scholarly journals Eighty Years after Its Discovery, Fleming's Penicillium Strain Discloses the Secret of Its Sex

2008 ◽  
Vol 7 (3) ◽  
pp. 465-470 ◽  
Author(s):  
Birgit Hoff ◽  
Stefanie Pöggeler ◽  
Ulrich Kück
Keyword(s):  
Antibacterial Activity ◽  
Sexual Reproduction ◽  
Strain Improvement ◽  
Mating Types ◽  
Penicillin Production ◽  
Industrial Strain ◽  
Pheromone Receptor ◽  
Improvement Programs ◽  
Alexander Fleming ◽  
Penicillium Strain

ABSTRACT Eighty years ago, Alexander Fleming discovered antibacterial activity in the asexual mold Penicillium, and the strain he studied later was replaced by an overproducing isolate still used for penicillin production today. Using a heterologous PCR approach, we show that these strains are of opposite mating types and that both have retained transcriptionally expressed pheromone and pheromone receptor genes required for sexual reproduction. This discovery extends options for industrial strain improvement programs using conventional genetical approaches.

PENICILLIN PRODUCTION BY MUTANT OF Penicillium chrysogenum

2016 ◽  
Vol 2 (1) ◽  
pp. 15
Author(s):  
Dudi Hardianto ◽  
Suyanto . ◽  
Erwahyuni Endang Prabandari ◽  
Lira Windriawati ◽  
Edy Marwanta ◽  
...  
Keyword(s):  
Ultraviolet Irradiation ◽  
Penicillium Chrysogenum ◽  
Bacterial Infections ◽  
Strain Improvement ◽  
Penicillin Production ◽  
Wild Type ◽  
Random Mutation ◽  
Type Mutant ◽  
Physical And Chemical ◽  
Alexander Fleming

Penisilin adalah antibiotika yang pertama kali ditemukan dan digunakan untuk pengobatan infeksi bakteri. Sejak ditemukan penisilin sebagai antibiotika oleh Alexander Fleming pada tahun 1928, banyak usaha dilakukan untuk meningkatkan produktivitas Penicillium chrysogenum. Pemuliaan galur untuk meningkatkan produksi penisilin dapat menggunakan mutasi acak secara fisika dan kimia. Pada penelitian ini, radiasi sinar ultraviolet digunakan untuk mendapatkan mutan P. chrysogenum. Produksi penisilin ditentukan menggunakan HPLC dan produktivitas mutan dibandingkan dengan induk P. chrysogenum. Mutan M12 menghasilkan penisilin 1,23 kali lebih banyak dibandingkan dengan induk P. chrysogenum.Kata kunci: Penisilin, Penicillium chrysogenum, ultraviolet, mutan, radiasi ABSTRACTPenicillin is the first antibiotic discovered and used for treatment of bacterial infections. Since the discovery of penicillin as antibiotic by Alexander Fleming in 1928, much effort has been invested to improve productivity of Penicillium chrysogenum. Strain improvement to increase the penicillin production can be carried out by physical and chemical random mutation. In this research, ultraviolet irradiation was used to obtain P. chrysogenum mutant. Penicillin production was determined by using HPLC and productivity of P. chrysogenum mutants was compared to the wild type. Mutant M12 produced 1.23 fold higher penicillin than the wild type did.Keywords: Penicillin, Penicillium chrysogenum, ultraviolet, mutant, radiation

Identification of biosynthetic intermediates for the mating hormone α2 of the plant pathogen Phytophthora

2021 ◽  
Author(s):  
Suguru Ariyoshi ◽  
Yusuke Imazu ◽  
Ryuji Ohguri ◽  
Ryo Katsuta ◽  
Arata Yajima ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Sexual Reproduction ◽  
Mating Type ◽  
Plant Pathogen ◽  
Type Strain ◽  
Mating Types ◽  
Synthetic Intermediates ◽  
The Cross

Abstract The heterothallic group of the plant pathogen Phytophthora can sexually reproduce between the cross-compatible mating types A1 and A2. The mating hormone α2, produced by A2 mating type and utilized to promote the sexual reproduction of the partner A1 type, is known to be biosynthesized from phytol. In this study, we identified two biosynthetic intermediates, 11- and 16-hydroxyphytols (1 and 2), for α2 by administering the synthetic intermediates to an A2 type strain to produce α2 and by administering phytol to A2 strains to detect the intermediates in the mycelia. The results suggest that α2 is biosynthesized by possibly two cytochrome P450 oxygenases via two hydroxyphytol intermediates (1 and 2) in A2 hyphae and secreted outside.

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 Gamete signalling underlies the evolution of mating types and their number

2016 ◽  
Vol 371 (1706) ◽  
pp. 20150531 ◽  
Author(s):  
Zena Hadjivasiliou ◽  
Andrew Pomiankowski
Keyword(s):  
Mathematical Model ◽  
Sexual Reproduction ◽  
Mating Types ◽  
Simple Mathematical Model ◽  
Unicellular Eukaryotes ◽  
Evolutionarily Stable

The gametes of unicellular eukaryotes are morphologically identical, but are nonetheless divided into distinct mating types. The number of mating types varies enormously and can reach several thousand, yet most species have only two. Why do morphologically identical gametes need to be differentiated into self-incompatible mating types, and why is two the most common number of mating types? In this work, we explore a neglected hypothesis that there is a need for asymmetric signalling interactions between mating partners. Our review shows that isogamous gametes always interact asymmetrically throughout sex and argue that this asymmetry is favoured because it enhances the efficiency of the mating process. We further develop a simple mathematical model that allows us to study the evolution of the number of mating types based on the strength of signalling interactions between gametes. Novel mating types have an advantage as they are compatible with all others and rarely meet their own type. But if existing mating types coevolve to have strong mutual interactions, this restricts the spread of novel types. Similarly, coevolution is likely to drive out less attractive mating types. These countervailing forces specify the number of mating types that are evolutionarily stable. This article is part of the themed issue ‘Weird sex: the underappreciated diversity of sexual reproduction’.

scholarly journals Impact of Classical Strain Improvement of Penicillium rubens on Amino Acid Metabolism during β-Lactam Production

2019 ◽  
Vol 86 (3) ◽  
Author(s):  
Min Wu ◽  
Ciprian G. Crismaru ◽  
Oleksandr Salo ◽  
Roel A. L. Bovenberg ◽  
Arnold J. M. Driessen
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Strain Improvement ◽  
Tryptophan Synthase ◽  
Cysteine Biosynthesis ◽  
Penicillin Production ◽  
Content Type ◽  
Classical Strain ◽  
The Impact

ABSTRACT To produce high levels of β-lactams, the filamentous fungus Penicillium rubens (previously named Penicillium chrysogenum) has been subjected to an extensive classical strain improvement (CSI) program during the last few decades. This has led to the accumulation of many mutations that were spread over the genome. Detailed analysis reveals that several mutations targeted genes that encode enzymes involved in amino acid metabolism, in particular biosynthesis of l-cysteine, one of the amino acids used for β-lactam production. To examine the impact of the mutations on enzyme function, the respective genes with and without the mutations were cloned and expressed in Escherichia coli, purified, and enzymatically analyzed. Mutations severely impaired the activities of a threonine and serine deaminase, and this inactivates metabolic pathways that compete for l-cysteine biosynthesis. Tryptophan synthase, which converts l-serine into l-tryptophan, was inactivated by a mutation, whereas a mutation in 5-aminolevulinate synthase, which utilizes glycine, was without an effect. Importantly, CSI caused increased expression levels of a set of genes directly involved in cysteine biosynthesis. These results suggest that CSI has resulted in improved cysteine biosynthesis by the inactivation of the enzymatic conversions that directly compete for resources with the cysteine biosynthetic pathway, consistent with the notion that cysteine is a key component during penicillin production. IMPORTANCE Penicillium rubens is an important industrial producer of β-lactam antibiotics. High levels of penicillin production were enforced through extensive mutagenesis during a classical strain improvement (CSI) program over 70 years. Several mutations targeted amino acid metabolism and resulted in enhanced l-cysteine biosynthesis. This work provides a molecular explanation for the interrelation between secondary metabolite production and amino acid metabolism and how classical strain improvement has resulted in improved production strains.

scholarly journals Genomic and Population Analyses of the Mating Type Loci in Coccidioides Species Reveal Evidence for Sexual Reproduction and Gene Acquisition

2007 ◽  
Vol 6 (7) ◽  
pp. 1189-1199 ◽  
Author(s):  
M. Alejandra Mandel ◽  
Bridget M. Barker ◽  
Scott Kroken ◽  
Steven D. Rounsley ◽  
Marc J. Orbach
Keyword(s):  
Sexual Reproduction ◽  
Mating Type ◽  
Mating Types ◽  
Coccidioides Immitis ◽  
Genome Sequences ◽  
Valley Fever ◽  
Population Analyses ◽  
Gene Acquisition ◽  
Close Proximity

ABSTRACT Coccidioides species, the fungi responsible for the valley fever disease, are known to reproduce asexually through the production of arthroconidia that are the infectious propagules. The possible role of sexual reproduction in the survival and dispersal of these pathogens is unexplored. To determine the potential for mating of Coccidioides, we analyzed genome sequences and identified mating type loci characteristic of heterothallic ascomycetes. Coccidioides strains contain either a MAT1-1 or a MAT1-2 idiomorph, which is 8.1 or 9 kb in length, respectively, the longest reported for any ascomycete species. These idiomorphs contain four or five genes, respectively, more than are present in the MAT loci of most ascomycetes. Along with their cDNA structures, we determined that all genes in the MAT loci are transcribed. Two genes frequently found in common sequences flanking MAT idiomorphs, APN2 and COX13, are within the MAT loci in Coccidioides, but the MAT1-1 and MAT1-2 copies have diverged dramatically from each other. Data indicate that the acquisition of these genes in the MAT loci occurred prior to the separation of Coccidioides from Uncinocarpus reesii. An analysis of 436 Coccidioides isolates from patients and the environment indicates that in both Coccidioides immitis and C. posadasii, there is a 1:1 distribution of MAT loci, as would be expected for sexually reproducing species. In addition, an analysis of isolates obtained from 11 soil samples demonstrated that at three sampling sites, strains of both mating types were present, indicating that compatible strains were in close proximity in the environment.

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