scholarly journals Cloning and expression of xylanase variants in Pichia pastoris

2017 ◽  
Author(s):  
◽  
Natasha Govindarajulu
Keyword(s):  
Pichia Pastoris ◽  
Animal Feed ◽  
Negative Impact ◽  
Paper Industry ◽  
Xylanase Activity ◽  
Restriction Enzymes ◽  
Cloning And Expression ◽  
Thermomyces Lanuginosus ◽  
High Yield ◽  
Heterologous Proteins

Microbial xylanases have attracted considerable research interest because of their various applications in biotechnology including the biobleaching of kraft pulp, to increase the nutritional value of foods and animal feed as well as for their potential use in the production of ethanol and methane. In the paper and pulp industry, the bleaching process involves the use of toxic chemicals and in the interim produces harmful gases that have a negative impact on the environment. The application of enzymes for this process will potentially reduce the environmental pollution by this industry. In addition, using an enzyme that is thermostable and alkali tolerant means that they will remain active under the required processing conditions. The xylanase gene, xynA derived from Thermomyces lanuginosus DSM 5826, was previously evolved to produce a number of xylanase variants, which were further enhanced for increased thermostability and alkalinity. In this study, these variants were cloned in Pichia pastoris using the pBGP1 vector to achieve extracellular production of the recombinant proteins. The xylanase genes were isolated using PCR. Both vector and DNA inserts were linearized with restriction enzymes EcoRI and XbaI and ligated. Electroporation was employed to transform the yeast with the recombinant plasmids. This was followed by the expression of the enzymes in P. pastoris grown in yeast peptone glucose (YPD) medium. Enzyme activity was thereafter assessed and the yeast was found to produce 164, 78, 96 and 142 IU/ml of S325, S340, G41 and G53 xylanase respectively, higher levels than bacterial hosts. The enzymes were then characterized and it was established that the optimum temperatures and pH for maximum xylanase activity were, 60°C, pH 6 for S325; 40°C, pH 5 for S340; 60°C, pH 6 for G41 and 60°C, pH 7 for G53. i The pH and temperature stabilities of the respective enzymes were investigated, the S325 variant was exceptionally stable at a pH between 5 and 7 and temperature range of 40-80°C and retained a minimum of 40% of activity at higher pH and temperature after an incubation period of 90 min. The S340 variant was the least thermostable and alkali stable from all four variants, it however retained 40% of activity when subjected to conditions of pH 9, 80°C after 90 min. The G41 and G53 were highly stable under the pH and temperature conditions that they were subjected to. Thus being suitable for potential application in the pulp and paper industry. The enzymes were able to retain 80% of activity at pH 9, 80°C after 120 min. P. pastoris has been proven to be a more suitable protein expression vector than E. coli for a number of reasons, including; the ability to perform complex post-translational modifications and grow to high densities in minimal media resulting in the production of a high yield of heterologous proteins.

Purification, application and immunolocalization of thermostable xylanases

2014 ◽  
Author(s):  
◽  
Stephanie Govender
Keyword(s):  
Reducing Sugars ◽  
Animal Feed ◽  
Paper Industry ◽  
Gel Filtration ◽  
Industrial Applications ◽  
Thermomyces Lanuginosus ◽  
Sds Page ◽  
Km Value ◽  
Enzyme Dosage ◽  
Paper And Pulp

Microbial enzymes are gaining worldwide attention due to their potential industrial applications. Microorganisms producing thermostable -xylanase and their associated hemicellulases have significant application in the paper and pulp, food, animal feed, and textile industries. The potential of partially purified xylanase from Thermomyces lanuginosus MC 134, Luminase PB 100, Luminase PB 200 (a commercial xylanase) and T. lanuginosus DSM 5826 (Sigma Aldrich) was evaluated in bleaching of bagasse pulp. The temperature and pH optima for all the enzymes were 60°C and pH 6, respectively. The temperature (50- 80°C) and pH (5-8) stability of the enzymes were also assessed. All the enzymes were relatively stable at 60°C and pH 6 for 180 min. T. lanuginosus MC 134 retained 80% of its activity at 60°C and pH 6 for 180 min and PB 200 retained 75% of its activity at 80°C for 180 min. T. lanuginosus MC 134 also exhibited good alkaline stability at pH 8. The commercial xylanases Luminase PB 100, Luminase PB 200, T. lanuginosus DSM 5826 (Sigma Aldrich) were purified to homogeneity using a gel filtration column packed with sephadex G-100 and characterized for Km and Vmax. However extracellular crude xylanases from T. lanuginosus MC 134 was purified to homogeneity using (N )2S04 precipitation and gel filtration column, packed with sephadex G-100. The purified xylanases exhibited a molecular mass of- 26 to 24 kDa, given range as determined by SDS page. The Km and Vmax values of Luminase PB 100, Luminase PB 200, T. lanuginosus MC 134, and T. lanuginosus DSM 5826, xylanases were determined by the Michaelis-Menten equation using birchwood xylan as the substrate. The Km value for Luminase PB 100, Luminase PB 200, T. lanuginosus DSM 5826 and T. lanuginosus MC 134 were, 8.1 mg/mL, 11.7 mg/mL and 14.3 mg/mL respectively. The Vmax for Luminase PB 100, Luminase PB 200, T lanuginosus DSM 5826 and T lanuginosus MC 134 were 232.6, 454.6 and 74.6 !Jl11ol/min/mg. Biobleaching conditions of the xylanases were also optimised and the release of reducing sugars and lignin derived compounds showed that an enzyme dosage of 50U/g of pulp was ideal for biobleaching at pH 6 and 60°C for 180 min. This brightness for T lanuginosus MC 134, Luminase PB 200, Luminase PB 100 was 45.5 ± 0.11%, 44.1 ± 0.007% and 42.7 ± 0.03% respectively at pH 6, compared to untreated samples. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. All the enzymes analysed exhibited similar trends in the release of lignin derived compounds and reducing sugars which indicated their potential in the pulp and paper industry.

The Progress in Cloning, Expression and Purification of Cholinesterase in Pichia pastoris: One Kind of Biomaterial for the Detection of Residual Insecticide Contamination

2015 ◽  
Vol 1120-1121 ◽  
pp. 847-852
Author(s):  
Jing Jing Tian ◽  
Yuan Hong Xie ◽  
Xiang Ning Chen ◽  
Xi Yue ◽  
Zhen Long Guo ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Cholinergic System ◽  
Expression Vector ◽  
Activity Analysis ◽  
Cloning And Expression ◽  
High Yield ◽  
Gene Cloning And Expression ◽  
Expression And Purification ◽  
Vector Construction ◽  
Key Enzyme

Cholinesterase serves as a key enzyme of the cholinergic system, which could be one kind of promising biomaterial to assay OP and CB residues. However, cholinesterase purified from tissues or blood is both time and cost intensive. In this essay, different methods via biotechnology to get this biomaterial in Pichia pastoris is summarized, including cholinesterase gene cloning and expression vector construction, construction of genetic modified yeast, screening high yield transformant, purification from supernatant and activity analysis.

scholarly journals High-level expression of improved thermo-stable alkaline xylanase variant in Pichia Pastoris through codon optimization, multiple gene insertion and high-density fermentation

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yihong Lu ◽  
Cheng Fang ◽  
Qinhong Wang ◽  
Yuling Zhou ◽  
Guimin Zhang ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Pichia Pastoris ◽  
Paper Industry ◽  
Xylanase Activity ◽  
Multiple Gene ◽  
E Coli ◽  
Gene Insertion ◽  
Alkaline Conditions ◽  
Pulp Properties ◽  
High Level

Abstract In paper industry, xylanases are used to increase the pulp properties in bleaching process as its eco-friendly nature. The xylanases activity is hindered by high temperature and alkaline conditions with high enzyme production cost in the paper industry. Here, XynHB, an alkaline stable xylanase from Bacillus pumilus HBP8 was mutated at N188A to XynHBN188A. Expressed mutant in E. coli showed 1.5-fold higher xylanase activity than XynHB at 60 °C. The mutant expressed in Pichia pastoris was glycosylated, remained stable for 30 min at 60 °C. XynHBN188A optimized based on codon usage bias for P. pastoris (xynHBN188As) showed an increase of 39.5% enzyme activity. The strain Y16 forming the largest hydrolysis halo in the xylan plate was used in shake flask experiments produced an enzyme activity of 6,403 U/ml. The Y16 strain had 9 copies of the recombinant xynHBN188As gene in the genome revealed by qPCR. The enzymatic activity increased to 48,241 U/ml in a 5 L fermentor. Supplement of 15 U/g xylanase enhanced the brightness of paper products by 2% in bleaching experiment, and thereby improved the tensile strength and burst factor by 13% and 6.5%, respectively. XynHBN188As has a great potential in paper industries.

scholarly journals Overexpression and partial characterization of a modified fungal xylanase in Escherichia coli

2009 ◽  
Author(s):  
◽  
Kyle Wakelin
Keyword(s):  
Escherichia Coli ◽  
Paper Industry ◽  
Extreme Environments ◽  
Xylanase Activity ◽  
Residual Activity ◽  
Growth Conditions ◽  
Thermomyces Lanuginosus ◽  
Start Codon ◽  
Lactose Induction ◽  
Fungal Dna

Protein engineering has been a valuable tool in creating enzyme variants that are capable of withstanding the extreme environments of industrial processes. Xylanases are a family of hemicellulolytic enzymes that are used in the biobleaching of pulp. Using directed evolution, a thermostable and alkaline stabl xylanase variant (S340) was created from the thermophilic fungus, Thermomyces lanuginosus. However, a host that was capable of rapid growth and high-level expression of the enzyme in large amounts was required. The insert containing the xylanase gene was cloned into a series a pET vectors in Escherichia coli BL21 (DE3) pLysS and trimmed from 786 bp to 692 bp to remove excess fungal DNA upstream and downstream of the open reading frame (ORF). The gene was then re-inserted back into the pET vectors. Using optimized growth conditions and lactose induction, a 14.9% increase in xylanase activity from 784.3 nkat/ml to 921.8 nkat/ml was recorded in one of the clones. The increase in expression was most probably due to the removal of fungal DNA between the vector promoter and the start codon. The distribution of the xylanase in the extracellular, periplasmic and cytoplasmic fractions was 17.3%, 51.3% and 31.4%, respectively. The modified enzyme was then purified to electrophoretic homogeneity using affinity chromatography. The xylanase had optimal activity at pH 5.5 and 70°C. After 120 min at 90°C and pH 10, S340 still displayed 39% residual activity. This enzyme is therefore well suited for its application in the pulp and paper industry.

Cloning and Expression of Recombinant Human Insulin Gene in Pichia pastoris

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Rafid A. Abdulkareem
Keyword(s):  
Pichia Pastoris ◽  
Human Insulin ◽  
Expression Vector ◽  
Expression System ◽  
Insulin Gene ◽  
Cloning And Expression ◽  
Pcr Analysis ◽  
Major Band ◽  
Human Insulin Gene ◽  
Pichia Pastoris Expression System

The main goal of the current study was cloning and expression of the human insulin gene in Pichia pastoris expression system, using genetic engineering techniques and its treatment application. Total RNA was purified from fresh normal human pancreatic tissue. RNA of good quality was chosen to obtain a first single strand cDNA. Human preproinsulin gene was amplified from cDNA strand, by using two sets of specific primers contain EcoR1 and Notl restriction sites. The amplified preproinsulin gene fragment was double digested with EcoRI and Not 1 restriction enzymes, then inserted into pPIC9K expression vector. The new pPIC9K-hpi constructive expression vector was transformed by the heat-shock method into the E.coli DH5α competent cells. pPic9k –hpi, which was propagated in the positive transformant E. coli cells, was isolated from cells and then linearised by restriction enzyme SalI, then transformed into Pichia pastoris GS115 using electroporation method. Genomic DNA of His+ transformants cell was extracted and used as a template for PCR analysis. The results showed, that the pPic9k – hpi was successfully integrated into the P. pastoris genome, for selected His+ transformants clones on the anticipated band at 330 bp, which is corresponded to the theoretical molecular size of the human insulin gene. To follow the insulin expression in transformans, Tricine–SDS gel electrophoresis and Western blot analysis were conducted. The results showed a successful expression of recombinant protein was detected by the presence of a single major band with about (5.8 KDa) on the gel. These bands correspond well with the size of human insulin with the theoretical molecular weight (5.8 KDa).

Production of foreign proteins in the yeast Pichia pastoris

1995 ◽  
Vol 73 (S1) ◽  
pp. 891-897 ◽  
Author(s):  
James M. Cregg ◽  
David R. Higgins
Keyword(s):  
Gene Expression ◽  
Pichia Pastoris ◽  
Heterologous Gene Expression ◽  
Expression System ◽  
Methylotrophic Yeast ◽  
Culture Broth ◽  
Heterologous Gene ◽  
Foreign Gene ◽  
Heterologous Proteins ◽  
Yeast Pichia Pastoris

The methanol-utilizing yeast Pichia pastoris has been developed as a host system for the production of heterologous proteins of commercial interest. An industrial yeast selected for efficient growth on methanol for biomass generation, P. pastoris is readily grown on defined medium in continuous culture at high volume and density. A unique feature of the expression system is the promoter employed to drive heterologous gene expression, which is derived from the methanol-regulated alcohol oxidase I gene (AOX1) of P. pastoris, one of the most efficient and tightly regulated promoters known. The strength of the AOX1 promoter results in high expression levels in strains harboring only a single integrated copy of a foreign-gene expression cassette. Levels may often be further enhanced through the integration of multiple cassette copies into the P. pastoris genome and strategies to construct and select multicopy cassette strains have been devised. The system is particularly attractive for the secretion of foreign-gene products. Because P. pastoris endogenous protein secretion levels are low, foreign secreted proteins often appear to be virtually the only proteins in the culture broth, a major advantage in processing and purification. Key words: heterologous gene expression, methylotrophic yeast, Pichia pastoris, secretion, glycosylation.

Cloning and Expression of a Novel Xylanase Gene (Auxyn11D) from Aspergillus usamii E001 in Pichia pastoris

2012 ◽  
Vol 167 (8) ◽  
pp. 2198-2211 ◽  
Author(s):  
Huimin Zhang ◽  
Minchen Wu ◽  
Jianfang Li ◽  
Shujuan Gao ◽  
Yanjun Yang
Keyword(s):  
Pichia Pastoris ◽  
Cloning And Expression ◽  
Xylanase Gene ◽  
Aspergillus Usamii

Process Technology for Production and Recovery of Heterologous Proteins with Pichia pastoris

2006 ◽  
Vol 22 (6) ◽  
pp. 1465-1473 ◽  
Author(s):  
M. Jahic ◽  
A. Veide ◽  
T. Charoenrat ◽  
T. Teeri ◽  
S.-O. Enfors
Keyword(s):  
Pichia Pastoris ◽  
Heterologous Proteins ◽  
Process Technology
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