Prevalence of microbial pathogens in blood cultures: an etiological and histopathological study

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Mejora de la producción de lípidos de un prometedor hongo oleaginoso Aspergillus sp. cepa EM2018 para la formación de biodiesel: optimización de las condiciones de cultivo e identificación

Oleaginous fungi have recently gained increasing attention among different microorganisms due to their ability for lipid production for the preparation of biofuel. In the present study, a locally isolated fungus E45, identified genetically as Aspergillus sp. strain EM2018, was found to produce 25.2% of the total lipids content of its dry cell weight (DCW). Optimization of culture conditions was performed and lipid accumula­tion increased by about 2.4 fold (from 25.2% to 60.1% of DCW) when the fungus was grown for seven days in the potato dextrose (50 g/L) liquid medium at pH 5.0, incubation temperature at 30 ºC and inoculum size of 2 × 106 spore/mL. Supplementation of the medium with yeast extract and NaNO3 at a concentration of 0.05% as organic and inorganic nitrogen sources, respectively, increased lipid production (53.3% lipid/dry biomass). Gas chromatography analysis of fungal lipids revealed the presence of saturated (mainly palmitic acid C16:0 (33%) and lignoceric acid C24:0 (15%)) and unsaturated fatty acids in different proportions (mainly linoleic acid C18:2 (24.4%), oleica cid C18:1 (14%) and arachidonic C20:4 (7.4%). These findings suggest this new oleaginous fungus as a promising feedstock for various industrial applications and for the preparation of biodiesel.Los hongos oleagino­sos recientemente están ganando una creciente atención entre diferentes microorganismos debido a sus capaci­dades de producción de lípidos para la preparación de biocombustibles. En el presente estudio, se descubrió que un hongo E45 aislado localmente, identificado genéticamente como la cepa Aspergillus sp. EM2018, produce un 25,2% de lípidos totales de su peso de células secas (DCW). Se realizó la optimización de las condiciones de cultivo y la acumulación de lípidos se incrementó aproximadamente 2,4 veces (del 25,2% al 60,1% de DCW) cuando el hongo creció durante siete días en un medio líquido de dextrosa de papa (50 g/L) a pH 5.0, 30 °C de temperatura de incubación y 2 × 106 esporas/ml de tamaño de inóculo. La suplementación del medio con extracto de leva­dura y NaNO3 a una concentración de 0,05% como fuentes de nitrógeno orgánico e inorgánico, respectivamente, aumentó aún más la producción de lípidos (53,3% de lípidos/biomasa seca). El análisis mediante cromatografía de gases de los lípidos fúngicos reveló la presencia de ácidos grasos saturados (principalmente palmítico C16:0 (33%) y lignocérico C24:0 (15%)) y ácidos grasos insaturados en diferentes proporciones (principalmente linoleico C18:2 (24.4%), oleico C18:1 (14%) y araquidónico C20:4 (7,4%). Estos hallazgos sugieren que este nuevo hongo oleaginoso es una materia prima prometedora para diversas aplicaciones industriales y preparación de biodiésel

Production and Properties of α-glucosidase from Hansenula anamola

Abstract: A large number of yeast isolates isolated from Egyptian soils were screened qualitatively and quentitavilly for their α-glucosidase activity. Isolate No. 96 was the most active isolate. This isolate was characterized and identified as Hansenula anamola. Results showed that its enzyme was intracellulary produced. Therefore permealization treatments were carried out using chemical and physical treatments. Data clear show that Toluene was the most suitable for releasing active enzyme with a good yield from yeast cell. On the other hand, the enzyme was found to be constitutively synthesized and is highest enzyme production was obtained when sucrose was used in medium with 1% final concentration, followed by maltose. Furthermore, different organic and inorganic nitrogen sources were added separately to the growth medium instead of its nitrogen source was used.The highest enzyme production was obtained in 43 4 the presence of urea followed by (NH ) PO . Partial purification of the enzyme using different saturations of ammonium sulphate followed by gel filtration on Sephadex G-100 was carried out. Studies on the purified enzyme showed that 43 C was the most suitable temperature for activity and the enzyme was o only stable when stored at 35 C for 60 min. At higher temperatures the enzyme was not stable which o clear indicate that the enzyme are not heat stable. In addition pH 7.0 was the most suitable pH for enzyme activity and stability. On the other hand α-glucosidase activity was increased and enhanced in the presence of potassium, ammonium, or magnesium ions in the assay mixture, while lithium or barium shows some inhibitory effects. In addition, enzyme showed high affinity toward ρ-Nitrophenyl-α-Dglucopyranoside followed by Sucrose

Transcriptome data mining towards characterization of single nucleotide polymorphisms (SNPs) controlling salinity tolerance in bread wheat

AbstractHere, we utilize the available next-generation sequencing (NGS) data to develop robust markers differentiating between salt-tolerant and sensitive wheat cultivars. First, we analyzed multi-transcriptomic datasets for salt-tolerant cultivars to identify the shared differentially expressed genes (DEGs). The identified shared DEGs (31 sDEGs) were extracted and compared to available wheat reference genomes to obtain all single-nucleotide polymorphisms (SNPs). Interestingly, six shared SNPs (sSNPs) were identified across four genes including the MIOX-1 gene. For in silico validation of MIOX-1 expression, we compared transcriptomes of salt-tolerant and sensitive wheat cultivars. Interestingly, the expression of the MIOX-1 gene was significantly down-regulated in the tolerant compared to the sensitive. Therefore, the SNP located in the promotor area of the MIOX-1 gene was further analyzed to predict the transcription factor binding sites. The results revealed that the occurrence of this sSNP is irreplaceable and positioned in the WRKY-1 binding site. The expression of the WRKY-1 gene was consistent between salt-tolerant and salt-sensitive wheat cultivars, indicating that the WRKY-1 had no influence on the MIOX-1 gene expression and these SNP might positively affect the salinity tolerance. For SNP in vitro validation, we used two Egyptian cultivars with opposite salinity responses (tolerant: Sakha-93 and sensitive: Gemmeiza-9). The allele-specific polymerase chain reaction results revealed that Gemmeiza-9 was heterozygous (C/G), whereas the Sakha-93 was homozygous (C/C), indicating that these SNPs might affect positively the response of wheat cultivars to tolerate the salinity. Ultimately, these SNPs could serve as a powerful marker for accelerating wheat breeding programs

Bioassay-led isolation of Myrothecium verrucaria and verrucarin A as germination inhibitors of Orobanche crenata

A total of 188 fungal isolates was obtained from the rhizosphere of Vicia faba grown in an Egyptian soil heavily infested with Orobanche species. Agar cultures of 58 isolates inhibited the germination of conditioned seed of Orobanche crenata exposed to the germination stimulant, GR24. Filtrates of inhibitory fungi grown in liquid medium for 9-15 days were also assayed and those of five isolates, which were morphologically similar, inhibited germination even when diluted 16-fold. The fungus was identified as Myrothecium verrucaria (Alb. A Schwein.) Ditmar by its morphology and the nucleotide sequence of the ITS1 and ITS2 regions of the ribosomal repeat unit. Purification of the inhibitor to homogeneity was accomplished by solvent partitioning, flash chromatography on silica gel, semi-preparative HPLC on a reversed phase C18 column, solid phase extraction and tlc on silica gel. The inhibitor was identified as verrucarin A by nuclear magnetic resonance spectroscopy and comparison of the spectra with those of an authentic sample of the compound. A preliminary experiment demonstrated that infection of V. faba by O. crenata could be prevented by addition of spores of the fungus to soil infested by the parasite

Evaluation of Aspergillus tamarii NRC 3 biomass as a biosorbent for removal and recovery of heavy metals from contaminated aqueous solutions

Abstract Background Biomass produced as a byproduct from the β-mannanase production process by Aspergillus tamarii NRC 3was evaluated as a biosorbent for the removal and recovery of some heavy metal ions. Results Under optimal conditions, the isolated strain recorded the highest β-mannanase activity (31.88 Uml−1). Thus, the biomass produced from mannanase production process as a byproduct was evaluated as a biosorbent for the removal and recovery of some heavy metal ions from aqueous solutions and an industrial wastewater. The fungal biomass was found to be efficient for the removal of Cu+2 and some heavy metal ions. The biosorption process of copper(II) by Aspergillus tamarii NRC 3 biomass was affected by changing of time, temperature, pH, metal ions concentration, the presence of some heavy metals, and biomass concentration. The rate of Cu+2 uptake from Cu+2solution proceeded rapidly, and it appeared to be virtually complete during the initial 5 min (92%); the maximum uptake of Cu+2 appeared at 30 °C, pH 5, and biomass concentration 5 g w/w. On the other hand, the fungal biomass was to remove considerable proportion of Pb2+, Co+2, Ni2+, Fe+3, and Cr3+ in addition to Cu2+. The uptake of Cu+2 by pretreated biomass was studied. Recovery of the sorbed metal ions by desorbing agents and the potential reuse of the regenerated biomass in metal ions uptake (reloading) were evaluated. Conclusions Aspergillus tamarii NRC 3 biomass seems to be quite feasible in the removal of heavy metal ions especially Cu+2 from aqueous solutions