خيارات البحث
النتائج 171 - 180 من 190
ISOLATION, IDENTIFICATION AND BIOCONTROL OF SALMONELLA TYPHIMURIUM IN KARIESH CHEESE BY BACTEIOPHAGE
2018
Atef Fayed | Ragia O. Mohamed | M.A. Hassan | A.E. Fayed
The study aims to assess the possibility of biological control on one of the most serious pathogenic microbes that found to infect Kariesh cheese, namely Salmonella typhimurium. To achieve this object, firstly a total of 20 Kariesh cheese samples were collected randomly from various markets located at Cairo and exposed to microbiological isolation and identification of S. typhimurium. The obtained results revealed that, S. typhimurium was detected in 30% of surveyed market Kariesh cheese according to the strain identified by polymerase chain reaction (PCR) technique. Secondary, five sewage water samples were obtained from Fac. of Agric., Ain Shams Univ., and Shoubra EL-Kheima station of drinking and sewage water for specific bacteriophage isolation and morphology particles of Salmonella bacteriophage was examined by transmission electron microscope. Third, pasteurized skimmed buffalo’s milk was converted into experimental Kariesh cheese at 40oC by milk inoculation with 2% of freshly activated yoghurt bacterial starter culture and then milk was divided into 5 equal portions. The 1st portion considered as control. The 2nd, 3rd, 4th and 5th portions were contaminated with equal level (1%) of S. typhimurium suspension containing 105 colony forming units (CFU)/mL, previously isolated from foregoing surveyed Kariesh cheese samples, followed by adding phage suspension, from which isolated from sewage water, containing 108 plaque forming units (PFU)/mL at the levels of nil, 1, 2 and 3% respectively. All portions were separately incubated at the same temperature up to curdling. The curds were cut and individually filled into stainless steel moulds lined with cheese cloth and consolidated by a slight pressure for 24 h. The blocks of curd were then cut, dry salted using 2% NaCl (w/w) and packaged into plastic containers. Experimentally, there were proportional reductions in lactic acid bacteria (LAB) population as the level of phage spiked into cheese milk increased, as which the reduction rate of LAB count during cold storage period (CSP) prolonging was however declined. In terms of health safety, although the number of pathogen microbe added was gradually reduced due to the acid developed by prolonging the Cold Storage Period in the absence of phage, but it stilled present until the end of experimental period. While, the pathogen was completely eliminated within 7 days of cheese age when the phage suspension (108 PFU/mL) has been spiked at the level of 1% at least. The contamination of experimental Kariesh cheese with S. typhimurium led to weaken the ability of cheese curd to drain whey as explained from the dry matter (DM) content which decreased due to the presence of pathogen and increased by the pathogen elimination with bacteriophage, which resulted also to increase the protein /DM content. The ash content reduced by both reasons, namely the contamination with S. typhimurium and/or the spiking level of phage suspension. The presence of S. typhimurium slowed the LAB population and acid production by them. Finally, as a conclusion, the spiking of Kariesh cheese milk with 1% Salmonella typhimurium phage suspension (108 PFU/mL) is quite enough to eliminate this microorganism when it present at the level of 1% suspension containing 105 CFU /mL.
اظهر المزيد [+] اقل [-]IMPACTS OF CYANOBACTERIA AND BRADYRHIZOBIUM INOCULATION ON LUPINE PLANTS UNDER DIFFERENT NITROGEN RATES IN SANDY SOIL
2018
fekry ghazal | Hala A.M. El-Sayed
A field experiment was conducted in sandy soil at Ismailia Agricultural Research Station, (Ismailia Governorate, Egypt, in two successive winter seasons of 2015/2016 and 2016/2017. The experiment aimed to study the response of lupine plants (Lupinus albus L.) variety Giza 2 to cyanobacteria applied with different methods under different nitrogen fertilizer rates and inoculated with rhizobia. Results revealed that application of cyanobacteria generally increased the mean values of nodules number, dry weight of nodules and shoot dry weight of lupine plants, nitrogen uptake, biological activity of the soil rhizosphere lupine plants, yield, yield components and seed protein content as compared to those recorded by the control treatment without cyanobacteria. Increasing nitrogen rates decreased the mean values of both nodules number and dry weight of nodules. On the contrary, increasing nitrogen rate up to 100% of the recommended one increased all the other tested parameters. The highest values of these parameters were recorded when cyanobacteria were applied as dry + soaking combined with 75 % N rate expect for those of number and nodules the dry weight of nodules that gave their highest values when the lupine plants received the treatment of dry + soaking combined with 50 % N rate. In conclusion, the use of cyanobacteria along with rhizobia as renewable nitrogen source for lupine production can save 25% N from that required for lupine.
اظهر المزيد [+] اقل [-]IN VITRO PROPAGATION OF KORONAKI AND CORATINA OLIVE CVS.
2018
Rehab N. Mostofa | M.A., Abu Rawash | H.F. Elwakeel | Vergini F. Noaman
Experiments carried out through 2016 revealed that a proper protocol for the in vitro propagation of Koronaki and Coratina olive cvs. as follows : Sterilization of stem node explants was carried out successfuly with copper sulphate at 50mg/l for Koronaki cv. And Ampicillin at 150mg/l for Coratina cv. both cultured on Olive medium.Multiplication on MS medium enriched with BAP at 1.5mg/l for both cvs. Rooting of Koronaki on half sterngth OM medium enriched with IBA at 0.5mg/l and Coratina on half sterngth MS medium enriched with NAA at 0.1mg/l. Acclimization of Koronaki plantlets derived from half strength OM rooting medium and acclimatized on peat : sand (1:1) and Coratina plantlets derived from MS rooting medium and acclimatized on peat :sand : vermiculite (1:1:1).
اظهر المزيد [+] اقل [-]VARIETAL VARIATIONS OF SESAME IN NITROGEN UTILIZATION EFFICACY
2018
Noha S. El-Khouly | H.S. Saudy | W.R. Abd El-Momen
From an eco–economic perspective, the efficient use of nitrogen is becoming incrementally worthwhile in crop management. Therefore, growth, yield and seed yield response index of three sesame varieties (Shandwel–1, Giza–32 and Sohag–1) as affected by four N rates (0, 72, 108 and 144 kg N ha−1) were investigated during two seasons of 2013 and 2014. The study illustrated that Sohag–1 was the superior variety for achieving SPAD value and seed yield ha−1. Sesame plants can be fertilized with N at a rate of 108 kg ha−1 being recorded higher seed yield ha−1. Integration between proper variety as a genetic factor with the appropriate N rate applied as an environmental one, i.e. Sohag–1 x 108 kg N ha−1 (or Sohag–1 x 144 kg N ha−1) considered a marked practice for gaining high sesame seed yield as an economic product. Being Sohag–1 exhibited less reduction in yield under low N rate and highly response with high N applied it belongs to ER group.
اظهر المزيد [+] اقل [-]REMOVAL OF ALIZARIN RED S FROM AQUEOUS SOLUTION USING SODIUM BENTONITE
2018
Eman A. El-Menofy | Omnia I. Ali | A.H.T. Kandil
In this work, sodium bentonite (Bn) was used for removal of alizarin red S (ARS) from aqueous solution using batch technique. Fourier transform infrared spectroscopy and X-ray diffraction were used to characterize sodium bentonite. Different parameters that would affect ARS dye removal such as initial pH, contact time, initial ARS dye concentration, bentonite dose, and temperature were explored. The realized data from kinetic studies demonstrated the high fitness of pseudosecond-order kinetic model for better interpretation of the experimental data. The adsorption isotherms studies showed that Freundlich isotherm had a high correlation coefficient among the studied isotherm models. Thermodynamic studies proposed that ARS adsorption onto Bn was spontaneous in nature at the lower temperatures and exothermic.
اظهر المزيد [+] اقل [-]SUSCEPTIBILITY OF DESERT LOCUST, SCHISTOCERCA GREGARIA (ORTHOPTERA: ACRIDIDAE) TO BACILLUS CEREUS ISOLATED FROM EGYPT
2018
M. Reda | T. Mashtoly | M. El-Zemaity | A. Abolmaaty | G. Abdelatef | A. Marzouk
Examination was done at preliminary bracketing bioassay on one old 4th nymphal instar of desert locust. Results showed that two isolates, namely NDL1 and NDL2 were having highly potentiality as entomopathogenic bioagents. Thirty isolates were isolated from dead/ infected nymphs of desert locust occurred in raring cages at Department of Locust and Grasshoppers Research, Plant Protection Research Institute, Agricultural Research Center, Dokki, Giza, Egypt. Molecular identification of isolated bacteria was done using universal primers of 16s rRNA, followed by DNA sequencing. Nucleotides were blasted at (https://www.ncbi. nlm.nih.gov /genbank/) to recognize that NDL1 and NDL2 isolates were two different isolates of Bacillus cereus with a high similarity (100%). Susceptibility of 4th nymphal instar of Schistocerca gregaria (Forskal) to the isolated B. cereus was determined using two bioassay procedures, Leaf-dip and per os. The insecticidal activity of both isolates against locust nymph in leaf dipping showed that NDL2 was more efficient than NDL1. However, the opposite trend was observed in using per os. Both Isolates have the potential to be a successful biocidal agent to control desert locust.
اظهر المزيد [+] اقل [-]CONTROL OF ANGULAR BACTERIAL LEAF SPOT DISEASE OF WATERMELON USING ADVANCED COPPER COMPOSITES
2018
M. Ebrahim | Wafaa Abd El-Sayed | N. Abd El-Ghafar | M. Paret | M. Young | S. Santra | J. Jones
Angular leaf spot, caused by P. syringae, is one of the most important bacterial disease of watermelon. For disease management, growers rely on copper bactericides, which are effective after the first two weeks of transplanting, while they couldn’t be applied before that due to the high phytotoxicity they may cause to the plant. This study was undertaken to evaluate the antibacterial activity of three new copper composites, core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu), as potential treatments to control the disease before the emergence of the first true leaf where copper is not available, and to identify the possibility of applying the newly designed copper composites during that period to significantly reduce secondary dispersal of disease inoculum. In vitro, 50 μg/ml of metallic copper from MV-Cu and FQ-Cu significantly reduced the P. syringae populations after 2hrs of exposure compared to the untreated control (P= 0.05) and were more effective than using the Kocide® 3000. Greenhouse studies demonstrated that MV-Cu and FQ-Cu significantly reduced the disease incidence compared to both Mankozeb+ Kocide® 3000 and untreated control when using the seed inoculation method. In contrast, none of the nano-composites significantly reduced disease incidence when using the spray inoculation method. MV-Cu and FQ-Cu managed to significantly reduce seedling to seedling disease transmission under greenhouse conditions (P = 0.05). This study highlights that copper composites have the potential to manage P. syringae in the first two weeks of transplanting and reducing the contamination rate from infected to healthy transplants
اظهر المزيد [+] اقل [-]AN EXPERT SYSTEM FOR SELECTING THE TECHNICAL SPECIFICATIONS OF DRIP IRRIGATION CONTROL UNIT
2018
Samar Ragab | A. El-Gindy | Y. Arafa | Maybelle Gaballah
The good design of irrigation system is one of the main steps of extent the life of the irrigation system, as well as increase the cultivated crop productivity by choosing the proper components of irrigation system control head unit ( such as pump, motor, filters, main line pipe, fertilization device, and the different control unit attachements). Different types of control unit components are used according to the system conditions for irrigation of agricultural areas. It is very difficult to find an expert at desired time and desired place for choosing correct control unit which are varied in different types and models. In this study, this problem was to be tried to solve by designing of an expert system for choosing proper components of control unit in irrigation network. A rule-based program named TSDI-ES (Technical Specification of Drip Irrigation-Expert System) was coded and compiled using Microsoft visual basic 2013 language. Generally, the expert system database obtained from commonly used all components of control unit in irrigation network in Egypt. selection of all components of control head unit in irrigation network were determined by taking into consideration the following parameters: water resource, irrigation methods, irrigation area, crop pattern, climate, soil properties, and well characteristics. Results of the investigation indicated that it is possible to use the TSDI-ES rule-based program for choosing all proper components of control head unit in drip irrigation network such as pump, filtration unit, fertilizers devices, and flow, pressure measuerement and control devices.
اظهر المزيد [+] اقل [-]USING OF SOME ENVIRONMENTALLY SAFE TREATMENTS TO IMPROVE THE STORABILITY OF NAVEL ORANGE (CITRUS SINENSIS L.) FRUITS
2018
Layla Tabbara | N. Abdel Hameid | A. Bondok
This investigation was carried out during two successive seasons 2013 and 2014 on fruits of Washington Navel orange (Citrus sinensis L.). The experiment was conducted to evaluate the influence of some environmentally safe matural products to improve the storability of Navel orange (citrus sinensis) fruits during 2013 and 2014 seasons, Jojoba oil (1,3,5)%, castor oil (0.5, 1,2)%, yeast (1,2,3)%, seaweed (1,2,3)%, hot water (45ᵒC and commercial wax were used for proposed study, After the application of the treatments on the fruits, fruits were stored at a temperature of 5°±1 C and 90%±5 of relative humidity for 60 days, physical characteristics (weight loss%, decay% and the peel's thickness of the crust) and chemical properties (total phenols) were determined. Results indicated that, castor oil (2 and 1)% and jojoba oil 5% reduced the deterioration in weight loss%, decay%, peel thickness, and phenols content, compared to the content was obtained in control. So the results show that, coating orange fruits with castor oil (1, 2)% and jojoba oil (5)% had the most effective in improve the storability of orange fruits Navel Orange (Citrus sinensis L.).
اظهر المزيد [+] اقل [-]THE ECONOMIC AND MARKETING SITUATION OF SOME DAIRY PRODUCTS MANUFACTURED IN EGYPT
2018
Kh. Zaki | M. Ragab | Mona Ryad
The problem of food supply is the main problem that worries the world in recent times, and the problem of developing countries is increasing in size to increase population growth rate. The problem of research is the low efficiency of production and processing of dairy products in Egypt. In addition to the low level of dairy processing operations, the aim of the research is to identify the current production status of milk and dairy products and to identify the monthly seasonal prices of these products as well as the margins. The most important results were the annual increase in the production of the study products, which were studied and the focus was on these products due to the availability of data on them without other products. It is clear from the study of the general time trend equation in Table (2) Dairy production increased by a statistical significance of about 13.3 thousand tons, an annual increase representing about 1% of the average total production during the period (2000-2014), and it was found that the coefficient of selection was about 560. That is, 56% of the changes that occur in the quantity of production The total dairy production is due to changes in the variables (2) indicates that the production of buffalo butter increased by a statistically significant increase of about 1.9 thousand tons, with an annual increase representing about 2.3% of the average total production during the period. (2000-2014). It was also found that the coefficient of selection was about 0.61, ie, 61% of the changes in the amount of buffalo butter production are due to variables whose effect reflects the time component. It is also clear from the study of the general time trend equation in Table (2) that the production of Jamousian cheese increased by a statistically significant increase of about 1.9 thousand tons, with an annual increase representing about 0.77% of the average total production during the period 2000-2014. The selection was about 0.48, which means that 48% of the changes in the quantity of cheese production are attributed to changes in variables whose effect reflects time.
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