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3 Biotech Jul 2021In this study, hydrolytic and oxidative activities of enzymes isolated from halophilic microbes were characterized and applied for biomass utilization. First, lipase...
In this study, hydrolytic and oxidative activities of enzymes isolated from halophilic microbes were characterized and applied for biomass utilization. First, lipase from , and peroxidase and laccase from and were selected and their catalytic activities were determined, respectively. The lipase encoding gene was synthesized after codon-optimization and could be successfully expressed in with the assist of the Tif chaperone protein. The purified enzyme showed 119.13 ± 7.18 and 34.42 ± 5.91 U/mL of lipase and esterase activities, respectively. Moreover, the lipase was applied for hydrolysis of the triglycerides mixture, which resulted in 182.9 ± 11.1 mg/L/h of glycerol productivity. Next, peroxidase and laccase activities of and were determined, and extracellular enzymes of was applied for lignocellulosic biomass degradation, which resulted in 91.9 μg glucose/mg lignocellulose of production yields. Finally, the hydrolytic and oxidative activities of the enzymes from halophilic microbes could be further utilized for biomass treatment and biochemical production.
PubMed: 34295605
DOI: 10.1007/s13205-021-02902-9 -
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 -
Molecules (Basel, Switzerland) Jul 2023A series of novel Mannich bases were designed, synthesized, and screened for their antimicrobial activity. The target compounds were synthesized from...
A series of novel Mannich bases were designed, synthesized, and screened for their antimicrobial activity. The target compounds were synthesized from 4-(3-chlorophenyl)-5-(3-fluorophenyl)-2,4-dihydro-3-1,2,4-triazole-3-thione and different piperazine derivatives. The structures of the products were confirmed by H and C NMR and elemental analysis. The activity of piperazine derivatives against bacteria (Gram-positive: , , , , and ; Gram-negative: , , , and ) and yeasts (, , and ) was determined by the minimum inhibitory concentration and minimum bactericidal concentration values. Significant activity was observed against Gram-positive bacteria, mainly staphylococci (-) and bacteria of the genes of and (), as well as selected strains of Gram-negative bacteria, including bacteria of the family (), while all tested compounds showed high fungistatic activity against spp. yeasts, especially , with MICs ranging from 0.49 µg/mL () to 0.98 µg/mL () and 62.5 µg/mL (). In conclusion, the results obtained confirm the multidirectional antimicrobial activity of the newly synthesized piperazine derivatives. Furthermore, in silico studies suggest that the tested compounds are likely to have good oral bioavailability. The results obtained will provide valuable data for further research into this interesting group of compounds. The library of compounds obtained is still the subject of pharmacological research aimed at finding new interesting biologically active compounds.
Topics: Piperazine; Mannich Bases; Bacteria; Gram-Positive Bacteria; Microbial Sensitivity Tests; Gram-Negative Bacteria; Candida; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 37513434
DOI: 10.3390/molecules28145562 -
PloS One 2022The higher airborne microbial concentration in indoor areas might be responsible for the adverse indoor air quality, which relates well with poor respiratory and general...
The higher airborne microbial concentration in indoor areas might be responsible for the adverse indoor air quality, which relates well with poor respiratory and general health effects in the form of Sick building syndromes. The current study aimed to isolate and characterize the seasonal (winter and spring) levels of culturable bio-aerosols from indoor air, implicating human health by using an epidemiological health survey. Microorganisms were identified by standard macro and microbiological methods, followed by biochemical testing and molecular techniques. Sampling results revealed the bacterial and fungal aerosol concentrations ranging between (300-3650 CFU/m3) and (300-4150 CFU/m3) respectively, in different microenvironments during the winter season (December-February). However, in spring (March-May), bacterial and fungal aerosol concentrations were monitored, ranging between (450-5150 CFU/m3) and (350-5070 CFU/m3) respectively. Interestingly, Aspergillus and Cladosporium were the majorly recorded fungi whereas, Staphylococcus, Streptobacillus, and Micrococcus found predominant bacterial genera among all the sites. Taken together, the elevated levels of bioaerosols are the foremost risk factor that can lead to various respiratory and general health issues in additional analysis, the questionnaire survey indicated the headache (28%) and allergy (20%) were significant indoor health concerns. This type of approach will serve as a foundation for assisting residents in taking preventative measures to avoid exposure to dangerous bioaerosols.
Topics: Air Microbiology; Air Pollution, Indoor; Aspergillus; Bacteria; Cladosporium; Environmental Monitoring; Humans; Seasons; Sick Building Syndrome
PubMed: 35213573
DOI: 10.1371/journal.pone.0264226 -
Bioscience, Biotechnology, and... Sep 2022It is of interest to determine whether and how egg-white proteins are maintained in fertile eggs. We previously observed that egg-white ovalbumin attained high stability...
It is of interest to determine whether and how egg-white proteins are maintained in fertile eggs. We previously observed that egg-white ovalbumin attained high stability during embryogenesis. Herein, we observed that the total mass of egg white and that of its gross protein content showed a decrease according to the days of incubation. The total bacteriolytic activity also lowered, in accord with previous observations. We purified lysozyme from egg-white samples on several incubation days. These purified lysozyme proteins were observed to have enzymatic and bacteriolytic activities against Micrococcus lysodeikticus as well as growth-inhibition potency against Staphylococcus aureus. As the embryogenesis proceeded, the purified lysozyme showed changes in Km and Vmax, a small decrease in the denaturation temperature, and symptoms of an increase in surface hydrophobicity. These results indicate that the lysozyme protein maintained its enzymatic and antibacterial activities until the late period of incubation while undergoing slight conformational changes.
Topics: Animals; Anti-Bacterial Agents; Chickens; Egg White; Embryonic Development; Muramidase; Ovalbumin
PubMed: 35948273
DOI: 10.1093/bbb/zbac133 -
Microbes and Environments 2022Phosphorus (P) is an essential macronutrient for plant growth and is mainly present in agricultural soil in unavailable forms. Phosphate-solubilizing microorganisms...
Phosphorus (P) is an essential macronutrient for plant growth and is mainly present in agricultural soil in unavailable forms. Phosphate-solubilizing microorganisms (PSMs) increase soil P availability. The objective of the present study was to assess the population and type of PSMs and their relationships with soil characteristics in the agricultural soil of Manokwari. Twenty-one composite soil samples (0-20 cm) were collected at the rhizospheres of plants in the Prafi and Masni Districts. A dilution technique and plate count method on Pikovskayas agar medium were used to examine the PSM population, phosphate-solubilizing index (PSI), and various soil properties. The results obtained showed that the total population of phosphate-solubilizing bacteria ranged between 25×10 and 550×10 CFU g of soil, while that of phosphate-solubilizing fungi was between 2.0×10 and 5.0×10 CFU g of soil at all locations. The PSI of the isolates ranged between 1.1 to 3.6 mm, with the most efficient and highest PSI being obtained for Bacillus sp. (strain 8) and the lowest for Pseudomonas sp. (strain 15). Six isolates found at all locations were identified at the genus level: Chromobacterium sp., Pseudomonas sp., Bacillus sp., Micrococcus sp., Caulobacter sp., and Aspergillus sp. A correlation was observed between the number of PSMs and the level of soil P availability and moisture content, indicating an increase in soil P availability with a greater abundance of PSMs in soil.
Topics: Agriculture; Demography; Phosphates; Soil; Soil Microbiology
PubMed: 35342122
DOI: 10.1264/jsme2.ME21041 -
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 -
Applied Microbiology and Biotechnology Dec 2024The myxobacteria are an attractive bioresource for bioactive compounds since the large size genome contains many biosynthetic gene clusters of secondary metabolites. The...
The myxobacteria are an attractive bioresource for bioactive compounds since the large size genome contains many biosynthetic gene clusters of secondary metabolites. The genome of the myxobacterium Melittangium boletus contains three biosynthetic gene clusters for lanthipeptide production. One of the gene clusters includes genes coding lanthipeptide precursor (melA), class II lanthipeptide synthetase (melM), and transporter (melT). The amino acid sequence of melA indicated similarity with that of known lanthipeptides mersacidin and lichenicidin A1 by the alignment. To perform heterologous production of new lanthipeptides, the expression vector containing the essential genes (melA and melM) was constructed by utilizing codon-optimized synthetic genes. The co-expression of two genes in the host bacterial cells of Escherichia coli BL21 (DE3) afforded new lanthipeptides named melittapeptins A-C. The structures of melittapeptins A-C including lanthionine/methyllanthionine bridge pattern were proposed based on protease digestion and MS/MS experiments. The native strain of M. boletus did not produce melittapeptins A-C, so heterologous production using the biosynthetic gene cluster was effective in obtaining the lanthipeptides. Melittapeptins A-C showed specific and potent antibacterial activity to the Gram-positive bacterium Micrococcus luteus. To the best of our knowledge, this is the first report of antibacterial lanthipeptides derived from myxobacterial origin. KEY POINTS: • New lanthipeptides melittapeptins were heterologously produced in Escherichia coli. • Melittapeptins showed specific antibacterial activity against Micrococcus luteus. • Melittapeptins were the first antibacterial lanthipeptides of myxobacterial origin.
Topics: Tandem Mass Spectrometry; Bacteriocins; Amino Acid Sequence; Anti-Bacterial Agents; Myxococcales; Escherichia coli
PubMed: 38229328
DOI: 10.1007/s00253-023-12834-4 -
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