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1.
Synth Syst Biotechnol ; 9(2): 340-348, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38549618

RESUMO

Plants produce diverse flavonoids for defense and stress resistance, most of which have health benefits and are widely used as food additives and medicines. Methylation of the free hydroxyl groups of flavonoids, catalyzed by S-adenosyl-l-methionine-dependent O-methyltransferases (OMTs), significantly affects their physicochemical properties and bioactivities. Soybeans (Glycine max) contain a rich pool of O-methylated flavonoids. However, the OMTs responsible for flavonoid methylation in G. max remain largely unknown. We screened the G. max genome and obtained 22 putative OMT-encoding genes that share a broad spectrum of amino acid identities (25-96%); among them, 19 OMTs were successfully cloned and heterologously expressed in Escherichia coli. We used the flavonoids containing the free 3, 5, 7, 8, 3', 4' hydroxyl group, such as flavones (luteolin and 7, 8-dihydroxyflavone), flavonols (kaempferol and quercetin), flavanones (naringenin and eriodictyol), isoflavonoids (daidzein and glycetein), and caffeic acid as substrates, and 15 OMTs were proven to catalyze at least one substrate. The methylation activities of these GmOMTs covered the 3, 7, 8, 3', 4'- hydroxyl of flavonoids and 7, 4'- hydroxyl of isoflavonoids. The systematic characterization of G. max flavonoid OMTs provides insights into the biosynthesis of methylated flavonoids in soybeans and OMT bioparts for the production of methylated flavonoids via synthetic biology.

2.
Environ Sci Pollut Res Int ; 30(29): 73730-73752, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37195613

RESUMO

Ghana, like most resource-rich countries, is saddled and inundated with resource curse challenges. Key among them is the problem of illegal small-scale gold mining activities (ISSGMAs), which is mercilessly robbing the nation of its ecological integrity, despite attempts by successive governments to remedy the situation. In the midst of this challenge, Ghana, year in and year out, performs abysmally on environmental governance score (EGC) variables. Against this framework, this study intends to uniquely establish the drivers behind Ghana's failure to overcome ISSGMAs. To achieve this, a total of 350 respondents were sampled through a structured questionnaire, with a mixed method approach from selected host communities, believed to be the epicenters of ISSGMAs in Ghana. The questionnaires were administered from March to August, 2023. AMOS Graphics and IBM SPSS vs 23 were used to analyze the data. In particular, the novel hybrid artificial neural network (ANN) and linear regression techniques were adopted to establish the relational linkages among the constructs of the study and their respective contribution to ISSGMAs in Ghana. The study displays intriguing results that explain why Ghana has failed to be victorious over ISSGMAs. In particular, the findings of the study demonstrate that the three key drivers of ISSGMAs in Ghana, in a sequential and consecutive order are as follows: bureaucratic licensing regime/weak legal framework, political/traditional leadership failures, and corrupt institutional officials. Moreover, socioeconomic factors and proliferation of foreign miners/mining equipment were also observed to contribute significantly to ISSGMAs. While the study contributes to the ongoing debate on ISSGMAs, it also proffers valuable and practical solutions to the menace as well as theoretical implications.


Assuntos
Conservação dos Recursos Naturais , Ouro , Gana , Política Ambiental , Mineração
3.
Insect Sci ; 30(4): 888-900, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36624657

RESUMO

The black soldier fly (BSF), Hermetia illucens, is a promising insect for mitigating solid waste problems as its larvae are able to bioconvert organic waste into valuable biomass. We recently reported a high-quality genome assembly of the BSF; analysis of this genome sequence will further the understanding of insect biology and identify genes that can be manipulated to improve efficiency of bioconversion. To enable genetic manipulation of the BSF, we have established the first transgenic methods for this economically important insect. We cloned and identified the ubiquitous actin5C promoter (Hiactin5C-p3k) and 3 endogenous U6 promoters (HiU6:1, HiU6:2, and HiU6:3). The Hiactin5C promoter was used to drive expression of a hyperactive variant of the piggyBac transposase, which exhibited up to 6-fold improvement in transformation rate when compared to the wild-type transposase. Furthermore, we evaluated the 3 HiU6 promoters using this transgenic system. HiU6:1 and HiU6:2 promoters provided the highest knockdown efficiency with RNAi and are thus promising candidates for future Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) development. Overall, our findings provide valuable genetic engineering toolkits for basic research and genetic manipulation of the BSF.


Assuntos
Dípteros , Animais , Dípteros/genética , Larva/genética , Animais Geneticamente Modificados/genética , Biomassa , Transposases
4.
Insect Sci ; 30(4): 901-911, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36719198

RESUMO

Sex-determination pathways are extremely diverse. Understanding the mechanism of sex determination in insects is important for genetic manipulation of the pest population and for breeding of economically valuable insects. Although sex determination has been well characterized in the model species Drosophila melanogaster, little is known about this pathway in Stratiomyidae. In the present study, we first identified the Drosophila intersex (ix) homolog in Hermetia illucens, also known as the black soldier fly, which belongs to the Stratiomyidae family and which is an important insect for the conversion of various organic wastes. Phylogenetic analyses and multiple sequence alignment revealed that Hiix is conserved compared with Drosophila. We showed that Hiix is highly expressed in internal genitalia. Disruption of the Hiix gene using CRISPR/Cas9 resulted in female-specific defects in external genitalia and abnormal and undersized ovaries. Taken together, our study furthers our understanding of sex determination in insects and could facilitate breeding of H. illucens.


Assuntos
Dípteros , Drosophila melanogaster , Feminino , Animais , Larva , Filogenia , Dípteros/genética , Drosophila
5.
Environ Sci Pollut Res Int ; 30(3): 6716-6729, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36006539

RESUMO

Low-carbon technology innovation (LTI) engenders environmental protection and socioeconomic development. Hence, low-carbon innovation of enterprises becomes a crucial policy arena for national development and climate mitigation strategy. LTI is now associated with enhanced reputation and competitive edge of enterprises. We constructed a framework to empirically explore the impact of simmelian ties (ST) on LTI, testing the moderating effect of stakeholder pressure in this relationship. We used a sample of 385 employees from industrial enterprises in China through a structured questionnaire. The study results show that: first, when the enterprise is in a strong ST, the top managers' awareness of environmental benefits has a significant positive impact on LTI. Second, when the enterprise is in a weak ST, top managers' awareness of environmental risk has a significant positive impact on LTI. Third, pressure of key stakeholders and pressure of secondary stakeholders positively moderate the interaction between ST and top managers' environmental awareness (TMEA) on the impact of LTI. Fourth, the moderating effect of key stakeholders' pressure was observed to be stronger than that of secondary stakeholders' pressure. Theoretically, this paper contributes to literature by developing a framework to investigate interaction between ST, TMEA and LTI under different stakeholder pressures. Based on this framework, we provide a theoretical reference for enterprises to choose the appropriate and optimal TMEA for competitive edge.


Assuntos
Conservação dos Recursos Naturais , Indústrias , Humanos , China , Invenções , Clima
6.
Polymers (Basel) ; 13(14)2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34301112

RESUMO

The compatibility of three types of silicone oil with polydimethylsiloxane, the phase separation of their mixture and the microstructure and properties of their composite coatings were investigated. The existing form of silicone oil in the coating and the precipitation behavior were also studied. The compatibility observed experimentally of the three silicone oils with PDMS is consistent with the results of the thermodynamic calculation. The silicone oil droplet produced by phase separation in the mixture solution can keep its shape in the cured coating, also affecting the microstructure and mechanical properties of the coating. It was found that methyl silicone oil and methyl fluoro silicone oil do not precipitate on the surface, and they have no effect on the surface properties of the coating. In contrast, phenyl silicone oil has obvious effect on the surface, which makes the water contact angle and diiodomethane contact angle of the coating decrease significantly.

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