Mycobiota of Oil-Contaminated Soil Samples and Their Abilities for Dibenzothiophene Desulfurization

High sulfur content of crude oil leads to poor quality of oil products and many other negative consequences such as corrosion, catalyst poisoning and environmental pollution. Saudi Arabia is seeking to reduce sulfur content in diesel and gasoline to 10 ppm and to lower benzene content in gasoline to 1%. Biotechnological processes such as biodesulfurization can be considered an alternative or complement to conventional oil refining technologies. So, the objective of the present project is to isolate and identify endogenous fungal isolates capable of oil biodesulfurization. From 60 oil-contaminated soil samples collected from Saudi Arabia, 15 species belonged to 9 fungal genera were collected and identified morphologically and with ITS sequencing. Members of Aspergillus, Penicillium and Fusarium were the most prevalent in the investigated samples. Among the collected fungal species, only Stachybotrys bisbyiisolates were able to utilize dibenzothiophene (DBT) as the sole sulfur source. Stachybotrys bisbyi TUSb1 could desulfurize 99% of the DBT (0.3 mM) as the sulfur source by a co-metabolism reaction with other carbon sources through the same pathway as 4S (involves sequential oxidation of the sulfur part and cleaving of the C–S bonds), and produced 2-hydroxy biphenyl (2-HBP) during 7 days of incubation at 30°C and 180 rpm. Stachybotrys bisbyi TUSb1 showed broad specificity for removing sulfur in different sulfur-containing compounds.     

The Effect of Different AR Nanostructures on the Optical Performance of Organic–Inorganic Halide Perovskite Semiconductor Solar Cell

Plasmonics - Nanostructures exhibit excellent antireflection (AR) properties allowing for broadband antireflection and increasing the light incoupling in solar cells. In this paper, the optical...     

Efficacy of cold fogging and oral herbal extracts on air quality and immune response of broilers

In this study, the effect of aerosolized and water-supplemented Lactobacillus casei, L. plantarum and Saccharomyces cerevisiae fermented herbal extract (FHE) on air quality and immune response of broilers was studied. The experiments were performed in commercial broiler barns each accommodating 22,000 broiler chicks. Chickens kept in the house that were fogged twice daily with 20 l FHE (10 % in tap water) and provided with FHE in drinking water were compared with those in a comparable non-treated house. The total dust, airborne bacteria and endotoxins were significantly reduced in the FHE-fogged house. Chickens treated with FHE had significantly higher total IgY, better immune response to Newcastle disease vaccination and greater body weight (2 %), while serum avidin was significantly reduced compared with non-treated chickens. On the other hand, water fogging significantly decreased the total dust in a treated house compared with untreated house. However, cold fogging of water did not significantly decrease the cultivable airborne microorganisms in the treated house, and there was no significant difference in hemagglutinating antibodies in chickens of the water-fogged and non-treated houses. Body weights and mortality rates between the water-fogged and non-treated houses were not significantly different as well. These results suggest that cold fogging and oral applications of FHE could reduce the bioaerosols in poultry farms and improve the immune system of chickens.     

Molecular Identification and Biofilm-Forming Ability of Culturable Aquatic Bacteria In Microbial Biofilms Formed in Drinking Water Distribution Networks

Drinking water distribution networks are known to harbor microbial biofilms. The aim of the present work is to (i) identify the culturable bacteria presented in the drinking-water distribution network, (ii) investigate the ability of isolated bacteria to form biofilm under some environmental stress conditions and some eliminating or removing treatments. To achieve it, 57 strains were isolated from biofilm (43 isolates) and water samples (14 isolates) collected from five stations in drinking-water distribution network in Taif city, Kingdom of Saudi Arabia (KSA). Partial sequences of 16S rRNA gene in the 57 isolates ensured the presence of only 22 different strains in biofilm samples. Among these strains, only 14 strains were also detected in water samples. Gram-negative Aeromonas hydrophila was the most occurred bacterium in the microbial biofilm obtained from the purified-water storage tanks followed by Gram-negative Pseudomonas sp. Gram-positive Bacillus subtilis was the most occurred bacterium in the microbial biofilm collected from the ends of the distribution pipes. Among the 22 isolated strains, 13 strains were strong biofilm producers at 30 and 37°C. The effects of environmental stresses including nutrient starvation (diluted TSB, 20:1), heating (100°C for 10 min), UV-treatment (240 nm for 10 min) and dynamic incubation (150 rpm min^?1) on the formation of biofilm were also investigated. These conditions affected the biofilm formation ability of the isolated strains at different levels. Nutrient starvation enhanced biofilm formation by most of the isolates. Among some biofilm deforming treatments, SDS and trypsin had considerable effects on preventing biofilm formation by most of the isolated strains. In conclusion, the results of the present work indicated that not all biofilm strains released from biofilm to the drinking water. Also, not all biofilm strains were able to form biofilm. Most of isolated bacteria had ability to form biofilm at suboptimum temperature of growth. These results may provide basic information on formation of microbial biofilms and overcome the problem of deteriorating of water quality in the drinking-water distribution networks.     

Molecular Characterization of Endophytic Bacteria from Metal Hyperaccumulator Aquatic Plant (Eichhornia crassipes) and Its Role in Heavy Metal Removal

In this study, among a collection of heavy metals resistant endophytic bacterial strains isolated from aquatic hyperaccumulator plant (Eichhornia crassipes), one plant growth promoting endophytic bacteria (PGPE), SVUB4 was selected for its ability to utilize 1-aminocyclopropane-1-carboxylic acid (ACC) as the sole N source and accumulate different heavy metals. The SVUB4 strain was characterized as Enterobacter sp. on the basis of its 16S rDNA sequences. Assessment of the parameters of plant growth promotion revealed the intrinsic ability of the strain for the production of IAA, siderophore and solubilization of insoluble phosphate. Furthermore, plasmid DNA analysis of Enterobacter sp. strain SVUB4 indicated the presence of a single large plasmid element. The results of plasmid curing experiments demonstrated that the ability of this strain to grow in presence of Cd and Zn was encoded by the 98 kb plasmid, whereas the ability to grow in the presence of Pb appeared to be encoded by the chromosome. The Cd and Zn removal capacity of the respective metal sensitive strain (plasmidless) were about 36 and 45 μg/g-1 DW, respectively, while the removal capacity of the both metal by metal resistant strain (p SVUB4) showed a significantly higher Cd and Zn removal capacity of 153 and 228 μg/g^?1 DW, respectively. However, both strains exhibited a similar pattern of Pb accumulation. The present observation also showed that for wild-type strain SVUB4 (pSVUB4), the overall level of IAA production in the absence and in the presence of Cd²⁺ or Zn²⁺was approximately the same. Nevertheless, strain SVUB4M in this respect appeared to be more sensitive to heavy metals: a noticeable decrease in IAA production was observed under the effect of both metals, especially with Cd²⁺.     

Optimization of Budesonide Compression-Coated Tablets for Colonic Delivery

The purpose of this study was to formulate budesonide (BUD) compression-coated tablets for colonic specific delivery. Pectin and guar gum were used as enzyme-dependent polymers. For comparison purposes, both pH- and time-dependent polymers were also tried. In vitro release studies were carried out at different pH (1.2, 6.8, and 7.4). Therapeutic efficacy of the prepared tablets compared to commercially available capsules and enema were evaluated in trinitrobenzenesulfonic acid-induced rabbit colitis model. In pH-dependent polymers, Eudragit (EUD) S100/EUD L100 (1:1) released 45.58% in the target area (colon). For time-dependent polymers, decreasing cellulose acetate butyrate (CAB) ratio increased the release in both pH 6.8 and 7.4 till it reached 40.58% and 93.65%, respectively, for 25% CAB. In enzyme-dependent polymers, increasing pectin ratio to 75% retarded the release (4.59% in pH 6.8 and 54.45% in pH 7.4) which was significantly enhanced to 99.31% using pectinolytic enzyme. Formula F14 coated with 75% pectin significantly reduced the inflammatory cells in the connective tissue core of the colon of the treated group and significantly decreased myeloperoxidase activity (3.90 U/g tissue weight). This study proved that BUD compression-coated with 75% pectin may be beneficial in the treatment of inflammatory bowel disease.     

Plasmid-mediated Molluscicide Bayluscide Degradation by Bacterial Strain Isolated from Schistosome Vector Snail Bulinus truncates

Pseudomonas spp. strain Bal1 was isolated from Schistosome vector snails Bulinus Truncates. Strain Bal1 was identified as Pseudomonas putida using partial sequence of 16s rRNA. This strain was able to utilize a Bayluscide as a sole source of carbon and nitrogen. The degradation of Bayluscide by Bal1 strain is mediated by pBal1 (110 Kb) plasmid. The loss of the plasmid resulted irreversibly in a derivative strain that was unable to degrade Bayluscide. The transfer of these plasmids from wild-type strain Bal1 to Bal1M derivative restored completely its capability to degrade the molluscicide. It is proposed that pBal1 is a conjugative plasmid and is involved in the Bayluscide degradation. The effect of bacterial degradation upon toxicity was tested, and it was shown that the molluscicidal action of Bayluscide was significantly reduced by bacterial action.     

The effect of gamma rays on the gonads of the olive fruit fly, Dacus oleae (Gmelin)

Pupae of the olive fruit fly, Dacus oleae (Gmelin) 1 to 2 days before adult emergence were irradiated with the suitable sterilizing dose of 80 Gy gamma rays. At intervals of 5, 10, 15, 20, 25 and 30 days after adult emergence, anatomical and biometrical studies were performed to determine the extent of recovery of D. oleae gonads during one month of adult life. There were some indications of gonad recovery after two weeks. This recovery was observed as a decrease in the percentage deviation from the corresponding controls of 20-day-old adult gonad (especially those of males). Generally, female gonads are more sensitive to gamma-rays than those of males.     

Ethylene as a Mediator of Rubigan Biological Action in Cowpea Plants

Rubigan (a systemic fungicide) inhibited the growth of Rhizoctonia solani in vitro when used at concentrations of 6, 12 and 24 μg/ml respectively. Application of Rubigan as a soil drench significantly reduced the damping-off incidence on cowpea (Vigna sinensis) plants. Symptoms of growth retardation appearing on cowpea plants treated with Rubigan could be mimiced using an ethylene releasing compound (Ethrel). Ethrel at 10 and 20 μl/ml added to the soil around the seeds induced severe dwarfing as evidenced from measurements of plant length, dry weight and leaf area. Gas chromatographic analysis revealed that ethylene was released either from Rubigan mixed or not with the soil. Rates of ethylene production from soils drenched with Rubigan were relatively inferiorto those produced by authentic Rubigan solutions not added to the soil. Moreover, in all cases ethylene was released at rates proportional to the Rubigan concentrations applied. Factors involved in growth retardation of Rubigan-treated cowpea plants were discussed in the light of the possible interaction between ethylene and endogenous gibberellin levels.     

Male uterus in the donkey and horse

The anatomy and histology of the male uterus were studied in the donkey and the horse. In the former it was found complete and long, while in the latter it was incomplete or absent. Some variations met with are described. A new concept of "internal male hermaphroditism' is presented and two types are differentiated.