scholarly journals Identification of a cytosine methyltransferase that improves transformation efficiency in Methylomonas sp. DH-1

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jun Ren ◽  
Hyang-Mi Lee ◽  
Thi Duc Thai ◽  
Dokyun Na

Abstract Background Industrial biofuels and other value-added products can be produced from metabolically engineered microorganisms. Methylomonas sp. DH-1 is a candidate platform for bioconversion that uses methane as a carbon source. Although several genetic engineering techniques have been developed to work with Methylomonas sp. DH-1, the genetic manipulation of plasmids remains difficult because of the restriction-modification (RM) system present in the bacteria. Therefore, the RM system in Methylomonas sp. DH-1 must be identified to improve the genetic engineering prospects of this microorganism. Results We identified a DNA methylation site, TGGCCA, and its corresponding cytosine methyltransferase for the first time in Methylomonas sp. DH-1 through whole-genome bisulfite sequencing. The methyltransferase was confirmed to methylate the fourth nucleotide of TGGCCA. In general, methylated plasmids exhibited better transformation efficiency under the protection of the RM system than non-methylated plasmids did. As expected, when we transformed Methylomonas sp. DH-1 with plasmid DNA harboring the psy gene, the metabolic flux towards carotenoid increased. The methyltransferase-treated plasmid exhibited an increase in transformation efficiency of 2.5 × 103 CFU/μg (124%). The introduced gene increased the production of carotenoid by 26%. In addition, the methyltransferase-treated plasmid harboring anti-psy sRNA gene exhibited an increase in transformation efficiency by 70% as well. The production of carotenoid was decreased by 40% when the psy gene was translationally repressed by anti-psy sRNA. Conclusions Plasmid DNA methylated by the discovered cytosine methyltransferase from Methylomonas sp. DH-1 had a higher transformation efficiency than non-treated plasmid DNA. The RM system identified in this study may facilitate the plasmid-based genetic manipulation of methanotrophs.

2020 ◽  
Author(s):  
Jun Ren ◽  
Hyang-Mi Lee ◽  
Thai Duc Thi ◽  
Dokyun Na

Abstract Background: Industrial biofuels and other value-added products can be produced from metabolically engineered microorganisms. Methylomonas sp. DH-1 is a candidate platform for bioconversion that uses methane as a carbon source. Although several genetic engineering techniques have been developed to work with Methylomonas sp. DH-1, the genetic manipulation of plasmids remains difficult because of the restriction-modification (RM) system present in the bacteria. Therefore, the RM system in Methylomonas sp. DH-1 must be identified to improve the genetic engineering prospects of this microorganism.Results: We identified a DNA methylation site, TGGCCA, and its corresponding cytosine methyltransferase for the first time in Methylomonas sp. DH-1 through whole-genome bisulfite sequencing. The methyltransferase was confirmed to methylate the fourth nucleotide of TGGCCA. In general, methylated plasmids exhibited better transformation efficiency under the protection of the RM system than non-methylated plasmids did. As expected, when we transformed Methylomonas sp. DH-1 with plasmid DNA harboring the psy gene, the metabolic flux towards carotenoid increased. The methyltransferase-treated plasmid exhibited an increase in transformation efficiency of 2.5 × 103 CFU/μg (124 %). The introduced gene increased the production of carotenoid by 26 %. In addition, the methyltransferase-treated plasmid harboring anti-psy sRNA gene exhibited an increase in transformation efficiency by 70 % as well. The production of carotenoid was decreased by 40 % when the psy gene was translationally repressed by anti-psy sRNA. Conclusions: Plasmid DNA methylated by the discovered cytosine methyltransferase from Methylomonas sp. DH-1 had a higher transformation efficiency than non-treated plasmid DNA. The RM system identified in this study may facilitate the plasmid-based genetic manipulation of methanotrophs.


2020 ◽  
Author(s):  
Jun Ren ◽  
Hyang-Mi Lee ◽  
Thai Duc Thi ◽  
Dokyun Na

Abstract Background: Industrial biofuels and other value-added products can be produced from metabolically engineered microorganisms. Methylomonas sp. DH-1 is a candidate platform for bioconversion that uses methane as a carbon source. Although several genetic engineering techniques have been developed to work with Methylomonas sp. DH-1, the genetic manipulation of plasmids remains difficult because of the restriction-modification (RM) system present in the bacteria. Therefore, the RM system in Methylomonas sp. DH-1 must be identified to improve the genetic engineering prospects of this microorganism.Results: We identified a DNA methylation site, TGGCCA, and its corresponding cytosine methyltransferase for the first time in Methylomonas sp. DH-1 through whole-genome bisulfite sequencing. The methyltransferase was confirmed to methylate the fourth nucleotide of TGGC*CA. In general, methylated plasmids exhibited better transformation efficiency under the protection of the RM system than non-methylated plasmids did. As expected, when we transformed Methylomonas sp. DH-1 with plasmid DNA harboring the psy gene, the metabolic flux towards carotenoid increased. The methyltransferase-treated plasmid exhibited an increase in transformation efficiency of 3.9 × 103 CFU/μg (110 %). The introduced gene increased the production of carotenoid by 7.2 %.Conclusions: Plasmid DNA methylated by the discovered cytosine methyltransferase from Methylomonas sp. DH-1 had a higher transformation efficiency than non-treated plasmid DNA. The RM system identified in this study may facilitate the plasmid-based genetic manipulation of methanotrophs.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Haojie Pan ◽  
Jia Wang ◽  
Haoliang Wu ◽  
Zhongjian Li ◽  
Jiazhang Lian

Abstract Background CO2 valorization is one of the effective methods to solve current environmental and energy problems, in which microbial electrosynthesis (MES) system has proved feasible and efficient. Cupriviadus necator (Ralstonia eutropha) H16, a model chemolithoautotroph, is a microbe of choice for CO2 conversion, especially with the ability to be employed in MES due to the presence of genes encoding [NiFe]-hydrogenases and all the Calvin–Benson–Basham cycle enzymes. The CO2 valorization strategy will make sense because the required hydrogen can be produced from renewable electricity independently of fossil fuels. Main body In this review, synthetic biology toolkit for C. necator H16, including genetic engineering vectors, heterologous gene expression elements, platform strain and genome engineering, and transformation strategies, is firstly summarized. Then, the review discusses how to apply these tools to make C. necator H16 an efficient cell factory for converting CO2 to value-added products, with the examples of alcohols, fatty acids, and terpenoids. The review is concluded with the limitation of current genetic tools and perspectives on the development of more efficient and convenient methods as well as the extensive applications of C. necator H16. Conclusions Great progress has been made on genetic engineering toolkit and synthetic biology applications of C. necator H16. Nevertheless, more efforts are expected in the near future to engineer C. necator H16 as efficient cell factories for the conversion of CO2 to value-added products.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1964 ◽  
Author(s):  
Zahra Shahrbabaki ◽  
Farshid Pahlevani ◽  
Narjes Gorjizadeh ◽  
Rumana Hossain ◽  
Mohammad Ghasemian ◽  
...  

The abundant application of metallized paper and the quick growth of their wastes lead to the removal of a huge amount of valuable resources from economic cycle. In this work, for the first-time, the thermal micronizing technique has been used to directly transform the metallized paper wastes to Al-Si nano-rod and Al nano-particles for use as the input in different manufacturing sectors such as additive manufacturing or composite fabrication. Structure of metallized paper has been investigated using FT-IR analysis and first-principle plane-wave calculation. Then, based on the structure of metallized paper, thermal micronizing technique has been modified to directly transform this waste into nano materials. Structure of nano-particles and nano-rods has been investigated using SEM, TEM, and XPS analysis. Results showed two main Al-Si nano-rod and Al nano-particle morphologies created as a result of the different surface tensions, which facilitate their separation by Eddy current separation technique. These quick transformation and facile separation together make this technique a unique process to deal with this complex waste and producing value-added products which can re-capture these high value materials from waste and make the reforming economically viable.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 702
Author(s):  
María del Carmen Cortés-Chitala ◽  
Héctor Flores-Martínez ◽  
Ignacio Orozco-Ávila ◽  
Carolina León-Campos ◽  
Ángela Suárez-Jacobo ◽  
...  

Plants have been used for thousands of years for various purposes because they have a wide variety of activities with biological significance. Mexican oregano is an aromatic plant of great importance to Mexico and north of Jalisco state as a spice with important economic value. Chromatographic identification and quantification of phenolic compounds and evaluation of their antioxidant activity were important tools to obtain a better characterization of this spice. Phytochemical analysis indicated the presence of flavonoids, triterpenes, saponins, quinones and tannins, the latter at high concentrations. Through chromatographic assays of Mexican oregano extracts, 62 compounds were identified, the major ones being quantified as: taxifolin, apigenin 7-O-glucoside, phlorizin, eriodictyol, quercetin, naringenin, hispidulin, pinocembrin, galangin and genkwanin (compound for the first time reported for this species). The results can be useful as a precedent to establish the bases of new quality characterization parameters and they have also suggested that Mexican oregano contains a wide variety of compounds with untapped importance for the development of new high value-added products.


2018 ◽  
Vol 28 (5) ◽  
pp. 1681-1684
Author(s):  
Georgi Toskov ◽  
Ana Yaneva ◽  
Stanko Stankov ◽  
Hafize Fidan

The European Commission defines the bioeconomy as "the production of renewable biological resources and the conversion of these resources and waste streams into value added products, such as food, feed, bio-based products and bioenergy. Its sectors and industries have strong innovation potential due to their use of a wide range of sciences, enabling and industrial technologies, along with local and implied knowledge." The Bulgarian food industry faces a lot of challenges on the local and national level, which have direct influence on the structure of the production companies. Most of the enterprises from the food sector produce under foreign brands in order to be flexible partners to the large Bulgarian retail chains. The small companies from the food sector are not able to develop as an independent competitive producer on the territory of their local markets. This kind of companies rarely has a working strategy for positioning on new markets. In order to consolidate their already built positions for long period of time, the producers are trying to optimize their operations in a short term. However, the unclear vision of the companies for the business segment does not allow them to fully develop. Tourism in Bulgaria is a significant contributor to the country's economy.


2020 ◽  
Vol 4 (7) ◽  
pp. 3726-3731
Author(s):  
Fenghui Ye ◽  
Jinghui Gao ◽  
Yilin Chen ◽  
Yunming Fang

Electroreduction of CO2 into value-added products is a promising technique in which the structure of the catalyst plays a crucial role.


2015 ◽  
Vol 81 (7) ◽  
pp. 2481-2488 ◽  
Author(s):  
Volker Winstel ◽  
Petra Kühner ◽  
Bernhard Krismer ◽  
Andreas Peschel ◽  
Holger Rohde

ABSTRACTGenetic manipulation of emerging bacterial pathogens, such as coagulase-negative staphylococci (CoNS), is a major hurdle in clinical and basic microbiological research. Strong genetic barriers, such as restriction modification systems or clustered regularly interspaced short palindromic repeats (CRISPR), usually interfere with available techniques for DNA transformation and therefore complicate manipulation of CoNS or render it impossible. Thus, current knowledge of pathogenicity and virulence determinants of CoNS is very limited. Here, a rapid, efficient, and highly reliable technique is presented to transfer plasmid DNA essential for genetic engineering to important CoNS pathogens from a uniqueStaphylococcus aureusstrain via a specificS. aureusbacteriophage, Φ187. Even strains refractory to electroporation can be transduced by this technique once donor and recipient strains share similar Φ187 receptor properties. As a proof of principle, this technique was used to delete the alternative transcription factor sigma B (SigB) via allelic replacement in nasal and clinicalStaphylococcus epidermidisisolates at high efficiencies. The described approach will allow the genetic manipulation of a wide range of CoNS pathogens and might inspire research activities to manipulate other important pathogens in a similar fashion.


2020 ◽  
Vol 9 (1) ◽  
pp. 55
Author(s):  
María Florencia Eberhardt ◽  
José Matías Irazoqui ◽  
Ariel Fernando Amadio

Stabilization ponds are a common treatment technology for wastewater generated by dairy industries. Large proportions of cheese whey are thrown into these ponds, creating an environmental problem because of the large volume produced and the high biological and chemical oxygen demands. Due to its composition, mainly lactose and proteins, it can be considered as a raw material for value-added products, through physicochemical or enzymatic treatments. β-Galactosidases (EC 3.2.1.23) are lactose modifying enzymes that can transform lactose in free monomers, glucose and galactose, or galactooligosacharides. Here, the identification of novel genes encoding β-galactosidases, identified via whole-genome shotgun sequencing of the metagenome of dairy industries stabilization ponds is reported. The genes were selected based on the conservation of catalytic domains, comparing against the CAZy database, and focusing on families with β-galactosidases activity (GH1, GH2 and GH42). A total of 394 candidate genes were found, all belonging to bacterial species. From these candidates, 12 were selected to be cloned and expressed. A total of six enzymes were expressed, and five cleaved efficiently ortho-nitrophenyl-β-galactoside and lactose. The activity levels of one of these novel β-galactosidase was higher than other enzymes reported from functional metagenomics screening and higher than the only enzyme reported from sequence-based metagenomics. A group of novel mesophilic β-galactosidases from diary stabilization ponds’ metagenomes was successfully identified, cloned and expressed. These novel enzymes provide alternatives for the production of value-added products from dairy industries’ by-products.


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