Bioremoval capacity of phenol by some selected endophytic fungi isolated from Hibiscus sabdariffa and batch biodegradation of phenol in paper and pulp effluents.

BACKGROUND AND OBJECTIVES: The use of endophytic fungi for management of phenol residue in paper and pulp industries has been shown as cost-effective and eco-friendly approach. In this study, isolation of endophytic fungi from roots, stems, and leaves of Hibiscus sabdariffa was conducted. Additionally, the isolated fungi were examined for their ability to degrade phenol and its derivatives in paper and pulp industrial samples, using different growth conditions. MATERIALS AND METHODS: Out of 35 isolated endophyitc fungi, 31 were examined for their phenol biodegradation capacity using Czapek Dox broth medium containing Catechol and Resorcinol as a sole carbon source at final concentrations of 0.4, 0.6 and 0.8%. RESULTS: A total of 35 fungal species belonging to 18 fungal genera were isolated and identified from different parts of H. sabdariffa plants. All strains have the capability for degrading phenol and their derivatives with variable extents. The optimum condition of degrading phenol in paper and pulp effluent samples by Fusarium poae11r7 were at pH 3-5, temperature at 28-35°C, good agitation speed at no agitation and 100 rpm. CONCLUSION: All endophytic fungal species can utilize phenol and its derivatives as a carbon source and be the potential to degrade phenol in industrial contaminants.

Three new polyacetylene glycosides (PAGs) from the aerial part of Launaea capitata (Asteraceae) with anti-biofilm activity against Staphylococcus aureus.

Four polyacetylenic glycosides, three of which are new, together with two known flavonoids were isolated from the methanol extract of the aerial parts of Launaea capitate, designated bidensyneoside A1 (1), 6´-O-acetyl-bidensyneoside A1 (2), bidensyneoside E (3), bidensyneoside F (4), luteolin (5) and luteolin-7-glucoside (6) also known as cynaroside. Their structures were elucidated by comprehensive analysis of 1D, 2D-NMR and HR-MS data. The absolute configuration of the bidensyneosides was determined by Mosher ester analysis and the optical rotation values. The isolated compounds were tested against biofilm formation of Staphylococcus aureus as well as against several pathogens including Gram-positive bacteria, Gram-negative bacteria, fungi and yeasts. Furthermore, they were tested for their cytotoxicity against two cancer cell lines L929 and KB-3-1. Compound 4 showed moderate inhibition of S. aureus biofilm formation with 30% and 25% at 256 and 128 µg/mL, respectively, while compounds 1 and 5 showed weak inhibition with 20% at 256 µg/mL. Compound 5 showed moderate cytotoxicity against both cell lines L929 and KB-3-1, with IC50 values of 18 µg/mL.

The role of the endophytic fungus, Thermomyces lanuginosus, on mitigation of heat stress to its host desert plant Cullen plicata.

INTRODUCTION: Endophytic fungi associated with desert plants have a crucial role to enable these plants to tolerate abiotic stress, such as heat and drought. METHODS: In this study, a thermophilic fungal endophyte was isolated from a hot desert-adapted plant, Cullen plicata Delile. The endophytic fungus was (molecularly) identified as Thermomyces lanuginosus, and inoculated plants were coded as E+ and the control as E-. RESULTS: This fungus had an effective growth-promoting activity on its host plant and increased the plant resistance to heat stress as well. DISCUSSION: Our findings demonstrate that thermophilic fungal endophytes can enhance drought and heat stress tolerance in desert plants by ecophysiological mechanisms and improve growth of its host plants.

Metabolomics and Transcriptomics in Legumes Under Phosphate Deficiency in Relation to Nitrogen Fixation by Root Nodules.

Phosphate (Pi) deficiency is a critical environmental constraint that affects the growth and development of several legume crops that are usually cultivated in semi-arid regions and marginal areas. Pi deficiency is known to be a significant limitation for symbiotic nitrogen (N2) fixation (SNF), and variability in SNF is strongly interlinked with the concentrations of Pi in the nodules. To deal with Pi deficiency, plants trigger various adaptive responses, including the induction and secretion of acid phosphatases, maintenance of Pi homeostasis in nodules and other organs, and improvement of oxygen (O2) consumption per unit of nodule mass. These molecular and physiological responses can be observed in terms of changes in growth, photosynthesis, and respiration. In this mini review, we provide a brief introduction to the problem of Pi deficiency in legume crops. We then summarize the current understanding of how Pi deficiency is regulated in legumes by changes in the transcriptomes and metabolomes found in different plant organs. Finally, we will provide perspectives on future directions for research in this field.

Bacillus methylotrophicus ASWU-C2, a strain inhabiting hot desert soil, a new source for antibacterial bacillopyrone, pyrophen, and cyclopeptides.

A strain of Bacillus methylotrophicus was isolated from a soil sample collected in Aswan eastern desert, which is known for its extremely arid climate. After fermentation of the strain in liquid culture and subsequent extraction, a bioassay-guided isolation procedure yielded five compounds: 2-benzyl-4H-pyran-4-one, named bacillopyrone (1), pyrophen (2), macrolactin A (3) and the cyclopeptides malformin A1 (4), and bacillopeptin A (5). The structures were determined by interpretation of nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HR-MS) data. This is the first report on the isolation of compounds 1 and 2 from Bacillus species; compound 1 was reported previously as synthetic product. Bacillopyrone (1) exhibited moderate activity against the Gram-negative Chromobacterium violaceum with minimum inhibitory concentration 266.6 µg/mL, while macrolactin A (3) and malformin A1 (4) inhibited Staphylococcus aureus (minimum inhibitory concentrations 13.3 and 133.3 µg/mL, respectively).

Biodegradation of poly (ε-caprolactone) (PCL) film and foam plastic by Pseudozyma japonica sp. nov., a novel cutinolytic ustilaginomycetous yeast species.

Aliphatic polyesters poly (ε-caprolactone) (PCL) and foam plastic have been shown to be biodegradable by microorganisms, which possess cutinolytic enzymes. Pseudozyma japonica-Y7-09, showed both high growth and enzyme activity on Yeast malt (YM) medium fed with PCL film than on YM medium. The hydrolytic enzyme activity of the culture on p-nitrophenyl butyrate indicated the occurrence of cutinase enzyme. This activity was confirmed by the degradation of PCL film which reached to the maximum (93.33 %) at 15 days and the degradation of foam plastic which reached 43.2 % at 30 days. These results suggest that the extracellular cutinase enzyme of Pseudozyma japonica-Y7-09 may be useful for the biological degradation of plastic wastes.

Identification and biological activity of antifungal saponins from shallot ( Allium cepa L. Aggregatum group).

The n-butanol extract of shallot basal plates and roots showed antifungal activity against plant pathogenic fungi. The purified compounds from the extract were examined for antifungal activity to determine the predominant antifungal compounds in the extract. Two major antifungal compounds purified were determined to be alliospiroside A (ALA) and alliospiroside B. ALA had prominent antifungal activity against a wide range of fungi. The products of acid hydrolysis of ALA showed a reduced antifungal activity, suggesting that the compound's sugar chain is essential for its antifungal activity. Fungal cells treated with ALA showed rapid production of reactive oxygen species. The fungicidal action of ALA was partially inhibited by a superoxide scavenger, Tiron, suggesting that superoxide anion generation in the fungal cells may be related to the compound's action. Inoculation experiments showed that ALA protected strawberry plants against Colletotrichum gloeosporioides , indicating that ALA has the potential to control anthracnose of the plant.

Discovery of a new source of resistance to Fusarium oxysporum, cause of Fusarium wilt in Allium fistulosum, located on chromosome 2 of Allium cepa Aggregatum group.

This study was carried out to evaluate the antifungal effect of Allium cepa Aggregatum group (shallot) metabolites on Fusarium oxysporum and to determine the shallot chromosome(s) related to Fusarium wilt resistance using a complete set of eight Allium fistulosum - shallot monosomic addition lines. The antifungal effects of hexane, butanol, and water extraction fractions from bulbs of shallot on 35 isolates of F. oxysporum were examined using the disc diffusion method. Only hexane and butanol fractions showed high antifungal activity. Shallot showed no symptom of disease after inoculation with F. oxysporum f. sp. cepae. The phenolic content of the roots and the saponin content of root exudates of inoculated shallot increased to much higher levels than those of the control at 3 days after inoculation. Application of freeze-dried shallot root exudates to seeds of A. fistulosum soaked in a spore suspension of F. oxysporum resulted in protection of seedlings against infection. Among eight monosomic addition lines and A. fistulosum, FF+2A showed the highest resistance to Fusarium wilt. This monosomic addition line also showed a specific saponin band derived from shallot on the thin layer chromatography profile of saponins in the eight monosomic addition lines. The chromosome 2A of shallot might possess some of the genes related to Fusarium wilt resistance.

Triterpenes from Euphorbia rigida.

Phytochemical studies of the aerial parts of Euphorbia rigida afforded three triterpenes: betulin (1), cycloart-23Z-ene-3, 25-diol (2) and cycloartan-3, 24, 25-triol (3), firstly isolated from this plant. The structures and relative stereochemistry were determined on the basis of extensive spectroscopic analyses, including 1D and 2D NMR experiments (1H NMR, 13C NMR, COSY, NOESY, HMQC and HMBC).

Cytotoxicity of 3-O-(beta-D-glucopyranosyl) etioline, a steroidal alkaloid from Solanum diphyllum L.

In continuation of our interest in phytochemical screening of the Egyptian flora for potential drugs, the reinvestigation of the methanolic extract of the roots of Solanum diphyllum, which grows naturally in the south of Egypt and is recorded as new to the Egyptian flora, afforded an interesting, highly cytotoxic compound, named 3-O-(beta-D-glucopyranosyl) etioline [(25S)-22,26-epimino-3beta-(beta-D-glucopyranosyloxy) cholesta-5,22(N)-dien-16alpha-ol]. The chemical structure of this compound was determined by comprehensive NMR studies, including DEPT, COSY, HMQC, and MS. The compound exhibited high cytotoxic effects against the cervical cancer cell line, Hela cells, with an IC50 value of 150 microg/mL.

alpha-Tomatine, the major saponin in tomato, induces programmed cell death mediated by reactive oxygen species in the fungal pathogen Fusarium oxysporum.

The tomato saponin alpha-tomatine has been proposed to kill sensitive cells by binding to cell membranes followed by leakage of cell components. However, details of the modes of action of the compound on fungal cells are poorly understood. In the present study, mechanisms involved in alpha-tomatine-induced cell death of fungi were examined using a filamentous pathogenic fungus Fusarium oxysporum. alpha-Tomatine-induced cell death of F. oxysporum (TICDF) occurred only under aerobic conditions and was blocked by the mitochondrial F(0)F(1)-ATPase inhibitor oligomycin, the caspase inhibitor D-VAD-fmk, and protein synthesis inhibitor cycloheximide. Fungal cells exposed to alpha-tomatine showed TUNEL-positive nuclei, depolarization of transmembrane potential of mitochondria, and reactive oxygen species (ROS) accumulation. These results suggest that TICDF occurs through a programmed cell death process in which mitochondria play a pivotal role. Pharmacological studies using inhibitors suggest that alpha-tomatine activates phosphotyrosine kinase and monomeric G-protein signaling pathways leading to Ca(2+) elevation and ROS burst in F. oxysporum cells.