Growth Of Fungal Strains Research Articles

Investigating the antimicrobial activity of neem and clove extract on biofilm-producing oral microflora

Periodontal disease, a serious gum infection, is reported to be widespread in the Indian population. A heterogeneous microbial population, predominantly consisting of gram-negative anaerobes such as Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Porphyromonas intermedia, is associated with periodontal plaque formation. This condition may be worsened by the invasion of soft tissues by different species of Candida. Natural products like clove (Syzygium aromaticum) and Neem (Azadirachta indica) are very popular and easily available in the Indian climate and have great potential in preventing periodontitis. Azadirachta indica (Neem) exhibits versatile modes of action, including reported antimicrobial effects against several species associated with periodontal disease. Therefore, this study aims to detect the antimicrobial and antifungal effects of Neem and clove on oral biofilm both before and after biofilm formation. Results of the study revealed that both neem and clove crude extracts and their different dilution showed a significant reduction in the growth of fungal strains (Candida sp.) isolated from oral samples from people with poor hygiene and the biofilm produced by them.

Biosorption potential and molecular characterization of metal-resistant autochthonous microbes from tannery solid waste.

This study encompasses isolation and screening of heavy metal-resistant fungal and bacterial strains from tannery solid waste (TSW). Twelve fungal strains and 25 bacterial strains were isolated from TSW. The growth of fungal strains was observed against different heavy metals ranging from 10 to 1050mg L-1 and the growth of bacteria was observed in metal concentrations ranging from 10 to 1200mg L-1. Five multi-metal-resistant fungal isolates belonging to the genus Trichoderma and ten bacterial isolates belonging to the genus Bacillus showed good metal resistance and biosorption potential. They were identified through molecular techniques, fungi based on ITS region ribotyping, and bacteria based on 16S rRNA ribotyping. The fungal strains were characterized as T. hamatum (TSWF-06), T. harzianum (TSWF-11), T. lixii (TSWF-02), and T. pseudokoningii (TSWF-03, TSWF-10). The bacterial strains were characterized as Bacillus xiamenensis (TSW-02), B. velezensis (TSW-05), B. piscis (TSW-06), B. safensis (TSW-10), B. subtilis (TSW-14, TSW-15, TSW-17) B. licheniformis (TSW-19), B. cereus (TSW-20), and B. thuringiensis (TSW-22). The fungal strains, namely, T. pseudokoningii (TSWF-03) and T. harzianum, proved to be two multi-metal-resistant strains with good biosorption efficiency. Unlike fungi, bacterial strains showed metal-specific resistance. The strains Bacillus xiamenensis, B. subtilis (TSW-14), and B. subtilis (TSW-15) showed good biosorption efficiency against Cr, B. safensis against Cu, B. piscis, and B. subtilis (TSW-17) against Pb and B. licheniformis and B. thuringiensis against Zn. The autochthonous fungal and bacterial strains can therefore be employed to clean metal-contaminated environments.

Biosynthesis of selenium nanoparticles by Aspergillus flavus and Candida albicans for antifungal applications

Biosynthesis of nanoparticles can replace the available chemical and physical methods by offering new procedures as green syntheses that have proved to be simple, biocompatible, safe, and cost-effective. Recently, antifungal resistance has been reported against different species of Aspergillus and Candida opportunistic fungi. Selenium nanoparticles (Se-NPs) were biosynthesized using standard strains of A. flavus and C. albicans. The presence of NPs was confirmed by UV-Vis, FT-IR, FESEM, EDX, XRD, and Zeta potential. Common fungal strains were cultured in Sabouraud dextrose agar medium to perform the sensitivity test based on the minimum inhibitory concentration (MIC) method in duplicate. The utilization of Se-NPs at concentrations of 1, 0.5, and 0.25 μg/mL or in some strains even more minor than 0.125 μg/mL resulted in zero growth of fungal agents. However, antifungal drugs inhibited their growth at concentrations of 2, 4, 8, 16, and 64 μg/mL itraconazole (ITC). Also, MIC breakpoints for amphotericin B (AMB) and anidulafungin (AFG) were 2 μg/mL for defining resistance in some isolates. Based on the obtained results, biological NPs produced by Aspergillus and Candida at different concentrations exhibited favourable inhibitory effects on the growth of fungal strains.

Ocena oddziaływania na grzyby drożdżopodobne olejku szałwiowego (Oleum Salviae)

Introduction. The essential oils were known and used in ancient Times. The oil and extracts of sage are utilized in folk medicine and for food condiment, in cosmetics and perfumes. Sage (Salvia officinalis) belonging to the Labiatae family. Plant grow all over the world. Sage has a number of properties in it antiflogistic and antimicrobial. The oil is used for the treatment of different kind of diseases, including bronchitis, cough, arthritis, rheumatism, ulcers, inflammation of skin, alimentary tract and in Alzheimer’s disease. Etheric oil contain following compounds: α- and β-thujone, 1,8-cineole, camphor, borneol, α-pinene, β-pinene, β-caryophyllene, β-sabinene, limonene, α-humulene, myrcene, α-terpineol, viridiflorol and camphene. The chemical compounds of the oil have antioxidant and antimicrobial properties. Aim. The aim of the dates was to evaluate the susceptibility of yeastlike fungi to sage. Material and methods. A total 30 strains of yeastlike fungi isolated from patients with oral candidosis was tested. The strains were identified with system API 20 C AUX (BioMèrieux), production chlamydospore and pseudohyphe. The susceptibility (MIC) yeastlike fungi to sage oil was determined by means plate dilution technique in Sabouraud’s agar. The suspension contained 105 CFU per spot were spread Steers replicator over the surface of agar containing oil or without sage agar plates (strains growth control). Inoculated agar plates were incubated in aerobic conditions at 37°C for 24-48 hrs. The MIC was defined as a lowest concentration of the oil inhibited growth of fungal strains. Results. The results indicated that the sage oil was active against yeastlike fungi in concentrations 0.5-≥ 2.0 mg/ml. The MIC for 66% strains from genus Candida albicans ≥ 2.0 mg/ml. Similarly C. krusei strains were susceptible in range 0.5-≥ 2.0 mg/ml. The oil was less active towards C. glabrata and C. tropicalis strains (MIC 1.0-≥ 2.0 mg/ml). The most susceptible were the strains from genus of C. parapsilosis. The growth was inhibited within the range from 0.5 to 1.0 mg/ml. The strain from genus of Rhodotorula rubra was susceptible on 0.12-0.5 mg/ml and Saccharomyces cerevisiae on 0.25 mg/ml. Conclusions. Sage oil showed antifungal activity. The more susceptible to oil were the strains of Candida parapsilosis, Rhodotorula rubra and Saccharomyces cerevisiae. Oil was less active toward strains Candida glabrata, Candida tropicalis and Geotrichum candidum.

Dinuclear rectangular-shaped assemblies of bis-benzimidazolydine salt coordinated to Ag(I) and Cu(I) N-heterocyclic carbene complexes and their biological applications

A benzimidazolydine-based novel ligand L2 was prepared from 1,2-bis(benzimidazol-1-yl)ethane (L1) and synthesis of metallocycle complexes such as Ag(I)–N-Heterocyclic Carbene abbreviated as Ag–NHC and Cu(I)–N-Heterocyclic Carbene complex as Cu–NHC were synthesized and then estimated for antimicrobial and antioxidant properties. Synthesis of Ag–NHC and Cu–NHC metallocycle complexes was described. The benzimidazolydine ligand precursor and its Ag–NHC and Cu–NHC were successfully characterized by FT-IR, FT-Raman, 1D and 2D NMR, HR-ESI mass spectra, and cyclic voltammetric studies. In the present work, antimicrobial study discloses that ligand (L1 and L2) do not show inhibitory activity against various pathogens; however, it was gradually increased, when they were coordinated to metals like Ag and Cu. Among the four compounds, the Ag–NHC strongly hampers the growth of fungal strains. The minimal inhibitory concentration (MIC) ranged between 46 and 750 μg mL−1. A distinctive cell growth reduction was observed in C. albicans when treated with minimum concentration of Ag–NHC complex. Ag–NHC exhibited the ability to prevent the growth of C. albicans by causing severe membrane damage and accumulation of intracellular reactive oxygen species (ROS), which were revealed by fluorescence spectroscopic studies. The tested (L1, L2, Ag–NHC and Cu–NHC) compounds demonstrated significant activity with IC50 values range (0.20–30 μM) for DPPH, OH and NO antioxidant activity. Ascorbic acid was used as standard drug. The radical scavenging potencies of the compounds were explored by employing DPPH, OH and NO assays, in which Ag–NHC exhibited highest inhibitory effect on the radicals [IC50 = 57.3 μM (DPPH), 57.7 μM (OH), 52.3 μM (NO)].

Efficiency of decolorization of different dyes using fungal biomass immobilized on different solid supports.

Different technologies may be used for decolorization of wastewater containing dyes. Among them, biological processes are the most promising because they seem to be environmentally safe. The aim of this study was to determine the efficiency of decolorization of two dyes belonging to different classes (azo and triphenylmethane dyes) by immobilized biomass of strains of fungi (Pleurotus ostreatus – BWPH, Gleophyllum odoratum – DCa and Polyporus picipes – RWP17). Different solid supports were tested for biomass immobilization. The best growth of fungal strains was observed on the washer, brush, grid and sawdust supports. Based on the results of dye adsorption, the brush and the washer were selected for further study. These solid supports adsorbed dyes at a negligible level, while the sawdust adsorbed 82.5% of brilliant green and 19.1% of Evans blue. Immobilization of biomass improved dye removal. Almost complete decolorization of diazo dye Evans blue was reached after 24 h in samples of all strains immobilized on the washer. The process was slower when the brush was used for biomass immobilization. Comparable results were reached for brilliant green in samples with biomass of strains BWPH and RWP17. High decolorization effectiveness was reached in samples with dead fungal biomass. Intensive removal of the dyes by biomass immobilized on the washer corresponded to a significant decrease in phytotoxicity and a slight decrease in zootoxicity of the dye solutions. The best decolorization results as well as reduction in toxicity were observed for the strain P. picipes (RWP17).

English

The present study was initiated to (i) determine burned forest-inhabiting fungi in Zouagha, TerriBeinene, Mila and (ii) study the antagonistic activities of Trichoderma sp against Fusarium sp, Penicillium sp, Rhizoctonia sp, and Alternaria sp. Eighteen fungal strains representing six genera were isolated from soil samples obtained from the burned forest of Zouagha in the Mila region: Trichoderma sp, Fusarium sp, Penicillium sp, Rhizoctonia sp, Alternaria sp, and Rhizopus sp. The direct antagonistic activity assays of Trichoderma sp on Potato Dextrose Agar medium (PDA) against the four fungi: Fusarium sp, Penicillium sp, Rhizoctonia sp, and Alternaria sp revealed that the fungus Trichoderma sp reduced the mycelium growth of Fusarium sp, Penicillium sp, Rhizoctonia sp and Alternaria sp to 23.13, 33.13, 33.75, and 38.31%, respectively, compared to the control after six days at room temperature. The results illustrated an inhibitory action of the antagonist Trichoderma sp characterized by slowing the mycelial growth of fungal strains. Strains of Fusarium sp, Penicillium sp, Rhizoctonia sp and Alternaria sp showed differences in the sensitivity to the antagonist. Because Trichoderma occurred more frequently in burned soils and were more antagonistic to phytopathogenic fungi in culture than isolates from unburned soils, the judicious use of fire may increase the abundance of Trichoderma isolates and their inhibitory action may be used for the control of fungal plant diseases. Key words: Fungi, burned soil, Zouagha, Antagonism, Trichoderma sp.

Growth of fungal strains on coffee industry residues with removal of polyphenolic compounds

Coffee silverskin (CS) and spent coffee grounds (SCG) are abundant residues generated by the coffee industry, but up till now they are practically unutilized being discharged to the environment or burned for elimination. In the present study, the ability of seven different fungal strains from the genera Aspergillus, Mucor, Penicillium, and Neurospora, to grow and release phenolic compounds from these residues under solid-state cultivation conditions was evaluated. All the strains were able to growth on CS and SCG, but Penicillium purpurogenum, Neurospora crassa and Mucor were able to release the highest amounts of phenolic compounds from both residues. Phenolic compounds have wide-range applications in the food and pharmaceutical industries, and thus, the extraction of these compounds could be a valuable alternative for the exploitation of CS and SCG. Additionally, the use of solid-state fermentation to obtain these compounds has a positive environmental impact because the use of chemical solvents is avoided.

Iron(III) complexes: Preparation, characterization, antibacterial activity and DNA-binding

Iron(III) have been combined to well known quinolones (ciprofloxacin) and some Schiff bases with the help of coordination approach. Characterization of these compounds have been done using elemental analysis, magnetic measurements, thermogravimetric analysis, IR, UV-VIS, 1H NMR and 13C NMR spectral investigation. Analytical studies suggest that the iron(III)-quinolone complexes assume a six-coordinated dimeric distorted octahedral geometry. All the compounds show a good antibacterial activity against broad range of bacteria like Bacillus cereus, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi and Serratia marcescens, whereas no significant inhibition towards growth of fungal strains like Aspergillus Niger, Aspergillus flavus and Lasiodiplodia theobromae. Analyses of all these compounds show effective sperm herring DNA inhibition.

Potential of Antimicrobial Agents to Inhibit Fungi to Aid Isolation of Campylobacter

In preliminary studies conducted to isolate thermophilic Campylobacter spp. from cull dairy cow fecal samples, growth of fungal strains on Abeyta-Hunt-Bark agar and charcoal cefoperazone desoxycholate agar (CCDA) interfered with isolation of target bacteria. Concentrations of antifungal substances in the agar media were not effective in suppressing growth of antibiotic resistant fungi. The objective of the current study was to determine the efficacy of supplemental antimicrobial agents to inhibit growth of fungi of fecal origin on Campylobacter isolation media where microbial growth is overwhelmed by fungi. The inhibitory effect of rifampicin and seven antimycotic agents--cycloheximide, 5-fluorouracil, 5-fluorocytosine, sodium propionate, potassium sorbate, nystatin, and amphotericin B--was evaluated. Antimicrobial agents were added singly or combined at concentrations ranging from 12.3 to 227 mg/L. Incubation was conducted at 42 degrees C for 24-48 h in gas jars (CO2+H2). The most effective antibiotic combinations that inhibited fungal growth without affecting Campylobacter growth were CCDA selective supplement SR155E with amphotericin B (59.5 or 114 mg/L) or a mixture of rifampicin, 5-fluorocytosine, and nystatin (119 or 227 mg/L each). Results of the present study indicate that addition of supplemental antifungal agents in the presence of antibiotics such as rifampicin may enhance suppression of fungal overgrowth on Campylobacter isolation agar media.