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Aloe dhufarensis Lavranos is an important medicinal plant, however, the endophytic microorganisms associated with this plant and their antagonistic activities are not known. In this study, endophytic fungi and bacteria were isolated from the leaf tissues of A. dhufarensis and their antagonistic activity against the plant pathogens Fusarium sp. and Cladosporium sp. were evaluated using a dual culture assay. A total of 3 fungal endophytes and 12 bacterial endophytes were isolated from the leaf tissue segments of A. dhufarensis. Among them, two endophytic fungal isolates designated as SQUCC-F2-2 and SQUCC-F3-1 exhibited inhibitory activity against the phytopathogenic fungi tested. In addition, scanning electron microscopy analysis showed that they induced shriveling, pit formation and disintegration of the hyphae of the phytopathogenic fungi. These two endophytic fungal isolates were identified as Sarocladium kiliense (SQUCC-F2-2) and Penicillium oxalicum (SQUCC-F3-1) on the basis of nuclear ribosomal DNA internal transcribed spacer (ITS) region. Analysis of the metabolites produced by these endophytes revealed the presence of fatty acids, fatty acid methyl esters, furfuryl alcohol, 1,2-diols and amide, which have been identified in the literature as antimicrobial compounds. P. oxalicum produced 7 compounds, of which 2-Furanmethanol, Dodecanoic acid and Tetradecanoic acid were dominant. S. kiliense produced 8 compounds with 2,3-Butanediol as the main constituent. This is the first report of endophytic fungi of A. dhufarensis with antagonistic activity against phytopathogenic fungi.

Evaluation of CA inhibition activity and the identification of the components of the essential oil of Frankenia pulverulenta (FPEO) and Boerhavia elegans (BEEO) were undertaken for the first time i...

This paper presents an in-depth characterization of a raw industrial sludge (IS-R) and its KOH-activated biochar pyrolyzed at 750 °C (IS-KOH-B) followed by their application to remove a cationic dye from aqueous solution. Materials characterization shows that compared to the IS-R, the IS-KOH-B has improved structural, textural, and surface chemical properties. In particular, the IS-KOH-B’s BET surface area and total pore volume are about 78 and 6 times higher than those found for the IS-R, respectively. The activated biochar efficiently retained the cationic dye under wide experimental conditions. Indeed, for an initial dye concentration of 50 mg L−1, removal yields were assessed to be more than 92.5%, 93.5%, and 97.8% for a large pH range (4–10), in the presence of high contents of competing cations (3000 mg L−1 of Ca2+, Mg2+, Na+, and K+), and a low used adsorbent dose (1 g L−1), respectively. The Langmuir’s adsorption capacities were 48.5 and 65.9 mg g−1 for of IS-R and IS-KOH-B, respectively, which are higher than those reported for various adsorbents in the literature. The dye removal was found to be monolayer, spontaneous, and endothermic for both the adsorbents. Moreover, this removal process seems to be controlled by chemical reactions for IS-KOH-B whereas by both physico–chemical reactions for IS-R. This study demonstrates that the raw industrial sludge and especially its KOH-activated derived biochar could be considered as promising adsorbents for the removal of dyes from aqueous solutions.

In the current investigation, the chemical composition of the essential oils (EOs) from the stem and leaves of Acridocarpus orientalis A. Juss. were evaluated by gas chromatography (GC) and gas-chr...

The biocontrol potential of antagonistic bacteria and yeasts isolated from tomato phyllosphere and fructoplane was evaluated against fruit rot of tomato caused by Alternaria alternata. A total of 4...

The production of antifungal compound(s) by an indigenous Pseudomonas resinovorans strain B11, showing antagonistic activity against Monosporascus cannonballus, the causal fungus of muskmelon Monosporascus root rot and vine decline disease was studied. The crude antibiotics were extracted from the cell-free culture filtrate of P. resinovorans B11 by solvent extraction. Analysis of the antibiotics preparation by thin layer chromatography revealed a prominent band with an Rf of 0.23 under ultraviolet light. Results of the gas chromatography–mass spectrometry analysis revealed that two compounds with retention time (RT) of 4.25 min and 10.58 min were present in the fluorescent band eluted at Rf 0.23. By comparing the mass spectra of these compounds with those found in the NIST/ Wiley database, these compounds were identified as 5-hydroxy-2-pentanone (RT: 4.25 min) and 4-hydroxy-4-methyl-2-pentanone (RT: 10.58 min) with molecular weights of 102.13 and 116.16, respectively. The compound 4-hydroxy-4-methyl-2-pentanone has been described as one of the components of antibiotics produced by other soil bacteria. However, this is the first report of production of 4-hydroxy-4-methyl-2-pentanone by P. resinovorans B11.

In this study, an entomopathogenic fungus was isolated from whitefly (Bemisia tabaci) cadaver samples collected from eggplant fields in Barka, Oman. The fungus was identified as Cordyceps javanica ...

The aim of this study was to evaluate the effect of diet and animal shearing on the feed and nutrient intakes, water intake, in vitro ruminal methane production, and blood parameters of Omani sheep. A pens trial was carried out for 16 days each in March and June of 2017 using 20 Omani non-castrated yearling rams selected from the sheep herd in the research station and randomly assigned to four groups with 5 animals per group. Group 1: sheared animals fed a high concentrate (HC) diet, group 2: fleeced animals fed a HC diet, group 3: sheared animals fed a low concentrate (LC) diet, group 4: fleeced animals fed a LC diet. Furthermore, a metabolic crates trial was carried out in July of 2017 on three animals from each group over a 10-day period. The effect of diet and shearing on the tested parameters was evaluated using the mixed linear model, where animals were fitted as a random effect to account for the individual animal deviation from the overall mean. Results showed that rams fed on the high concentrate diet had a significantly increased organic matter intake of the total diet (62 g/kg 0.75 Live Weight (LW) in HC group to 54 g/kg 0.75 LW in LC group), an increased water intake (6.3 L/day vs 4.8 L/day in LC group), and a reduced in vitro methane production (i.e. the invitro ruminal CH4 was measured and converted to daily CH4 using the daily feed intake data and was 20.4 g CH4 per head/day in HC group vs 27.3 g CH4 per head/day in LC group), compared with rams fed on the low concentrate diet. Furthermore, shearing had a significant effect (P < 0.01) on increased feed and nutrients intake. The apparent and organic matter digestibility was significantly different (P < 0.01) between the experimental groups and was greater for those rams fed on the HC diet. Partial substitution of low-quality Rhodes grass hay by high-quality concentrate significantly improved the total diet organic matter digestibility (P < 0.01) and nutrients digestibility, whereas no significant effects on biochemical blood parameters or animal health were observed. These results show the importance of utilizing effective feeding and shearing plans to improve the productivity and reduce the methane emission of Omani sheep.

As a herbal medicine, essential oil is used for the treatment of several chronic diseases, however, the clinical evidence of essential oil is insufficient. In this context, we have made an effort to quantify its percentage of chemical composition and the biological potency of essential oil of the leaves of Psidium guajava. The content of essential oil was found in 0.38% (v/w) and the oil was isolated by using hydro distillation from the leaves of the selected plant. The isolated oil was analyzed by using gas chromatography–mass spectrometry (GC–MS) equipped with a HP-5MS fused silica capillary column (30 m × 0.25 i.d., film thickness 0.25 μm). The antimicrobial and cytotoxic activities of the isolated leaves oil at different concentrations were determined by agar gel diffusion and brine shrimp lethality bioassay. The antimicrobial activity of the essential oil at various concentrations was determined against three Gram (+) Enterococcus faecalis, Staphylococcus aureus and Streptococcus aureus and three Gram (−) Escherichia coli, Haemophilus influenzae, and Pseudomonas aeruginosa bacterial strains. A total of 54 chemical compounds were detected by using GC–MS which is representing 98.172% of the total oil. The dominating ingredients in the leaves oil were iso-caryophyllene (33.53%), veridiflorene (13.00%), farnesene (11.65%), dl-limonene (9.84%), δ-cadinene (1.75%), α-copaene (2.80%), α-humulene (3.74%) and τ-cadinol (0.08%). The oil showed significant antimicrobial activity against both Gram (+ and −) bacterial strains with an inhibition range of 0–13 mm. However, the isolated leaves oil did not show any activity at any concentration against brine shrimp lethality bioassay. The isolated oil showed significant antimicrobial activity and it could be used as natural antibiotics.

Background and purpose: The formation of postoperative intra-abdominal adhesion band formation may lead to severe complications. This study aimed to evaluate the preventive effect of local administration of frankincense n-hexane extract (FHE) on the formation of postsurgical adhesion bands. Materials and methods FHE was extracted from the resin of a Boswellia sacra tree and its components were identified by gas chromatography-mass spectrometry (GC-MS). In an animal model, the expression levels of TNF-α and TGF-β1 cytokines after application of FHE were assessed to check the inflammatory and fibrotic cues, respectively. Results Following FHE compound analysis, in vivo experiments demonstrated that intraoperative local administration of FHE resulted in the prevention of adhesion band formation. The adhesion grades in the FHE-treated group were significantly lower than those in the negative control (NC) and the positive control (Interceed). The infiltration of inflammatory cells observed by histopathology revealed a significant anti-inflammatory potential of FHE. Furthermore, the gene expression results proved that significant suppression of TNF-α and TGF-β1 was responsible for its antiadhesion properties. Conclusions The study reported the potential of FHE as an ointment for the prevention of adhesion bands.

Constructed wetlands have been successfully used in the treatment of produced water brought to the surface in large quantities during oil extraction activities. However, with the increasing use of partially hydrolyzed polyacrylamide (HPAM) in enhancing oil recovery, the impacts of HPAM on the biological processes of wetlands is still unknown. Microbial mats in wetlands play a key role in hydrocarbon degradation. Here, we compared the bacterial communities of four wetland microbial mats after flooding with different concentrations of HPAM. Two mats (i.e. the HPAM-free and the 500 ppm HPAM pre-exposed mats) were selected to further investigate the effect of HPAM on respiration and biodegradation activities. The field mats exhibited clear differences in their bacterial community structure, where Cyanobacteria and Alphaproteobacteria became dominant in the presence of HPAM. In the laboratory experiments, the generated CO2 by the HPAM-free and the 500 ppm HPAM pre-exposed mats did not vary significantly when HPAM was added, although CO2 values were slightly higher in the presence of oil. Both mats were still able to degrade between 15 ± 14.4 to 50 ± 13.0% of C10 to C30 alkanes in 28 days, and this degradation was not affected by HPAM addition. The HPAM concentration decreased by 22–34% of the initial amount after 28 days of incubation in the HPAM-free mat, versus only 7–18.4% decrease in the 500 ppm HPAM pre-exposed mat. We conclude that the wetland microbial mats seem to have become well adapted to HPAM and could maintain their respiration and hydrocarbon degradation activities.

Advanced oxidation technologies (AOTs) focusing on nonthermal plasma induced by dielectric barrier discharge are adequate sources of diverse reactive oxygen species (ROS) beneficial for water and wastewater treatment. In this study, indigo, peroxytitanyl sulphate and terephthalic acid methods were used to approximate the concentrations of O3, H2O2 and OH produced in a double cylindrical dielectric barrier discharge (DCDBD) plasma configuration. The effect of pH and scavengers as well as the amount of chemical probes on the generation of oxidants was investigated. The efficiency of the DCDBD reactor was further evaluated using methylene blue (MB) as model pollutant. The results demonstrated that the formation of oxidants O3, H2O2 and OH in the DCDBD reactor was pH-dependent. Furthermore, the presence of scavengers such as phosphates, bicarbonates and carbonates in the solution diminished the amount of OH in the system and hence could impact upon the degree of detoxification of targeted pollutants during water and wastewater treatment. The MB simulated dye was totally decomposed into H2O, dissolved CO2 and simpler aqueous entities. Herein the DCDBD design is an adequate AOT that can be used worldwide for effective decontamination of water and wastewater.

Cupriavidus necator H16 Re2058/pCB113 could effectively utilize oil sources to synthesize P(3HB-co-3HHx). In this study, P(3HB-co-3HHx) biosynthesis procedure with optimally controlled (between 2–28) 3HHx mol% was established for C. necator H16 Re2058/pCB113 by regulating the amounts of dual carbon sources supplied; date molasses and date seed oil. Alone, date molasses supplied at 20 g/L total sugar equivalents to recombinant C. necator resulted in pure P(3HB) biosynthesis, with accumulation up to 28 wt% of cell dry weight (CDW), and effective total biomass of 4 g/L. Whereas, date seed oil supply alone or in combination with date molasses resulted in P(3HB-co-3HHx) biosynthesis. P(3HB-co-3HHx) with as high as 28 mol% 3HHx, up to 80 wt% of CDW and total biomass of 7.6 g/L were produced using 10 g/L date seed oil as the sole carbon source. The results of PHA production in the presence of date seed oil as a sole carbon source was obtained with a modest yield at a range of 0.38–0.62 g-PHA per g-date oil used. Gel permeation chromatography (GPC) analyses of these P(3HB-co-3HHx) copolymers exhibited weight average molecular weights (Mw) between 500 − 690 kDa. Differential scanning calorimetry (DSC) analyses showed Tm values of 157 °C and 85 °C for P(3HB) and P(3HB-co-28 mol% 3HHx), respectively. NMR analyses (1H and 13C) of P(3HB-co-3HHx) copolymers confirmed the incorporation of 3HHx monomers between 2–28 mol% depending on the supplied dual carbon source composition.

A study was conducted on the possible in vitro production of phytotoxins by the melon root rot pathogen, Monosporascus cannonballus. The culture filtrate of a highly virulent isolate of the fungus was tested for its phytotoxic activity on cucumber by detached leaf assay, electrolyte leakage assay and seedling vigour test. In detached leaf bioassay, necrotic symptoms developed on cucumber leaves 5–7 days after application of the culture filtrate. The culture filtrate of M. cannonballus caused substantial reduction in seed germination, vigor of cucumber seedlings and an increase in electrolyte leakage from leaf tissues compared to the control. Studies on the effect of heat and dialysis on the phytotoxic activity of the culture filtrate revealed that the toxic metabolites are thermostable and have low molecular weight (

Mangroves (Avicennia marina) growing in intertidal areas are often exposed to diesel spills, adversely damaging the ecosystem. Herein, we showed for the first time that mangrove seedlings' associations with bacteria could reprogram host-growth, physiology, and ability to degrade diesel. We found four bacterial strains [Sphingomonas sp.-LK11, Rhodococcus corynebacterioides-NZ1, Bacillus subtilis-EP1 Bacillus safensis-SH10] exhibiting significant growth during diesel degradation (2% and 5%, v/v) and higher expression of alkane monooxygenase compared to control. This is in synergy with reduced long-chain n-alkanes (C24-C30) during microbe-diesel interactions in the bioreactor. Among individual strains, SH10 exhibited significantly higher potential to improve mangrove seedling's morphology, anatomy and growth during diesel treatment in rhizosphere compared to control. This was also evidenced by reduced activities and gene expression of antioxidant enzymes (catalases, peroxidases, ascorbic peroxidases, superoxide dismutases and polyphenol peroxidases) and lipid peroxidation during microbe-diesel interactions. Interestingly, we noticed significantly higher soil-enzyme activities (phosphatases and glucosidases) and essential metabolites in seedling's rhizosphere after bacteria and diesel treatments. Degradation of longer n-alkane chains in the rhizosphere also revealed a potential pathway that benefits mangroves by bacterial strains during diesel contaminations. Current results support microbes' application to rhizoengineer plant growth, responses, and phytoextraction abilities in environments contaminated with diesel spills. AVAILABILITY OF DATA AND MATERIALS: The datasets generated during the current study are available in the NCBI GenBank ((https://www.ncbi.nlm.nih.gov).

Visible light absorption enhanced silver nanoparticles (Ag NPs) decorated zinc oxide nanorods (ZnO NRs) were synthesized using microwave-assisted growth method and utilized as supported catalysts in degradation of pharmaceutical compound. The optimal concentration of silver nitrate precursor and annealing temperature for synthesized ZnO–Ag catalysts were investigated. Different concentrations (5–20 ppm) of paracetamol were used as test contaminant in photocatalytic degradation process. The highest photocatalytic degradation (92%) of 5 ppm paracetamol was achieved for ZnO–Ag in comparison to (54%) degradation for pristine ZnO after 4 h visible light irradiation. The stability of ZnO–Ag catalyst was also investigated. The degradation performance decreased only 2% for ZnO–Ag and 24% for pristine ZnO using 5 ppm paracetamol after four repeated cycles showing high ZnO–Ag stability. Enhanced photocatalytic activity of ZnO–Ag catalyst was due to efficient charge separation as well as visible light absorption and reduced recombination of electron and hole.

Biodiesel, a good partial or total substitute for petrodiesel, is a renewable clean burning fuel which can be produced from transesterification of vegetable oils and animal fats with an alcohol in presence of a catalyst. Since the feedstock costs in this process constitutes more than 70 % of the overall cost, use of wasted vegetable oil (i.e. consumed cooking oil) for biodiesel production is a big challenge in terms of cost reduction and environmental impacts. Nonetheless, the content of residues in the wasted vegetable oil, formed during frying, is a major drawback could be faced in this direction. In this research, we applied an unconventional design of flying jet dielectric barrier discharge plasma torch to treat several specimens of wasted cooking oil collected from different resources before transesterification. In other experiments, the jet plasma itself was used to catalyze the reaction process. The examined plasma torch was found more feasible than conventional DBD reactor design in terms of gas and power consumptions. Upon inducting plasma treatment, the transesterification process resulted in higher biodiesel yield, lower reaction time and easier product separation than the conventional path. Upon catalyzing the reaction by the sole jet plasma effect, the biodiesel content of saturated methyl esters was higher than conventional tranesterification. Also, the yield and properties were found within commercial standards.

Mentha arvensis and Citrullus colocynthus are important medicinal plants for Arab people as herbal remedy. The present study was designed to evaluate the components present in wild growing Mentha arvensis and Citrullus colocynthus using various advanced analytical techniques. After wet digestion plants samples were analyzed for metal contents using flame photometric and inductively coupled plasma (ICP) analyses. Volatile compounds present in essential oil of Mentha arvensis were determined using Gas chromatographic coupled with Mass spectrometry. Fatty acid composition of Citrullus colocynthus was determined using Gas chromatograph equipped with flame ionization detector (FID). Linoleic acid was found as a major component of Citrullus colocynthus seed oil. Phenolics and flavonoids present in Mentha arvensis and Citrullus colocynthus were detected using High performance liquid chromatography (HPLC). HPLC analysis of Citrullus colocynthus seed oil confirms the presence of anti-diabetic and cholester...

Catharanthus roseus is among the most important anticancer agents providing plants in the world. In the current study, vinca leaves were cultured on MS medium supplemented with 1.5 mg/L BAP and 1.5 mg/L 2,4D. The callus obtained was subcultured on 15 different combinations of growth hormones for 28 days. The callus extracts from different treatments were analyzed by HPLC with respect to the vincristine and vinblastine producing capacity in comparison to the wild plant. The biomass was maximized with growth hormone combinations 2,4D/NAA and IAA/NAA but the biosynthesis of alkaloids were minimized. Vincristine production was potentiated in almost all growth hormones combinations with Kin/IAA producing the highest concentration. However, vinblastine was potentiated in growth hormone combinations Kin/IAA, IAA/Gb, BAP/Gb and NAA/Gb only, with Kin/IAA showing the highest concentration of vinblastine. The main motivating result was the biosynthesis of the essential anticancer dimeric alkaloids, vincristine which was hardly detected in the wild plant and vinblastine which showed a 3.39-fold increase compared to the wild plant.

Traditionally wild plants including Zygophyllum spp., containing many bioactive constituents, are used as medicine. Zygophyllum luntii from Zygophyllaceae family is wildly grown in Oman and has been used for medical purposes. The present study investigated the antibacterial activity of the crude extracts (leaves, stem and roots) and oil (leaves) from Z. luntii. These extracts were tested against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa in well diffusion assays utilizing Muller Hinton Agar (MHA). The hydrocarbon contents and the fatty acid methyl ester (FAME) components of the extracts were also determined by GC-MS. Significant antibacterial activity was observed in the Z. luntii leaves extract and significant differences (F=14.06, df=2, P=0.002) were found among E. coli, P. aeruginosa and S. aureus. The highest inhibition was observed against P. aeruginosa (15.5 ± 2.64 mm) then E. coli (11.25 ± 1.50mm) and S. aureus (3.50±4.72 mm). The Z. luntii extracts showed about 50-60% effectiveness against E. coli and P. aeruginosa compared to Ciprofloxacin. A total of 20, 19 and 8 compounds were detected from leaves, stem and roots extracts, respectively. Heneicosane, Docosane and Tricosane were found in the highest concentration in leaves; HOP-22(29)-EN-3.BETA.-OL and β-Sitosterol in stems, and Docosane and Tricosane in roots of Z. luntii. Nine types of fatty acids methyl esters were detected in oil extracted from leaves and methyl esters of Palmitic acid, Linolenic acid and Oleic acid constitutes 90% of the oil. This is the first report on antibacterial activity and chemical composition of Z. luntii.

Thymus vulgaris L. belongs to the Lamiaceae family and has a pleasant smell. It is native to the Westren Mediterranean region and southern Italy. The fresh plant material was collected in the month of April from Al Jabal Al Abyadh in Sharqiya region of Oman. The aerial parts of T. vulgaris were separated from fresh plant material and essential oil was isolated by steam distillation method using Clevenger's apparatus. The oil was analyzed by GC-MS. A total of eighteen constituents were identified, the major constituent was durenol (56.2 %). Other main constituents were thymol (15.04 %), p-cymene (8.69 %), δ-terpinene (5.24 %), and α-pinene (2.65 %).

It is quite challenging to recover heavy crude oil due to its high viscosity and long chain hydrocarbon contents. In this study the isolation of thermophilic bacterial consortia from crude oil contaminated soil samples and their ability to degrade heavy crude oil were investigated. Thermophilic spore forming bacteria were inoculated with heavy oil in minimal salt media. Maximum growth was observed on 21st day of incubation at 40 °C. Samples were analyzed for biosurfactant production, where a substantial decrease in surface tension and interfacial tension was not observed. A well-assay was used to check the potential of bacterial consortia for oil-clearing zones on oil agar plate with bacterial cultures and their cell-free filtrates. 16S rRNA sequencing of 27 isolates from oil contaminated soil showed that isolates belonged to three classes: Alpha-proteobacteria, gamma-proteobacteria and Bacilli. Scanning electron microscopy showed that the oil utilizing bacteria were rod-shaped with rough surface and fimbria. Gas chromatography analysis of treated oil after 21 days showed that bacterial consortia efficiently degraded heavy crude oil to light hydrocarbons ranging from C11–C27, from initial C37+ carbon chain of untreated controls. These bacterial consortia showed potential in heavy crude oil biodegradation by breaking it down to smaller hydrocarbon composition.

Objective To investigate the anti-cancer effect of frankincense derived heavy oil obtained by Soxhlet extraction method on breast cancer cells (MDA-MB-231), and to study its chemical profile using gas chromatography mass spectrometry analysis. Methods Hexane was used to extract heavy oil from frankincense resin. Chemical profiling of heavy oil was done using Perkin Elmer Clarus GC system with mass spectrometer. MDA-MB-231 cells were treated with different dilutions (1:1 000, 1:1 500, 1:1 750, 1:2 000, 1:2 250, 1:2 500, 1:2 750, 1:3 000, 1:3 250) of heavy oil for 24 h. The cells were observed by using light microscopy. Cell viability was measured by MTT assay. Results Gas chromatography mass spectrometry chemical profiling of frankincense derived heavy oil revealed the presence of terpenes such as α-pinene (61.56%), α-amyrin (20.6%), β-amyrin (8.1%), β-phellandrene (1.47%) and camphene (1.04%). Heavy terpene cocktail induced significant MDA-MB-231 cell death at each concentration tested. Noticeably, very low concentration of Soxhlet derived heavy terpenes elicits considerable cytotoxicity on MDA-MB-231 cells compared to hydro distillated essential oil derived from frankincense resin. Conclusions Extracting anti-cancer active principle cocktail by simple Soxhlet method is cost effective and less time consuming. Our in vitro anti-cancer data forms the rationale for us to test heavy terpene complex in breast cancer xenograft model in vivo. Furthermore, fractionation and developing frankincense heavy terpene based breast cancer drug is the major goal of our laboratory.

Objective To identify the major volatile constituents and evaluate the antibacterial activity of essential oil isolated from the aerial parts of Ocimum basilicum ( O. basilicum ) Linn. grown in Oman. Methods The fresh plant material was collected in the month of September from Seeb Nursery in Muscat Governorate, Sultanate of Oman. The aerial parts of O. basilicum Linn. were separated from fresh plant and essential oil was isolated by hydrodistillation method by using Clevenger apparatus. A greenish yellow oil was obtained in 0.6% v/w yield which was analyzed by gas chromatography–mass spectrometry for its chemical composition. The antibacterial activity of oil was also evaluated against three Gram–positive and four Gram–negative pathogenic bacterial strains by agar well diffusion method. Results A total of thirty six chemical constituents were identified and linalool (69.87%) was found to be the major constituent. Other main identified constituents included geraniol (9.75%), p-allylanisole (6.02%), 1,8–cineole (4.90%), trans–α–bergamotene (2.36%) and neryl acetate (1.24%). The essential oil of O. basilicum showed excellent antibacterial activity against Gram–positive bacteria and moderate activity against Gram–negative bacteria. Conclusions Omani basil is characterized by a high content of linalool which makes it useful in food, pharmaceutical and perfumery industries.

Synthesis and characterization of nano-sized activated alumina from kaolin using an innovative three-step method are presented. Adsorption study of the as-synthesized activated alumina using phenol solution as absorbate was carried out. The Brunauer–Emmett–Teller (BET) specific surface area, pore diameter and pore volume of the as-synthesized activated alumina were 202.3 m2/g, 1.212 nm and 0.0613 cm3/g respectively. Chemical, mineralogical, morphological and thermal analyses of the as-synthesized activated alumina were carried out using X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The as-synthesized activated alumina possessed 83.47 wt.% Al2O3. Its XRD pattern possessed characteristic peaks gamma phase of alumina. The as-synthesized activated alumina possessed nano-size morphology; having crystal size value of 12.5 nm. It was thermally stable; the differential thermogravimetric (DTG) analysis showed that only 17 wt.% mass depletion was observed for heating from 30 to 900 °C. Adsorption isotherm of the as-synthesized activated alumina using Freundlich, Langmuir and Dubinin–Radushkevich (D–R) models, gave coefficients of determination of 0.948, 0.962 and 0.867 respectively. The Kf, b, and Kads isotherm constants for were 0.934 mg/g, 0.0116 L/mg and 2.05 × 10− 5 mol2/kJ2 for the Freundlich, Langmuir and D–R models respectively.

Six common soft coral species ( Sarcophyton sp., Sinularia sp.1 and sp.2, Cladiella sp., Scleronephthya sp. and Dendronephthya sp.) from Bandar Al-Khayran (Sultanate of Oman) had significantly lower bacterial density in comparison with surfaces of empty shells. Methanol: chloroform (1:1) extracts of these species were tested against Gram positive ( Micrococcus luteus, Staphlococcus aureus, Bacillus subtilis, Bacillus sp.) and Gram negative ( Salmonella enterica, Pseudomonas aeruginosa, Escherichia coli, Cytophaga sp., Pseudomonas sp., Shewanella sp.) marine biofouling and pathogenic bacterial strains. All tested extracts had some activity against human pathogens and the highest antimicrobial activity was observed for extracts of Sinularia sp.1 and Cladiella sp. (inhibited 50% and 60% of the strains, respectively). Only ethyl acetate extracts of Cladiella sp. inhibited growth of biofouling bacteria. The active fraction was purified and identified as a mixture of hexadecyl palmitate and hexadecyl stearate. Pure hexadecyl palmitate inhibited growth ( Bacillus sp. and Psychrobacter sp.) and attachment ( Bacillus sp., Cytophaga sp., Pseudomonas sp., Psychrobacter sp., Shewanella sp.) of the marine biofouling bacteria. The results of this study suggest that soft corals have developed mechanisms to combat microbial infections and inhibit bacterial fouling.

Marine sources have been known to yield novel compounds with a wide range of bioactivity with various commercial applications. In this study, the abilities of bacteria isolated from eight marine organisms to produce α-amylase were examined. All eight organisms were found to harbor amylase producing bacteria. Two bacterial species isolated from the green alga Ulva rigida and the sponge Mycale sp. were further identified and their α-amylases were purified and characterized. The bacterial species isolated from U. rigida and Mycale sp. were identified by DNA sequencing as Cellulosimicrobium sp. and Demequina sp., respectively. Cellulosimicrobium sp. obtained maximum cell growth and amylase production at 29.C and in the presence of lactose as a carbon source. Optimal cell growth and amylase production by Demequina sp. was observed at 35.C. While lactose enhanced cell growth of Demequina sp., maximum amylase production was found when fructose and glycerol were the available sources of carbon. Both strains grew better in the presence of tryptone, whilst peptone stimulated amylase production. Maximal cell growth and amylase production by both of the strains was found at a medium salinity of 3% NaCl.

Central Instrumentation Laboratory, College of Agricultural and Marine Sciences, Sultan Qaboos University, P.O. Box 34, P.C. 123, Muscat, Sultanate of Oman E-mail : jamal@squ.edu.om Department of Biology, College of Science, Sultan Qaboos University, P.O. Box 36, P.C. 123, Muscat, Sultanate of Oman E-mail : apnsiva@squ.edu.om Department of Research, Saveetha University, Thandalam, Chennai-602 105, India E-mail : drsuku3@gmail.com Manuscript received online 02 March 2016, accepted 12 February 2017 Millingtonia hortensis commonly known as Tree Jasmine or Indian Cork Tree, is indigenous to Burma and the Malay Archipelago and cultivated as an ornamental plant in some countries. The flowers, root and bark are used medicinally. In this study, the volatile oil (VO) obtained by the hydro-distillation of the flowers of the plant grown in Sultanate of Oman, has been analyzed by GC-MS. A total of 32 compounds have been identified that formed major part (97.7%) of the volatile oil. The main components of VO were L-linalool (29.16%), α-farnesene (11.80%), nerolidol (11.34%), pentacosane (9.69%), 1-octen-3-ol (7.62%), (e)-isoeugenol (4.87%), α-terpineol (3.82%), linalool oxide (3.68%), heptacosane (3.03%) and tricosane (2.63%). The volatile oil has been tested for its antimicrobial activity against eleven bacteria wherein it exhibited significant inhibition against seven, moderate against two and no response against two strains. The minimum inhibitory concentration (MIC) has also been determined for the volatile oil.

Objective To analyze three essential oils isolated from three different brands' clove samples collected from Gulf region and tested their antimicrobial activities. Methods The essential oils were isolated from powder clove samples by water distillation method and analyzed and identified by gas chromatography-mass spectrometry. Antimicrobial activities of the three isolated essential oils were calculated on the diameter inhibition zone by disc diffusion method against three bacterial strains with amoxicillin standard. Results Twenty-eight, twenty-two and twenty-six chemical ingredients with high percentage were characterized based on gas chromatography retention time from clove essential oils collected from Saudi Arabia, United Arab Emirate and Jordan. The highest antimicrobial activity was obtained from Saudi Arab against Escherichia coli, Pseudomonus aeruginosa and Staphylococcus aureus and the lowest was from Jordan and the order of antimicrobial activity was Saudi Arabia>United Arab Emirate>Jordan. Conclusions All three essential oils from Gulf region are containing very portent chemical ingredients and it could be used as medicine or antibiotics for different aliments.

Juniperus excelas is an important flowering medicinal plant belonging to the Cupressaceae family. Essential oil was obtained from fresh fruit of J. excelas by hydro-distillation in a Clevenger apparatus and analysed by gas chromatography–mass spectrometry (GC–MS). The chemical constituents of the essential oil were identified by their mass spectra, retention time and retention indices. The yield was 0.27%. We identified 48 chemical compounds accounting for 89.74% of the composition. The major chemical components were α-terpinene (23.85%), limonene (23.42%), fenchene (6.57%), camphene (6%), δ-3-carene (4.17%), 4-terpineol (2.93%), germacrene B (2.21%), myrcene (1.96%), α-pinene (1.77%), β-pinene (1.53%) and abietatriene (1.13%). The antimicrobial activity of the essential oil of J. excelas was determined against one Gram-positive and two Gram-negative foodborne pathogenic bacteria, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. No activity was detected.

Two oil-polluted sediments (PD and KH) were sampled from a coastal region in Oman for the isolation of hydrocarbon-degrading bacteria and for testing different bioremediation approaches. Fourty strains were isolated, eighteen were affiliated to Marinobacter whereas the rest belonged to Pseudomonas , Halomonas , Hahella and Alcanivorax . All strains grew well at 2–7% salinity and between 20 and 60 °C. The strains exhibited a better growth on long chain than on short chain alkanes. Biostimulation and bioaugmentation were compared in both sediments and oil biodegradation was followed by measuring CO 2 evolution and by gas chromatography (GC). The evolved CO 2 reached 0.45 ± 0.02 and 2.23 ± 0.07 mg CO 2 g −1 sediment after 88 days in the untreated PD and KH sediments, respectively. While the addition of inorganic nutrients resulted in 1.2–3.7 fold increase in CO 2 evolution in both sediments, the addition of the bacterial consortium was only effective in the PD sediment. The maximum CO 2 evolution was measured when both nutrients and bacteria were added and this corresponded to a total oil mineralization of 2.6 ± 0.12 and 1.49 ± 0.04% of the initial oil after 88 days in the PD and KH sediments, respectively. GC analysis confirmed the CO 2 data and showed that most of the degraded compounds belonged to alkanes. We conclude that the Omani polluted sediments contain halotolerant and thermotolerant bacteria and biostimulation is more efficient than bioaugmentation for their cleanup.

Background: Camel milk is widely used for its reported anti-diabetic and health promoting effects. Lipids derived from the milk have also been shown to exhibit potent anti-inflammatory effects. The mechanism through which these lipids and constituent fatty acids exert these effects remains elusive. The aim of this study was to investigate the effect of camel milk on glycated protein-mediated macrophage inflammation. Methods: To determine the effect of Total Lipids (TL) and Total Fatty Acids (TFA) derived from camel milk on an in vitro model of diabetic inflammation, differentiated THP-1 (dTHP-1) cells stimulated with glycated serum albumin (gBSA) was employed. Cells were pre-treated with TL or TFA before challenging cells with gBSA. Results: Gas Chromatography-Mass Spectrometry ( GC-MS) analysis found that TL was 96% triacylglycerol (TAG) while the TFA comprised 65% saturated and 35% unsaturated fatty acids. Both TL and TFA significantly (p

The production of acid lime (Citrus aurantifolia) has declined in many parts of the world due to phytoplasmal infection by “Candidatus Phytoplasma aurantifolia”. The resulting Witches’ Broom Disease of Lime (WBDL) causes stem and leaf proliferation and clustering that starts on a few branches and continues to spread until trees are killed within 5-7 years. Recent studies have shown that Phytoplasma alters the chemical composition of leaves. Leaves from WBDL-symptomatic lime trees were collected to determine their volatile compound composition. Phytoplasmal infection was confirmed by a polymerase chain reaction (PCR) assay using primers P1/P7 and R16F2n/R16R2 in direct and nested PCR, respectively. Restriction fragment length polymorphism (RFLP) profiles of acid lime Phytoplasma were identical with those of WBDL Phytoplasma. The phytochemical composition of symptomatic (infected) and asymptomatic (healthy) leaves of acid lime were determined using GC-MS analysis of steam distilled extract. The WBDL-symptomatic leaves had higher concentration in ?-limonene, β-ocimene and trans-caryophyllene and a reduction in other compounds (i.e. citral, citronellal, cisverbenol, neryl acetate, and linalool). Variations in the leaf phytochemical concentration indicate a possible role in the development of the WBDL disease symptoms.