Kinetic modeling and optimization of ethanol fermentation by the marine yeast Wickerhamomyces subpelliculosus ZE75.

The study aims to enhance ethanol production by Wickerhamomyces subpelliculosus ZE75 isolated from marine sediment. In addition, analyzing the kinetic parameters of ethanol production and optimization of the fermentation conditions was performed. The marine yeast isolate ZE75 was selected as the front runner ethanol-producer, with an ethanol yield of 89.77 gL-1. ZE75 was identified relying on the phenotypic and genotypic characteristics of W. subpelliculosus. The genotypic characterization based on the Internal Transcribed Spacer (ITS) sequence was deposited in the GenBank database with the accession number OP715873. The maximum specific ethanol production rate (vmax) was 0.482 gg-1 h-1 at 175 gL-1 glucose concentration, with a high accuracy of R2 0.95. The maximum growth specific rates (µmax) were 0.141 h-1 obtained at 150 gL-1 glucose concentration with R2 0.91. Optimization of the fermentation parameters such as pH and salinity has been achieved. The highest ethanol yield 0.5637 gg-1 was achieved in a 100% natural seawater-based medium. The maximum ethanol production of 104.04 gL-1 was achieved at pH 4.5 with a specific ethanol rate of 0.1669 gg-1 h-1. The findings of the present study recommend the possibility of ethanol production from a seawater-based medium on a large scale using W. subpelliculosus ZE75.

Neuro-immunohistochemical and molecular gene expression variations during hibernation and activity phases between Rana mascareniensis and Rana ridibunda.

Low temperatures and the lack of food during the winter lead the marsh frog Rana ridibunda and the grass frog Rana mascareniensis to hibernate in order to survive. The present study aimed to investigate the cytoarchitecture of brain sub-regions affected by the thermal cycle's fluctuations during the hibernation and activity period, besides the regional distribution quantitative expression of Na(+)/K(+)-ATPase and Pax6 transcriptional factor, the molecular gene expressions of some heat shock proteins, uncoupling protein, and metallothionein. The two frog species were isolated from the field during summer and hibernation time in winter. During hibernation it was notable the destitution of degenerated, pyknotic and vasogenic neurons in different brain areas with high rate nearby the pallium. The immunohistochemical expression of Na+/ K+-ATPase and Pax 6 is decreased during hibernation in different brain sub-regions in the two species suggesting their tendency for energy conservation strategy during hibernation. Additionally, RT-qPCR recorded the up regulation of a number of heat shock protein genes during hibernation with sharing increase between two species for hsp90 besides and the non-significant expression in summer and hibernation periods for hsp47 for both species. Moreover, uncoupling protein (ucp1and ucp2) and metallothionein genes in olfactory bulb were with significant up regulation during the hibernation suggesting that these proteins possibly have a protective effect against reactive oxygen species ROS. So, brain adaptations to low temperature play a crucial role in coordinating stress responses. The present study shed light on the importance of the olfactory bulb in the thermoregulation and sensation of temperature elevations during the hibernation period and defended by the expression of heat shock proteins and uncoupling proteins preventing the cellular damage and proteins misfolding. Neuronal energy production and regeneration activities among amphibians are markedly reduced with decreasing body temperature.

Direct transesterification of fatty acids produced by Fusarium solani for biodiesel production: effect of carbon and nitrogen on lipid accumulation in the fungal biomass.

AIMS: The present work aims to explore a new oleaginous Fusarium isolate potential to accumulate lipids in its biomass from inexpensive substrates. In addition, impacts of carbon and nitrogen sources and their ratios on lipid production by the interested fungal isolate were also studied. METHODS AND RESULTS: Lipid was assayed by sulfo-phospho-vanillin colorimetric method. Among 11 Fusarium isolates obtained on potato dextrose agar from rhizosphereic soils, Fusarium RAS18 was selected as the highest producer that accumulates above 20% lipid. It was identified based on phenotypic characterization and the internal transcribed spacer sequence as Fusarium solani, that was recorded in the GenBank database under the accession number MK167372.1. The optimized lipid yield (34·5%) is obtained using glycerol (35 g l-1 ) and peptone (1·5 g l-1 ) as carbon and nitrogen sources respectively. The produced fatty acid methyl esters (biodiesel) is composed of linoleic acid (56·81%), palmitic acid (17·81%), oleic acid (11·81%) and stearic acid (11·12). The unsaturated fatty acids accounted for 69% and this is nearly similar to the plant oils commonly used in biodiesel production. CONCLUSIONS: These findings suggest the applicability of F. solani RAS18 as a promising strain to accumulate lipids from glycerol as a feedstock for biodiesel production. SIGNIFICANCE AND IMPACT OF THE STUDY: Fusarium solani RAS18 is a new oleaginous fungal isolate that is able to produce lipid (34·5%, g g-1 ) from glycerol. Glycerol is a cheap substrate and is formed as a byproduct from transesterification process and others industries. Thus, recyclation of glycerol for lipid production by micro-organisms is an important point of economic view. Direct transesterification of the produced fatty acids indicated its similarity to the plant oil composition used in biodiesel production. So, F. solani RAS18 might be a potential lipid source as a feedstock for biodiesel production.

The action mechanism and biocontrol potentiality of novel isolates of Saccharomyces cerevisiae against the aflatoxigenic Aspergillus flavus.

Inhibition of Aspergillus flavus growth and its aflatoxins production using the biocontrol agent Saccharomyces cerevisiae as well as to explore its mode of action was studied. Eight strains of S. cerevisiae strains were able to suppress the growth of A. flavus Z103. The maximum growth inhibition of A. flavus Z103 was obtained by living cells of S. cerevisiae EBF101 and S. cerevisiae 117 with 85 and 83%, respectively. The sporulation inhibition and hyphae deterioration of A. flavus Z103 by S. cerevisiae cells adhesion were observed under SEM; up to 99·8% inhibition of aflatoxins biosynthesis by A. flavus Z103 was resulted when the fungus was treated by autoclaved extracellular crude of S. cerevisiae. Also, the tested strains are potential to produce exo-chitinase which could be suggested as another mode of action for its antifungal activity. GC-MS analysis of S. cerevisiae 117 extracellular secondary metabolites revealed the existence of 4-Hydroxyphenethyl alcohol (46·32%), 4, 4-Dimethyloxazole (9·14%) and 1,2-Benzenedicarboxylic acid dioctyl ester (2·8%). Significance and Impact of the Study: The use of Saccharomyces cerevisiae instead of chemical preservatives in fermented food, animal and fish feed and storage cereal grains could encourage the food industry to produce organic food free of chemical additives. Overall, our data suggest the possibility of using S. cerevisiae as an alternative treatment in the food industries to control the dispersion and aflatoxins production by Aspergillus flavus during storage. This method could provide an additional probiotic effect in the digestive tract of consumers after ingestion of the treated food. So, our study clarifies the exact mechanisms responsible for the reduction of the aflatoxin contents by S. cerevisiae.

Extracellular mycosynthesis of gold nanoparticles using Trichoderma hamatum: optimization, characterization and antimicrobial activity.

Synthesis of gold nanoparticles (AuNPs) has become a needed domain of applied science. Biological method for synthesis of AuNPs by Trichoderma hamatum SU136 aqueous mycelial extract was achieved. The culture filtrate of the fungus was exposed to three different concentrations of gold chloride. The culture filtrate of the fungus was exposed to three different concentrations of gold chloride (0·25, 0·5 and 1·0 mmol l-1 ). In all cases, the gold ions (Au3+ ) were reduced to Au0 , leading to the formation of stable AuNPs. The AuNPs were identified by UV-visible spectrometry, TEM and FT-IR. The presence of a surface plasmon band around 530 nm indicates AuNPs synthesis. Trichoderma hamatum SU136 synthesized 5-30 nm sized; spherical, pentagonal and hexagonal morphologies of AuNPs by TEM. The existence and binding of proteins with nanoparticles was approved by FT-IR study. Parameters optimization showed the smallest size of AuNPs was obtained with (0·5 mmol l-1 gold chloride, pH 7 at 38°C). Interestingly, AuNPs exhibited antimicrobial activity against four pathogenic bacterial strains in the presence of the standard antibiotic, streptomycin. SIGNIFICANCE AND IMPACT OF THE STUDY: Mycosynthesis of AuNPs by Trichoderma hamatum would provide some useful data for oriented biosynthesis of AuNPs. In addition, the applications of mycosynthesized AuNPs were studied against some pathogenic bacteria. Therefore, the gained results detect that these antimicrobial nanoparticles could be explored as hopeful candidates for a variety of biomedical and pharmaceutical applications. This study should provide a further prudence for the fungal-mediated synthesis of AuNPs.

Economic burden of hepatitis C in Egypt: the future impact of highly effective therapies.

BACKGROUND: The prevalence of hepatitis C virus (HCV) infection in Egypt is the highest in the world, yet the total economic burden has not been quantified. Improved understanding of costs and the impact of treatment strategies will provide for better allocation of resources to reduce HCV disease and economic burden. AIM: A modelling approach was used to quantify the current HCV-infected population, future disease progression and associated costs in Egypt. METHODS: Direct healthcare costs were calculated from a nationally representative hospital and a disability adjusted life year (DALY) template was used with monetary value assigned to lost life years. Three scenarios were considered: (i) Historical treatment scenario: 50% SVR; 65,000 treated annually, (ii) Current treatment scenario: 90% sustained virologic response (SVR); 65,000 treated annually, (iii) Increased treatment scenario: 90% SVR; 325,000 treated annually by 2018. RESULTS: Cumulative DALYs (2015-2030) under Scenario 1 were estimated at 7.88 million and cumulative costs estimated at $89.07 billion. Annual DALYs increased 16% during 2015-2030 while annual costs more than doubled. Scenario 2 reduced cumulative DALYs and costs by 7% and 4%, respectively. Under Scenario 3, total costs declined 73% to $1047 million during 2015-2030. As compared to Scenario 1, cumulative DALYs and costs decreased 37% and 35%, respectively. CONCLUSIONS: This is the first estimate of the total economic burden of HCV in Egypt. Extraordinary measures are necessary to substantially reduce HCV disease and cost burden. With newer therapies, strategies to reduce disease burden are feasible and cost-effective.

Interactive effccts of salinity stress and nicoinamide on physiological and biiochemical parameters of faba bean plntt / Efectos combinados del estrés por salinidad y la nicotinamida sobre parámetros bioquímicos y fisiológicos en plantas de haba

A possible survival strategy for plants under saline conditions is to use some compounds that could alleviate the salt stress effect. One of these compounds is nicotinamide (vitamin B3/niacin). The effect of exogenous application of nicotinamide with different concentrations (0, 200 or 400 mg l-1) on faba bean (Vicia faba L.) plant grown at different NaCl levels (0, 50 or 100 mM) was investigated in the wire house of the National Research Centre, Cairo, Egypt. Salinity stress significantly reduced the photosynthetic pigments, polysaccharides, total carbohydrates, total-N contents of shoot, plant height, leaves number, fresh and dry weights of shoot, seed yield, total carbohydrates and total crude protein of the yielded seeds compared with those of the control plants. In contrast, salinity induced marked increases in sucrose, total soluble sugars, total free amino acids, proline, lipid peroxidation product (MDA) and some oxidative enzymes (polyphenol-oxidase and peroxidase). Also, salinity stress increased Na+ contents with the decreases of other macro and micro elements contents (P, K+, Mg2+, Ca2+, Fe2+, Mn2+, Zn2+ and Cu2+) of shoots and the yielded seeds of faba bean. Foliar spraying of nicotinamide alleviated the adverse effects of salinity stress through increased the photosynthetic pigments, polysaccharides, total carbohydrates, total N concentration of shoot, plant height, leaves number, fresh and dry weights of shoot, and seed yield as well as, sucrose, total soluble sugars, total free amino acids and proline, compared with those of the corresponding salinity levels, while decreased lipid peroxidation product as malondialdehyde (MDA) and the oxidative enzymes (polyphenol oxidase and peroxidase enzymes). Nicotinamide inhibited the uptake of Na+ and accelerated the accumulation of P, K+, Mg2+, Ca2+, Fe2+, Mn2+, Zn2+ and Cu2+ concentrations in the shoots of salt stressed plants and enhanced total carbohydrate and total crude protein percentage and solutes concentrations in seeds of salinity treated plants. Nicotinamide, not only neutralized the effect of salinity stress but resulted in a significant improvement in physiological and biochemical parameters as well as the concentrations of soluble sugars, proline, amino acids, and total N and other mineral contents.

Una posible estrategia de supervivencia para plantas que se desarrollan bajo condiciones de salinidad es emplear algunos compuestos que les permitan disminuir el estrés salino. Uno de estos compuestos es la nicotinamida (vitamina B3/ niacina). Se investigó el efecto de la aplicación exógena de nicotinamida en diferentes concentraciones (0, 200 o 400 mg l-1) sobre plantas de haba (Vicia faba L.) creciendo a diferentes niveles de NaCl (0, 50 o 100 mM) en los terrenos del National Research Centre, Cairo, Egipto. El estrés por salinidad reduce significativamente los contenidos de pigmentos fotosintéticos, polisacáridos, carbohidratos totales, nitrógeno total, peso de las plantas, número de hojas, pesos fresco y seco de tallos, rendimiento de semillas, y contenido de carbohidratos y proteina cruda total en semillas comparado con plantas control. En contraste, la salinidad induce incrementos marcados en sacarosa, azúcares solubles totales, aminoácidos libres totales, prolina, productos de peroxidación de lípidos como el malondialdehido (MDA) y algunas enzimas oxidativas (polifenol oxidasa y peroxidasa). También, el estrés por salinidad incrementa el contenido de Na+ y genera disminución de otros macronutrientes y micronutrientes (P, K+, Mg2+, Ca2+, Fe2+, Mn2+, Zn2+ y Cu2+) de los tallos y el rendimiento de semillas en plantas de haba. La aspersión foliar de nicotinamida disminuye los efectos adversos del estrés salino incrementando los pigmentos fotosintéticos, polisacáridos, carbohidratos totales, concentración total de nitrógeno en tallos, peso de las plantas, número de hojas, pesos frescos y secos de tallos, y rendimiento de semillas; así como los niveles de sacarosa, azúcares solubles totales, aminoácidos libres totales y prolina, comparado con aquellos correspondientes al estrés por salinidad, mientras disminuyeron los productos de peroxidación de lípidos (MDA) y las enzimas oxidativas (polifenol oxidasas y peroxidasas). La nicotinamida inhibe la toma de Na+ y acelera la acumulación de P, K+, Mg2+, Ca2+, Fe2+, Mn2+, Zn2+ y Cu2+ en los tallos de plantas bajo estrés salino, y aumenta el porcentaje total de carbohidratos y proteína cruda y la concentración de solutos en semillas obtenidas de plantas tratadas contra el estrés salino. La nicotinamida no solo neutraliza el efecto del estrés salino, sino que mejora significativamente parámetros fisiológicos y bioquímicos tales como la concentración de azúcares solubles, prolina, aminoácidos y contenido total de nitrógeno y otros minerales.

Attitude to blood donation in Saudi Arabia.

BACKGROUND AND OBJECTIVES: The blood donor system in the Kingdom of Saudi Arabia depends on a combination of voluntary and involuntary donors. The aim of this study is to explore the attitudes, beliefs and motivations of Saudis toward blood donation. MATERIALS AND METHODS: The study was conducted at the Donor Centers at King Khalid University Hospital (KKUH) Blood Bank and King Saud University Students Health Center, Riyadh. A self-administered questionnaire was distributed to donors (n = 517) and nondonors (n = 316), between February and June 2008. All were males. RESULTS: Ninety-nine percent of the respondents showed positive attitude toward blood donations and its importance for patients care, and object the importation of blood from abroad. Blood donors: Ninety-one percent agree that that blood donation is a religious obligation, 91% think no compensation should be given, 63% will accept a token gift, 34% do not object to donating six times/year and 67% did not mind coming themselves to the donor center to give blood. Nondonors: Forty-six percent were not asked to give blood and those who were asked mentioned fear (5%) and lack of time (16%) as their main deterrents. Reasons for rejection as donors include underweight and age (71%) and health reasons (19%). Seventy-five percent objected to money compensation but 69% will accept token gifts and 92% will donate if a relative/friend needs blood. CONCLUSION: These results reflect an encouraging strong positive attitude toward blood donation. Further future planning with emphasis on educational/publicity programs and careful organization of donor recruitment campaigns could see the dream of total voluntary nonremunerated blood donations should not take long to be true.

Transfusion medicine in a developing country - alloantibodies to red blood cells in multi-transfused patients in Saudi Arabia.

BACKGROUND: Multiple transfusions are frequently complicated by alloimmunization. This retrospective study aims to determine whether alloimmunization could be accounted for by racial differences between donors and recipients. MATERIALS AND METHODS: The development of alloantibodies were determined in 68 multi-transfused patients (thalassaemia, n=38) and (sickle cell anemia, n=30). RESULTS: The overall frequency of alloantibody formation in our patients is 22.06%. Thirteen patients received blood from the same ethnic group (Arab) and none developed antibodies, while of 47 patients who received multi-ethnic blood, 10 developed alloantibodies. CONCLUSIONS: Alloantibodies formation can be reduced by limiting the transfusion of RBC, collected from donors of the same ethnic origin.