Anti-biofilm activity of Salvadora persica on cariogenic isolates of Streptococcus mutans: in vitroand molecular docking studies
Saleh Al-Sohaibani and Kasi Murugan*
Department of Botany and Microbiology, College of Science, King Saud University, PO Box 2455, Riyadh – 11451, Saudi Arabia
 
(Received 4 June 2011; final version received 3 December 2011)
Salvadora persica sticks are used for chewing and oral-hygiene measures worldwide. The growth inhibition and antibiofilm effects of various extracts on cariogenic Streptococcus mutans isolates were evaluated. Biofilm inhibition, gas chromatography–mass spectrometry (GC–MS) analyses for phytochemicals and their possible mode of interaction with biofilm response regulators were revealed using LigandFit docking protocols. All S. persica extracts showed considerable inhibitory activity and the cariogenic S. mutans showed varied susceptibility when compared with controls. The percentage reduction in biofilm inhibition obtained for methanol, ethanol, chloroform, acetone, and
aqueous extracts were 87.92%, 85.75%, 72.44%, 61.66% and 58.68%, respectively. GC–MS analyses revealed 428
compounds, of which benzyl (6Z,9Z,12Z)-6,9,12-octadecatrienoate, 3-benzyloxy-1-nitro-butan-2-ol and 1,3- cyclohexane dicarbohydrazide interacted efficiently with the bacterial communication quorum-sensing (QS) regulators Streptococcus OmpP and Staphylococcus Lux proteins. The bioactive, dual-function, anti-biofilm agents in S. persica not only inhibit growth, but also control the colonization and accumulation of caries-causing S. mutans.

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Exploitation of Various Crude Plant Extracts Against Black Scurf Disease of Potato in Saudi Arabia
Monira R. Al-Othman
Botany and Microbiology Department, College of Science, King Saud University, Riyadh 1145, Kingdom of Saudi Arabia
e-mail: Monira_alothman@yahoo.com
Published online: 6 September 2012
# Potato Association of America 2012
 
Abstract
 
 Antifungal activities of five plant species (Thym usvulgaris, Lavandula vera, Menta viridis, Rosmarinus officinalis and Cassia italic) extracts weret es te daga inst Rhizoctonia solani using three different solvents (methanol, acetoneand chloroform). Using linear growth technique, the percentages of growth inhibition caused by extracts were deter-mined. The methanol extracts of all test plants were the most effective to inhibit the mycelial growth of test fungus. The percent of growth inhibition of R. solani was least affected by the chloroform extract. Whereas, a t 8 % c on centration, methanol extracts of R. officinalis and T. vulgaris caused complete (100 %) inhibition of R. solani growth. Similar results for M. viridis were attained only at 10 % concentration, compared to control treatment. The analysis of High performance liquid chromatography of five plants indicated that, the extraction with different solvents will lead to different types and concentrations of phenolic compounds.

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Salt tolerance and mycorrhization of Bacopa monneiri

grown under sodium chloride saline conditions
Khaliel A. S.1*, Shine K.1 and Vijayakumar K.1,2
1Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.
2Kerala State Council for Science, Technology and Environment, Thiruvananthapuram, Kerala, India.
Accepted 19 May, 2011
Salinity of soil is a serious problem affecting plant growth and is increasing steadily in many parts of the world, particularly in arid and semi-arid areas. Arbuscular mycorrhiza (A M) is the most wide spread and significant mutualistic fungi having universal in their association including plants of agricultural and medicinal importance. A. mycorrhiza fungi have been shown to promote plant growth and salinity tolerance by various mechanisms. The effects of inoculation with two A. mycorrhizal fungi Glomus mosseae and Glomus intraradices have been investigated on B. monneiri, an important medicinal plant grown with five different levels of salinity (0.40, 80, 120 and 160 mM). Root colonization, leaf chlorophyll content and tolerance of the plants to salinity were determined. The results indicated that the A. mycorrhizal fungi could infect and colonize the roots effectively under high salinity levels and increased chlorophyll content. Dry mass production was significantly enhanced in the inoculated plants and the effect was more evident at the high salinity levels. More over, A. mycorrhizal colonization has increased Na+ and Cl- uptake and reduced rhizosphere NaCl level significantly. A. mycorrhizal association significantly increased tolerance of plants to salinity and was found as an effective measure to enhance establishment of the plant and to decrease soil salinity.
Key words: Arbuscular mycorrhiza, Glomus mosseae, Glomus intraradices, Bacopa monneiri, salt tolerance,
proline.
 
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FUNGAL BIOTA AND OCCURRENCE OF AFLATOXIGENIC
Aspergillus IN POSTHARVEST CORN GRAINS
Mohamed A. Yassin 1, 2, *, AbdEl-Rahim M.A. El-Samawaty1, 2,
Mohamed Moslem1, Ali Bahkali 1 and Kamel Abd-Elsalam1, 2
1Botany and Microbiology Department, Faculty of Science, King Saud University, Riyadh, Saudi Arabia
2Agricultural Research Center, Plant Pathology Research Institute, Giza, Egypt
A survey of fungi associated with corn and popcorn samples, collected from markets throughout the Riyadh region of Saudi Arabia, was investigated. Seventeen species belonging to nine genera were recovered from corn grains, while 11 species belonging to six genera were recovered from popcorn grains. Frequencies of the isolated genera were statistically compared. Aspergillus flavus, A. niger and Rhizopus stolonifer were most frequently isolated from non-sterilized grains, Aspergillus niger, Fusarium proliferatum and F. verticillioides were dominant in sterilized corn grains, while Aspergillus clavatus, A. flavus var. columnaris and Fusarium subglutinans were dominant in sterilized popcorn grains. Potential ability to produce aflatoxins (AFs) B1, B2, G1 and G2, was studied for isolated cultures by using HPLC analysis. Most A. flavus isolates (75%) and some A. niger isolates (25%) were toxin producers. About 67% of A. flavus var. columnaris isolates produced aflatoxins, mostly B2, while A. flavus produced mostly B1, G1 and G2 aflotoxins. A. niger produced the least aflatoxin levels. These findings indicate that aflatoxigenic
A. flavus is predominant in imported corn which may lead to contamination of this food item with aflatoxins. Thus, more effort should be made to minimize the risk of aflatoxin accumulation in imported commodities.
 
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© by PSP Volume 20 – No 6. 2011 Fresenius Environmental Bulletin
BIO-FUNGICIDAL ACTIVITY OF ALOE VERA SAP AGAINST MYCOTOXIGENIC SEED-BORNE FUNGI
AbdEl-Rahim M.A. El-Samawaty1, 2, Mohamed A. Yassin1,2, Ali Bahkali1, Mohamed Moslem1 and Kamel Abd-Elslam1,2,*
1Botany and Microbiology Department, Faculty of Science, King Saud University, Riyadh, Saudi Arabia
2Agricultural Research Center, Plant Pathology Research Institute, Giza, Egypt
 
ABSTRACT
Mycotoxigenic fungi isolated from corn, sorghum grains and peanut kernels were identified. Nine fungal species belonging to three genera were recovered from the tested samples. With the exception of the sorghum isolate, all tested Aspergillus flavus isolates were capable of pro-ducing variable amounts of G1 and B1 aflatoxin ranging from 1-6 parts per billion (ppb). The highest amount of aflatoxin B1 (8ppb) was produced by A. flavus isolated from corn grains. The sorghum isolate of Penicillium oxalicum was the highest producer of citreoviridin (37ppb). Fusa-rium subglutinans isolate recovered from popcorn was capable of producing fumonisin B1, zearalenone and vomitoxin (DON). Corn isolate of Fusarium proliferatum however, failed to produce fumonisin B1 and sorghum isolate of Fusarium verticillioides produced only fumoni-sin B1. The antifungal activity of yellow liquid fraction of Aloe vera against toxigenic fungi was tested. All tested concentrations were effective in inhibiting fungal growth.
 
 
 
SUITABILITY OF INTERGENIC SPACER OR INTERNAL TRANSCRIBED SPACER MICROSATELLITE-PRIMED PCR FOR THE IDENTIFICATION OF RHIZOCTONIA SOLANI AND SOME PHYTOFUNGI
ABD-ELSALAM K.A.1,*, GUO J-R2., MOSLEM M. A1., BAHKALI A.H1. and VERREET J-A2.

1King Saud University, Faculty of Science, Botany and Microbiology Department, P.O. Box: 2455, Riyadh 1145, Saudi
2Institute of Phytopathology, University of Kiel, Hermann-Rodewald-Str. 9, D-24118, Kiel, Germany
 
Corresponding author TEL: 00966566581006; FAX: 0096014675834;EMAIL: abdelsalamka@gmail.com
ABSTRACT
The intergenic spacer (IGS) region or internal transcribed spacer (ITS) region used in pair-combinations with microsatetllite-primed PCR (MP-PCR) primers to establish whether additional polymorphisms can be yielded. A total of 24 Rhizoctonia solani isolates representing thirteen anstomosis groups and nine different fungal species isolate recovered from different areas and hosts. Forty different primers combinations were tested for their ability to provide discrete bands and an individual isolates readily interpretable and reproducible IGS/ITS-MP-PCRprofiles. Both approaches produced highly reproducible and complex genomic fingerprints, with fragments ranging in size from 100 to 2000 bp (IGS-MP-PCR) and 50 to 2000 bp (ITS-MP-PCR). MP-PCR markers yielded more bands than IGS/ITS-MP-PCRbecause of their higher redundancy in the fungal genome. The number of fragments generated by both techniques varied according to the fungal species and also with the primer combination used.Each primer used could differentiate all of the fungal isolates examined in this study. The profiles generated were identical, and reproducible between repeated PCRexperiments.
 
  
In-house Protocol for Isolation of Restrictable and Amplifiable Genomic DNA from Plants, Fungi and Bacteria
 
Ali H. Bahkali1• Kamel A. Abd-Elsalam1* • Mohammed A. Moslem1•
Abdulaziz A. Al-Khedhairy2
 
1King Saud University, Faculty of Science, Botany and Microbiology Department, P. O. Box 2455, Riyadh 1145, Saudi Arabia
2King Saud University, Faculty of Science, Zoology Department, P.O. Box: 2455, Riyadh 1145, Saudi Arabia
 
Corresponding author: * abdelsalamka@gmail.com
 
ABSTRACT
Several rapid DNA isolation protocols are not available for plant and microorganisms with the same method. The method was applied to 5 plant species (tomato, cowpea, cotton, date palm and wild mint), 4 fungal species (Penicillium, Trichoderma, Fusarium and Rhizoctonia) and 4 bacterial species (Erwinia, Pseudomunas, Bacillius and Xanthomonas). Optimal extraction was achieved by incorporating an RNAse A and proteinase K enzymatic digestion step. The protocol produced an acceptable quantity of high-quality DNA. Up to 50 μg of DNA were routinely obtained from a minimal amount of 100 mg of fungal bacterial and plant sample. Fungal DNA prepared by this method was used as a template for PCR to amplify the internal transcribed spacer (ITS) and microsatellite-primed PCR and gave reproducible patterns. The amplicon length of the fragment ITS1/ITS4, ranged in size from 620 to 700 bp. The amplified PCR products of ITS regions in plants ranged in size from 550 to 700 bp, indicating polymorphisms of size in this region. The resultant amplicon was then incubated with the restriction endonucleases RsaI and CofI prior to analysis by gel electrophoresis. The protocol presented here offers an interesting and efficient alternative, eliminating most expensive kits, discounting the material cost per sample to $0.10.
 
Genes, Genomes and Genomics 2 (1), 77-80
 
  
Morphological changes in Vicia faba L.  cv. Baladey grown under impact of atmospheric gas pollutants in Riyadh city, KSA
 
Mohammed N. El-Yemeni  and Akram A. Ali*
Botany & Microbiology Dept., College of Science, King Saud Univ., Riyadh 11451, PO Box: 2455, KSA
 
*Corresponding author permanent address: Department of Botany, Faculty of Science, Zagazig University, Zagazig, Egypt
*E-mail: akram692000@yahoo.com
 

ABSTRACT
Atmospheric ozone (O3) is part and parcel of global climate change and at the ground level it is a greenhouse gas with a negative impact on plants. We selected five localities in Riyadhcity (covered city from North to South) exposed to different levels of gas pollutants. First,Vicia faba  L. cv. Baladey plants were cultivated in pots at Botany and Microbiology Department green house, King Saud University, KSA till reach to vegetative maturity and then transferred to polluted localities. Complete monitoring to major gases (O3, SO2, NO2) during the whole season of research duration. Gradual increases in number of damaged plants per pot, number of damaged leaves and area damaged in leaves per plant especially in Malaz and Manfoha localities reaching 35%. On the other hand, length of bean plants decreased in the same highly polluted localities reached 8-9%. This study concluded that bean plants are best indicator to harmful ozone pollution on plants.
 
Key words: Ambient O3, bean plants, responses, resistance, Riyadh.
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