Karin Jacobs

Prof. Karin Jacobs

orcid

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2016 in Pedobiologia
Verified
Journal Article
Closed access
ZVZander Samuel Venter
Zander Samuel Venter
KJKarin Jacobs
Karin Jacobs
HHHeidi-Jayne Hawkins
Heidi-Jayne Hawkins

1 April 2004 in Mycological Research
Verified
Journal Article
Closed access
KJKarin Jacobs
Karin Jacobs
DBDale R. Bergdahl
Dale R. Bergdahl
MWMichael J. Wingfield
Michael J. Wingfield
SHShari Halik
Shari Halik
KSKeith A. Seifert
Keith A. Seifert
BWBrenda Wingfield
Brenda Wingfield

1 July 2021 in Phytopathology®
Verified
Journal Article
Closed access
DGDavid M. Geiser
David M. Geiser
Abdullah Al-HatmiAbdullah Al-Hatmi
Abdullah Al-Hatmi
TATakayuki Aoki
Takayuki Aoki
TATsutomu Arie
Tsutomu Arie
VBVirgilio Balmas
Virgilio Balmas
XZXue Zhang
Xue Zhang
Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user’s needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.

1 May 2006 in Studies in Mycology
Verified
Journal Article
Open access
RZRenate D. Zipfel
Renate D. Zipfel
ZBZ. Wilhelm De Beer
Z. Wilhelm De Beer
KJKarin Jacobs
Karin Jacobs
BWBrenda Wingfield
Brenda Wingfield
MWMichael J. Wingfield
Michael J. Wingfield
Ophiostoma species have diverse morphological features and are found in a large variety of ecological niches. Many different classification schemes have been applied to these fungi in the past based on teleomorph and anamorph features. More recently, studies based on DNA sequence comparisions have shown that Ophiostoma consists of different phylogenetic groups, but the data have not been sufficient to define clear monophyletic lineages represented by practical taxonomic units. We used DNA sequence data from combined partial nuclear LSU and beta-tubulin genes to consider the phylogenetic relationships of 50 Ophiostoma species, representing all the major morphological groups in the genus. Our data showed three well-supported, monophyletic lineages in Ophiostoma. Species with Leptographium anamorphs grouped together and to accommodate these species the teleomorph-genus Grosmannia (type species G. penicillata), including 27 species and 24 new combinations, is re-instated. Another well-defined lineage includes species that are cycloheximide-sensitive with short perithecial necks, falcate ascospores and Hyalorhinocladiella anamorphs. For these species, the teleomorph-genus Ceratocystiopsis (type species O. minuta), including 11 species and three new combinations, is re-instated. A third group of species with either Sporothrix or Pesotum anamorphs includes species from various ecological niches such as Protea infructescences in South Africa. This group also includes O. piliferum, the type species of Ophiostoma, and these species are retained in that genus. Ophiostoma is redefined to reflect the changes resulting from new combinations in Grosmannia and Ceratocystiopsis. Our data have revealed additional lineages in Ophiostoma linked to morphological characters. However, these species are retained in Ophiostoma until further data for a larger number of species can be obtained to confirm monophyly of the apparent lineages.

1 May 2016 in Pedobiologia
Verified
Journal Article
Closed access
CJCharlene Janion-Scheepers
Charlene Janion-Scheepers
JMJohn Measey
John Measey
BBBrigitte Braschler
Brigitte Braschler
SCSteven L. Chown
Steven L. Chown
LCLouise Coetzee
Louise Coetzee
JWJohn R.U. Wilson
John R.U. Wilson

2 April 2019 in Mycology
Verified
Journal Article
Open access
MGMariska Riana Greeff-Laubscher
Mariska Riana Greeff-Laubscher
IBIlze Beukes
Ilze Beukes
GMGert Johannes Marais
Gert Johannes Marais
KJKarin Jacobs
Karin Jacobs
Mycotoxins are toxic secondary metabolites produced by various filamentous fungi, of which Fusarium, Aspergillus and Penicillium are the three main genera. Fusarium verticillioides is one of the most dominant toxigenic fungal species, associated with fumonisin contamination in grain-based feeds, such as compound abalone feed. Mycotoxin production is influenced by temperature and available nutrients. In this study the aims were: to determine if abalone feed as growth substrate favours mycotoxin production for toxigenic fungi; to determine the most effective temperature for fumonisin production by F. verticillioides on abalone feed; and to assess the effect of the aquatic environment on fumonisin-contaminated abalone feed. A total of 93 fungal isolates were inoculated onto abalone feed, including species belonging to the genera Fusarium, Aspergillus and Penicillium. Feed inoculated with F. verticillioides were incubated at two different temperatures and fumonisin-contaminated feed was submerged into seawater for 24 h. Results showed that mycotoxins were produced when abalone feed was inoculated with toxigenic fungi, and that F. verticillioides produced higher concentrations of fumonisins at a lower temperature. Submerging fumonisin-contaminated feed in seawater showed that this toxin leached into the seawater, lowering the risk of fumonisins to be consumed by abalone.