Chemical constituents and bactericidal and fungicide potential of the essential oil of Pimenta dioica Lindl against pathogenic microorganisms

This study evaluated the chemical profile and antimicrobial activity of essential oil (EO) of P. dioica. The EOs were extracted by hydrodistillation and chemically characterized by gas chromatography coupled to mass spectrometry (GC/MS). The total phenolics were quantified by the Folin Ciocalteu method. For the antimicrobial assay, the Disc Diffusion and Broth Dilution method were applied to obtain the minimum inhibitory concentration and minimum bactericidal concentration. The main constituent of the EO was eugenol. The EO showed bactericidal activity against E. coli, S. aureus, P. aeruginosa, Salmonella sp., B. cereus, P. mirabilis, K. pneumoniae, S. sonnei, C. albicans, Fusarium sp., Penicillium sp. and Aspergilus sp. The results obtained are encouraged by the potential use of the EO studied in the control and combat of pathogenic microorganisms.

Profiling of Indigenous Biosurfactant-Producing Bacillus Isolates in the Bioremediation of Soil Contaminated by Petroleum Products and Olive Oil

Petroleum is, up to this date, an inimitable nonrenewable energy resource. Petroleum leakage, which arises during transport, storage, and refining, is the most important contaminant in the environment, as it produces harm to the surrounding ecosystem. Bioremediation is an efficient method used to treat petroleum hydrocarbon-contaminated soil using indigenous microorganisms. The degradation characteristics for a variety of hydrocarbons (hexane, benzene, gasoline, and diesel) were qualitatively and quantitatively investigated using Bacillus isolates. Microbiological and biochemical methods have been used including isolation of oil-degrading bacteria, enzymatic activities, the determination of physicochemical parameters, biosurfactant production and extraction assay, oil displacement assay, antimicrobial assay of the biosurfactants, and bioremediation kinetics. Consequently, of the 60 isolates capable of degrading different hydrocarbons at fast rates, 34 were suspected to be Bacillus isolates capable of growing in 24 h or 48 h on BH medium supplemented with 2% of hexane, benzene, gasoline, diesel, and olive oil, respectively. Among the 34 isolates, 61% (21/34) are capable of producing biosurfactant-like molecules by using gasoline, 70% (24/34) with diesel oil, 85% (29/34) with hexane, and 82% (28/34) with benzene. It was found that biosurfactant-producing isolates are extractable with HCl (100%), ammonium sulphate (95%), chloroform (95%), and ethanol (100%). Biosurfactants showed stability at 20°C, 37°C, 40°C, and 60°C. Biosurfactant secreted by Bacillus strains has shown an antagonistic effect in Escherichia coli, Shigella flexneri 5a M90T, and Bacillus cereus. The selected isolates could therefore be safely used for biodegradation. Substrate biodegradation patterns by individual isolates were found to significantly differ. The study shows that benzene was degraded faster, followed by hexane, gasoline, and finally diesel. The Bacillus consortium used can decrease hydrocarbon content from 195 to 112 (g/kg) in 15 days.

Phytochemical analysis, Antimicrobial and Antioxidant assay of Bhut Jolokia pepper

The presented work represents phytochemical analysis, Antioxidant assay and Antimicrobial activity of Bhut jolokia pepper (Capsicum chinense Jacq) extracted by ethanol as solvent. The ethanolic extract of Bhut jolokia pepper showed the presence of terpenoids, steroids, saponins and flavonoids. Antimicrobial assay was done with varying concentration (250-1000µg/ml) of pepper extract using tetracycline as control by well diffusion method, the extract at 750µg/ml shown best inhibition zone and Staphylococcus aureus showed the highest zone of inhibition at all concentration compared to other bacteria species with maximum zone of inhibition of 27mm. The DPPH scavenging assay for antioxidant activity at 517nm showed positive activity for scavenging, scavenging increased with the concentration of extract. Thus, Bhut jolokia could be effective in treating diseases caused by Staphylococcus aureus from antimicrobial assay result.

Anthraquinones from the Roots of Kniphofia insignis and Evaluation of Their Antimicrobial Activities

Sequential extraction using a cold maceration method and column chromatographic separation of the roots Kniphofia insignis headed to the isolation of three anthraquinones: one monomeric anthraquinone (1) and two dimeric anthraquinones (2 and 3). It was further purified by Sephadex LH-20 and recrystallized. The structures of these compounds were established based on the spectroscopic analyses including NMR (1H-NMR and 13C-NMR and infrared) and comparison with reported literatures. In an in vitro antimicrobial assay of the crude extracts, the isolated compounds were made against four bacterial strains (S. aureus ATCC 25923, B. subtilis ATCC 6633, E. coli ATCC 35218, and P. aeruginosa ATCC 27853) and Fusarium spp. fungal strain. In the crude extracts of chloroform, substantial antimicrobial activity was seen with the highest activity against B. subtilis (16 mm) and E. coli (22 mm). Meanwhile, compound 1 has a better zone of inhibition with 14 mm against P. aeruginosa, whereas compound 2 showed better activity (13 mm) against Fusarium spp. fungal strain.

Potential Antibacterial Activity of Bioactive β-sitosterol from Root Bark of Rhizophora apiculata from Lampung Coastal

β-sitosterol is an essential bioactive phytosterol naturally present in plant cell membranes. It has a coincident structure with animal cholesterol. This investigation reported isolation, structure analysis, and an antimicrobial assay of β-sitosterol from the root bark of Bakau Minyak (Rhizophora apiculata) from Lampung coastal. The isolation of β-sitosterol was carried out through maceration using methanol, separation by vacuum liquid chromatography (VLC), and purification by column chromatography (CC) using ethyl acetate/n-hexane (2:8) as eluent. The structure of β-sitosterol was determined using spectroscopic analysis (UV-Vis, FT-IR, 13C-NMR, 1H-NMR, DEPT, and GC-MS). The pure β-sitosterol has 107.4 mg of white needle crystalline compound, the compound melting point about 140.7-141.2oC, the molecular mass confirmed by m/z 414, and UV absorption detected at λ 203.9 nm. The β-sitosterol antimicrobial bioactivity assay has shown potential activity to be developed as a lead compound against E. coli.

Nanolayered Metal Phosphates as Biocompatible Reservoirs for Antimicrobial Silver Nanoparticles

There is an increasing demand on synthesizing pharmaceuticals and biomaterials that possess antimicrobial and/or antiviral activities. In this respective silver nanoparticles are known for their excellent antimicrobial activity. Nevertheless, their uncontrolled release in a biological medium can induce a cytotoxic effect. For this, we explored the use of nanolayered metal phosphates based on titanium and zirconium as materials that can be enriched with silver nanoparticles. Employing the hydrothermal route, crystalline α-phases of zirconium and titanium phosphates (α-ZrP, α-TiP) were synthesized and there after surface-enriched with silver nanoparticles. The structural assessment confirmed the stability of the structures and their sizes are in the nanoscale at least in one dimension. The cytocompatibility assays confirmed the biocompatibility of the pristine phases and the antimicrobial assay confirmed that both silver-enriched nanolayered structures maintain an antibacterial effect at reasonably low concentrations.