scholarly journals Biotransformation of dehydroepiandrosterone (DHEA) by environmental strains of filamentous fungi

RSC Advances ◽  
2017 ◽  
Vol 7 (50) ◽  
pp. 31493-31501 ◽  
Author(s):  
Ewa Kozłowska ◽  
Monika Urbaniak ◽  
Anna Kancelista ◽  
Monika Dymarska ◽  
Edyta Kostrzewa-Susłow ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
High Yield ◽  
Fungus Species

Study on the ability of selected filamentous fungus species to transform dehydroepiandrosterone was performed (DHEA) and interesting DHEA derivatives were obtained with high yield.

scholarly journals Random Mutagenesis of Filamentous Fungi Strains for High-Yield Production of Secondary Metabolites: The Role of Polyamines

2020 ◽  
Author(s):  
Alexander A. Zhgun
Keyword(s):  
Filamentous Fungi ◽  
Random Mutagenesis ◽  
Strain Improvement ◽  
Main Tool ◽  
High Yield ◽  
Individual Species ◽  
Airborne Spores ◽  
Yield Production ◽  
Improvement Programs ◽  
The Individual

A filamentous fungus (also called molds or moldy fungus) is a taxonomically diverse organism from phylum Zygomycota and Ascomycota with filamentous hyphae and has the ability to produce airborne spores or conidia. Currently, more than 70,000 molds are known, and some of them contain unique and unusual biochemical pathways. A number of products from such pathways, especially, the secondary metabolite (SM) pathways are used as important pharmaceuticals, including antibiotics, statins, and immunodepresants. Under different conditions, the individual species can produce more than 100 SM. The strain improvement programs lead to high yielding in target SM and significant reduction of spin-off products. The main tool for the strain improvement of filamentous fungi is random mutagenesis and screening. The majority of industrial overproducing SM strains were developed with the help of such technique over the past 50–70 years; the yield of the target SM increased by 100- to 1000-fold or more. Moreover, most of the strains have reached their technological limit of improvement. A new round of mutagenesis has not increased overproduction. Recently, it was shown that that the addition of exogenous polyamines may increase the production of such improved strains of filamentous fungi. The possible molecular mechanism of this phenomenon and its biotechnological applications are discussed.

scholarly journals Defining individual size in the model filamentous fungus Neurospora crassa

2016 ◽  
Vol 283 (1826) ◽  
pp. 20152470 ◽  
Author(s):  
Linda Ma ◽  
Boya Song ◽  
Thomas Curran ◽  
Nhu Phong ◽  
Emilie Dressaire ◽  
...  
Keyword(s):  
Neurospora Crassa ◽  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Reproductive Potential ◽  
Fungal Mycelium ◽  
Dependent Property ◽  
Mycelial Network ◽  
And Function ◽  
Individual Size ◽  
Over Time

It is challenging to apply the tenets of individuality to filamentous fungi: a fungal mycelium can contain millions of genetically diverse but totipotent nuclei, each capable of founding new mycelia. Moreover, a single mycelium can potentially stretch over kilometres, and it is unlikely that its distant parts share resources or have the same fitness. Here, we directly measure how a single mycelium of the model ascomycete Neurospora crassa is patterned into reproductive units (RUs), meaning subpopulations of nuclei that propagate together as spores, and function as reproductive individuals. The density of RUs is sensitive to the geometry of growth; we detected 50-fold smaller RUs when mycelia had expanding frontiers than when they were constrained to grow in one direction only. RUs fragmented further when the mycelial network was perturbed. In mycelia with expanding frontiers, RU composition was strongly influenced by the distribution of genotypes early in development. Our results provide a concept of fungal individuality that is directly connected to reproductive potential, and therefore to theories of how fungal individuals adapt and evolve over time. Our data show that the size of reproductive individuals is a dynamic and environment-dependent property, even within apparently totally connected fungal mycelia.

scholarly journals Transient Silencing of DNA Repair Genes Improves Targeted Gene Integration in the Filamentous Fungus Trichoderma reesei

2017 ◽  
Vol 83 (15) ◽  
Author(s):  
Pak Yang Chum ◽  
Georg Schmidt ◽  
Markku Saloheimo ◽  
Christopher P. Landowski
Keyword(s):  
Dna Repair ◽  
Trichoderma Reesei ◽  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Unintended Consequences ◽  
Dna Repair Genes ◽  
Content Type ◽  
Targeted Integration ◽  
Gene Integration ◽  
Repair Genes

ABSTRACT Trichoderma reesei is a filamentous fungus that is used worldwide to produce industrial enzymes. Industrial strains have traditionally been created though systematic strain improvement using mutagenesis and screening approaches. It is also desirable to specifically manipulate the genes of the organism to further improve and to modify the strain. Targeted integration in filamentous fungi is typically hampered by very low frequencies of homologous recombination. To address this limitation, we have developed a simple transient method for silencing genes in T. reesei. Using gene-specific small interfering RNAs (siRNAs) targeted to mus53, we could achieve up to 90% knockdown of mus53 mRNA. As a practical example, we demonstrated that transient silencing of DNA repair genes significantly improved homologous integration of DNA at a specific locus in a standard protoplast transformation. The best transient silencing of mus53 with siRNAs in protoplasts could achieve up to 59% marker gene integration. IMPORTANCE The previous solution for improving targeted integration efficiency has been deleting nonhomologous end joining (NHEJ) DNA repair genes. However, deleting these important repair genes may lead to unintended consequences for genomic stability and could lead to the accumulation of spontaneous mutations. Our method of transiently silencing NHEJ repair pathway genes allows recovery of their important repair functions. Here we report a silencing approach for improving targeted DNA integration in filamentous fungi. Furthermore, our transient silencing method is a truly flexible approach that is capable of knocking down the expression of a target gene in growing mycelial cultures, which could facilitate the broad study of gene functions in T. reesei.

Farnesol-induced cell death in the filamentous fungus Aspergillus nidulans

2011 ◽  
Vol 39 (5) ◽  
pp. 1544-1548 ◽  
Author(s):  
Taísa Magnani Dinamarco ◽  
Maria Helena S. Goldman ◽  
Gustavo Henrique Goldman
Keyword(s):  
Cell Death ◽  
Aspergillus Nidulans ◽  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Model System ◽  
Farnesyl Pyrophosphate

FOH (farnesol), a non-sterol isoprenoid produced by dephosphorylation of farnesyl pyrophosphate, has been shown to inhibit proliferation and induce apoptosis. We have been using Aspergillus nidulans and FOH as a model system and cell death stimulus, respectively, aiming to understand by which means filamentous fungi are driven towards cell death. Here, we review some of our findings about FOH-induced cell death in A. nidulans.

THE DAMPENING OF LIPID DROPLET OSCILLATORY MOVEMENT IN NITROGEN STARVED FILAMENTOUS FUNGI BY A LOW DOSE OF MITOCHONDRIAL RESPIRATION INHIBITOR

2021 ◽  
Author(s):  
Tanja Pajic ◽  
◽  
Miroslav Zivic ◽  
Mihailo Rabasovic ◽  
Aleksandar Krmpot ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Sodium Azide ◽  
Mitochondrial Respiration ◽  
Lipid Droplets ◽  
Low Dose ◽  
Eukaryotic Cells ◽  
Confined Space ◽  
Phycomyces Blakesleeanus ◽  
Oscillatory Movement

Lipid droplets (LDs) are small mobile organelles conserved in all eukaryotic cells. We wanted to test if the LD movement can be muffled by an incomplete inhibition of mitochondrial respiration, induced by treating hyphae of filamentous fungus Phycomyces blakesleeanus with 0.5 mM sodium azide. Nitrogen starved hyphae were used, in order to obtain LDs in larger sizes and numbers. The data obtained unequivocally showed: 1. Sodium azide treatment dramatically reduces the LD velocity and the distances LDs travel; 2. LDs in both controls and in azide-treated hyphae oscillate in a small confined space instead of travelling through the cell; 3. Azide-treated LDs oscillate less frequently and in smaller confinement than controls.

scholarly journals Modulating Endoplasmic Reticulum-Golgi Cargo Receptors for Improving Secretion of Carrier-Fused Heterologous Proteins in the Filamentous Fungus Aspergillus oryzae

2014 ◽  
Vol 81 (2) ◽  
pp. 533-543 ◽  
Author(s):  
Huy-Dung Hoang ◽  
Jun-ichi Maruyama ◽  
Katsuhiko Kitamoto
Keyword(s):  
Endoplasmic Reticulum ◽  
Filamentous Fungi ◽  
Protein Secretion ◽  
Filamentous Fungus ◽  
Protein Production ◽  
Heterologous Protein ◽  
Heterologous Proteins ◽  
Content Type ◽  
Heterologous Protein Secretion ◽  
Golgi Compartment

ABSTRACTFilamentous fungi are excellent hosts for industrial protein production due to their superior secretory capacity; however, the yield of heterologous eukaryotic proteins is generally lower than that of fungal or endogenous proteins. Although activating protein folding machinery in the endoplasmic reticulum (ER) improves the yield, the importance of intracellular transport machinery for heterologous protein secretion is poorly understood. Here, usingAspergillus oryzaeas a model filamentous fungus, we studied the involvement of two putative lectin-like cargo receptors,A. oryzaeVip36 (AoVip36) and AoEmp47, in the secretion of heterologous proteins expressed in fusion with the endogenous enzyme α-amylase as the carrier. Fluorescence microscopy revealed that mDsRed-tagged AoVip36 localized in the Golgi compartment, whereas AoEmp47 showed localization in both the ER and the Golgi compartment. Deletion of AoVip36 and AoEmp47 improved heterologous protein secretion, but only AoVip36 deletion had a negative effect on the secretion of α-amylase. Analysis of ER-enriched cell fractions revealed that AoVip36 and AoEmp47 were involved in the retention of heterologous proteins in the ER. However, the overexpression of each cargo receptor had a different effect on heterologous protein secretion: AoVip36 enhanced the secretion, whereas AoEmp47 promoted the intracellular retention. Taken together, our data suggest that AoVip36 and AoEmp47 hinder the secretion of heterologous proteins by promoting their retention in the ER but that AoVip36 also promotes the secretion of heterologous proteins. Moreover, we found that genetic deletion of these putative ER-Golgi cargo receptors significantly improves heterologous protein production. The present study is the first to propose that ER-Golgi transport is a bottleneck for heterologous protein production in filamentous fungi.

scholarly journals A technique for replica platingCoprinus lagopus, a filamentous fungus

1971 ◽  
Vol 17 (3) ◽  
pp. 279-281 ◽  
Author(s):  
Philippa J. Kaplan ◽  
D. Walls
Keyword(s):  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Sodium Deoxycholate ◽  
Regular Pattern ◽  
Plating Technique ◽  
Replica Plating

SUMMARYThe problem of replica plating filamentous fungi such asCoprinus lagopusis overcome by inducing micro-colonies with sodium deoxycholate and using ‘Velcro’, a hooked material, to replace velveteen in the standard replica plating technique. ‘Velcro’ is advantageous in that it has a regular pattern of closely spaced hooks which transfer small inocula from the colonies on the master plate.

scholarly journals Biotransformation of 11-ketoprogesterone by Filamentous Fungus, Fusarium lini

2011 ◽  
Vol 3 (2) ◽  
pp. 347-356 ◽  
Author(s):  
M. A. Al-Maruf ◽  
N. T. Khan ◽  
M. A. A. Saki ◽  
M. I. Choudhary ◽  
M. U. Ali ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Filamentous Fungus ◽  
Spectroscopic Analysis ◽  
Microbial Transformation ◽  
Oxidative Metabolites

Microbial transformation of 11-ketoprogesterone (1) by the filamentous fungi Fusarium lini was investigated. Biotransformation of 1 with F. lini resulted in the production of ten oxidative metabolites (2-11). Structures of these metabolites were deduced by spectroscopic analysis and seven of them, 5-11, were found to be new metabolites.Keywords: 11-Ketoprogesterone; Steroid; Microbial transformation; Hydroxylation; Filamentous fungi; Fusarium lini.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi:10.3329/jsr.v2i2.6221                J. Sci. Res. 3 (2), 347-356 (2011)

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
Keyword(s):  
Domain Structure ◽  
Trichoderma Reesei ◽  
Filamentous Fungus ◽  
Signal Sequence ◽  
Single Copy ◽  
Hinge Region ◽  
High Yield ◽  
Domain Structures ◽  
Yield Production ◽  
Cellulose Binding

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.

Quality films from carbon fiber evaporation for thorough coverage of TEM grids

1988 ◽  
Vol 46 ◽  
pp. 418-419
Author(s):  
N. Tempel ◽  
M. C. Ledbetter
Keyword(s):  
Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Carbon Films ◽  
Low Noise ◽  
Vacuum Evaporation ◽  
High Yield ◽  
Good Adhesion ◽  
Noise Structure ◽  
Resolution Electron ◽  
Carbon Foils

Carbon films have been a support of choice for high resolution electron microscopy since the introduction of vacuum evaporation of carbon. The desirable qualities of carbon films and methods of producing them has been extensively reviewed. It is difficult to get a high yield of grids by many of these methods, especially if virtually all of the windows must be covered with a tightly bonded, quality film of predictable thickness. We report here a method for producing carbon foils designed to maximize these attributes: 1) coverage of virtually all grid windows, 2) freedom from holes, wrinkles or folds, 3) good adhesion between film and grid, 4) uniformity of film and low noise structure, 5) predictability of film thickness, and 6) reproducibility.Our method utilizes vacuum evaporation of carbon from a fiber onto celloidin film and grid bars, adhesion of the film complex to the grid by carbon-carbon contact, and removal of the celloidin by acetone dissolution. Materials must be of high purity, and cleanliness must be rigorously maintained.

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