Molds are able to reproduce sexually, unlike we thought for 100 years

January 8, 2013 by Dr. Julia Weiler
Scanning electron microscopic image of asexual conidiospores from the penicillin producer Penicillium chrysogenum © Lehrstuhl Allgemeine und Molekulare Botanik, RUB

For over 100 years, it was assumed that the penicillin-producing mould fungus Penicillium chrysogenum only reproduced asexually through spores. An international research team led by Prof. Dr. Ulrich Kück and Julia Böhm from the Chair of General and Molecular Botany at the Ruhr-Universität has now shown for the first time that the fungus also has a sexual cycle, i.e. two "genders". Through sexual reproduction of P. chrysogenum, the researchers generated fungal strains with new biotechnologically relevant properties - such as high penicillin production without the contaminating chrysogenin.

The team from Bochum, Göttingen, Nottingham (England), Kundl (Austria) and Sandoz GmbH reports in PNAS. The article will be published in this week's Online Early Edition and was selected as a cover story.

Only penicillin producer

About 100 years ago, demonstrated the formation of penicillin in Penicillium chrysogenum. To date, there is no other known producer of the antibiotic penicillin, which has an annual global market value of about six billion Euros.

Combining genes and breeding offspring with new properties

Not only animals and plants, but also many microorganisms such as fungi and algae can reproduce sexually. The advantage: the progenies possess a combination of genes from both mating partners and thus have new properties. in fungi is, however, not the rule. Most reproduce via which, in the case of moulds, occur as white, green or black deposits on spoiled food. These spores only bear the genes of one parent fungus. "Five years ago we already detected the existence of so-called sex genes in Penicillium chrysogenum", says Prof. Kück. Now, the researchers have discovered specific environmental conditions in which the fungus actually reproduces sexually. The decisive thing was to breed fungal strains in the dark under conditions in a nutrient medium supplemented with the vitamin biotin. The offspring exhibited new properties, both at the molecular level, as well as in their phenotypes.

Results could be applicable to other fungi

Using so-called microarray analysis, the biologists also investigated the activity of all the approximately 12,000 genes of the mould . The result: the sex genes control the activity of biologically relevant genes, for example those for penicillin production. "We presume that the findings can also be applied to other fungi", says Ulrich Kück, "such as Penicillium citrinum and Aspergillus terreus that produce cholesterol-lowering statins, or Penicillium brevicompactum and Tolypocladium inflatum, which produce immunosuppressives that are used in all organ transplantations". The researchers conducted the work in the Christian Doppler Laboratory "Biotechnology of Fungi" at the Ruhr-Universität with funding from the Christian Doppler Society (Vienna).

Explore further: Self-fertility in fungi — the secrets of 'DIY reproduction'

More information: J. Böhm, B. Hoff, C.M. O'Gorman, S. Wolfers, V. Klix, D. Binger, I. Zadra, H. Kürnsteiner, S. Pöggeler, P.S. Dyer, U. Kück (2013): Sexual reproduction and mating-type – mediated strain development in the penicillin-producing fungus Penicillium chrysogenum, PNAS, DOI: 10.1073/pnas.1217943110

Related Stories

Sex life of killer fungus finally revealed

December 1, 2008

Biologists at The University of Nottingham and University College Dublin have announced a major breakthrough in our understanding of the sex life of a microscopic fungus which is a major cause of death in immune deficient ...

Fleming's fungus still surprising scientists

November 21, 2011

(PhysOrg.com) -- From the moment that a spore of fungus fell onto Alexander Fleming's culture plate in 1928 and killed the bacteria around it, that fungus was destined to become one of the most studied organisms on the planet. ...

Recommended for you

New insights into the production of antibiotics by bacteria

July 31, 2015

Bacteria use antibiotics as a weapon and even produce more antibiotics if there are competing strains nearby. This is a fundamental insight that can help find new antibiotics. Leiden scientists Daniel Rozen and Gilles van ...

Out of the lamplight

July 31, 2015

The human body is governed by complex biochemical circuits. Chemical inputs spur chain reactions that generate new outputs. Understanding how these circuits work—how their components interact to enable life—is critical ...

Cell aging slowed by putting brakes on noisy transcription

July 30, 2015

Working with yeast and worms, researchers found that incorrect gene expression is a hallmark of aged cells and that reducing such "noise" extends lifespan in these organisms. The team published their findings this month in ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.