicity against P388 murine leukemia cells with an IC of 13 µM.
Topics: Alphaproteobacteria; Animals; Anthozoa; Anti-Bacterial Agents; Antibiotics, Antineoplastic; Catechols; Drug Screening Assays, Antitumor; Fermentation; Leukemia P388; Mice; Microbial Sensitivity Tests; Micrococcus luteus; Molecular Structure; Oxazoles; Ralstonia; Siderophores
PubMed: 31118481
DOI: 10.1038/s41429-019-0192-x -
International Journal of Cancer Apr 2021The underlying molecular mechanisms involved in the pathogenesis of endometrial cancer (EC) are still not well understood. Our goal was to investigate the composition...
The underlying molecular mechanisms involved in the pathogenesis of endometrial cancer (EC) are still not well understood. Our goal was to investigate the composition of the endometrial microbiota and the association with inflammatory cytokines in EC. Endometrial microbiota profiles of women with EC (n = 25) and benign uterine lesions (BUL, n = 25) were assessed by 16S ribosomal RNA gene amplicon sequencing. The expression levels of interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-17 (IL-17) mRNA and protein in the endometrial tissues of the two groups were determined by real-time quantitative polymerase chain reaction and Western blot, respectively. There were significant differences in alpha diversity based on the observed operational taxonomic units (P = .002), Pielou evenness (P = .001), and Shannon index (P < .001) between EC and BUL groups. Significant differences were also found in Bray-Curtis (P = .001) and unweighted UniFrac (P = .001) beta diversity measures between the two groups. At the genus level, Micrococcus was more abundant in the EC group. Pseudoramibacter_Eubacterium, Rhodobacter, Vogesella, Bilophila, Rheinheimera, and Megamonas were enriched in the BUL group. There were no differences in IL-8 and IL-17 protein levels between the two groups, except IL-6 protein levels. However, the mRNA expression levels of IL-6, IL-8, and IL-17 were significantly different. Moreover, the relative abundances of Micrococcus was positively correlated with IL-6, and IL-17 mRNA levels. In conclusion, our results suggested that dysbiosis of endometrial microbiota and the inflammatory cytokines were associated with Micrococcus in EC patients, which might be useful for exploration of the mechanism between the endometrial microbiota and inflammatory responses in future studies.
Topics: Bilophila; Correlation of Data; Cytokines; Dysbiosis; Endometrial Neoplasms; Female; Firmicutes; Humans; Interleukin-17; Interleukin-6; Interleukin-8; Microbiota; Micrococcus; Middle Aged; RNA, Ribosomal, 16S; Real-Time Polymerase Chain Reaction; Rhodobacter
PubMed: 33285000
DOI: 10.1002/ijc.33428