scholarly journals Reduced viscosity mutants of Trichoderma reesei with improved industrial fermentation characteristics

2021 ◽  
Author(s):  
Elizabeth Bodie ◽  
Aleksandra Virag ◽  
Robert J Pratt ◽  
Nicholas Leiva ◽  
Michael Ward ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Insertional Mutagenesis ◽  
Biomass Concentration ◽  
Volumetric Productivity ◽  
Specific Productivity ◽  
Secreted Protein ◽  
Single Strain ◽  
Reduced Viscosity ◽  
High Specific Productivity ◽  
Morphological Mutants

Abstract Morphological mutants of Trichoderma reesei were isolated following chemical or insertional mutagenesis. The mutant strains were shown to have reduced viscosity under industrially-relevant fermentation conditions and to have maintained high specific productivity of secreted protein. This allowed higher biomass concentration to be maintained during the production phase and, consequently, increased volumetric productivity of secreted protein. The causative mutations were traced to four individual genes (designated sfb3, ssb7, seb1 and mpg1). We showed that two of the morphological mutations could be combined in a single strain to further reduce viscosity and enable a 100 per cent increase in volumetric productivity.

scholarly journals Dynamic Co-Cultivation Process of Corynebacterium glutamicum Strains for the Fermentative Production of Riboflavin

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 11
Author(s):  
Fernando Pérez-García ◽  
Arthur Burgardt ◽  
Dina R. Kallman ◽  
Volker F. Wendisch ◽  
Nadav Bar
Keyword(s):  
Corynebacterium Glutamicum ◽  
Xanthomonas Campestris ◽  
Product Formation ◽  
Volumetric Productivity ◽  
Riboflavin Production ◽  
Xylose Consumption ◽  
Single Strain ◽  
Sugar Mixtures ◽  
Fed Batch Fermentation ◽  
Overexpressing Strain

Residual streams from lignocellulosic processes contain sugar mixtures of glucose, xylose, and mannose. Here, the industrial workhorse Corynebacterium glutamicum was explored as a research platform for the rational utilization of a multiple sugar substrate. The endogenous manA gene was overexpressed to enhance mannose utilization. The overexpression of the xylA gene from Xanthomonas campestris in combination with the endogenous xylB gene enabled xylose consumption by C. glutamicum. Furthermore, riboflavin production was triggered by overexpressing the sigH gene from C. glutamicum. The resulting strains were studied during batch fermentations in flasks and 2 L lab-scale bioreactors separately using glucose, mannose, xylose, and a mixture of these three sugars as a carbon source. The production of riboflavin and consumption of sugars were improved during fed-batch fermentation thanks to a dynamic inoculation strategy of manA overexpressing strain and xylAB overexpressing strain. The final riboflavin titer, yield, and volumetric productivity from the sugar mixture were 27 mg L−1, 0.52 mg g−1, and 0.25 mg L−1 h−1, respectively. It reached a 56% higher volumetric productivity with 45% less by-product formation compared with an equivalent process inoculated with a single strain overexpressing the genes xylAB and manA combined. The results indicate the advantages of dynamic multi strains processes for the conversion of sugar mixtures.

O-linked but not N-linked glycosylation is necessary for the secretion of endoglucanases I and II by Trichoderma reesei

1987 ◽  
Vol 33 (8) ◽  
pp. 698-703 ◽  
Author(s):  
C. P. Kubicek ◽  
T. Panda ◽  
G. Schreferl-kunar ◽  
F. Gruber ◽  
R. Messner
Keyword(s):  
Trichoderma Reesei ◽  
Protein Glycosylation ◽  
The Other ◽  
Detectable Effect ◽  
Secreted Protein ◽  
Intracellular Protein ◽  
Molecular Weights ◽  
Sds Page ◽  
Wide Range ◽  
Molecular Masses

The effect of inhibiting protein glycosylation was studied in nongrowing mycelia and protoplasts of Trichoderma reesei which secreted two endoglucanases (I and II) upon addition of sophorose. Tunicamycin (40 μg∙mL−1) inhibited incorporation of N-acetylglucosamine into secreted protein, but had no effect on secretion of total protein or endoglucanases. The secreted endoglucanases I and II exhibited relative molecular masses of 58 and 45 kilodaltons, respectively, irrespective of the presence of tunicamycin. On the other hand 2-deoxy-D-glucose inhibited the biosynthesis of extracellular as well as intracellular protein over a wide range of concentrations; at 50 μg∙mL−1, however, it inhibited the synthesis of extracellular protein more strongly. The synthesis of endoglucanases I and II was decreased accordingly under these conditions. SDS–PAGE did not reveal the secretion of endoglucanases with smaller molecular weights. When the two endoglucanases were purified and subjected to Endo H treatment or β-elimination, the former had no detectable effect, whereas the latter released all carbohydrate from the protein. Nevertheless, endoglucanases I and II contained 1.3 and 0.5 mol of glucosamine per mol enzyme, respectively. It is concluded that endoglucanases I and II from T. reesei contain mainly O-linked neutral carbohydrate, which is required for their secretion.

Low Molecular Weight High–Mannose Type Glycans in a Secreted Protein of the Filamentous Fungus Trichoderma Reesei

1987 ◽  
Vol 5 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Irma Salovuori ◽  
Marja Makarow ◽  
Heikki Rauvala ◽  
Jonathan Knowles ◽  
Leevi Kääriäinen
Keyword(s):  
Molecular Weight ◽  
Trichoderma Reesei ◽  
Filamentous Fungus ◽  
Low Molecular Weight ◽  
Secreted Protein ◽  
High Mannose

scholarly journals The production, molecular weight and viscosifying power of alginate produced by Azotobacter vinelandii is affected by the carbon source in submerged cultures

DYNA ◽  
2015 ◽  
Vol 82 (194) ◽  
pp. 21-26 ◽  
Author(s):  
Mauricio A. Trujillo-Roldán ◽  
John Fredy Monsalve-Gil ◽  
Angélica Maria Cuesta-Álvarez ◽  
Norma A. Valdez-Cruz
Keyword(s):  
Molecular Weight ◽  
Carbon Source ◽  
Biomass Concentration ◽  
Sugarcane Juice ◽  
Added Value ◽  
Specific Productivity ◽  
Molecular Characteristics ◽  
Submerged Cultures ◽  
Alginate Production ◽  
The Impact

Alginate is a linear polymer composed of <span style="font-family: symbol;">b</span>-1,4 linked mannuronic acid and its epimer, <span style="font-family: symbol;">a</span>-L-guluronic acid, and frequently extracted from marine algae, as from bacteria such as Azotobacter and Pseudomonas. Here, we show the impact of conventional and unconventional carbon sources on A. vinelandii growth, alginate production, its mean molecular weight (MMW) and its viscosifying power. Starting with 20 g/L of sugars, the highest biomass concentration was obtained using deproteinized and hydrolyzed whey (6.67±0.72 g/L), and sugarcane juice (6.68±0.45 g/L). However, the maximum alginate production was achieved using sucrose (5.11±0.37 g/L), as well the highest alginate yield and specific productivity. Otherwise, the higher alginate MMW was obtained using sugarcane juice (1203±120 kDa), and the higher viscosifying power was obtained using deproteinized/ hydrolyzed whey (23.8±2.6 cps L/galg). This information suggests that it is possible to manipulate the productivity and molecular characteristics of alginates, as a function of the carbon source used. All this, together with the knowledge of the effects of environmental conditions will allow for high yields of high added value biopolymers.

Productivity of the plum (Prunus domestica L.) cultivars and elite forms in the conditions of the Right-Bank Lisosteppe of Ukraine

2021 ◽  
pp. 45-51
Author(s):  
V.V. Filiov ◽  
◽  
O.A. Kishchak ◽  
Yu.P. Kishchak ◽  
V.A. Kryvoshapka ◽  
...  
Keyword(s):  
Cross Section ◽  
Specific Productivity ◽  
Research Station ◽  
Prunus Domestica ◽  
Horizontal Projection ◽  
Productivity Level ◽  
Crown Volume ◽  
High Specific Productivity ◽  
Early Ripening ◽  
The Right

The authors present the assessment of the yield, vigor and productivity of the plum cultivars and elite forms in the conditions of the Right-Bank Lisosteppe of Ukraine. The researches were carried out during 2018-2020 at the L.P. Symyrenko Research Station of Pomology of the Institute of Horticulture of NAAS of Ukraine. 14 cultivars bred at the mentioned institution were studied as well as 9 elite forms. The significant differences were revealed as concerns the trees vigor and crown habitus. According to the vigour cvs and elite forms were divided into groups as follows: low-holed (with the crown volume up to 15 m3), in particular, Oda, Nenka, Herman, 12516, 8124, 8143; middle-growing (15-20 m3) – Record, Zamanchyva, Dobra, Stanley, Bluefree, President, 9605, 7756, 9996; vigorous (over 20 m3) – Reinclaude Karbysheva, Čačanska Najbolja, Yantarna Mliivska, Tophit, Shtuthart, 8087, 7794, 8110. According to its results concerning the productivity, level early-ripening cultivars Nenka, Oda and Herman (14.2-15.1 t/ha) distinguished themselves, in the group of medium-ripening ones – Čačanska Najbolja, Yantarna Mliivska, Zamanchyva, Dobra and the elite form 12516 (15.6-16.5 t/ha), among late-ripening cultivars – Bluefree and the hybrids 8124 and 8143 with a yield of 16.3-16.4 t/ha. The same cultivars are characterized with high specific productivity, which reflects the density of the crop per unit of the crown volume, the area of its horizontal projection and the cross section of the trunk – 2.7-3.9 kg/m3, 5.2-6.6 kg/m2 and 0.12-0.20 kg/dm2 respectively. The optimum density of the placement of the trees with the different vigor of the rootstock myrobalan plum with the orbicular small sized crown was established applying the method of the mathematical modelling, in particular for low-growing cultivars -1111 trees/ha, middle-growing varieties – 667 trees/ha, vigorous strains – 555 trees/ha.

scholarly journals Insertion of the LINE Retrotransposon MGL Causes a Conidiophore Pattern Mutation in Magnaporthe grisea

2000 ◽  
Vol 13 (8) ◽  
pp. 892-894 ◽  
Author(s):  
Marie Nishimura ◽  
Nagao Hayashi ◽  
Nam-Soo Jwa ◽  
Gee W. Lau ◽  
John E. Hamer ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Aspergillus Nidulans ◽  
Insertional Mutagenesis ◽  
Magnaporthe Grisea ◽  
Morphological Mutants

We obtained three Magnaporthe grisea morphological mutants that had the LINE transposon MGL inserted into the ACR1 locus. Sequence analysis revealed that ACR1 is homologous to medA, a developmental regulator of Aspergillus nidulans conidiation. These results demonstrated that MGL elements could transpose and cause insertional mutagenesis in M. grisea.

scholarly journals Cereal extrusion with steam recuperation process

2019 ◽  
Vol 81 (3) ◽  
pp. 17-22
Author(s):  
V. I. Stepanov ◽  
V. V. Ivanov ◽  
A. Y. Sharikov ◽  
M. V. Amelyakina ◽  
D. V. Polivanovskaya
Keyword(s):  
Technology Development ◽  
Raw Materials ◽  
Extrusion Process ◽  
Operating Conditions ◽  
Specific Productivity ◽  
Special Configuration ◽  
Control Factors ◽  
Processed Material ◽  
High Specific Productivity ◽  
Food And Feed

The extrusion process advantage of agricultural raw materials processing into food and feed over traditional technologies is the high specific productivity, energy efficiency and versatility of use. The presence of a large number of control factors and influence on the raw materials quality, such as operating parameters and structural elements, make extrusion a difficult reproducible process when scaling or moving from one installation to another. But this aspect is the reason for the maximum flexibility of extrusion systems and the possibility of their continuous improvement. One of the ways for the extrusion technology development is the improvement of equipment and design solutions in the field of energy saving. Investigations of the thermoplastic extrusion process of wheat grinding with the application of the recovery of steam heat generated by a special configuration of screw elements and its degassing with the feeding into the processed material were carried out in the work. The modernized extruder Werner & Phleiderer Continua 37, supplemented by a developed recuperative unit and a steam line, was used to achieve this goal. An assessment of changes in energy consumption during steam recovery was carried out. The physicochemical properties of the experimental and control samples of wheat grain extrudates obtained under various operating conditions were investigated and determined. It was found out that the steam recovery mode is a statistically significant reason for increasing the humidity of the extruded product from 3.8 to 5.0 bulk density - by 15% relative to the mode without recovery. A decrease in the explosion coefficient and the water-holding capacity of the extrudates during operation in the regenerative mode of extrusion was noticed. The presented method with additional thermal effects on the processed raw materials allows us to expand the technological capabilities of the process of thermoplastic extrusion in obtaining products of various functional and technological purposes.

Inductive Cold Crucible Melting and Characterization of Uranium and Thorium Bearing Murataite Ceramics

2007 ◽  
Author(s):  
O. A. Knyazev ◽  
A. G. Ptashkin ◽  
S. V. Stefanovsky ◽  
M. A. Zen’kovskaya ◽  
S. V. Yudintsev ◽  
...  
Keyword(s):  
Large Scale ◽  
Unit Cell ◽  
Specific Productivity ◽  
Cold Crucible ◽  
Synthesis Conditions ◽  
The Core ◽  
Transmission Electron ◽  
Actinide Partitioning ◽  
High Specific Productivity ◽  
The Difference

Murataite-based ceramics containing 10 wt.% either UO2 or ThO2 were produced by inductive cold crucible melting (ICCM) at operating frequencies of 1.76 MHz and 5.28 MHz and examined using X-ray diffraction and scanning and transmission electron microscopy. High specific productivity was achieved. Average melting ratio was 8.3 kW×h/kg. We identified three distinct murataite polytypes in the U-bearing ceramics: a five- (5C), eight- (8C), and three-fold (3C) fluorite unit cell composing respectively the core, intermediate and rim zones of the grains. In contrast, in the Th-bearing ceramic one of the polytypes with eight-fold (8C) fluorite unit cell was found to be prevailing over two others (5C and 3C). Computer simulation of the major reflection due to the murataite phase in the Th-bearing sample also exhibits superposition of peaks due to three distinct polytypes but one of them (8C) is predominant. The core zone of the murataite in the U-bearing specimens is characterized by UO2 concentrations as high as 12.1 wt%, which successively diminishes in concentration through the intermediate zone to the rim, the latter of which contains 5.2 wt% UO2. Thorium distribution within the murataite crystals is more uniform. The other phases found in the ceramics are crichtonite, rutile and traces of perovskite, Fe/Mn titanate ilmenite/pyrophanite, zirconolite, and vitreous phase. The difference in phase composition and actinide partitioning in the ceramics is influenced by synthesis conditions. Thus, application of large-scale cold crucibles is a prospective route for the development of industrial-scale process and technology for ceramization of actinide-bearing HLW. The advantage of this method is production of zoned crystals with the highest concentrations of actinides and rare earth elements in the core, effectively isolating these elements from potential leach solutions.

Sign in / Sign up

Export Citation Format

Share Document