Ismail Saadoun

• BScs, MSc, PhD
• Head of Department of Applied Biology at University of Sharjah

In the context of adaptation of the water resources sector to climate change, water reuse is widely proposed and encouraged especially in arid and semi-arid areas like the Middle East. We consider riverbank filtration (RBF) an appropriate technology that efficiently and dependably procure quality water from Zarqa River thus making a contribution to...

Streptomyces is a rich source for a wide variety of useful secondary metabolites and mainly antibiotics. In the present work, a preliminary screening program for isolation of inhibitory bioactive compounds-producing streptomyctes from UAE soils is initiated to search for novel anti-bacterial and anti-tumor antibiotics. Several bacteria and yeasts w...

Asthma is the most common respiratory disorder, and is characterized by distal airway inflammation and hyperresponsiveness. This disease challenges human health because of its increasing prevalence, severity, morbidity, and the lack of a proper and complete cure. Asthma is characterized by TH2-skewed inflammation with elevated pulmonary levels of I...

Tolerance of various plant seeds to different concentrations of phenol, and growth of bacteria on phenol as a sole carbon source has been investigated. Three different types of bacterial colonies have been recovered on the agar plates. Biochemical and culture morphology examination of the recovered bacteria revealed that they mainly belonged to the...

The dichloromethane extract of culture filtrate from Streptomyces aburaviensis R9 was evaluated using various rapid bioassays to determine po-tential inhibitory effects towards phytopathogenic fungi (Colletotrichum acutatum, C. fragariae, C. gloeosoprioids, Botrytis cinerea, Fusarium oxy-sporum, Phomopsis viticola and P. obscurans), fish bacterial...

Physicochemical features of Wadi Al-Arab Dam (reservoir), Jordan Variations in physical and chemical conditions were investigated at Wadi Al-Arab Dam Reservoir (Jordan). Mean surface water temperature was 22.5°C and two distinctive temperature layers, epilimnion (down to 15 m, mean temperature 28.6°C) and hypolimnion (down to 35 m, mean temperature...

Tolerance of various plant seeds to different concentrations of diesel has been investigated. A noticeable decline in Cochorus olitorius seed germination of 57.7-76.9% was shown at 100 mg kgG diesel 1 or higher. However, seeds of Hordeum spontaneum, Triticum aestivum and Atriplex halimus showed a decline of less than 30 % at 100 mg kgG diesel or hi...

Cronobacter spp. (formerly Enterobacter sakazakii), are a group of Gram-negative pathogens that have been implicated as causative agents of meningitis and necrotizing enterocolitis in infants. The pathogens are linked to infant formula; however, they have also been isolated from a wide range of foods and environmental samples. In this study, 233 sa...

Isolation of microorganisms antagonistic to Orobanche was attempted using Orobanche plants and rhizosphere soil of Orobanche -infected crops in Jordan. Six fungi ( Cephalosporium sp., Cylindrocladium sp., Epicoccum sp., Fusarium sp., F. oxysporum and F. solani ) were isolated. Of these, isolates that belonged to the Fusarium genus were the most com...

The purpose of this study was to determine the influence of growth conditions and medium composition on the production ofchitinase by Streptomyces sp. (strain S242). Production of chitinase by strain S242 was detected on colloidal chitin agar (CCA) medium after 8 days of incubation at 28 degrees C resulting in a clear zone 10 mm around the colony....

Total count and diversity of the airborne yeasts and filamentous fungi in the medical surgery operation theatres (OT) of six hospitals in northern Jordan were investigated. Sixty five air samples of 100 liters volume/min were collected by a microbiological air sampler from these units during the period June-Decemeber/2005. Air samples were impacted...

The composition of phytoplankton species thriving in Wadi Al-Arab Dam Reservoir, Jordan and their seasonal variation in relation to water ecology were studied between February 2001 and February 2002. A total of 75 species of phytoplankton were identified: Bacillariophyceae (diatoms) contributed with the highest number of taxa (39) followed by Chlor...

The investigation aimed to examine the Streptomyces flora of hydrocarbon-contaminated soil and study their capability to grow on diesel fuel as a sole carbon source and their analysis for the presence of the alkane hydroxylase gene (alkB) by PCR. A total of 16 Streptomyces isolates were recovered from hydrocarbon-contaminated soil samples on starch...

Microbial populations' inhabitants in crude petroleum contaminated soils were analyzed in relation with the soil characteristics. A noticeable greater decline of bacterial counts and diversity but a prevalence of the genus Pseudomonas over the other identified genera in the fresh contaminated soils as compared to the old ones was observed.

Five strains of Agrobacterium tumefaciens were isolated and characterized from 12 different plant tumors. The susceptibility of these phytopathogens to antibiotics and to soil Streptomyces isolates was tested. Among the 90 Streptomyces isolates, only 12 were able to inhibit the growth of at least one A. tumefaciens strain. Four strains of A. tumefa...

The purpose of this study was to investigate the effect of the primary production of phytoplankton on water quality of Wadi Al-Arab Dam Reservoir in Northern Jordan. Species successive change and composition in addition to increased rain inflow and nutrient loading seems to be the major factors behind fluctuation of total chlorophyll a (chl a) cont...

A total of 231 different soil Streptomyces isolates were recovered from 16 different locations in North Jordan. They were assessed for their phytotoxic activity on seeds of cucumber (Cucumis sativus L.) and ryegrass (Lolium perenne L.) placed adjacent to a 2 cm wide Streptomyces culture strips grown at 28C degrees for 3 weeks on starch casein nitra...

In this study, we revealed rapid detection of streptomycin-producing Streptomyces spp. by extraction of total soil DNA from 14 soil samples using a modified lysis method followed by PCR amplification ofa genus-specific sequence in the Streptomyces' 16S rDNA gene. DNA band of the expected size (438 bp) was seen with all the samples. Additionally, sp...

The purpose of this study was to determine the influence of growth conditions and medium composition on the cellulase enzyme production by Streptomyces sp. Production of cellulase enzyme by a Streptomyces strain (J2) was detected on cellulose agar (CA) medium after 4 days of incubation at 28 °C that exhibited a clear zone of 22 mm around the colony...

A total of 161 different Streptomyces isolates were recovered from 5 soil samples representing the driest habitats of Jordan. These were then characterized and assessed for their antagonistic activity against four clinical multi-drug resistant Pseudomonas aeruginosa test pathogens. Results indicated that only 3 strains out of 139 and 6 out of 22 is...

There is considerable interest in different fiber hydrolytic enzymes such as cellulases, xylanases and pectinases for their potential applications in the paper, food and feed industries. Therefore, this study aimed to screen for soil streptomycetes producing such enzymes and characterize them. A total of 110 isolates of streptomycetes were recovere...

One hundred and nine Agrobacterium isolates were recovered from 68 samples (51 plant tumor and 17 soil) that were collected from different habitats in Northern Jordan. The isolated cultures were grouped into 3 biovars based on their biochemical characteristics and biovar I, II, and III comprised a total number of 46,41, and 22 isolates, respectivel...

The white cottony stem rot pathogen Sclerotinia scierotiorum was subjected to 70 different isolates of actinomycetes indigenous to Jordan as biological control agents. Forty of them demonstrated chitinase activity on crab shell chitin agay (CCA) media and they were segregated into three groups: 14 highly active, 12 moderately active, and 14 with lo...

The mutagenic activities of two insecticides [Vapcocidine-20 FL (Fenvalerate) and Cypermethrin-10 FL (Cypermethrin)] that are commonly used in Jordan were tested by Ames test. None of the insecticides was mutagenic to Salmonella typhimurium his^- tester strain TA 1530 and TA 1537. Treatment of both tester strains with these insecticides i...

Ralstonia solanacearum has worldwide economical importance because of its destructive and soil-borne nature. Clearly chemical measures have lost their attractiveness because of development of resistant strains and undesirable effects on our environment. Consequently, biological control of pathogens is gaining great importance worldwide. To investig...

Enumeration and recovery of the dominant bacteria from a chronically fuel contaminated soil has been investigated. Bacterial counts from these polluted soils ranged between 0.70x10(8) and 28.20x10(8) CFU/g soil. Three different types of bacterial colonies have been recovered on the agar plates. Biochemical examination of the recovered bacteria reve...

The effect of glucose, glycerol and yeast-extract (YE) on 2-methylisoborneol (MIB) production by Streptomyces violaceusniger (C4-S strain) was determined. Glycerol as a sole carbon source promoted MIB production was maximum concentration (40.65 microg/l) after 10 days incubation, while glucose favored biomass production. Increasing YE concentration...

This is the first report of antifungal activity of Iranian actinomycete isolates against Rhizoctonia solani Kuhn AG-3 (Teleomorph: Thanatephorus cucumeris [(Frank) Donk]). Biological control offers an environmentally friendly alternative to the use of antimicrobials for controlling plant diseases. A collection of about 200 actinomycete strains was...

This is the first report of antibacterial activity of Iranian actinomycetes isolates against Erwinia carotovora subsp . carotovora (Jones) Dye. E. carotovora subsp. carotovora is a soil born destructive plant pathogen with worldwide economical importance. Chemical measures have lost their attractiveness because of development of resistant strains o...

The investigation of Bacillus thuringiensisin 40 different samples collected from 12 different Jordanian habitats involved the isolation of 80 Bacillus thuringiensis isolates. Out of these isolates, 47 were pathogenic to the third instar larvae of Drosophila melanogaster. The highest viable count of Bacillus thuringiensis was estimated among soil s...

This is the first report of antifungal activity of Iranian Actinomycetes isolates against Alternaria solani Sorauer, Alternaria alternata (Fr.) Keissler, Fusarium solani (Mart.) Sacc., Phytophthora megasperma Drechsler, Verticillium dahliae Klebahn and Saccharomyces cerevisiae Meyen ex Hansen. Biological control of plant diseases has received world...

Enumeration of bacteria and recovery of the dominant species have been conducted for soils contaminated with fuel spills for more than 10 years at seven gas stations in Jordan. Bacterial counts of these polluted soils ranged between 0.68 108 and 32.8 108 c.f.u./g soil with two different bacterial colony types recovered on agar plates. Phenotypic ex...

This is the first report on antifungal activity of a new strain of Streptomyces plicatus (strain101) against four Iranian phytopathogenic isolates of Verticillium dahliae. In the recent decades, biological control of plant diseases has received more attention mainly as a response to public concern about the use of hazardous chemicals in the environ...

In this study, two designed primers were evaluated to identify soil Streptomyces and to detect streptomycin production by strb1 targeted PCR. Potential Streptomyces-specific signatures were identified in their 16S rDNA sequences in regions located around nucleotide positions 576 and 995. Primer pair RI7/RI8 derived from these regions was investigat...

The aim of this study is to use the diagnostic utility of smear technique for the detection of Mycobacterium tuberculosis in clinical specimens obtained from patients suspected of having pulmonary tuberculosis. A total of 305 respiratory specimens (broncoalveolar lavage, sputum and pleural fluid) were collected from 298 patients having pulmonary in...

Random amplified polymorphic DNA (RAPD) analysis has been used to determine the relatedness of 73 antibiotic-producing soil Streptomyces isolates that were recovered from different soil habitats in Jordan based on their RAPD-PCR fingerprints. Genetic polymorphisms between these isolates showed three common bands of 2777, 800 and 250 bp shared by ap...

A total of 60 different Streptomyces isolates were recovered from 12 soil samples collected from the Badia region north-eastern of Jordan. These were then characterized by conventional methods and assessed for their antagonistic activity against three pathogenic and antibiotic-resistant bacteria. Results indicated that grey and white colour series...

Potential hydrocarbon degrader bacteria were isolated from soil samples that have been exposed to crude petroleum oil spills. Bacterial population of these polluted soils showed counts ranging between 9.5 x 10(5) and 237.5 x 10(5) CFU/g soil with 2 different colony types of bacterial strains which have been recovered on the agar plates. Results ind...

Detection and identification of members of the genus Streptomyces are of great value because they provide a rich source of antibiotics. Toward the goal of identifying additional novel antibiotics, a total of 292 different Streptomyces isolates were recovered from 54 soil samples collected from 28 different locations in Jordan. These were then chara...

A total of 80 isolates of Bacillus thuringiensis were recovered from different habitats of Northern Jordan. These isolates were grouped into three classes based on crystal morphology (spherical, bipyramidal, and both bipyramidal and cuboidal). The isolates that produced spherical crystals were the most common and the most toxic to diptera. SDS-PAGE...

To assess the toxic potential of different local Jordanian Bacillus thuringiensis isolates on larvae of Drosophila melanogaster and Culex sp. Scanning electron microscopy revealed the presence of spherical, bi-pyramidal, and bi-pyramidal and cuboidal parasporal bodies produced by the toxic isolates. Spherical inclusions dominated. The toxicity of t...

A cyanobacterium isolated from a source-water reservoir during a spring odor and taste episode and identified as Anabaena sp. consistently produced geosmin during laboratory culture on modified BG-11 liquid medium. Maximal geosmin/biomass occurred at 20 degrees C and a light intensity of 17 microE/m2/s; geosmin/chla values directly correlated with...

A cyanobacterial isolate recovered from Lake Ogletree, the principal drinking water supply for the city of Auburn, Alabama (USA) was identified as Anabaena sp. The isolate was shown to produce the most common off-flavor compound, geosmin.

Eighteen percent of 116 different isolates of Streptomyces recovered from soils of northern Jordan showed activity against Candida albicans. The recovered isolates were distributed into three groups according to the diameter of the inhibition zone on the agar plate: group 1 (5–10 mm, slightly active); group 2 (11–15 mm, moderately active); and grou...

A survey of Bacillus thuringiensis was conducted for 17 locations in Northern Jordan representing 12 different habitats. Eighty isolates were identified as B. thuringiensis in the majority of the tested samples. Results showed that soils contaminated with the slaughterhouses waste materials had the highest content of spore-forming bacteria [(4.05-2...

The effect of the parasitic plant Orobanche cernua extract was evaluated on 5 different Gram-positive and Gram-negative bacteria. Dilution experiments show that the minimum inhibitory concentration (MIC; microgram/ml) of the extract was as follows: Staphylococcus aureus-1526.5; Streptococcus sp.-3125; Streptococcus pyogenes-25,000 and both for Baci...

The Bacillus subtilis ATCC 6633 strain synthesizes a mutagenic metabolite from sodium azide and O-acetylserine. Mutagenicity of azide was decreased in growth media containing 10(-4) M glutathione, L-cysteine or L-djenkolic acid whereas dithiothritol (DTT) added at the same concentration did not reduce the mutagenicity of azide. Likewise, glutathion...

Plasmids or covalently closed circular (CCC)-DNA molecules are abundant in the genus Streptomyces, and have been suggested to be involved in the genetic control of the production of many antibiotics in these organisms. In this study, 21 active antibiotic-producing Streptomyces isolates were screened for their plasmid content by an alkaline lysis me...

Sixteen isolates of Bacillus thuringiensis recovered from different Jordanian habitats were compared using random amplification of polymorphic DNA (RAPD) to determine whether they could be differentiated at the molecular level. Total genomic DNA from each isolate and three reference strains were amplified using 10-mer primers. Electrophoretic analy...

Nine different isolates of aquatic actinomycetes identified as Streptomyces spp. were studied for their morphological and cultural characteristics. One of these isolates (C4-S, Streptomyces violaceusniger) was extensively studied for its inhibitory effect against a wide range of Gram-positive, Gram-negative bacteria, Mycobacterium vaccae ATCC 29678...

The microbial biodegradability of mineral oil and other hydrocarbons, namely hexane, decane and tetradecane was determined using the Warburg constant volume respirometer. Results of oxygen uptake indicated that hexane and tetradecane were more degradable than mineral oil and decane. Rhodococcus erythropolis and Erwinia cancerogena showed the highes...

A total of 90 different Streptomyces isolates were recovered from 36 soil samples and assessed for their antibacterial activity. Nine isolates were identified by the absence of an aerial mycelium. The rest were grouped into six colour series, namely grey, white, yellow, green, red and polymorphic colours (pink, orange or violet) with total numbers...

Random amplified polymorphic DNA (RAPD) was used for identification and assessment of genetic diversity between isolates of Streptomyces from soil. Genomic DNA from 18 Streptomyces isolates and 2 reference strains were amplified using four different 10-mer primers. Different DNA fingerprinting patterns were obtained for all the isolates. Electropho...

Various species of actinomycetes and cyanobacteria can impart earthy/musty off-flavours to drinking water supplies and to pond-raised fish and other aquatic food animals. The genetic determinants for production of the most common off-flavour compounds [geosmin and 2-methylisoborneol (MIB)] have not been extensively studied. An attempt has been rrla...

Biodegradation of geosmin produced by Streptomyces halstedii (A-1 strain) was investigated using seven Gram-positive bacteria. Bacterial action on the A-1 extract was followed at 15, 45 and 120 min. Bacillus cereus ssp. thuringiensis HD-1, B. cereus 3711 and B. cereus ssp. mycoides 4379 showed no effect. However, Arthrobacter atrocyaneus, Arth. glo...

The removal of bacteria and viruses from drinking water is of increasing interest particularly if the purification system is inexpensive and readily available. A new material obtained by locally processing the solid residues from olive mill products was investigated as a potential sorbent for removing micro-organisms from drinking water. Indicator...

Geosmin and 2-methylisobomeol (MIB) are microbial metabolites that can cause earthy or musty off-flavors in aquatic food animals as well as seasonal taste and odor episodes in drinking water. This paper compares effects of selected environmental factors on biomass and geosmin production by the actinomycete Streptomyces halstedii and the cyanobacter...

The Zarqa River within Jordan, is heavily contaminated with treated domestic and industrial wastewater, but still serves as the source for irrigation. To evaluate the performance of riverbank filtration (RBF) technology that significantly reduce the microbial contaminants, water samples from Zarqa River and water from a RBF well at 5 meter from the...

The purpose of this study was to determine the effect of some cultural conditions on the xylanase enzyme production by Streptomyces sp. (strain Ib 24D) and to investigate its potential to produce xylanase utilizing tomato pomace as a substrate. Xylanase activity was detected using the dinitrosalicylic acid assay method. The crude enzyme was maximal...