Vol. 21 Issue 3
Nasser EL-Banna
Bacterial strains identified as Bacillus megaterium NB-3, Bacillus cereus NB-4, Bacillus cereus NB-5, Bacillus subtilis NB-6 and Bacillus circulans NB-7, were isolated from the air of Jerash Private University, Jerash, Jordan. They were found to produce several antimicrobial substances that exhibited potent antifungal activity against filamentous fungi and yeasts. Bacillus subtilis NB-6 showed activity against filamentous fungi, yeasts and gram-positive bacteria, while bacillus megaterium NB-3 exhibited a broad spectrum of activity against filamentous fungi, yeasts, gram-positive bacteria and gram-negative bacteria. In batch culture, the bacterial isolates produced the antibiotics late ub tge growth phase and accumulated a main portion in the culture fluids. The data presented in this study exhibit a novel source for the isolation of antimicrobial substances producing microorganisms in Jordan, which were not previously described. The isolation of these strains suggests their potential as a source od novel antibiotics.
Ahmed Mazen
Pot experiments were conducted to explore concerns regarding agricultural use of sewage sludge for crop production. The extent of heavy metal accumulation and its subsequent impact on the physiological performance of six food plants grown on sludge mixed soils was explored. The effect of liming of sludge amended soil on the reduction of metal uptake by the raised plants was also tested. The contents of tested heavy metals were several times higher in pure sludge than in garden soil. Heavy metals were accumulated by plants cultivated on sludge mixed soil (SMS) or limed sludge mixed soil (LSMS) to levels significantly higher than those in control plants grown in garden soil (GS). The magnitude of accumulation was dependent on plant species and was generally higher in roots than in the shoot system. ALthough contents of all metals in tissues of SMS were significantly higher than those of GS plants, they were reduced by liming. No toxicity or deficiency symptoms were observed on SMS plants but contrary to expectations, cultivation of plants on SMS was generally enhancing to all tested physiological criteria in all tested plants. For example, plant growth, the end product of physiological performance, was improved by 30%, 40%, 25%, and 25% in Corchorus, Eruca, Raphanus and Spinacia respectively. Similar effects were recorded for chlorophyll content, activity of leaf nitrate reductase and total soluble proteins. Results are discussed from the viewpoint of the practicality of using sewage sludge in agriculture in the State of Qatar.
M.O. Abd El-Monem
Forty-one bacterial isolates were obtained from gastric juice and gastric biopsy specimens from persons 30-70 years old. The samples were taken from patients who chewed qat (the fresh leaves of the plant Catha edulis) and patients who didn't chew qat. The specimens were collected at different hospitals in Taiz city, Republic of Yemen. These bacterial isolates were identified as four species: Helicobacter pylori, Helicobacter bizzozeronii, Campylobacter jejuni and Campylobacter sputorum. H. pylori was recorded as occurring in a higher percentage of qat chewers (42%) than in non chewers (25%), in gastric biopsies (37%) than in gastric juice specimens (20%) and in those aged from 50-70 years (35%) than in those aged from 30-50 years (33%). Antibacterial activity of Christ's thorn honey and garlic, onion, and cabbage extracts against 14 isolates of H. pylori revealed that the most promising effect was achieved with Christ's thorn honey followed by garlic, onion and cabbage extracts. The antibacterial effect of garlic and onion at concentration 15% increased by mixing it with honey in a ratio 1:1.
Kamal F. Elkhalifa
The present study is devoted to the establishment of abanus (Dalbergia melanoxylon) by seed propagation in the nursery as the tree is of high economic importance, of weak natural regeneration, and listed as an endangered species. The study attempts to determine optimal conditions for raising the seedlings artificially in order to supplement natural regeneration. Seedlings of abanus were raised under partial shade. They were grown in sand, clay or a mixture of sand and clay (1:1 by volume). They were irrigated daily for two weeks for initial establishment and irrigated either daily, every two days or every four days thereafter. The results showed that seedlings should be grown in a mixture of sand and clay so as to obtain the greatest shoot length, shoot fresh weight, root fresh weight and shoot and root dry weights. They may be raised in sand to the greatest root length and number of leaves. Seedlings should be irrigated daily for two weeks for initial establishment, and then every two days thereafter so as to obtain the greatest shoot length, root length and shoot fresh weight.
Wafa K. Taia and Hayfaa A. El-Olyan
This work deals with the study of the vegetation in an area completely protected from camels and an area partially exposed to camels. During they study eighteen species were recorded in the areas. Ten of these species were present inside the fence and the rest of the species were present in both areas. Vegetation analysis throughout the three studied seasons revealed that species richness and diversity were higher outside the fence with a significant difference in the first two seasons (winter and autumn) whereas it was insignificant during the third season (spring). Single linkage Euclidean distance were gathered in the studied quadrants in a homogenous matter. The results are discussed and the partial conservation of the plant life rather than complete conservation is recommended as the regular seasonal grazing throughout the three studied seasons appeared to have apositive effect on the vegetation.
Nayef S. Al-Muaikel
A new class of poly hydrazides containing thiadiazole moiety in the main chain was synthesized. A solution polycondensation technique was used in the synthesis of these polymers. The monomer VII was synthesized from the nucleophilic replacement of VI with ethyl chloroacetate, followed by hydrazinolysis. The model compound VIII was synthesized from the monomer VII with benzoyl chloride and characterized by 1H-NMR, IR, and elemental analyses. The polyhydrazides IX-XIV were synthesized from the polymerization of the monomer VII with different aliphatic, aromatic or thianthrene diacid chlorides. These polymers were characterized by elemental and spectral analyses, viscometry and solubility. The thermal properties of these polymers were determined by TGA, and DTG, and correlated with their structure. The crystallinity of some polymers was tested by X-ray analyses and the morphological properties were detected by SEM.
Medhat M. Seif-El-Nasr
The development of biotechnology in Egypt since 1990 is reviewed. The National Strategy for Genetic Engineering and Biotechnology is outlines and the priorities for its implementation are given. The numerous research and development activities on biotechnology under the auspices of the Ministry of State for Scientific Research, the Ministry of Agriculture, collaborative programs and eight large universities are delineated. Activities of public and private industrial units are summarized. Finally, the public- private sector collaboration experience at the Agriculture Genetic Engineering Research Institute is described.
Saud L. Raja Al Rowaily
Most of the Saudi Arabia land can be classified as arid or semi arid ecosystems, thus, rangelands make up over 74% of the total area. Grazing and agriculture have traditionally been the pattern of life for centuries. Before the turn of the century, rangelands offered most of the livestock needs, when the country population was low and the hema system existed. During the last few decades, livestock population in the country increased in association with an increase in human population, because of change in dietary and lifestyle, and a significant increase in demand for meat and milk. Overgrazing, over exploitation of rangelands, human activities, and poor management policies disrupted desert ecosystem causing dramatic changes in vegetation and soil leading to rangeland deterioration and thus desertification.
This paper highlights the significance of the rangelands of Saudi Arabia, their features and distribution, and a conceptual model of three levels of degradation and management inputs. It is important to recognize early degradation, because costs increase with increased levels of degradation