92 research outputs found

    Use of Native Promoter-eGFP as a Gene Reporter on Onion Epidermis to Analyze Gene Expression of AVR-Pia, an Avirulence Effector of Rice Blast Pathogen

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    Rice blast disease, caused by Magnaporthe oryzae, is a major rice disease over the world. Recent studies have identified avirulence effectors from the blast fungus that trigger rice immune against the pathogen invasion after specific interaction with resistance (R) proteins in rice. AVR-Pia is one of avirulence effectors that correspond to Pia-resistant protein, inducing hypersensitive response (HR). Enhanced Green fluorescent protein (eGFP) was used as a reporter of AVR-Pia expression in this study. We synthesized expression vector containing native promoter of AVR-Pia (PRR) fused to eGFP gene. Rice sheath assay was done to observe the fluorescence and the signal was found in appressoria and invasive hypha of M. oryzae, suggesting that AVR-Pia is expressed in appressorium and invasive hyphae after penetration. Although, rice sheath assay is a reliable way to study rice-pathogen interaction, it is a consuming-time method. Onion epidermis was tested to check the availability to use as model system instead of rice sheath. After inoculation M. oryzae containing PPR::eGFP on onion epidermis, fluorescence was observed in appressoria and invasive hypha of transformants similar to observation on rice sheath. Therefore, onion epidermis can be used as plant cell model to study M. oryzae effectors expression by fluorescence observation

    Biodesulfurization of the mixture of dibenzothiophene and its alkylated derivatives by Sphingomonas subarctica T7b

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    Organosulfur compounds classified as dibenzothiophenes (DBTs) and their derivatives are contained in petroleum. When used as fuel, these substances release SOx emissions, thus contributing to air pollution, acid rain, and climate change. Therefore, it is necessary to reduce the content of these organic sulfur compounds in fuels and one way to achieve this is through bacterial desulfurization. This study reports the biodesulfurization process of a mixture of DBT, 4-hexyl DBT, 4,6-dibutyl DBT, and various organosulfur compounds in light gas oil (LGO). The experiment was conducted by treating 1 mL of aromatic organosulfur compounds with 100 mg/L in \textit{n}-tetradecane or 1 mL LGO with 5 mL mineral salts in sulfur-free medium, incubated at 27 °C for 5 days with shaking at 273 rpm. Gas chromatography analyses revealed that the growing Sphingomonas subarctica T7b cells desulfurized and converted 88.29% of DBT to 2-hydroxybiphenyl as a metabolite while a mixture of DBT and 4,6-dibutyl DBT was desulfurized at 86.40\% and 7.00%, respectively. Furthermore, the mixture of DBT, 4-hexyl DBT, and 4,6-dibutyl DBT had a desulfurization percentage of 84.40%, 41.00%, and 6.66%, respectively, after five days of incubation. The compounds were observed to desulfurize slightly better as single compounds compared to when mixed with other aromatic sulfur compounds

    Microflora and Selected Metabolites of Potato Pulp Fermented with an Indonesian Starter Ragi Tapé

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    When potato pulp was mixed with Indonesian starter ragi tapé and incubated, both lactic acid and ethanol were gradually formed and attained certain concentrations during 2 days of fermentation. Viable counts of fungi in fresh weight matter, yeasts and lactic acid bacteria after fermentation were 105, 107 and 105 CFU/g, respectively. Denaturing gradient gel electrophoresis of the PCR-amplified internal transcribed spacer of 18S–28S rRNA genes detected Amylomyces rouxii-Rhizopus oryzae, Mucor indicus, Candida tropicalis and Saccharomycopsis fibuligera and revealed that Amylomyces rouxii-Rhizopus oryzae dominated throughout the fermentation period. Amylomyces rouxii cannot be discriminated from the lactic acid-accumulating group of Rhizopus oryzae because the amplified sequences of these fungi were shown to be identical. Morphological characteristics were then studied for Rhizopus-like fungi isolated from fermented potato pulp. Those strains that had produced an enormous number of chlamydospores in the aerial and substrate mycelium were identified as Amylomyces rouxii. The microflora of fermented potato pulp was similar to that made from glutinous rice, namely tapé ketan

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Main microorganisms involved in the fermentation of Ugandan ghee

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    Mashita, a traditional fermented butter-like product is widely produced in western Uganda. However, no detailed studies have been done to identify the microorganisms involved in mashita fermentation. Therefore, the aim of this study was to identify the microorganisms involved in mashita fermentation using culture-dependent and culture-independent techniques. The most commonly identified strains of lactic acid bacteria (LAB) in mashita using culture-dependent techniques were Lactobacillus paracasei, Lactobacillus helveticus, Lactobacillus plantarum and Lactobacillus perolens constituting 37.3%, 10.1%, 8.1% and 7.7% of total bacterial colonies isolated respectively. L. paracasei was the only bacterial species identified in all mashita samples. PCR-DGGE results indicated that acetic acid bacteria (AAB) and LAB were the dominant bacterial groups in mashita. Acetobacter aceti, Acetobacter lovaniensis, Acetobacter orientalis and Acetobacter pasteurianus were the main species of AAB identified in the mashita whereas Bifidobacterium sp., Enterococcus faecium, Lactobacillus brevis, Lactobacillus helveticus, Lactobacillus acetotolerans, Lactobacillus sp., Lactococcus raffinolactis, Lactococcus sp. and Streptococcus salivarius as the main strains of LAB in mashita. PCR-DGGE of the D1 region of yeasts showed that Brettanomyces custersianus, Candida silvae, Geotrichum candidum, Issatchenkia occidentalis, Issatchenkia orientalis, Kluyveromyces marxianus, Saccharomyces cerevisiae, and Trichosporon asahii were part of the mashita microbial community. These results indicate that AAB, LAB and yeasts are involved in mashita fermentation
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