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FEBS Open Bio Mar 2019The emergence of new antibiotic-resistant bacterial strains means it is increasingly important to find alternatives to traditional antibiotics, such as bacteriolytic...
The bacteriolytic activity of native and covalently immobilized lysozyme against Gram-positive and Gram-negative bacteria is differentially affected by charged amino acids and glycine.
The emergence of new antibiotic-resistant bacterial strains means it is increasingly important to find alternatives to traditional antibiotics, such as bacteriolytic enzymes. The bacteriolytic enzyme lysozyme is widely used in medicine as an antimicrobial agent, and covalent immobilization of lysozyme can expand its range of possible applications. However, information on the effect of such immobilized preparations on whole bacterial cells is quite limited. Here, we demonstrate the differential effects of glycine and charged (basic and acidic) amino acids on the enzymatic lysis of Gram-positive and Gram-negative bacteria by soluble and immobilized lysozyme. Glycine and basic amino acids (histidine, lysine, and arginine) significantly increase the rate of lysis of Gram-negative cells in the presence of soluble lysozyme, but they do not substantially affect the rate of enzymatic lysis of Gram-positive . Glutamate and aspartate significantly enhance enzymatic lysis of both and . When using immobilized lysozyme, the effects of amino acids on the rate of cell lysis are significantly reduced. For immobilized lysozyme, the presence of an external diffusion mode on cell lysis kinetics at bacterial concentrations below 4 × 10 colony-forming units·mL was shown. The broadening of the pH optimum of lysozyme activity after immobilization has been demonstrated for both Gram-positive and Gram-negative bacteria. The Michaelis constant () values of immobilized lysozyme were increased by 1.5-fold for cell lysis and 4.6-fold for cell lysis compared to soluble enzyme. A greater understanding of the effect of amino acids on the activity of native and immobilized lysozyme is important for both the development of new materials for medical purposes and elucidating the interaction of lysozyme with bacterial cells. Of particular interest is our finding that lysozyme activity against Gram-negative bacteria is enhanced in the presence of glycine and charged amino acids over a wide range of concentrations.
Topics: Amino Acids; Animals; Anti-Bacterial Agents; Chickens; Enzymes, Immobilized; Escherichia coli; Glycine; Microbial Sensitivity Tests; Micrococcus luteus; Muramidase; Particle Size; Sepharose; Surface Properties
PubMed: 30868059
DOI: 10.1002/2211-5463.12591 -
Molecules (Basel, Switzerland) Apr 2017The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of L....
The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of L. in refined and unrefined form was characterized using iodine, saponification, acid values, and gas chromatography, and was employed for the preparation of stable oil-in-water emulsions. The emulsions were prepared using pairs of non-ionic surfactants (Tween, Span). The effects of the emulsification method (spontaneous emulsification vs. high-intensity stirring), hydrophilic lipophilic balance (HLB), type and concentration of surfactant, and oil type on the size and distribution of the emulsion particles were investigated. It was found that the ability to form stable emulsions with small, initial particle sizes is primarily dependent on the given method of preparation and the HLB value. The most efficient method of emulsification that afforded the best emulsions with the smallest particles (151 ± 1 nm) comprised the high-energy method, and emulsions stable over the long-term were observed at HBL 9 with 10 wt % concentration of surfactants. Under high-intensity emulsification, refined and unrefined oils performed similarly. The oils as well as their emulsions were tested against the growth of selected bacteria using the disk diffusion and broth microdilution methods. The antibacterial effect of hemp seed oil was documented against and subsp. . The formulated emulsions did not exhibit the antibacterial activity that had been anticipated.
Topics: Anti-Bacterial Agents; Cannabis; Emulsions; Hydrophobic and Hydrophilic Interactions; Microbial Sensitivity Tests; Micrococcus luteus; Particle Size; Plant Extracts; Plant Oils; Seeds; Staphylococcus aureus
PubMed: 28448475
DOI: 10.3390/molecules22050700 -
Folia Microbiologica Jul 2017Myxobacteria, a group of antimicrobial producing bacteria, have been successfully cultured and characterized from ten soil samples collected from different parts of...
Myxobacteria, a group of antimicrobial producing bacteria, have been successfully cultured and characterized from ten soil samples collected from different parts of Slovakia. A total of 79 myxobacteria belonging to four genera (Myxococcus, Corallococcus, Sorangium, and Polyangium) were isolated based on aspects of their life cycle. Twenty-five of them were purified, fermented, and screened for antimicrobial activities against 11 test microorganisms. Results indicated that crude extracts showed more significant activities against Gram-positive than against Gram-negative bacteria or fungi. Based on a higher degree and broader range of antimicrobial production, the two most potential extracts (K9-5, V3-1) were selected for HPLC fractionation against Micrococcus luteus and Staphylococcus aureus and LC/MS analysis of potential antibiotic metabolites. The analysis resulted in the identification of polyketide-peptide antibiotics, namely corallopyronin A and B (K9-5) and myxalamid B and C (V3-1), which were responsible for important Gram-positive activity in the observed strains. A sequence similarity search through BLAST revealed that these strains showed the highest sequence similarity to Corallococcus coralloides (K9-5, NCBI accession number KX256198) and Myxococcus xanthus (V3-1, NCBI accession number KX256197). Although screening of myxobacteria is laborious, due to difficulties in isolating cultures, this research represented the first report covering the isolation and cultivation of this challenging bacterial group from Slovakian soils as well as the screening of their antimicrobial activity, cultural identification, and secondary metabolite identification.
Topics: Anti-Bacterial Agents; Micrococcus luteus; Myxococcales; Phylogeny; Polyketides; Soil Microbiology; Staphylococcus aureus
PubMed: 28161814
DOI: 10.1007/s12223-017-0502-2 -
Microorganisms Apr 2021Although malodour formation on textiles and in washing machines has been reported to be a very relevant problem in domestic laundry, the processes leading to bad odours...
Although malodour formation on textiles and in washing machines has been reported to be a very relevant problem in domestic laundry, the processes leading to bad odours have not been studied intensively. In particular, the smell often described as "wet-and-dirty-dustcloth-like malodour" had not been reproduced previously. We developed a lab model based on a bacterial mixture of , , and , which can produce this odour type and which might allow the detailed investigation of this problem and the development of counteractions. The model uses bacterial strains that have been isolated from malodourous textiles. We could also show that the three volatile compounds dimethyl disulfide, dimethyl trisulfide, and indole contribute considerably to the "wet-fabric-like" malodour. These substances were not only found to be formed in the malodour model but have already been identified in the literature as relevant malodourous substances.
PubMed: 33946384
DOI: 10.3390/microorganisms9050974 -
The Journal of Antibiotics Mar 2024A novel actinobacterial strain, designated as JXJ CY 30 , was isolated from the phycosphere of Microcystis aeruginosa FACHB-905 (Maf) collected from Lake Dianchi,...
A novel actinobacterial strain, designated as JXJ CY 30 , was isolated from the phycosphere of Microcystis aeruginosa FACHB-905 (Maf) collected from Lake Dianchi, China. The strain was a Gram-stain-positive, aerobic and coccus-shaped actinobacterium. It had alanine, glutamic acid, aspartic acid, and lysine in the peptidoglycan, and mannose, ribose and arabinose in its cell wall sugars, anteiso-C and iso-C as the main cellular fatty acids, MK-7 and MK-8 as the major respiratory quinones, and phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, glycolipid, and an unidentified phospholipid as the polar lipids. The DNA G + C content was 73.08%. Its 16 S rRNA gene sequence shared 99.14%, and 98.75% similarities with Micrococcus flavus DSM 19079 and M. porci KD337-16, respectively, and ≤98.41% similarities with other type strains of the genus Micrococcus. It formed independent clade with M. flavus DSM 19079 on the phylogenetic trees. The digital DNA-DNA hybridization and average nucleotide identity values between strain JXJ CY 30 and M. flavus DSM 19079 and M. porci KD337-16 were 48.0% and 92.1%, 25.5% and 83.2%, respectively. These data above indicated that strain JXJ CY 30 represented a new species of the genus Micrococcus, and the species epithet is proposed as Micrococcus lacusdianchii sp. nov. (type strain JXJ CY 30 = KCTC 49378 = CGMCC 1.17508 ). Strain JXJ CY 30 can potentially provide Maf with various nutrients such as available phosphorus and nitrogen, plant hormones, various vitamins and carotenoids for growth, while it was inhibited by metabolites from its symbiotic algae Maf.
Topics: Phylogeny; Micrococcus; Phospholipids; Fatty Acids; DNA; RNA, Ribosomal, 16S; DNA, Bacterial; Sequence Analysis, DNA; Bacterial Typing Techniques; Vitamin K 2
PubMed: 38148391
DOI: 10.1038/s41429-023-00690-3 -
International Journal of Biological... Sep 2021Marine microorganisms are reported to produce polyhydroxybutyrate (PHB) that has wide range of medical and industrial applications with the advantage of...
Marine microorganisms are reported to produce polyhydroxybutyrate (PHB) that has wide range of medical and industrial applications with the advantage of biodegradability. PHBs are synthesized as an energy and carbon storage element under metabolic pressure. The scope of this work is enhancing PHB production using marine microbial isolate, Micrococcus luteus by selectively optimizing various growth conditions such as different media components and growth parameters that influence the cell growth and PHB production were sampled. Micrococcus luteus produced 7.54 g/L of PHB utilizing glucose as a carbon source and ammonium sulphate as a nitrogen source with maximum efficiency. The same optimized operational conditions were further employed in batch fermentation over a time span of 72 h. Interestingly higher cell dry weight of 21.52 g/L with PHB yield of 12.18 g/L and 56.59% polymer content was observed in batch fermentation studies at 64 h. The chemical nature of the extracted polymer was validated with physio-chemical experiments and was at par with the commercially available PHB. This study will spotlight M. luteus as a potential source for large-scale industrial production of PHB with reducing environmental pollutions.
Topics: Butyrates; Fermentation; Geologic Sediments; Hydrogen-Ion Concentration; Hydroxybutyrates; Industrial Microbiology; Micrococcus luteus; Molecular Structure; Temperature; Time Factors
PubMed: 34246666
DOI: 10.1016/j.ijbiomac.2021.07.029 -
Journal of Insect Physiology Apr 2017Immune function is often involved in physiological trade-offs because of the energetic costs of maintaining constitutive immunity and mounting responses to infection....
Immune function is often involved in physiological trade-offs because of the energetic costs of maintaining constitutive immunity and mounting responses to infection. However, immune function is a collection of discrete immunity factors and animals should allocate towards factors that combat the parasite threat with the highest fitness cost. For example, animals on dispersal fronts of expanding population may be released from density-dependent diseases. The costs of immunity, however, and life history trade-offs in general, are often context dependent. Trade-offs are often most apparent under conditions of unusually limited resources or when animals are particularly stressed, because the stress response can shift priorities. In this study we tested how humoral and cellular immune factors vary between phenotypes of a wing dimorphic cricket and how physiological stress influences these immune factors. We measured constitutive lysozyme activity, a humoral immune factor, and encapsulation response, a cellular immune factor. We also stressed the crickets with a sham predator in a full factorial design. We found that immune strategy could be explained by the selective pressures encountered by each morph and that stress decreased encapsulation, but not lysozyme activity. These results suggest a possible trade-off between humoral and cellular immunity. Given limited resources and the expense of immune factors, parasite pressures could play a key factor in maintaining insect polyphenism via disruptive selection.
Topics: Animals; Female; Gryllidae; Immunity, Cellular; Immunity, Humoral; Micrococcus; Muramidase; Phenotype; Stress, Physiological; Wings, Animal
PubMed: 28109904
DOI: 10.1016/j.jinsphys.2017.01.009 -
Natural Product Research May 2019A new eremophilane sesquiterpene, xylareremophil (1), together with five known eremophilanes, 1α,10α-epoxy-3α-hydroxyeremophil-7(11)-en-12,8β-olide (2),...
A new eremophilane sesquiterpene, xylareremophil (1), together with five known eremophilanes, 1α,10α-epoxy-3α-hydroxyeremophil-7(11)-en-12,8β-olide (2), 1,10α,13-trihydroxyeremophil-7(11)-en-12,8-olide (3), 1α,10α-epoxy-13-hydroxyeremophil-7(11)-en-12,8β-olide (4), mairetolides B (5) and G (6) were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from Sophora tonkinensis. Their structures were elucidated on the basis of spectroscopic data analysis. The absolute configurations of 1 was determined by comparing computed electronic circular dichroism (ECD) and optical rotation (OR) with experimental results. Compounds 1, 5 and 6 showed antibacterial activities against Proteus vulgaris, Micrococcus luteus, Micrococcus lysodeikticus and Bacillus subtilis with MIC values of 25-100 μg/mL.
Topics: Anti-Bacterial Agents; Bacillus subtilis; Circular Dichroism; Drug Evaluation, Preclinical; Endophytes; Microbial Sensitivity Tests; Micrococcus luteus; Molecular Structure; Sesquiterpenes; Sophora; Xylariales
PubMed: 29764195
DOI: 10.1080/14786419.2018.1472597 -
Investigative Ophthalmology & Visual... Jun 2018The aim of this study was to examine cohesion, coaggregation, and coculture between bacteria commonly isolated from contact lens cases.
PURPOSE
The aim of this study was to examine cohesion, coaggregation, and coculture between bacteria commonly isolated from contact lens cases.
METHODS
Staphylococcus epidermidis, Staphylococcus haemolyticus, Micrococcus luteus, and Acinetobacter radioresistens (two strains each) isolated from contact lens cases of two asymptomatic wearers were used in this study. In the cohesion assay, bacteria were grown, washed, and examined by incubating lens cases with two different types of bacteria sequentially and assessing the number of adhered cells of each isolate. The ability of isolates to interfere with the growth of other isolates was tested by growing strains in cocultures for 24 hours and determining the numbers of cells of individual strains. For coaggregation, equal proportions of two bacterial suspensions were mixed and allowed to coaggregate for 24 hours. Inhibition of coaggregation was tested by the addition of lactose (0.06 M) or sucrose (0.06 M) or pronase.
RESULTS
The initial adhesion of M. luteus or A. radioresistens significantly (P < 0.05) enhanced the subsequent adhesion of the staphylococci. The addition of A. radioresistens in liquid media significantly (P < 0.05) enhanced the growth of staphylococci. S. epidermidis or S. haemolyticus coaggregated with M. luteus or A. radioresistens. The degree of coaggregation varied between 30% and 54%. The highest coaggregation (54% ± 5%) was seen between A. radioresistens 22-1 and S. epidermidis 22-1, isolated from the same lens case. Only lactose or sucrose treatment of staphylococci could partly inhibit coaggregation of some pairs.
CONCLUSIONS
Coaggregation, cohesion, and growth promotion may facilitate the process of bacterial colonization of contact lens cases.
Topics: Acinetobacter; Bacteria; Bacterial Adhesion; Bacteriological Techniques; Contact Lenses; Equipment Contamination; Micrococcus luteus; Staphylococcus epidermidis; Staphylococcus haemolyticus
PubMed: 29860459
DOI: 10.1167/iovs.17-23155 -
Scientific Reports Jan 2020A desert soil sample was saturated with crude oil (17.3%, w/w) and aliquots were diluted to different extents with either pristine desert or garden soils. Heaps of all...
A desert soil sample was saturated with crude oil (17.3%, w/w) and aliquots were diluted to different extents with either pristine desert or garden soils. Heaps of all samples were exposed to outdoor conditions through six months, and were repeatedly irrigated with water and mixed thoroughly. Quantitative determination of the residual oil in the samples revealed that oil-bioremediation in the undiluted heaps was nearly as equally effective as in the diluted ones. One month after starting the experiment. 53 to 63% of oil was removed. During the subsequent five months, 14 to 24% of the oil continued to be consumed. The dynamics of the hydrocarbonoclastic bacterial communities in the heaps was monitored. The highest numbers of those organisms coordinated chronologically with the maximum oil-removal. Out of the identified bacterial species, those affiliated with the genera Nocardioides (especially N. deserti), Dietzia (especially D. papillomatosis), Microbacterium, Micrococcus, Arthrobacter, Pseudomonas, Cellulomonas, Gordonia and others were main contributors to the oil-consumption. Some species, e.g. D. papillomatosis were minor community constituents at time zero but they prevailed at later phases. Most isolates tolerated up to 20% oil, and D. papillomatosis showed the maximum tolerance compared with all the other studied isolates. It was concluded that even in oil-saturated soil, self-cleaning proceeds at a normal rate. When pristine soil receives spilled oil, indigenous microorganisms suitable for dealing with the prevailing oil-concentrations become enriched and involved in oil-biodegradation.
Topics: Actinobacteria; Arthrobacter; Biodegradation, Environmental; Environmental Pollution; Micrococcus; Nocardioides; Petroleum; Soil Microbiology; Soil Pollutants
PubMed: 31980664
DOI: 10.1038/s41598-019-57224-x