Ali H. Bahkali

Bio: Ali H. Bahkali is an academic researcher from King Saud University. The author has contributed to research in topics: Dothideomycetes & Pleosporales. The author has an hindex of 50, co-authored 287 publications receiving 9411 citations. Previous affiliations of Ali H. Bahkali include Yeungnam University & Landcare Research.

Revision of genera in Asterinales

Abstract: The order Asterinales comprises a single family, Asterinaceae. In this study, types or specimens of 41 genera of Asterinaceae are re-examined and re-described and illustrated by micrographs. Seventeen genera, namely Asterina (type genus), Asterinella, Asterotexis, Batistinula, Cirsosia, Echidnodella, Halbania, Lembosia, Meliolaster, Parasterinopsis, Platypeltella, Prillieuxina, Schenckiella (=Allothyrium), Trichasterina, Trichopeltospora, Uleothyrium and Vizellopsis, are maintained within Asterinaceae. Echidnodes, Lembosiella, Lembosina, Morenoina, and Thyriopsis are transferred to Aulographaceae based on morphological and molecular characteristics. Anariste is transferred to Micropeltidaceae, while Lembosiopsis is transferred to Mycosphaerellaceae. Placoasterella and Placosoma are morphologically close to taxa in Parmulariaceae, where they are transferred. Aulographina is placed in Teratosphaeriaceae, while Asterodothis, Asterinema, Dothidasteromella, Leveillella, Petrakina and Stephanotheca are transferred to Dothideomycetes, genera incertae sedis. Eupelte, Macowaniella, Maheshwaramyces, Parasterinella, and Vishnumyces are treated as doubtful genera, because of lack of morphological and molecular data. Aphanopeltis, Asterolibertia, Neostomella, Placoasterina, and Symphaster are synonyms of Asterina based on morphology, while Trichamelia, Viegasia, and Yamamotoa are synonyms of Lembosia. The characteristics of each family are discussed and a phylogenetic tree is included.

Co-inoculation of rhizobacteria promotes growth, yield, and nutrient contents in soybean and improves soil enzymes and nutrients under drought conditions.

Abstract: Drought stress is the major abiotic factor limiting crop production. Co-inoculating crops with nitrogen fixing bacteria and plant growth-promoting rhizobacteria (PGPR) improves plant growth and increases drought tolerance in arid or semiarid areas. Soybean is a major source of high-quality protein and oil for humans. It is susceptible to drought stress conditions. The co-inoculation of drought-stressed soybean with nodulating rhizobia and root-colonizing, PGPR improves the root and the shoot growth, formation of nodules, and nitrogen fixation capacity in soybean. The present study was aimed to observe if the co-inoculation of soybean (Glycine max L. (Merr.) nodulating with Bradyrhizobium japonicum USDA110 and PGPR Pseudomonas putida NUU8 can enhance drought tolerance, nodulation, plant growth, and nutrient uptake under drought conditions. The results of the study showed that co-inoculation with B. japonicum USDA110 and P. putida NUU8 gave more benefits in nodulation and growth of soybean compared to plants inoculated with B. japonicum USDA110 alone and uninoculated control. Under drought conditions, co-inoculation of B. japonicum USDA 110 and P. putida NUU8 significantly enhanced the root length by 56%, shoot length by 33%, root dry weight by 47%, shoot dry weight by 48%, and nodule number 17% compared to the control under drought-stressed. Co-inoculation with B. japonicum, USDA 110 and P. putida NUU8 significantly enhanced plant and soil nutrients and soil enzymes compared to control under normal and drought stress conditions. The synergistic use of B. japonicum USDA110 and P. putida NUU8 improves plant growth and nodulation of soybean under drought stress conditions. The results suggested that these strains could be used to formulate a consortium of biofertilizers for sustainable production of soybean under drought-stressed field conditions.

Chrysin-Loaded Chitosan Nanoparticles Potentiates Antibiofilm Activity against Staphylococcus aureus.

Abstract: The application of nanotechnology in medicine is gaining popularity due to its ability to increase the bioavailability and biosorption of numerous drugs. Chrysin, a flavone constituent of Orocylumineicum vent is well-reported for its biological properties. However, its therapeutic potential has not been fully exploited due to its poor solubility and bioavailability. In the present study, chrysin was encapsulated into chitosan nanoparticles using TPP as a linker. The nanoparticles were characterized and investigated for their anti-biofilm activity against Staphylococcus aureus. At sub-Minimum Inhibitory Concentration, the nanoparticles exhibited enhanced anti-biofilm efficacy against S. aureus as compared to its bulk counterparts, chrysin and chitosan. The decrease in the cell surface hydrophobicity and exopolysaccharide production indicated the inhibitory effect of the nanoparticles on the initial stages of biofilm development. The growth curve analysis revealed that at a sub-MIC, the nanoparticles did not exert a bactericidal effect against S. aureus. The findings indicated the anti-biofilm activity of the chrysin-loaded chitosan nanoparticles and their potential application in combating infections associated with S. aureus.

Inoculation of Klebsiella variicola Alleviated Salt Stress and Improved Growth and Nutrients in Wheat and Maize

Abstract: Although wheat and maize are the major economically important cereal crops and staple food sources in the world, their productivity is highly affected by excess salts in soil (salinity). Applications of multifarious halophilic plant growth-promoting rhizobacteria (PGPR) in saline soil protect the plants from osmotic damages and promote plant growth through the secretion of plant growth promoting (PGP) and osmolytes. In this study, Klebsiella variicola SURYA6—a PGPR—was evaluated for plant-growth-promotion and salinity amelioration in wheat and maize, and enrichment of soil nutrients. The results of the present study revealed that K. variicola SURYA6 grows luxuriously under high salinity stress conditions and produces copious amounts of three principal salinity ameliorating traits, such as 1 aminocyclopropane-1-carboxylate deaminase (ACCD), indole-3-acetic acid (IAA), exopolysaccharides (EPS), and osmolytes—such as proline, sugars, proteins, and amino acids. The isolate also exhibited sensitivity to a wide range of antibiotics, lack of hemolytic ability, and absence of catalase and oxidase activities confirming its nonpathogenic nature. Inoculation of wheat and maize seeds with this multifarious strain, improved the physicochemical properties of soil, improved seed germination by 33.9% and 36.0%, root length by 111.0%, 35.1%, shoot height by 64.8% and 78.9%, and chlorophyll content by 68.4% and 66.7% in wheat and maize seedlings, respectively, at 45 days after sowing (DAS) under salinity stress. The improvement in plant growth can be correlated with the secretion of PGP traits and improved, uptake of minerals such as nitrogen (N), phosphorus (P), sodium (Na), potassium (K), and magnesium (Mg). While amelioration of salinity can be the result of secretion of osmolytes and the change in pH from salinity to neutrality. This inoculation also significantly improved the soil nutrients under salinity stress conditions. Inoculation of K. variicola SURYA6, resulted in more improved growth and nutrients contents in plants and enriched soil nutrients under salinity stress as compared to normal (non-saline) conditions. Such multifarious strain can serve as a potent bio-inoculant for growth promotion of wheat and maize in saline soil. However, multi-year field trials under different agro-climatic conditions are required to confirm the bio-efficacy of K. variicola SURYA6.

Effective treatment of resistant opportunistic fungi associated with immuno-compromised individuals using silver biosynthesized nanoparticles

Abstract: Drug resistance in filamentous fungus to antifungal medicines is a huge problem in biomedical applications; so, an effective strategy for treating opportunistic fungal infections is needed. Mentha piperita is a very fascinating plant to treat a variety of ailments as home remedies. Eighteen strains of Aspergillus species were used for this study which are having a unique antifungal resistance profile in presence of silver nanoparticles (AgNPs). AgNPs were prepared, using an aqueous extract of M. Piperita and characterized it by various techniques. Structural properties of AgNPs were systematically studied using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FT-IR), and Raman measurement, which emanate the single-phase fcc structure of silver nanoparticles. The spherical nature and elemental analysis of as-synthesized AgNPs were confirmed using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy, respectively. The optical study has been analyzed using UV-Vis spectroscopy and band gap was calculated as 2.51 eV, using Tauc plot. To analyze and validate the good efficacy of the disc approach, antifungal activity of AgNPs nanoparticles in different concentrations against isolates was achieved in both disc and broth microdilution. The extracellular enzymatic activity of A. fumigatus was found to explore the precise impact of nanoparticles on fungal metabolism. The antifungal efficacy of AgNPs against all fungi was highly successful in disc method. The broth approach underlined the favorable results of the disc method. It provided more precise results in determining the minimum inhibition concentration (MIC), as well as the minimum effective concentration (MEC). A. fumigatus (AM6) enzymatic activity was boosted by AgNPs. Also, ß-galactosidase, ß-glucuronidase, and ß-glucosidase are necessary enzymes whose activity has been boosted. Consequently, M. piperita AgNPs can play a major and intriguing function against resistant Aspergillus species with a significant shift in the enzymatic activity profile of fungi due to this action.

A new species

Abstract: We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

A European Database of Fusarium graminearum and F. culmorum Trichothecene Genotypes

Abstract: Fusarium species, particularly Fusarium graminearum and F. culmorum, are the main cause of trichothecene type B contamination in cereals. Data on the distribution of Fusarium trichothecene genotypes in cereals in Europe are scattered in time and space. Furthermore, a common core set of related variables (sampling method, host cultivar, previous crop, etc.) that would allow more effective analysis of factors influencing the spatial and temporal population distribution, is lacking. Consequently, based on the available data, it is difficult to identify factors influencing chemotype distribution and spread at the European level. Here we describe the results of a collaborative integrated work which aims (1) to characterize the trichothecene genotypes of strains from three Fusarium species, collected over the period 2000–2013 and (2) to enhance the standardization of epidemiological data collection. Information on host plant, country of origin, sampling location, year of sampling and previous crop of 1147 F. graminearum, 479 F. culmorum, and 3 F. cortaderiae strains obtained from 17 European countries was compiled and a map of trichothecene type B genotype distribution was plotted for each species. All information on the strains was collected in a freely accessible and updatable database (www.catalogueeu.luxmcc.lu), which will serve as a starting point for epidemiological analysis of potential spatial and temporal trichothecene genotype shifts in Europe. The analysis of the currently available European dataset showed that in F. graminearum, the predominant genotype was 15-acetyldeoxynivalenol (15-ADON) (82.9%), followed by 3-acetyldeoxynivalenol (3-ADON) (13.6%), and nivalenol (NIV) (3.5%). In F. culmorum, the prevalent genotype was 3-ADON (59.9%), while the NIV genotype accounted for the remaining 40.1%. Both, geographical and temporal patterns of trichothecene genotypes distribution were identified.