Vol. 23, June, 2006.

1/23 EFFECT OF SOME OSMOTIC SUBSTANCES ON GERMPLASM

CONSERVATION OF DATE PALM (PHOENIX DACTYLEFIRA

L.) ZAGHLOUL CV. EMBRYONIC CALLUS

H.A. Bosila, *S.F. El-Shrabasy and **O. El-Sheaty

Horticulture Department, Faculty of Agriculture, Al-Azhar University

* The Central Lab for date palm Research and Development, Agricultural Research

Center

** Ornamental Department, Faculty of Agriculture, Cairo University

This work was conducted in Shora Biotechnology Lab, Tanta, Gharbea Governorate, Egypt, and The Central Lab for date palm Research and Development, Agricultural Research Center during 2004-2005 in order to find out the most suitable treatment for germplasm conservation of date palm (Phoenix dactylefira L.) Zaghloul cv. embryonic callus. The conserve media consist of MS basal nutrient medium contained 0.1 mg/l NAA and 3g/l activated charcoal and supplemented with agar concentrations (3, 6, 9, and 12 g/l) or/and gerlite levels (1, 2, 4 and 8 g/l) and different sugar sources (sorbitol, sucrose, and mannitol) in the different levels (0. 15, 30, 60 and 120 g/l). The cultures were incubated at 16 or 24 °C in darkness. Within each osmotic substance levels, incubation of date palm embryonic callus cultures under 16°C for 6 or/and 12 months improved germination and conversion (97.9%) frequencies comparing with 24°C one. Embryonic callus cultured on MS media contain 3 or/and 12, g/l of agar and osmotic substances levels improve germination and conversion frequencies comparing with control, but they failed to improve germination and conversion frequencies in comparison with 6 or/and 9 g/l agar in most cases through the different osmotic substances. Supplementation of MS media contain gerlite with the different osmotic substances (sorbitol, sucrose and mannitol) significantly (p < 0.05) improved the germplasm conversion of date palm embryos callus relative to the un supplemented control. And increase in germination, apparent conversion, and actual conversion frequencies. Adding the different sucrose levels significantly improved conversion of date palm embryos callus relative to the other osmotic sources used in this study, regardless of gerlite or / and temperature treatments, when evaluated after 6 months. 100% of embryonic callus cultures were grown healthy in MS media contain 1 or/and 2 g/l gerlite supplemented with the different sucrose levels used under 16°C for 6 Months. The same results were recorded for embryonic callus cultures which were grown healthy in MS media contain 2 g/l gerlite supplemented with the different sucrose levels used under 24°C for 6 Months. 100% of embryonic callus cultures were also normally grown for 6 months on MS media contain 1 or/and 2 g/l gerlite supplemented with 15 or/and 30 g/l sorbitol, regardless of temperature degrees.

2/23 EFFECT OF SOME ENVIRONMENTAL FACTORS ON IN VITRO ACCLIMATIZATION OF DATE PALM (PHOENIX DACTYLIFERA L) ZAGHLOUL CV.

S.F. El-Shrabasy, *H.A. Bosilaand and **O. El-Sheaty

The Central Lab for date palm Research and Development, Agricultural Research

Center

* Horticulture Department, faculty of Agriculture, Al-Azhar University

** Ornamental Department, Faculty of Agriculture, Cairo University

This work was carried out in Shora Biotechnology Lab, Tanta, Gharbea Governor ate, Egypt.and The Central Lab for date palm Research and Development, Agricultural Research Center during 2004-2005. The investigation was designed to study the effect of temperature, light and humidity treatments on the growth and development of plantlet capable to in vitro acclimatization of date palm (Phoenix dactylifera L) Zaghloul cv. Zaghloul cv. plantlets derived from tissue culture rooting stage (8-10 cm length and 1-2 adventitious roots) were transferred to MS basal medium supplemented with 0.1 mg/l NAA, 3 mg/l activated charcoal, 7 g/l agar and 30 g/l sucrose. Cultures were incubated at 25 or 30°C under 1000, 3000, and 9000 lux of light intensity and 50 or 75 % relative humidity. The viability of acclimatization in term of plant length, thickness of bass shoot, number of adventitious roots, number of primary and secondary roots were evaluated. Plantlet length significantly affected by the acclimatization regime used in this study being optimum under 9000 lux of light regime, 30°C and. 75 % Relative humidity. The highest number of primary and/ or root side roots was formed by the plantlets grown on the same medium under 1000 Lux light intensity, 30°C of temperature and 75 % relative humidity without any differences with that grown under 3000 Lux light intensity, 30°C of temperature and 75 % relative humidity.

3/23 BIODEGRADATION OF THE PHOSPHONATE HERBICIDE GLYPHOSATE BY ASPERGILLUS FLA VUS AND TRICHODERMA HARZIANUM AS THE PHOSPHORUS AND NITROGEN SOURCES.

H.M.S. Khalifa and M.B. Mahmoud

Plant Protection Department, Faculty of Agriculture, (Cairo) Al-Azhar University.

Ability of Aspergillus flavus and Trichoderma harzianum to biodegrade the phosphonate herbicide glyphosate was studied in order to show there uses to dispose the excess stock of formulated glyphosate (Roundup). The fungi were isolated from soil, previously treated with the herbicide at 500 /J.g/g soil. The results indicated that glyphosate concentration in complete Czapek- Dox medium enhanced the growth of the two isolated fungi up to 200jug/ml. However, reduction of the growth of both isolates was occurred when medium contained 250 or 300 /j.g/ml of glyphosate, this reduction was more obvious for T. harzianum than A. flavus. Both fungal isolates grow on phosphorus-or nitrogen-free medium amended with different concentrations of glyphosate, which greatly enhanced the fungal growth compared to the herbicide -free medium. However the fungi grow more effectively on phosphorus-free medium than nitrogen free medium. This indicated that A. flavus and T, harzianum could utilize glyphosate as sources of phosphorus or nitrogen. Additionally, total proteins and phosphorus determination in mycelial matrix of both isolates confirmed this investigation. Increasing, the concentration of glyphosate in either phosphorus-or-nitrogen-jree media accomplished with increasing total proteins in maycelial mass of the two isolates; However, the determined proteins in A. flavus were higher than T. harzianum. Also, the phosphorus content determination in both fungi indicated that increase of the herbicide concentration in phosphorus free medium resulted in increment the phosphorus content in mycelial matrix of both fungi, A.flavus content higher phosphorus content than T. harzianum. Alkaline phosphatase activity determination showed that the enzyme activity increased in the two isolates by increasing the concentrations of glyphosate up to 200 ng/ml. the enzyme activity was higher in an A. flavus than T. harzianum. Using HPLC the glyphosate residues in either complete or uncompleted Czapek- Dox liquid media were determined. It was found that the herbicide disappearance was higher in phosphorus free medium than that in nitrogen free medium. Also the disappearance was high in the case of A. flavus than T. harzianum. The results showed that the two isolates had higher potential to biodegrade glyphosate in phosphorus free medium, but less degradation was found in nitrogen free medium. The ability of A. flavus was more than T. harziauum confirming the higher grow of the former fungus than the latter one and it may be used for disposing the excess of the formulated herbicide.

4/23 CHARACTERIZATION AND PARTIAL PURIFICATION OF THREE CELLULASES ENZYMES (CMC-ase, FP-ase and Cb-ase) PRODUCED BY ASPERGILLUS TERREUS AND TRICHODERMA

LIGNORUM

H.M. Soliman, F.F. Migahed, S.M. El-Dohlob and A.Sh. El-Husseiny

Botany Department, Faculty of Science, Mansoura University, Mansoura, Egypt.

The production of the extracellular celluloses, Carboxymethylcellulase, CMC-ase,(l,4-[5-D-glucan glucano hydrolase EC 3.2.1.4), Filter-paper-cellulase, FP-ase (1,4,- ft -D-galucan cellobiohydrolase, CBH, EC 3.2.1.91) and p-glucosidase, Cb-ase (cellobiase or ft-D-glucoside glucohydrolase EC 3.2.1.21), by the strong documents biodeteriorating fungal strains; Aspergillus terreus and Trichoderma lignorum using Whatman filter paper No. 1 as carbon source in liquid state fermentation have been studied. CMC-ase, FP-ase and Cb-ase enzymes of A. terreus and T. lignorum showed a relatively high activity in broad temperature range, with maximum activity at 60°C. They showed also a fairly high activity in a broad pH range with maximum activity at 5-5.6 for FP-ase, 5.6-6 for CMC-ase and 4.5 for Cb-ase. The optimum incubation time for FP-ase was 18 and 20 hours but the time of 60 minutes showed to be the optimum for CMC-ase and Cb-ase. The extracellular cellulases produced by the investigatd fungal isolates in liquid medium containing Whatman filter paper No.l as carbon source after 15 days incubation were partially purified by precipitation using ammonium sulfate precipitation and dialysis and showed good cellulase activities. The total cellulose proteins of A. terreus and L lignorum were determined which were 329 and 833ug/ml, respectively. Also, the molecular weight of cellulase proteins of A. terreus and T. lignorum were also determined by SDS-PAGE.

5/23 UTILIZATION OF FUNGAL BIOMASS FOR SAFETY CADMIUM REMOVAL

E.H. Ashour

Microbiology Dept., Faculty of Agriculture, Mansoura University, Mansoura, Egypt.

Cadmium contamination of the environment has become an important issue due to the potential health threats it poses. Conventional technologies to clean up heavy metal ions from contaminated waters have been utilized but these technologies are cost and non effective. Fungal biomass which are abundant and cheap, could remove cadmium from contaminated aqueous solutions. In batch experiments, using biomass of seven species of mould (Aspergillus niger, A. ficuum, A. nidulans, Penicillium rugulasutn, P. chrysogenum, P. purpurogenum, Rhizopus oligospora) and one species of yeast (Saccharomyces cerevisiae), the removal of cadmium from aqueous solution was carried out. A. ficuum showed most efficient removal performance of Cd. Maximum Cd biosorption (1456.8 uM Cd/g, 60 min) was achieved with A. ficuum biomass which removed almost 75% of 2.0 mM Cdfrom the aqueous solution. Cd-sorption kinetics of A. ficuum biomass was fast and an appreciable quantity of metal (655.4 fiM Cd/g) was adsorbed during 10 min of incubation. The metal biosorption capacity of the fungus was accelerated with increasing cadmium concentration, while it was reverse with increase of initial biomass. The optimum pH and temperature for Cd removal by fungal biomass were 7.0 and 35°C, respectively. However, Cd removal was inhibited in the presence of other metals (Co, Cu, Ni, Cr, Pb, Zn and Hg). Desorption data showed that over 96% of the Cd adsorbed on A. ficuum could be desorbed using 0.1N NaOH. Study with the cyclic use of a batch of A. ficuum repeatedly after desorption, showed that it retain its activity up to five sorption and desorption cycles.

6/23 PURIFICATION AND PROPERTIES OF A

PHOSPHOTRIESTERASE PRODUCED BY AN EGYPTIAN

PSEUDOMONAS ISOLATE

Y.A. Mawgoud and M.E.A. Dawoud

Botany Department, Faculty of Science, Cairo University, Giza 12613, Egypt.

The phosphotriesterase produced by a Pseudomonas isolate (Pseudomonas sp. F2) was purified up to homogeneity (1130-fold) using a combination ofAmm. Sulfate precipitation and phenyl-Sepharose column chromatography techniques. The enzyme is a monomeric protein having a molecular weight of 37400 and 59 bp in length. A single zinc atom is bound to the phosphotriesterase enzyme and is required for its catalytic activity. Incubation of the reaction mixture with metal chelating compounds, EDTA, histidine or cysteine inactivates the enzyme and the activity was recovered by the addition ofZnCli. In addition to paraoxon, the phosphotriesterase was found to hydrolyze most of the organophosphorus pesticides commonly used in the Egyptian cultivated soils such as, coumaphos, cyanophos, diazinon, parathion and methyl parathion. The purified enzyme would be suitable for the bioremediation process of organophosphorus pesticides.

7/23 BIOLOGICAL AND CHEMICAL STUDY OF RHAMNUS LYCIOIDES L. FRUITS GROWING IN EGYPT.

S.E. El-Dondaity

Department of Pharmacognosy, Faculty of Pharmacy (boys) Al-Azhar University, Cairo, Egypt.

The LDso of 70% alcohol extract of Rhamnus lycioides L. fruits is 12.91 g/kg (mice) with fiducial limit of 11.02 and 15.14 g/kg (mice) which revealed the safety margin of the fruits. The biological activity of 70% alcohol extract ofRhamnus lycioides L. fruits were studied on patients complaining of warts, and condylomata acuminata against salicylic acid and 5-flurouracil respectively. Also the biological activity of eye ointment containing 0.01% emodin-6-O- a-L-rhamnopyranoside was studied on patients complaining of dendritic ulcer against 3% acyclovir. Good results were obtained. Chemical study of Rhamnus lycioides L. fruits led to isolation and identification of 8 compounds viz., chrysophanol, physcion, emodin, rhamnocitrin, kaempferol, quercetin, emodin-6-O- a-L-rhamnopyranoside and emodin-6-O- (3-D-glucopyranoside. Their structures were determined by spectral data. This represents the first report for isolation of emodin-6-O- a-L-rhamnopyranoside and emodin-6-O-fi-D-glucopyranoside from Rhamnus lycioides L.


8/23 PREPARATION OF "RAS" CHEESE SLURRY MADE WITH ANTIBIOTICS INDUCED RESISTANT STARTER CULTURE

R.B.A. El-Tantawy; M.A. Degheidi, NA.H. Elewa and H.M. El-Garhi

Department of Dairy Science, Faculty of Agric. AL-Fayoum, University

The Ras cheese slurry was manufactured from 1-milk without antibiotics then the starter cultures (Str.salivarius Subsp.thermophilus and Lb.casei. subsp casei) was added, this treatment was considered as control. 2-The second treatment was made from milk treated with 100 ug /ml streptomycin along with induced resistance starter cultures (Str.salivarius subsp. thermophilus and Lb.casei. subsp casei (IRSs). 3- The third treatment was made from milk treated with lOOug /ml streptomycin and parent starter cultures (PSs). 4-The forth treatment was made from milk with 3.0IU/ml penicillin along with induced resistance starter cultures. (IRSp). 5-The fifth treatment was made from milk with 3. OIU /ml penicillin along with parent starter cultures. (PSs). Chemical analysis of cheese slurry revealed that the acidity% was higher in both the control, IRSs and IRSp compared to PSs and PSp after one day of preparation up to twenty days, while WSN/TN ratio was higher in both the control, IRSs and IRSp thr-ought the first 10 days of incubation period at 30 °C. The pH values •were affected in a contrary way. Microbiological examination showed that the total bacterial counts (TC), were higher in all treatments during the first Sdays of incubation period at 30°C, after that the (TC) slightly decreased till the end of the first lOdays and it sharply decreased till the end of the incubation period (20 days). The streptococci count was higher in both the control, IRSs and IRSp treatments compared to PSs and PSp during the first 10 days of incubation period, while it was similar in all treatments during the second stage of incubation period (20days). The lactobacilli count was higher in both the control, IRSs and IRSp compared to PSs and PSp in the first day of incubation at 30°C, while it was increased thr ought the first 10 days of incubation period at 30°C, and it decreased till the end of incubation period (20days) at 14°C. It could be concluded that 'Ras' cheese slurry manufactured with antibiotics induced resistant starter cultures produced good products .which were almost similar to the control. On the contrary, the. use of parent Str.salivarius.subsp.thermophilus and Lb.casei subsp. casei with the same proportion of the two antibiotics undertaken, produced poor products with less metabolic activity of lactic acid bacteria.

9/23 IMPROVEMENT OF CHO CELL LINE (CHINESE HAMSTER OVARY) GROWTH TO ENHANCE PRODUCTION OF ERYTHROPOIETIN HORMONE

A.A. El-Moghazy

Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University and Biotechnology Center, EIPICO.

Many proteins for pharmaceutical purposes can be produced by recombinant mammalian cells. The most commonly cells used for this purpose is Chinese hamster ovary (CHO). In this study recombinant CHO cell line carrying erythropoietin gene (International Center for Genetic Engineering and Biotechnology, Italy) was investigated for large scale production of erythropoietin hormone. This study showed that the CHO cell line was able to attach and grow efficiently on surface of tissue culture flask with doubling time about 20 hours and reached to 100 % confluence after 5 days. Dissociation and detachment of cells from the surface of tissue culture flask was completed with incubation of cells in trypsinfor 10 minutes which removed hundred percent of cells from surface without any effect on cell viability. The reduction of serum percentage on growth media from 10 % to 5 % did not affect cell growth, and cells finally was adapted to grow on serum-free media for protein expression. No difference on growth rate was detected when cells were incubated at 35°C instead of37°C, while lowering culture temperature less than 35°C suppressed cell growth. Addition of3.2g/L sodium bicarbonate instead of2.4g/L and 4mMofL-glutamine improved cell growth. This study approve successfully that CHO cells can produce erythropoietin in large quantities. These large quantities of erythropoietin produced face the high need of the local market from this important hormone which used for treatment of patients suffering from anemia, renal failure and cancer.

10/23 NOVEL PHYSICAL PROPERTY FOR LEV AN AS A HARMLESS FLOCCULATING AGENT

D.A.R. Mahmoud

Department of Chemistry of Natural and Microbial Products, National Research

Centre, Dokki, Cairo, Egypt.

Bacillus subtilis NRC33a produced extracellularly an excellent biopolymer flocculant in a large amount when it was grown aerobically in a culture medium containing crude sucrose as a carbon source. The biopolymer flocculant was viscous material composed mainly of fructose residues identified to be a levan polymer which characterized by its harmlessness toward humans and environment . Molecular weight of the biopolymer flocculant can be controlled by the sucrose concentration in the fermentation medium. Specific molecular weight of biopolymer flocculant (levan) would be required to achieve the effective flocculating activity. Levan with a high molecular weight (280 KDa) could flocculate activated carbon suspension effectively in presence of Ca2+ and/ or other cations such as Na + ,K+ ,Mg2+ • Heating levan at different temperatures for 15 min decreases its flocculating activity.

11/23 EFFECT OF SEWAGE WATER ON GROWTH, METABOLISM

AND YIELD OF BEAN.

I.M. Zeid., S.M. Ghazi and H.M. Abou El Ghate.

Botany Department, Faculty of Science, Helwan University, Cairo 11792, Egypt.

Seed germination and early growth of bean (Phaseolus vulgaris L.) seedlings -were stimulated by irrigation with sewage water. The stimulation of growth was accompanied by induction in synthesis of pigments, carbohydrates, nucleic acids, nitrogenous compounds, except amino-N contents which were decreased. The activity ofamylase, invertase, and protease enzymes increased may be due to the presence of some mineral ions which act as activators for enzymes. Treatment of sewage -water by precipitation, rice residue or EDTA decreased its enhancing effect. Protein banding patterns of the produced seeds indicated that the appearance of new bands having high molecular weights was the marked feature in sewage water irrigated plants. The concentration ofZn, Cu, CdandPb increased greatly in the different plant organs in response to sewage application. Treating the sewage by precipitation, rice residue, or EDTA reduced their accumulation, particularly with precipitation treatment.

12/23 RESPONSE OF BEAN TO SOME HEAVY METALS IN SEWAGE WATER

I.M. Zeid., S.M. Ghazi, and H.M. Abou El Ghate.

Botany Department, Faculty of Science, Helwan University, Cairo, Egypt.

Irrigation of bean (Phaseolus vulgaris L.) seeds with mixture ofCu, Zn, Cd, and Pb at concentrations of sewage water reduced seed germination and early growth of bean seedlings. Leaf content ofphotosynthetic pigments, carbohydrates, nucleic acids, and total nitrogen also decreased. Cd and Pb significantly inhibited the activity ofa-and fi-amylases, and protease enzyme during germination. Treatment of the mixture solution by precipitation, rice residue or EDTA decreased its retarding effect. The effect of precipitation was more pronounced. Whilst the lower concentration of Cu and Zn stimulated germination, growth and metabolism of bean seedling, the higher concentrations showed inhibitory effects. Even at very low concentrations ofCd and Pb germination, growth and metabolism of bean significantly decreased. Precipitation treatment alleviated the adverse effects of higher concentrations ofZn, Cu, Cd and Pb. Whilst rice residue and EDTA treatments slightly enhanced germination of seeds treated with higher concentrations ofZn and Cu, they did not affect germination of seeds treated with Cd or Pb.

13/23 SEED COAT MICROMORPHOLOGY AND SDS-PAGE AND ITS IMPLICATIONS IN THE TAXONOMY OF CERTAIN TAXA OF THE LABIATAE JUSS.

E. A. Kamel, M. H. A. Loutfy and *Z. A. Elwan

Department of Biological Sciences and Geology, Faculty of Education,

*Department of Botany, Faculty of Science, Ain Shams University, Cairo, Egypt.

SEM of seed coat and SDS-PAGE of seed protein profiles were performed on 20 taxa of the Labiatae representing the subfamilies Lamioideae and Nepetoideae. The obtained data were analyzed by the NTsys-pc program package using the UPGMA clustering method. The produced phenogram was constructed. This preliminary study showed that variation in seed coat and protein bands pattern of Lavendula angustifolia and L. latifolia may suggest that grouping them in one section may be in need of revision. A similarity was observed between Lavendula latifolia (Lavenduleae) and Ocimum basilicum (Ocimeae), supporting earlier views of the relations between the two tribes. Monarda media and Mentha spp. showed a remarked similarity. Variations were observed in Salvia species, supporting to some extent, the suggestions of the non-monophyletic nature of this genus.

14/23 MICROMORPHOLOGICAL FEATURES OF STEMS AND LEAVES OF SOME EGYPTIAN SPECIES OF SUBFAMILY ASCLEPIADOIDEAE

A.M. Shaheenand *S. Heneidak

Aswan Faculty of Science, South Valley University, Egypt

*Biological Sciences Department, Suez Faculty of Education, Suez Canal University, Egypt.

The characteristics of stem and leaf anatomy of 15 species of subfamily Asclepiadoideae (Apocynaceae) were examined with light microscope (LM) for their taxonomic value. 23 studied characters proved to be taxonomically useful, of these: stem outline shape, number of layers in the cortex, hypdermis status, endodermis cell shape, structure of the vascular system, phloem and xylem sructure, cambium status, pith structure, secondary growth, anomalous structures and palisade tissue status. Some of these characters afford a valuable taxonomic evidence reliable for delimiting the species investigated at both generic and specific levels.

15/23 NUTRITIONAL VALUE OF SOYBEAN AND LUPIN PROTEIN EXTRACTS: IMPROVEMENT BY LACTIC ACID FERMENTATION

Ashraf A. Khalil, *Samira S. Mohamed and *Fakhriya S. Taha

Protein Technology, Genetic Engineering and Biotechnology Research Institute, Mubarak City for Scientific Research, Alexandria, Egypt

*Department of Fats and Oils, National Research Centre, Cairo, Egypt

Germination and/or fermentation processes for Egyptian breeds of soybean and lupine seeds were examined as approaches for the improvement of nutritive value of extracted proteins. Fermentation was carried out using three Lactobacillus strains namely, L. reuteri, L. casei, and L. heleviticus. Results revealed increase in protein content for all treated soybean and lupin meals. Best improvement for protein digestibility of soybean protein was observed in ungerminated-fermented samples using L. reuteri, whereas the highest digestibility in lupin was obtained in germinated-fermented samples using L. casei. Treated lupin and soybean proteins contained most of the essential amino acids in concentrations comparable to those recommended by the FAO/WHO, with the exception of the sulphur-containing amino acids. Germination followed by fermentation was more effective in reducing trypsin inhibitor and urease activities, as well as phytate content compared to either germination or fermentation treatments. L. heleviticus was the most efficient culture out of the three species in reducing both the trypsin inhibitor and urease activities. All fermented soybean samples showed an improvement in the antioxidative properties. Germinated soybeans fermented with either L. heleviticus or L. reuteri resulted in the highest antioxidant activity. All treated and untreated lupin samples did not show any antioxidant activity. The fermented legume protein isolates can be a source of nutritive food ingredients.

16/23 SCREENING OF NEW BACTERIAL STRAINS PRODUCING POLYGLUTAMIC ACID BIOPOLYMER FLOCCULANT

Doaa A.R. Mahmoud

Department of Chemistry of Natural and Microbial products, National Research Centre, Dokki, Cairo, Egypt.

Two hundred bacterial strains were isolated form soil sample collected from field near Rostock, Germany. Their culture broths were screened for their ability to flocculate kaolin suspension. Ten of them presented considerable flocculating activity. Cultivation of these strains in medium containing glutamic acid and glucose as nitrogen and carbon sources indicated that four strains produced large amount of extracellular biopolymer flocculant. The produced agent could be considered to be a homopolymer of glutamic acid by using paper and thin layer chromatography and possibly to be poly-glutamic acid. Among the four selected strains, a new flocculant-producing bacteria Serratia proteamaculans and Pseudomonas flourescens recorded the highest flocculating activity. Their bioflocculant efficiently flocculated organic and inorganic suspensions. Bioflocculant of Psuedomonas fluorerscens had the ability to flocculate kaolin suspension in presence of Na+, K+ and Fe3+ and was completely inhibited in presence of Fe2+. In contrast, the flocculating activity of Serratia proteamaculans was inhibited by both Na+ and Fe2+.

17/23 THE EFFECT OF SALICYLATE ON THE ANTIBACTERIAL ACTIVITIES OF DIFFERENT ANTIBIOTICS

M.A. El-Nakeeb, M.A. Fawzy, N.M. El-Guink and N.K.Moussa

Department of Pharmaceutical Microbiology, Faculty of Pharmacy,

Alexandria University, Egypt

The effect of five concentrations of salicylate (0.1, 0.25, 0.5, 0.75 and 1 mg/ml) on the antibacterial (biostatic and biocidal) activities of different antibiotics amoxicillin, bacitracin, cefoperazone, chloramphenicol, erythromycin, gentamicin, tetracycline and ofloxacin against three bacterial standard strains (S. aureus, E. coli and Ps. aeruginosa) was determined by the checkerboard broth dilution technique. Variable responses were obtained with S. aureus and Ps. aeruginosa, while salicylate was mostly synergistic with E. coli. Generally, salicylate had antagonistic effects on amoxicillin against the three tested strains. The effect of salicylate on the antibacterial activities of two sub-bacteriostatic concentrations of the chosen antibiotics against six bacterial standards and clinical isolates was determined using the turbidimetric method. Variable results were produced with the tested organisms due to the salicylate incorporation. The effect of salicylate on the bactericidal activities of the concerned antibiotics produced by 0.1 and 0.01 mg/ml salicylate was then tested against six bacterial standards and isolates using the viable count technique. The low concentration of salicylate resulted in antagonism in some case while the high concentration was synergistic to the action of some antibiotics. Salicylate was, generally, antagonistic to most of the tested antibiotics against Gram-positive organisms.

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