scholarly journals High-Yield Production of a Bacterial Xylanase in the Filamentous Fungus Trichoderma reesei Requires a Carrier Polypeptide with an Intact Domain Structure

2003 ◽  
Vol 69 (12) ◽  
pp. 7073-7082 ◽  
Author(s):  
Marja Paloheimo ◽  
Arja Mäntylä ◽  
Jarno Kallio ◽  
Pirkko Suominen

ABSTRACT A bacterial xylanase gene, Nonomuraea flexuosa xyn11A, was expressed in the filamentous fungus Trichoderma reesei from the strong cellobiohydrolase 1 promoter as fusions to a variety of carrier polypeptides. By using single-copy isogenic transformants, it was shown that production of this xylanase was clearly increased (up to 820 mg/liter) when it was produced as a fusion protein with a carrier polypeptide having an intact domain structure compared to the production (150 to 300 mg/liter) of fusions to the signal sequence alone or to carriers having incomplete domain structures. The carriers tested were the T. reesei mannanase I (Man5A, or MANI) core-hinge and a fragment thereof and the cellulose binding domain of T. reesei cellobiohydrolase II (Cel6A, or CBHII) with and without the hinge region(s) and a fragment thereof. The flexible hinge region was shown to have a positive effect on both the production of Xyn11A and the efficiency of cleavage of the fusion polypeptide. The recombinant Xyn11A produced had properties similar to those of the native xylanase. It constituted 6 to 10% of the total proteins secreted by the transformants. About three times more of the Man5A core-hinge carrier polypeptide than of the recombinant Xyn11A was observed. Even in the best Xyn11A producers, the levels of the fusion mRNAs were only ∼10% of the level of cel7A (cbh1) mRNA in the untransformed host strain.

2007 ◽  
Vol 73 (10) ◽  
pp. 3215-3224 ◽  
Author(s):  
Marja Paloheimo ◽  
Arja Mäntylä ◽  
Jarno Kallio ◽  
Terhi Puranen ◽  
Pirkko Suominen

ABSTRACT We have previously shown that the Nonomuraea flexuosa Xyn11A polypeptides devoid of the carbohydrate binding module (CBM) have better thermostability than the full-length xylanase and are effective in bleaching of pulp. To produce an enzyme preparation useful for industrial applications requiring high temperature, the region encoding the CBM was deleted from the N. flexuosa xyn11A gene and the truncated gene was expressed in Trichoderma reesei. The xylanase sequence was fused to the T. reesei mannanase I (Man5A) signal sequence or 3′ to a T. reesei carrier polypeptide, either the Man5A core/hinge or the cellulose binding domain (CBD) of cellobiohydrolase II (Cel6A, CBHII). The gene and fusion genes were expressed using the cellobiohydrolase 1 (cel7A, cbh1) promoter. Single-copy isogenic transformants in which the expression cassette replaced the cel7A gene were cultivated and analyzed. The transformants expressing the truncated N. flexuosa xyn11A produced clearly increased amounts of both the xylanase/fusion mRNA and xylanase activity compared to the corresponding strains expressing the full-length N. flexuosa xyn11A. The transformant expressing the cel6A CBD-truncated N. flexuosa xyn11A produced about 1.9 g liter−1 of the xylanase in laboratory-scale fermentations. The xylanase constituted about 25% of the secreted proteins. The production of the truncated xylanase did not induce the unfolded protein response (UPR) pathway. However, the UPR was induced when the full-length N. flexuosa xyn11A with an exact fusion to the cel7A terminator was expressed. We suggest that the T. reesei folding/secretion machinery is not able to cope properly with the bacterial CBM when the mRNA of the full-length N. flexuosa xyn11A is efficiently translated.


2019 ◽  
Vol 9 (3) ◽  
pp. 344-352 ◽  
Author(s):  
L.I. Stefanovich ◽  
O.Y. Mazur ◽  
V.V. Sobolev

Introduction: Within the framework of the phenomenological theory of phase transitions of the second kind of Ginzburg-Landau, the kinetics of ordering of a rapidly quenched highly nonequilibrium domain structure is considered using the lithium tantalate and lithium niobate crystals as an example. Experimental: Using the statistical approach, evolution equations describing the formation of the domain structure under the influence of a high-frequency alternating electric field in the form of a standing wave were obtained. Numerical analysis has shown the possibility of forming thermodynamically stable mono- and polydomain structures. It turned out that the process of relaxation of the system to the state of thermodynamic equilibrium can proceed directly or with the formation of intermediate quasi-stationary polydomain asymmetric phases. Results: It is shown that the formation of Regular Domain Structures (RDS) is of a threshold character and occurs under the influence of an alternating electric field with an amplitude less than the critical value, whose value depends on the field frequency. The conditions for the formation of RDSs with a micrometer spatial scale were determined. Conclusion: As shown by numerical studies, the RDSs obtained retain their stability, i.e. do not disappear even after turning off the external electric field. Qualitative analysis using lithium niobate crystals as an example has shown the possibility of RDSs formation in high-frequency fields with small amplitude under resonance conditions


animal ◽  
2021 ◽  
pp. 100293
Author(s):  
J. Simões ◽  
J.A. Abecia ◽  
A. Cannas ◽  
J.A. Delgadillo ◽  
D. Lacasta ◽  
...  

2021 ◽  
pp. 2101017
Author(s):  
Frank Mickoleit ◽  
Sabine Rosenfeldt ◽  
Mauricio Toro‐Nahuelpan ◽  
Miroslava Schaffer ◽  
Anna S. Schenk ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yumeng Chen ◽  
Xingjia Fan ◽  
Xinqing Zhao ◽  
Yaling Shen ◽  
Xiangyang Xu ◽  
...  

Abstract Background The filamentous fungus Trichoderma reesei is one of the best producers of cellulase and has been widely studied for the production of cellulosic ethanol and bio-based products. We previously reported that Mn2+ and N,N-dimethylformamide (DMF) can stimulate cellulase overexpression via Ca2+ bursts and calcium signalling in T. reesei under cellulase-inducing conditions. To further understand the regulatory networks involved in cellulase overexpression in T. reesei, we characterised the Mn2+/DMF-induced calcium signalling pathway involved in the stimulation of cellulase overexpression. Results We found that Mn2+/DMF stimulation significantly increased the intracellular levels of cAMP in an adenylate cyclase (ACY1)-dependent manner. Deletion of acy1 confirmed that cAMP is crucial for the Mn2+/DMF-stimulated cellulase overexpression in T. reesei. We further revealed that cAMP elevation induces a cytosolic Ca2+ burst, thereby initiating the Ca2+ signal transduction pathway in T. reesei, and that cAMP signalling causes the Ca2+ signalling pathway to regulate cellulase production in T. reesei. Furthermore, using a phospholipase C encoding gene plc-e deletion strain, we showed that the plc-e gene is vital for cellulase overexpression in response to stimulation by both Mn2+ and DMF, and that cAMP induces a Ca2+ burst through PLC-E. Conclusions The findings of this study reveal the presence of a signal transduction pathway in which Mn2+/DMF stimulation produces cAMP. Increase in the levels of cAMP activates the calcium signalling pathway via phospholipase C to regulate cellulase overexpression under cellulase-inducing conditions. These findings provide insights into the molecular mechanism of the cAMP–PLC–calcium signalling pathway underlying cellulase expression in T. reesei and highlight the potential applications of signal transduction in the regulation of gene expression in fungi.


2012 ◽  
Vol 97 (8) ◽  
pp. 3343-3353 ◽  
Author(s):  
Claudia Korneli ◽  
Rebekka Biedendieck ◽  
Florian David ◽  
Dieter Jahn ◽  
Christoph Wittmann

RSC Advances ◽  
2016 ◽  
Vol 6 (54) ◽  
pp. 49060-49067 ◽  
Author(s):  
Micka Bah ◽  
Natalya Alyabyeva ◽  
Richard Retoux ◽  
Fabien Giovannelli ◽  
Mustapha Zaghrioui ◽  
...  

We reported self-organized and hierarchized domain structures on various length scales ranging from micrometer to nanometer scale in K0.5Na0.5NbO3 crystals.


2021 ◽  
Author(s):  
Benjamin Schmuck ◽  
Gabriele Greco ◽  
Andreas Barth ◽  
Nicola M. Pugno ◽  
Jan Johansson ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document