Vol. 1, January, 2002.

1/1

 

EFFECT OF GAMMA-IRRADIATION

 

ON

 

 

 

SOME EGYPTIAN HONEYS

W.N. El -Tayeb and H.N. El-Hifnawi*

Microbiology Department, Faculty of Pharmacy (Girls), Al-Azhar University

*Drug Radiation Research Department, National Centre for Radiation Research and Technology (NCRRT) P. O .Box 29,Nasr City, Cairo, Egypt.

There is increasing usage of unprocessed honey as a dressing of infected wound, burns and ulcers. However, to make clinical use of honey acceptable, it should be sterile. It is well established that the antibacterial activity is heat-labile so would be destroyed if honey was sterilized by autoclaving. Therefore an investigation was carried out to assess the effect of the two doses 18 kGy and 25 kGy of gamma-irradiation on the antibacterial activity of 8 different Egyptian honeys. The honeys were tested against bacterial species: Salmonella typhimurium, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus in an agar well diffusion assay, with reference to phenol as a standard. The difference among floral sources in the antibacterial activity was significant but there was no significant alteration in the antibacterial activity of almost all honeys tested when subjected to both of the two doses 18 kGy and 25 kGy of gamma-irradiation. Presumably glucose oxidase which produces hydrogen peroxide is not easily damaged by irradiation.

2/1 PRODUCTION OF SINGLE CELL PROTEIN BY ASPRGILLUS NIGER FROM POTATO WASTE WATER

H.A. Hussein and A.A. Hassan

National Centre for Radiation Research and Technology (NCRRT),

Nasr City, Cairo, Egypt.

The ability of A. niger strain isolated from potato waste water (PW) for hydrolysis of non reducing sugars and producing single cell protein was examined. The biomass increased 74.7% and 191.6% by adding 1 gm/L molasses and 4 gm/L fish meal respectively. On adding the two wastes together the biomass increased 233.3% and to 557.4% after exposing the fungal spores to 9420 µw s/cm2 ultraviolet ray. Total protein of the fungal mat increased from 26.16% to 27.72% and finally to 30.8% on adding 1 gm/L molasses, 4gm/L fish meal together, and after irradiated fungal spores respectively. The hydrolysis of non reducing sugars increased from 15.8% to 22.9% and to 67.9% on adding 4gm /L fish meal and 1 gm/L molasses to PW respectively. Adding both of the previous wastes together increased the hydrolosysis of non reducing sugars to 69.2%. After irradiating the A. niger spores the hydrolysis increased to 81.6%.          

3/1 BEHAVIOUR OF SOME LACTIC ACID BACTERIA

IN THE PRESENCE OF PESTICIDES RESIDUES

F.H. Ahmed*, M.A. Nour, G.M. Abd El-Tawab and S.A.M. El-Behairy*

Department of Dairy, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt

* National Organization for Drug Control and Research, Cairo, Egypt. P. 0.29

Food contamination with pesticides has lately been quite a contemporary problem to producers and manufacturers. Milk is one of the basic food which is very liable to be contaminated by pesticide residues through the milking animals and feeding stuffs . These residues may react with milk constituents and cause technological problems in addition impact on health. The obtained data concerning the effect of studied pesticides [methomyl (Lannat) and Cypermthrin] at certain concentrations (1, 2.5, 7.5, 10, 100, 200 and 300 p.p.m. for both pesticides) on bacterial growth of industrial yoghurt culture (Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) showed no antibacterial effect and normal clotting was observed. Similar trend was noticed by using pure strains of some lactic acid bacteria (Lactococcus lactis subsp. lactis, S. salivarius subsp. thermophilus, L.delbrueckii subsp. bulgaricus, L. helviticus and L. acidophilus). Substitution of both methomyl and cypermethrin separately once instead of nitrogen and secondly carbon source in the suggested synthetic medium namely Pridham revealed the ability of the prementioned strains in addition of Bacillus subtilis, Pseudomonanas fluorescens, Staphylococcus aureus and C. albicans to utilize methomyl   as a carbon and nitrogen source while they utilize cypermethrin as a source of nitrogen only.

4/1 ASPECTS OF HIGH CONCENTRATIONS OF CERTAIN ORGANOPHOSPHORUS INSECTICIDES ON THE ِACTIVITY AND STRUCTURE OF SOME BIODEGRADING SOIL FUNGI AND THEIR RESPONSE TO GAMMA RADIATION.

A.A. Abou Zeid*; H.A.Hussein**and A.A.Shahin**

*Botany Department, Faculty of Science, Zagazig University, Egypt.

**National Center for Radiation Research and Technology, Nasr city, Cairo, Egypt.

Five soil samples treated with high concentrations (20000 ppm) of two organophosphorus insecticides (Malathion and Selecron) were used to isolate resistant and biodegrading soil fungi. Insecticide degrading fungi represented to 6-23% of total resistant fungi depending on soil type and applied insecticide. The highest degrading fungi were related to genera (Aspergillus and Fusarium). The biodegradation activity of selected fungi decreased with the increasing of insecticide concentration, where great drop was recorded after 20000 ppm. The effect of increasing concentrations of both insecticides on the morphological characteristic showed great variation in morphology, sporulation and colonies size of treated selected fungal isolates. Subjecting the highest biodegrading malathion isolate (F. solani) and selecron isolate (Asp. niger) to increasing doses of gamma radiation revealed that low doses (0.25, 0.5 and 0.75 kGy) caused a temporary initiation in their biodegrading activities, after which significant decreases in biodegradation were observed. The calculated D10 values of Asp. niger and F. solani in absence and presence of tested insecticides were (1.02 & 0.766 kGy) and (0.471 & 0.280 kGy) respectively. The effect of high concentration of selecron (20000 ppm) on germination and ultra structure of Asp. niger recorded in photographs revealed abnormal delay in germination steps of treated spores of Asp. niger than control. Electron microscopy investigation showed different cell structural changes including cell wall rapture and cells devoid of cell wall containing cytoplasmic constituents gathered and accumulated in the cell center.


5/1 EFFECT OF PHYSIOLOGICAL AGE AND DOSE RATE ON RADIATION RESISTANCE OF SOME RADIORESISTANT BACTERIAL SPECIES

A.S. Bashandy and H.N. El Hifnawi

Microbiology Department and Drug Radiation Research Department

National Center for Radiation Research and Technology,

Nasr City, Cairo, Egypt

The effect of physiological age(different growth phase)onthe radiation resistance of some radioresistant spore forming bacilli (Bacillus cereus, Bacillus brevis, Bacillus pumilus and Bacillus coagulans) and one radiosensitive strain (E. coli) was studied. The results obtained from the dose response curves of the studied strains showed that the radiation resistance of Bacillus cereus, Bacillus brevis and Bacillus coagulans and E. coli is more high in the mid-log phase than in the stationary phase of growth, while the strain B. pumilus exhibited an opposite manner, it is susceptible to g- radiation in the mid-log phase than in the stationary phase of growth Also, the study of the effect of dose rate on the radiation resistance of the studied strains showed that all the strains are highly radioresistant when exposed to gamma radiation at low dose rate 1.24 kGy/hr than exposure to g- radiation at high dose rate 6.727 kGy/hr in the same growth phase. The most interesting observation is that there were no cell growth of any of the studied strains when exposed to g- radiation at high dose rate 6.727 kGy/hr after incubation for 28 and 48 hr. It is concluded that the radiation resistance depends upon the growth phase and dose rate before exposure to g- radiation.

6/1 PHYTOCHEMICAL AND ANTI MICROBIAL ACTIVITY OF SEQUOIA SEMPERVIRENS (D.DON) ENDLL. LEAVES CULTIVATED IN EGYPT

N.A. Ghanem, M.B. Haroun, *A.A. El-Hela, A.T. Salama and A. Talha

Department of Botany, Faculty of Science, Al – Azhar University,

Nasr City, Cairo, Egypt.

*Department of Pharmacognosy, Faculty of Pharmacy, Al-Azhar University,

Nasr City, Cairo, Egypt.

The volatile oil, amino acids, fatty acids, photosynthetic pigments and major minerals of Sequoia sempervirens (D.Don) Endll. Leaves cultivated in Egypt were analyzed. The volatile constituents obtained by hydrodistillation from Sequoia sempervirens D.Don) Endll. It yielded ca 1.6% w/w of the volatile fraction calculated on the fresh weight basis. The volatile oil was analyzed by GC / MS technique. Twenty six compounds of the total volatile constituents were identified and account 82.86 % of the total components.The main compounds of the volatile oil was diphenylamine 14.79%, terpinol 10.38% and elemol 8.35% respectively. The analysis of amino acids revealed the presence of 18 amino acid. Porline (21.02%), is the main amino acid. The fatty acids methyl ester analysis revealed the presence of 19 fatty acids of which only 14 compounds were identified. Oleic acid was the major component (36.9%) of the total of the fatty acids. Analysis of photosynthetic pigments revealed that the concentration of chlorophyll "a" is 3.6 % and chlorophyll "b" is 3.1%, while the cartenoids is 6.9 mg %. Major minerals (Na+ , K+, Ca2+, Mg2+, and P3-) were determined and revealed that Potassium is the major component (1.5 g %). The volatile constituents exhibited antimicrobial activity against Gram positive bacteria (Staphylococcus aurous, Bacillus subtili,) and Gram negative bacteria (E. coli), while anti fungal screening of the volatile compounds showed no significant activity.

7/1 DETERMINATION BIODEGRADABILITY OF XENOBIOTIC COMPOUNDS USING LOCAL PSEUDOMONADS BY DIFFUSED REFLECTANCE FOURIER TRANSFORM INFRARED (FT-IR) SPECTROSCOPY.

R.A. Bayoumi

Botany & Microbiology Dept., Faculty of Science, Al-Azhar University, P.N.: 11884, Cairo, Egypt.

The present work is concerned with the isolation, purification, and characterization of twelve bacterial isolates from some industrial wastewater, and investigating the ability to biodegrade acrylamide, catechol, m-cresol and p-cresol. Twelve bacterial isolates were identified on the basis of cell shape, cell arrangement, Gram stain, motility, and relation to oxygen. They were found to be belonging to one genus and five species. These were suggestive of being belonging to: Pseudomonas pseudomallei (six isolates), Pseudomonas caryophylli (two isolates), Pseudomonas alcaligenes (two isolates), Pseudomonas aeruginosa (one isolate), and Pseudomonas resinovorans (one isolate). Identified bacterial isolates were tested for their ability to utilize acrylamide, catechol, crude oil, m-, and p-cresols. The most potent two isolates viz. Pseudomonas pseudomallei-I-11 and Pseudomonas aeruginosa –I-33 were investigated for biodegradation of the previously compounds by FTIR analysis singly and in combination. Combination between the most potent two bacterial isolates exhibited the disappearance of specific characteristic peaks in FTIR spectrum analysis so that it was recommended to use this combination for bioremediation of wastewater when polluted by such compounds. Data also emphasize that disappearance of specific characteristic peaks in FTIR spectrum analysis in acrylamide, catechol, m-cresol, and p-cresol due to the biodegradation process by Ps. pseudomallei-I-11 and Ps. aeruginosa –I-33 may give a good evidence for the possible use of these isolates to eliminate or even to minimize such xenobiotic compounds in industrial wastewater.

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