93 research outputs found
Agri-Food Value Chain Performance during the COVID-19 Pandemic: An Empirical Study of Chu-mango Business Linkages in Dong Thap, Vietnam
This study aims to identify important factors that directly influence value chain performance (quality, responsiveness, flexibility and efficiency), which are explained by value chain integration (collaboration, commitment, coordination and joint decision-making) in the case of unexpected risk (the COVID-19 pandemic). This study contributes to maintaining the business linkage model among farmers â cooperatives â enterprises in the caseof the COVID-19 pandemic and quickly recovering after the COVID-19 pandemic. Structural equation modelling (SEM) was used for data analysis following an iterative process based on theoretical and empirical analyses toobtain a structural model fit and test the research hypothesis. The findings indicate that the VCI positively influenced the VCP of Chu-mango business linkages at the 1% significance level through coordination (Beta = 0.345;construct reliability (CR) = 3.272), collaboration (Beta = 0.289; CR = 3.128), and joint decision-making (Beta = 0.324; CR = 3.245). This study provides empirical data on the relationship between VCI and VCP through the Chu -mango value chain in Dong Thap Province during the COVID-19 pandemic to raise awareness from stakeholders and encourage value chain thinking to improve performance. This result may pave the way for relevant policymakers to look for policies and strategies for better inclusiveness of stakeholders to show the importance of the VCI in improving the performance. Moreover, the study is an empirical case contributing to the agribusiness value chain in a developing country; it applies the agribusiness value chain of the tropical fruit domain and can be used for otheragricultural products in other cases of unexpected risks
Site-directed mutagenesis of the steroid-15beta-hydroxylase (CYP106A2) from Bacillus megaterium ATCC 13368 to alter the regio-selectivity of progesterone hydroxylation
CYP106A2 is known as 15b-hydroxylase, but also shows 11a-hydroxylase activity for progesterone, an important pharmaceutical compound. This work focused on the production of a regio-selective hydroxy derivative of progesterone at the C-11 position using site directed mutagenesis of CYP106A2. Based on the docked progesterone-CYP106A2 model, a saturation mutagenesis library (13100 transformants) at positions A395 and G397 had been created to verify the effect of these residues on the regio-selective hydroxylation. Forty of these transformants were randomly selected and screened for higher 11a-hydroxyprogesterone production. Mutants A395I and A395W/G397K showed the highest 11a-hydroxyprogesterone production (19.5 and 56.4-fold, respectively) despite a lower catalytic activity as compared with the WT. Therefore, these mutants were further mutated to improve their catalytic efficiency. Eight new mutants were found to have a higher turnover rate along with an improved 11a-hydroxyprogesterone production. Mutants A106T/A395I and T89N/A395I showed the highest amounts of 11a-hydroxyprogesterone, 2.8- and 4.4-fold increased, respectively, compared with the parent mutants, and 54.9- and 85.2-fold, respectively, compared with the WT. Interestingly, the in vivo conversion of progesterone with the mutant T89N/A395I nearly produced the 11a-hydroxyprogesterone. Since the 11a-hydroxyprogesterone exhibits an antiandrogeneic activity and plays a role in the regulation of the blood pressure, the mutant has a potential scope as biocatalyst.CYP106A2 ist als 15b-Hydroxylase bekannt, zeigt aber auch 11a-Hydroxylase Aktivität fĂźr Progesteron. Ziel dieser Arbeit war die Produktion regio-selektiver Hydroxyderivaten des Progesterones an Position C-11 mittels zielgerichteter Mutagenese am CYP106A2. Eine 13100 Transformanten umfassende Mutantenbank, hergestellt mittels Sättigungsmutagenese, ausgehend von einem mit Progesteron gedockten Modell, diente als Grundlage. Zur Untersuchung des Einflusses der Aminosäuren auf die Regio-selektivität wurden 40 Transformanten zufällig ausgewählt und auf eine hĂśhere 11a-Hydroxyhydroxylierung gescreent. Die Mutanten A395I und A395W/G397K zeigten, verglichen mit dem WT, die hĂśchste 11a-Hydroxyprogesterone Produktion (19,5- bzw. 56,4-fach), trotz geringerer katalytischer Aktivität. Diese Mutanten wurden nochmals mutiert, um die katalytische Effizienz zu erhĂśhen. Acht neue Mutanten mit einer hĂśheren Umsatzrate und verbesserter 11a-Hydroxyprogesterone Produktion wurden gefunden. Die Mutanten A106T/A395I und T89N/A395I bildeten 2,8- bzw. 4,4-mal mehr 11a-Hydroxyprogesteron als die jeweilige Ausgangsmutante und sogar 54,9- bzw. 85,2-mal mehr als der WT. Interessanterweise hydroxylierte die Mutante T89N/A395I während des in vivo Umsatzes Progesteron fast ausschlieĂlich an der 11a-Position. Da 11a-Hydroxyprogesteron eine antiandrogene Aktivität zeigt und eine Rolle bei der Regulierung des Blutdrucks spielt, ist zu sagen, diese Mutanten einem groĂer Erfolg und eine gute Vorraussetzung zur biotechnologischen Anwendung ist
Isolation and identification of indole acetic acid producing bacteria from the coasts of Ben Tre and Tra Vinh Provinces
Beneficial plant-growth-promoting bacteria (PGPB) have been reasonably applied to rescue crucial issue for agriculture by salinity soil. Observed most of PGPB was found in endophyte, rhizosphere and soil. Indole acetic acid (IAA)-producing bacteria could naturally stimulate and facilitate plant growth. The knowledge of IAA production and content of bacteria resident in the marine environment has been typically insufficient and limited to date. In recent years, unwarrantable intrusions of sea water have been enlarged in the Mekong River Delta of Vietnam, threatening productive rice fields, local fruits, and cash crops. Therefore, finding PGPB in the coastal regions in the Mekong River Delta as a creative resource for sustainable agriculture is necessary and is a prompt challenge. In this study, IAA-producing bacteria from coastal regions of Ben Tre and Tra Vinh Provinces were isolated and adequately identified. Out of 202 bacterial isolates, 10 isolates showed the possible ability to produce IAA from L-tryptophan. These 10 isolates were objectively evaluated the capacity to produce IAA under 5% (w/v) NaCl in King B and marine broths. The results revealed that IAA production decreased in 5% NaCl, even though bacterial growth increased. These 10 IAA-producing bacteria were classified at the species level, Marinobacter hydrocarbonoclasticus, M. pelagius, M. daepoensis, and Mameliella phaeodactyli by 16S rRNA gene analysis. The most IAA producer in Kingâs B broth, the isolate C7, was investigated in more detail. The isolate C7 produced the maximum IAA amount (192.2 Âą 1.14 Âľg/ml) under the presence of 20 g/l yeast extract, 2 g/l of L-tryptophan and 1% NaCl. The isolate C7 was able to grow at 1â17% (w/v) NaCl (optimum, 4%), but not in the absence of NaCl, indicating it is a moderate halophilic bacteria. This study highlighted the considerable ability to produce IAA of marine bacteria, which could be thoughtfully considered to use naturally as biofertilizers to promote plant growth in saline intrusion lands.
Degradation of 2,3,7,8-TCDD by a consortium of bacterial strains isolated from heavil herbicide/dioxin contaminated soil in Bienhoa airbase
From two different soil sources in Bienhoa airbase (heavy herbicide/dioxin contaminated West-South region and bioremediated cell), five microbial strains were isolated and their 2,3,7,8-TCDD biodegrability in consortium was investigated. Based on the colony and cell morphological characteristics as well as 16S rRNA gene sequences, these strains were classified into 5 genera, including Methylobacterium (strain BHBi1), Hydrocarboniphaga (strain BHBi4), Agrobacterium (strain BHBi5), Bosea (strain BHBi7) and Microbacterium (strain BH09). Two strains BHBi7 and BHBi4 were the first representatives of the genera Bosea and Hydrocarboniphaga that were isolated from heavyly herbicide/dioxin contaminated soil. All five strains were able to grow well in mineral salt medium (MSM) supplemented with soil extract (SE) containing 2,3,7,8-TCDD (this congener is the main soil total compound toxicity) and other congeners, including PCDDs, PCDFs, 2,4,5-T, 2,4-D, PAHs and their intermediates. This microbial consortium degraded 2,537.34 ngTEQ/kg of 2,3,7,8-TCDD congener in soil, equivalent to 59.1% lost of total toxicity in comparison to the control without bacterial seeding (4,294.12 ng TEQ/kg). Such a high ratio of dioxin degradation by a bacterial consortium was reported here for the first time, contributing more evidences for convincing the successful dioxin bioremediation of âActive Landfillâ technology at large scale in Z1 area at Bienhoa airbase, Dongnai, Vietnam
Mining cytochrome p450 genes through next generation sequencing and metagenomic analysis from Binh Chau hot spring
Cytochrome P450s (CYPs) are one of the largest distributed enzymes, which catalyze more than 20 different reactions. At present, there has been an increasing realization of the power of P450 biocatalysts for the industrial synthesis of pharmaceuticals, agrochemicals, bulk chemicals, food ingredients, etc. On the other hand, the conditions of industrial processes at high temperature, high-pressure or in chemical solvent require the enzymes, which catalyze the bioconversion, have a specific properties such as thermostability, chemical tolerance or barophilicity. Up to date, the number of thermostable P450s is limited. Nowadays, DNA-metagenome technique gives us a chance to catch novel genes and unique interesting enzymes from microbial community in certain ecology. In this paper, metagenomic DNA extracted from water samples from Binh Chau hot spring was sequenced using Illumilaâs HiSeq platform and was analysed to mining putative genes encoding cytochrome P450. The sequencing generated 9.4 Gb of reads containing 156,093 putative ORFs, of these, 106,903 genes were annotated in NCBI non-redundant protein sequence database. Among all the ORFs were annotated, 68 putative ORFs encoding cytochrome P450 were found belong to 36 specific groups of cytochrome P450 protein family. Of these, the melting temperature (Tm) from thirty-six completed ORFs was predicted for a better understanding of thermodynamic stability.
The Factors Affecting the Level of Information Disclosure on Financial Statements in the Industrial Enterprises Listed on Ho Chi Minh Stock Exchange
This research analyzes the factors affecting the level of information disclosure on financial statements in the industrial enterprises listed on Ho Chi Minh stock exchange. Using financial statements of 87 industrial enterprises of the fiscal year 2017, the research shows that there are 6 factors affecting and having a positive relations with the level of information disclosure. These include: the scale of business, Duration of operation, Audit firm reputation, Solvency, Financial leverage and Return on Equity (ROE). The result points to signals that help the State Securities Commission to control better of information disclosure of firms. In addition, the study recommends measures for shareholders, especially those in large companies to strengthen the supervision, control managers in the disclosure of business information
The Modern Induced Matter Approach of General Relativity for Quantum Mechanics
Wesson and his co-workers developed so-called space-time-matter theory (5D-STM) as a generalization of Kaluza-Klein theory, where the extra-dimension in the 5D space-time is no more compacted, but keeping extended in a macroscopic scale to describe the properties of matter in 4D physics. In a trend of 5D-STM approach (or the induced-matter theory), following a bi-cylindrical model of geometrical dynamics, a recent study has shown that the higher 6D-dimensional gravitational equation leads to bi-geodesic description in an extended timespace symmetry which ďŹts Hubble expansion in a âmicroscopicâ cosmological model. As a duality, the geodesic solution is mathematically equivalent to the basic Klein-Gordon-Fock equations of free massive elementary particles. The 4D-embedded dual solutions of the higher dimensional gravitational equation could shed light on origin of physical reality in quantum mechanics, which is to compare with the achievements of the 5D-STM theory
The Potential of the Rice Value Chain in the Mekong Delta to Develop High Value Export Markets
This study aims at analyzing the current status of the rice value chain in the Mekong Delta focusing on export channels. The study assessed primary data collected from respondents related to the chain in the year 2020. Research results show that about 35% of rice in the region is used for export, of which most of the rice exported belongs to the high quality segment. Although improvements achieved recently, the regional rice value chain still faces many limitations. The study proposes solutions to strengthen the rice value chain and increase the volume of high quality rice exported into more demanding high income markets
Flavonoid glycosides from Viscum album
Using combined chromatographic methods, four flavonoid glycosides, (2S)-homoeriodictyol-7-O-β-D-apiofuranosyl-(1â2)-O-β-D-glucopyranoside (1), (2S)-5-hydroxy-7,3â˛-dimethoxyflavanone-4â˛-O-β-D-apiofuranosyl-(1â2)-O-β-D-glucopyranoside (2), homoflavoyadorinin-B (3), and 3â˛-methoxyapiin (4) were isolated from the methanol extract of the leaves and twigs of Viscum album. Their structures were elucidated by 1D- and 2D-NMR spectra and in comparison with those reported in the literature. Keywords. Viscum album, flavonoid glycoside
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