28 research outputs found

    The significance of wing and body morphometry in discriminating six species of Eurema butterflies (Lepidoptera: Pieridae) of Peninsular Malaysia

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    Six species of Eurema butterflies comprised of 261 adult individuals collected from various sampling sites in Peninsular Malaysia were identified. The morphometric measurement of the specimens was carried out by using seven characters measured from the wing and body regions. Morphometric analysis was determined through the multivariate analysis of Discriminant Function Analysis (DFA) and Cluster Analysis. The results of DFA showed that two out of seven characters utilized have the lowest values of Partial’s Wilks Lambda; basal length and hindwing length. These characters therefore are significant for the discrimination of the Eurema species. The classification matrix shows that both E. hecabe and E. blanda were completely discriminated by the characters set. Moreover, there was great overlaps occurred between the species groups when plotting a conical graph except for species E. blanda that formed homogenous group. Basal length was also suggested as the species-specific character for grouping the species E. blanda. In Cluster Analysis, E. hecabe tends to be closer to E. sari with the lowest value of agglomeration. The results from dendogram generated from average linkage also showed several relationship patterns among the six species

    Diversity of microfungi in ornithogenic soils from Beaufort Island, continental Antarctic

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    This paper presents the results of a biodiversity study of microfungi in ornithogenic soils from Beaufort Island (Ross Sea, continental Antarctic). During the 2004/05 austral sum-mer, we sampled a wide range of soil habitats from an abandoned penguin rookeries to examine the biodiversity of soil microfungi. Beaufort Island is predominantly ice and snow covered, isolated, difficult to access and known to have been visited only infre-quently. Warcup's soil plating method was used for fungal cultivation. A total of ten fungal taxa were isolated, consisting of seven ascomycetes, two anamorphic fungi and one yeast. In terms of their thermal classes, a total of four psychrophilic, five psychro-tolerant and 1 mesophilic fungi were isolated. Thelebolus microsporus, Geomyces sp. and Thelebolus sp. were the most common isolated fungi. Internal Transcribed Spacer (ITS) and 18S rDNA sequences were obtained from 17 fungal isolates, confirming their identification as Thelebolus microsporus, Thelebolus sp., Phoma herbarum and Geo-myces sp

    Antimicrobial activity of microfungi from maritime Antarctic soil

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    The search for cold-adapted and cold-active fungi in extreme environments provides the potential for discovering new species and novel bioactive compounds. In this study, soil samples were collected from Deception Island, Wilhelmina Bay (north-west Antarctic Peninsula, Graham Land) and Yankee Bay (Greenwich Island), maritime Antarctica, for the isolation of soil fungi and determination of their antimicrobial activity. The soil-plate method, agar block, disc diffusion and broth micro-dilution assays were applied to characterize the thermal classes and antimicrobial activity of the isolated fungi. A total of 27 isolates of fungi were obtained from 14 soil samples, including 13 Ascomycota, 4 Zygomycota and 10 anamorphic fungi. Cold-active (psychrotolerant) fungi predominated over cold-adapted (psychrophilic) fungi. In the antimicrobial assay, 16 isolates showed substantial inhibitory activity against test bacterial pathogens. Ethyl acetate extracts of 10 competent isolates showed significant inhibition of bacterial pathogens. Antifungal activity was observed in the disc diffusion assay, but not in the agar block assay. Minimum inhibitory, bactericidal and fungicidal concentrations were determined using the broth micro-dilution method, with an average in the range of 0.78-25 mg ml-1 on the test microorganisms. Isolate WHB-sp. 7 showed the best broad spectrum antimicrobial activity, with the potential for biotechnological studies in antibiotic development

    Antimicrobial properties and the influence of temperature on secondary metabolite production in cold environment soil fungi

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    The Arctic and Antarctic share environmental extremes. To survive in such environments, microbes such as soil fungi need to compete with or protect themselves effectively from other soil microbiota and to obtain the often scarce nutrients available, and many use secondary metabolites to facilitate this. We therefore (i) screened for antimicrobial properties of cold-environment Arctic and Antarctic soil fungi, and (ii) identified changes in the secreted secondary metabolite profiles of a subset of these strains in response to temperature variation. A total of 40 polar soil fungal strains from King George Island, maritime Antarctic and Hornsund, Svalbard, High Arctic, were obtained from the Malaysian National Antarctic Research Centre culture collections. The plug assay technique was used to screen for antimicrobial potential against Gram-positive and Gram-negative human pathogenic bacteria (Bacillus subtilis, B. cereus, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli). About 45% of the tested fungal strains showed antimicrobial activity against at least one tested microorganism. Three fungal isolates showed good bioactivity and were subjected to secondary metabolite profiling at different temperatures (4, 10, 15 and 28 °C). We observed a range of responses in fungal metabolite production when incubated at varying temperatures, confirming an influence of environmental conditions such as temperature on the production of secondary metabolites

    Temperature and pH Profiling of Amylase from Antarctic and Arctic Soil Microfungi

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    While diversity studies and screening for enzyme activities are important elements of understanding fungal roles in the soil ecosystem, extracting and purifying the target enzyme from the fungal cellular system is also required to characterize the enzyme. This is, in particular, necessary before developing the enzyme for industrial-scale production. In the present study, partially purified α-amylase was obtained from strains of Pseudogymnoascus sp. obtained from Antarctic and Arctic locations. Partially purified α-amylases from these polar fungi exhibited very similar characteristics, including being active at 15 °C, although having a small difference in optimum pH. Both fungal taxa are good candidates for the potential application of cold-active enzymes in biotechnological industries, and further purification and characterization steps are now required. The α-amylases from polar fungi are attractive in terms of industrial development because they are active at lower temperatures and acidic pH, thus potentially creating energy and cost savings. Furthermore, they prevent the production of maltulose, which is an undesirable by-product often formed under alkaline conditions. Psychrophilic amylases from the polar Pseudogymnoascus sp. investigated in the present study could provide a valuable future contribution to biotechnological applications

    Population Genetic Structure of Peninsular Malaysia Malay Sub-Ethnic Groups

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    Patterns of modern human population structure are helpful in understanding the history of human migration and admixture. We conducted a study on genetic structure of the Malay population in Malaysia, using 54,794 genome-wide single nucleotide polymorphism genotype data generated in four Malay sub-ethnic groups in peninsular Malaysia (Melayu Kelantan, Melayu Minang, Melayu Jawa and Melayu Bugis). To the best of our knowledge this is the first study conducted on these four Malay sub-ethnic groups and the analysis of genotype data of these four groups were compiled together with 11 other populations' genotype data from Indonesia, China, India, Africa and indigenous populations in Peninsular Malaysia obtained from the Pan-Asian SNP database. The phylogeny of populations showed that all of the four Malay sub-ethnic groups are separated into at least three different clusters. The Melayu Jawa, Melayu Bugis and Melayu Minang have a very close genetic relationship with Indonesian populations indicating a common ancestral history, while the Melayu Kelantan formed a distinct group on the tree indicating that they are genetically different from the other Malay sub-ethnic groups. We have detected genetic structuring among the Malay populations and this could possibly be accounted for by their different historical origins. Our results provide information of the genetic differentiation between these populations and a valuable insight into the origins of the Malay sub-ethnic groups in Peninsular Malaysia

    Genetic differentiation and gene flow between populations of blood-cockles, Anadara granosa, along the Malay peninsular coast

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    Abstracts of 2nd UNU-ORI joint international workshop for marine environment第2回海洋環境国際ワークショップ講演要

    Phylogenetics and population structure of Lake Malawi cichlids

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Genetic differentiation and gene flow between populations of blood-cockles, Anadara granosa, along the Malay peninsular coast

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    Phylogenetic relationships of selected genera of Lutjanidae inferred from mitochondrial regions, with a note on the taxonomic status of Pinjalo pinjalo

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    Phylogenetic relationships of 43 species in 11 genera, representing four subfamilies of the family Lutjanidae and two genera of the family Caesionidae, were inferred using mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI). Further assessment using the mtDNA control region (CR) was carried out to infer the relationship between the Indian and western Pacific types of Lutjanus russellii collected from the coast of Peninsular Malaysia. A total of 11 and 12 species were sequenced for COI and CR genes, respectively. Clade formation reflects, to some extent, the species groupings based on morphological characteristics and their biogeography. The close phylogenetic relationship between Pinjalo pinjalo and the Lutjanus red snappers (Lutjanus malabaricus and Lutjanus sebae) warrants a taxonomic revision of the former as the two genera are currently separated based on non-exclusive morphological characters. A sequence divergence of 4.2% between the Indian and western Pacific types of L. russellii as well as the morphological and biogeographical differences may suggest two separate species.
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