Construction of a New Genetic Engineering Bacterium for Preparation of Superoxide Dismutase with High Productivity

2011 ◽  
Vol 314-316 ◽  
pp. 1973-1976
Author(s):  
Yi Zhao ◽  
Yang Li ◽  
Ren Qiang Li
Keyword(s):  
Genetic Engineering ◽  
Maximum Activity ◽  
Bacterial Protein ◽  
Expression Plasmid ◽  
Gene Encoding ◽  
Good Thermal Stability ◽  
High Productivity ◽  
E Coli ◽  
Bacillus Subtilis Atcc ◽  
Bacillus Spp

A new Mn-SOD gene encoding 202 amino acids was cloned from genomic DNA of Bacillus subtilis ATCC 9372 for construction of a genetic engineering bacterium to produce SOD. Its phylogenetic relationships with other Bacillus spp. revealed that this predicted protein is most closely related to B. atrophaeus NRS-213 (AY197616) and B. subtilis 168. This gene was inserted into expression plasmid pET28a and first successfully expressed in E. coli BL21. The SOD was expressed accounted for approximately 45.6% of total bacterial protein. The activity of the SOD was 2553.211 U/mg, the enzyme showed maximum activity at about pH 8.0 and relatively stable from pH 6.0 to 11.0. This SOD had a good thermal stability with >75% retaining of the relative enzymatic activity after incubation at 50 °C for 90 min. This study demonstrated that a new genetic engineering bacterium to produce SOD with high productivity has been successfully constructed.

scholarly journals Treponema pallidum 3-Phosphoglycerate Mutase Is a Heat-Labile Enzyme That May Limit the Maximum Growth Temperature for the Spirochete

2001 ◽  
Vol 183 (16) ◽  
pp. 4702-4708 ◽  
Author(s):  
Stéphane Benoit ◽  
James E. Posey ◽  
Matthew R. Chenoweth ◽  
Frank C. Gherardini
Keyword(s):  
Treponema Pallidum ◽  
Maximum Growth ◽  
Biochemical Properties ◽  
Maximum Activity ◽  
Phosphoglycerate Mutase ◽  
Heat Sensitivity ◽  
Dependent Manner ◽  
Gene Encoding ◽  
E Coli ◽  
Key Enzyme

ABSTRACT In the causative agent of syphilis, Treponema pallidum, the gene encoding 3-phosphoglycerate mutase, gpm, is part of a six-gene operon (tro operon) that is regulated by the Mn-dependent repressor TroR. Since substrate-level phosphorylation via the Embden-Meyerhof pathway is the principal way to generate ATP inT. pallidum and Gpm is a key enzyme in this pathway, Mn could exert a regulatory effect on central metabolism in this bacterium. To study this, T. pallidum gpm was cloned, Gpm was purified from Escherichia coli, and antiserum against the recombinant protein was raised. Immunoblots indicated that Gpm was expressed in freshly extracted infective T. pallidum. Enzyme assays indicated that Gpm did not require Mn2+ while 2,3-diphosphoglycerate (DPG) was required for maximum activity. Consistent with these observations, Mn did not copurify with Gpm. The purified Gpm was stable for more than 4 h at 25°C, retained only 50% activity after incubation for 20 min at 34°C or 10 min at 37°C, and was completely inactive after 10 min at 42°C. The temperature effect was attenuated when 1 mM DPG was added to the assay mixture. The recombinant Gpm from pSLB2 complemented E. coli strain PL225 (gpm) and restored growth on minimal glucose medium in a temperature-dependent manner. Increasing the temperature of cultures of E. coli PL225 harboring pSLB2 from 34 to 42°C resulted in a 7- to 11-h period in which no growth occurred (compared to wild-type E. coli). These data suggest that biochemical properties of Gpm could be one contributing factor to the heat sensitivity of T. pallidum.

scholarly journals Kloning fragmen gen penyandi β-ketoacyl-ACP synthase II dari dua tipe kelapa sawit dengan kandungan asam oleat yang berbeda Cloning of gene fragment encoding β-ketoacyl-ACP synthase II from two types of oil palm with different oleic acid content

2016 ◽  
Vol 78 (1) ◽  
Author(s):  
Asmini BUDIANI1 ◽  
Abdul Razak PURBA
Keyword(s):  
Oleic Acid ◽  
Genetic Engineering ◽  
Oil Palm ◽  
Acid Content ◽  
Elaeis Guineensis ◽  
Oleic Acid Content ◽  
Rt Pcr ◽  
Gene Encoding ◽  
Elaeis Oleifera ◽  
E Coli

AbstractIn addition to increase productivity, oil palm breeding is also aimed to increase oil quality, one of which is oleic acid content. Conventionally, the increase of oleic acid is carried out by crossing between Elaeis guineensis which is high in oilcontent and Elaeis oleifera which contain high oleic acid. Genetic engineering to increase oleic acid might be done by over expressing gene encoding β-Ketoacyl-ACP Synthase II (KASII) in the mesocarp of oil palm. As a preliminary workof genetic engineering to increase oleic acid content, this research was aimed to clone DNA fragment of gene encoding KASII by using RT-PCR. Total RNA were isolated from the mesocarp of two different types of oil palms, namelySimalungun (E. guineensis) and Hibrida (E. guineensi x E. oleifera), and used for synthesis of first strand cDNA. Amplification of KASII DNA fragments was carried out using first strand cDNA as a template with specific primers. TheRT-PCR product was verified by electrophoresis on agarose gel, isolated and purified from the gel, sequenced and then cloned into E. coli using pGEM-T Easy cloning vector. Analysis of the target DNA in transformed E. coli was done by colony PCR. Recombinant plasmid was isolated from recombinant E. coli followed by DNA sequencing and analysis. DNA sequences were analysed using BLASTn to test the homology with similar genes. The results show that DNAfragment of RT-PCR products from Simalungun and Hibrida types of oil palm have been cloned in E. coli, and the sequences have been confirmed as a fragment of KASII gene. Analysis of the two sequences indicated that there were differences of four nucleotides at position no of 91, 103, 115, and 148. AbstrakSelain meningkatkan produksi, pemuliaan kelapa sawit juga ditujukan untuk meningkatkan kualitas minyak sawit, salah satunya adalah meningkatkan kandungan oleat. Secara konvensional peningkatan kandungan oleat dilakukan melalui penyilangan antara Elaeis guineensis yang tinggi rendemenminyaknya dengan Elaeis oleifera yang tinggi kandungan oleatnya. Rekayasa genetika untuk peningkatan kandungan oleat dapat ditempuh antara lain dengan mening-katkan ekspresi gen penyandi β-Ketoacyl-ACP Synthase II (KASII)pada mesokarp buah sawit. Sebagai bagian dari upaya peningkatan kandungan oleat, penelitian ini bertujuan untuk mengklon fragmen gen penyandi KASII dengan pendekatanRT-PCR. RNA total diisolasi dari mesokarp dua tipe kelapasawit yaitu Simalungun dan Hibrida (E. guineensis x E. oleifera), kemudian digunakan dalam sintesis utas pertama cDNA. Amplifikasi fragmen DNA penyandi KASII dilakukan menggunakan primer spesifik dan templat cDNAutas pertama hasil sintesis. Produk RT-PCR diverifikasi dengan elektroforesis pada gel agarosa, diisolasi dan dimurnikan dari gel, disekuen kemudian diklon dalam E. coli menggunakan vektor kloning pGEM-T Easy. Analisis adanyafragmen DNA target dalam sel E. coli transforman dilakukan dengan PCR koloni. Plasmid rekombinan diisolasi dari sel rekombinan dan diverifikasi pada gel agarose kemudian disekuen kembali untuk mengkonfirmasi bahwa fragmenDNA terklon adalah bagian dari gen penyandi KASII. Sekuen DNA dianalisis menggunakan BLASTn untuk mengetahui homologinya dengan gen yang sama. Hasil penelitian menunjukkan bahwa fragmen DNA produk RTPCR dari kelapa sawit tipe Simalungun dan Hibrida telah terklon dalam E. coli dan sekuen DNAnya dikonfirmasi sebagai fragmen gen penyandi KASII. Hasil analisis sekuen DNA KASII dari tipe Simalungun dengan tipe Hibrida juga mengindikasikan adanya perbedaan pada empat nukleotida yaitu pada posisi ke-91, ke-103, ke-115, dan ke-148.

scholarly journals Kloning fragmen gen penyandi β-ketoacyl-ACP synthase II dari dua tipe kelapa sawit dengan kandungan asam oleat yang berbeda Cloning of gene fragment encoding β-ketoacyl-ACP synthase II from two types of oil palm with different oleic acid content

2016 ◽  
Vol 78 (1) ◽  
Author(s):  
Asmini BUDIANI1 ◽  
Abdul Razak PURBA
Keyword(s):  
Oleic Acid ◽  
Genetic Engineering ◽  
Oil Palm ◽  
Acid Content ◽  
Elaeis Guineensis ◽  
Oleic Acid Content ◽  
Rt Pcr ◽  
Gene Encoding ◽  
Elaeis Oleifera ◽  
E Coli

AbstractIn addition to increase productivity, oil palm breeding is also aimed to increase oil quality, one of which is oleic acid content. Conventionally, the increase of oleic acid is carried out by crossing between Elaeis guineensis which is high in oilcontent and Elaeis oleifera which contain high oleic acid. Genetic engineering to increase oleic acid might be done by over expressing gene encoding β-Ketoacyl-ACP Synthase II (KASII) in the mesocarp of oil palm. As a preliminary workof genetic engineering to increase oleic acid content, this research was aimed to clone DNA fragment of gene encoding KASII by using RT-PCR. Total RNA were isolated from the mesocarp of two different types of oil palms, namelySimalungun (E. guineensis) and Hibrida (E. guineensi x E. oleifera), and used for synthesis of first strand cDNA. Amplification of KASII DNA fragments was carried out using first strand cDNA as a template with specific primers. TheRT-PCR product was verified by electrophoresis on agarose gel, isolated and purified from the gel, sequenced and then cloned into E. coli using pGEM-T Easy cloning vector. Analysis of the target DNA in transformed E. coli was done by colony PCR. Recombinant plasmid was isolated from recombinant E. coli followed by DNA sequencing and analysis. DNA sequences were analysed using BLASTn to test the homology with similar genes. The results show that DNAfragment of RT-PCR products from Simalungun and Hibrida types of oil palm have been cloned in E. coli, and the sequences have been confirmed as a fragment of KASII gene. Analysis of the two sequences indicated that there were differences of four nucleotides at position no of 91, 103, 115, and 148. AbstrakSelain meningkatkan produksi, pemuliaan kelapa sawit juga ditujukan untuk meningkatkan kualitas minyak sawit, salah satunya adalah meningkatkan kandungan oleat. Secara konvensional peningkatan kandungan oleat dilakukan melalui penyilangan antara Elaeis guineensis yang tinggi rendemenminyaknya dengan Elaeis oleifera yang tinggi kandungan oleatnya. Rekayasa genetika untuk peningkatan kandungan oleat dapat ditempuh antara lain dengan mening-katkan ekspresi gen penyandi β-Ketoacyl-ACP Synthase II (KASII)pada mesokarp buah sawit. Sebagai bagian dari upaya peningkatan kandungan oleat, penelitian ini bertujuan untuk mengklon fragmen gen penyandi KASII dengan pendekatanRT-PCR. RNA total diisolasi dari mesokarp dua tipe kelapasawit yaitu Simalungun dan Hibrida (E. guineensis x E. oleifera), kemudian digunakan dalam sintesis utas pertama cDNA. Amplifikasi fragmen DNA penyandi KASII dilakukan menggunakan primer spesifik dan templat cDNAutas pertama hasil sintesis. Produk RT-PCR diverifikasi dengan elektroforesis pada gel agarosa, diisolasi dan dimurnikan dari gel, disekuen kemudian diklon dalam E. coli menggunakan vektor kloning pGEM-T Easy. Analisis adanyafragmen DNA target dalam sel E. coli transforman dilakukan dengan PCR koloni. Plasmid rekombinan diisolasi dari sel rekombinan dan diverifikasi pada gel agarose kemudian disekuen kembali untuk mengkonfirmasi bahwa fragmenDNA terklon adalah bagian dari gen penyandi KASII. Sekuen DNA dianalisis menggunakan BLASTn untuk mengetahui homologinya dengan gen yang sama. Hasil penelitian menunjukkan bahwa fragmen DNA produk RTPCR dari kelapa sawit tipe Simalungun dan Hibrida telah terklon dalam E. coli dan sekuen DNAnya dikonfirmasi sebagai fragmen gen penyandi KASII. Hasil analisis sekuen DNA KASII dari tipe Simalungun dengan tipe Hibrida juga mengindikasikan adanya perbedaan pada empat nukleotida yaitu pada posisi ke-91, ke-103, ke-115, dan ke-148.

Enhanced Biocatalytic Activity of Recombinant Lipase Immobilized on Gold Nanoparticles

2019 ◽  
Vol 20 (6) ◽  
pp. 497-505 ◽  
Author(s):  
Abeer M. Abd El-Aziz ◽  
Mohamed A. Shaker ◽  
Mona I. Shaaban
Keyword(s):  
Gold Nanoparticles ◽  
Lipolytic Activity ◽  
Market Demand ◽  
Biotechnological Applications ◽  
Lipase Gene ◽  
Expression Plasmid ◽  
E Coli ◽  
Nickel Affinity Chromatography ◽  
Recombinant Production ◽  
Sds Page

Background: Bacterial lipases especially Pseudomonas lipases are extensively used for different biotechnological applications. Objectives: With the better understanding and progressive needs for improving its activity in accordance with the growing market demand, we aimed in this study to improve the recombinant production and biocatalytic activity of lipases via surface conjugation on gold nanoparticles. Methods: The full length coding sequences of lipase gene (lipA), lipase specific foldase gene (lipf) and dual cassette (lipAf) gene were amplified from the genomic DNA of Pseudomonas aeruginosa PA14 and cloned into the bacterial expression vector pRSET-B. Recombinant lipases were expressed in E. coli BL-21 (DE3) pLysS then purified using nickel affinity chromatography and the protein identity was confirmed using SDS-PAGE and Western blot analysis. The purified recombinant lipases were immobilized through surface conjugation with gold nanoparticles and enzymatic activity was colorimetrically quantified. Results: Here, two single expression plasmid systems pRSET-B-lipA and pRSET-B-lipf and one dual cassette expression plasmid system pRSET-B-lipAf were successfully constructed. The lipolytic activities of recombinant lipases LipA, Lipf and LipAf were 4870, 426 and 6740 IUmg-1, respectively. However, upon immobilization of these recombinant lipases on prepared gold nanoparticles (GNPs), the activities were 7417, 822 and 13035 IUmg-1, for LipA-GNPs, Lipf-GNPs and LipAf-GNPs, respectively. The activities after immobilization have been increased 1.52 and 1.93 -fold for LipA and LipAf, respectively. Conclusion: The lipolytic activity of recombinant lipases in the bioconjugate was significantly increased relative to the free recombinant enzyme where immobilization had made the enzyme attain its optimum performance.

scholarly journals On-column Refolding of an Insoluble His6-tagged Recombinant EC-SOD Overexpressed in Escherichia coli

2005 ◽  
Vol 37 (4) ◽  
pp. 265-269 ◽  
Author(s):  
Xi-Qiang Zhu ◽  
Su-Xia Li ◽  
Hua-Jun He ◽  
Qin-Sheng Yuan
Keyword(s):  
Escherichia Coli ◽  
Inclusion Bodies ◽  
Mass Ratio ◽  
Chain Reaction ◽  
Expression Plasmid ◽  
Protein Subunits ◽  
E Coli ◽  
Metal Affinity ◽  
Polymerase Chain ◽  
Escherichia Coli Expression

Abstract The EC-SOD cDNA was cloned by polymerase chain reaction (PCR) and inserted into the Escherichia coli expression plasmid pET-28a(+) and transformed into E. coli BL21(DE3). The corresponding protein that was overexpressed as a recombinant His6-tagged EC-SOD was present in the form of inactive inclusion bodies. This structure was first solubilized under denaturant conditions (8.0 M urea). Then, after a capture step using immobilized metal affinity chromatography (IMAC), a gradual refolding of the protein was performed on-column using a linear urea gradient from 8.0 M to 1.5 M in the presence of glutathione (GSH) and oxidized glutathione (GSSG). The mass ratio of GSH to GSSG was 4:1. The purified enzyme was active, showing that at least part of the protein was properly refolded. The protein was made concentrated by ultrafiltration, and then isolated using Sephacryl S-200 HR. There were two protein peaks in the A280 profile. Based on the results of electrophoresis, we concluded that the two fractions were formed by protein subunits of the same mass, and in the fraction where the molecular weight was higher, the dimer was formed through the disulfide bond between subunits. Activities were detected in the two fractions, but the activity of the dimer was much higher than that of the single monomer. The special activities of the two fractions were found to be 3475 U/mg protein and 510 U/mg protein, respectively.

Glycosylated flavones as selective inhibitors of topoisomerase IV.

1997 ◽  
Vol 41 (5) ◽  
pp. 992-998 ◽  
Author(s):  
F X Bernard ◽  
S Sablé ◽  
B Cameron ◽  
J Provost ◽  
J F Desnottes ◽  
...  
Keyword(s):  
Dna Cleavage ◽  
Topoisomerase Ii ◽  
Coli Strain ◽  
Selective Inhibitors ◽  
Topoisomerase Iv ◽  
Gene Encoding ◽  
Cottonseed Flour ◽  
Dna Topoisomerase ◽  
E Coli ◽  
Pbr322 Dna

Three flavonoids which promoted Escherichia coli topoisomerase IV-dependent DNA cleavage were isolated from cottonseed flour and identified as quercetin 3-O-beta-D-glucose-[1,6]-O-alpha-L-rhamnose (rutin), quercetin 3-O-beta-D-galactose-[1,6]-O-alpha-L-rhamnose, and quercetin 3-O-beta-D-glucose (isoquercitrin). The most active one (rutin) also inhibited topoisomerase IV-dependent decatenation activity (50% inhibitory concentration, 64 microg/ml) and induced the SOS response of a permeable E. coli strain. Derivatives of quercetin glycosylated at position C-3 were shown to induce two site-specific DNA cleavages of pBR322 DNA, which were mapped by DNA sequence analysis to the gene encoding resistance to tetracycline. Cleavage at these sites was hardly detectable in cleavage reactions with quercetin or fluoroquinolones. None of the three flavonoids isolated from cottonseeds had any stimulatory activity on E. coli DNA gyrase-dependent or calf thymus topoisomerase II-dependent DNA cleavage, and they were therefore specific to topoisomerase IV. These results show that selective inhibitors of topoisomerase IV can be derived from the flavone structure. This is the first report on a DNA topoisomerase inhibitor specific for topoisomerase IV.

The HiPIP from the acidophilic Acidithiobacillus ferrooxidans is correctly processed and translocated in Escherichia coli, in spite of the periplasm pH difference between these two micro-organisms

Microbiology ◽  
2005 ◽  
Vol 151 (5) ◽  
pp. 1421-1431 ◽  
Author(s):  
Patrice Bruscella ◽  
Laure Cassagnaud ◽  
Jeanine Ratouchniak ◽  
Gaël Brasseur ◽  
Elisabeth Lojou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acidithiobacillus Ferrooxidans ◽  
Biochemical Properties ◽  
Gene Encoding ◽  
Iron Sulfur Cluster ◽  
E Coli ◽  
Iron Sulfur ◽  
Sulfur Protein ◽  
Tat System ◽  
Micro Organisms

The gene encoding a putative high-potential iron–sulfur protein (HiPIP) from the strictly acidophilic and chemolithoautotrophic Acidithiobacillus ferrooxidans ATCC 33020 has been cloned and sequenced. This potential HiPIP was overproduced in the periplasm of the neutrophile and heterotroph Escherichia coli. As shown by optical and EPR spectra and by electrochemical studies, the recombinant protein has all the biochemical properties of a HiPIP, indicating that the iron–sulfur cluster was correctly inserted. Translocation of this protein in the periplasm of E. coli was not detected in a ΔtatC mutant, indicating that it is dependent on the Tat system. The genetic organization of the iro locus in strains ATCC 23270 and ATCC 33020 is different from that found in strains Fe-1 and BRGM. Indeed, in A. ferrooxidans ATCC 33020 and ATCC 23270 (the type strain), iro was not located downstream from purA but was instead downstream from petC2, encoding cytochrome c 1 from the second A. ferrooxidans cytochrome bc 1 complex. These findings underline the genotypic heterogeneity within the A. ferrooxidans species. The results suggest that Iro transfers electrons from a cytochrome bc 1 complex to a terminal oxidase, as proposed for the HiPIP in photosynthetic bacteria.

scholarly journals A Novel Gene Encoding Xanthan Lyase of Paenibacillus alginolyticus Strain XL-1

2000 ◽  
Vol 66 (9) ◽  
pp. 3945-3950 ◽  
Author(s):  
Harald J. Ruijssenaars ◽  
Sybe Hartmans ◽  
Jan C. Verdoes
Keyword(s):  
Signal Sequence ◽  
Fold Increase ◽  
Side Chain ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
E Coli ◽  
Mature Enzyme ◽  
Locust Bean ◽  
Encoding Gene ◽  
Amino Acid Signal

ABSTRACT Xanthan-modifying enzymes are powerful tools in studying structure-function relationships of this polysaccharide. One of these modifying enzymes is xanthan lyase, which removes the terminal side chain residue of xanthan. In this paper, the cloning and sequencing of the first xanthan lyase-encoding gene is described, i.e., thexalA gene, encoding pyruvated mannose-specific xanthan lyase of Paenibacillus alginolyticus XL-1. ThexalA gene encoded a 100,823-Da protein, including a 36-amino-acid signal sequence. The 96,887-Da mature enzyme could be expressed functionally in Escherichia coli. Like the native enzyme, the recombinant enzyme showed no activity on depyruvated xanthan. Compared to production by P. alginolyticus, a 30-fold increase in volumetric productivity of soluble xanthan lyase was achieved by heterologous production in E. coli. The recombinant xanthan lyase was used to produce modified xanthan, which showed a dramatic loss of the capacity to form gels with locust bean gum.

scholarly journals Phosphorylation of Nucleosides by the Mutated Acid Phosphatase from Morganella morganii

2000 ◽  
Vol 66 (7) ◽  
pp. 2811-2816 ◽  
Author(s):  
Yasuhiro Mihara ◽  
Takashi Utagawa ◽  
Hideaki Yamada ◽  
Yasuhisa Asano
Keyword(s):  
Acid Phosphatase ◽  
Random Mutagenesis ◽  
Reaction Yield ◽  
Mutant Library ◽  
Morganella Morganii ◽  
Gene Encoding ◽  
E Coli ◽  
Acid Phosphatase Gene ◽  
Phosphate Source

ABSTRACT A novel nucleoside phosphorylation process using the food additive pyrophosphate as the phosphate source was investigated. TheMorganella morganii gene encoding a selective nucleoside pyrophosphate phosphotransferase was cloned. It was identical to theM. morganii PhoC acid phosphatase gene. Sequential in vitro random mutagenesis was performed on the gene by error-prone PCR to construct a mutant library. The mutant library was introduced intoEscherichia coli, and the transformants were screened for the production of 5′-IMP. One mutated acid phosphatase with an increased phosphotransferase reaction yield was obtained. With E. coli overproducing the mutated acid phosphatase, 101 g of 5′-IMP per liter (192 mM) was synthesized from inosine in an 88% molar yield. This improvement was achieved with two mutations, Gly to Asp at position 92 and Ile to Thr at position 171. A decreasedKm value for inosine was responsible for the increased productivity.

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