Characterization of Paecilomyces variotii and Talaromyces amestolkiae in Korea Based on the Morphological Characteristics and Multigene Phylogenetic Analyses

A New Species and Five New Records of Talaromyces (Eurotiales, Aspergillaceae) Belonging to Section Talaromyces in Korea

Talaromyces is a genus within the phylum Ascomycota (class Eurotiomycetes, order Eurotiales, family Trichocomaceae). Many species in this genus are known to produce diverse secondary metabolites with great potential for agricultural, medical, and pharmaceutical applications. During a survey on fungal diversity in the genus Talaromyces in Korea, six strains were isolated from soil, indoor air, and freshwater environments. Based on morphological, physiological, and multi-locus (ITS, BenA, CaM, and RPB2) phylogenetic analyses, we identified five previously unrecorded species in Korea (T. brevis, T. fusiformis, T. muroii, T. ruber, and T. soli) and a new species (T. echinulatus sp. nov.) belonging to section Talaromyces. Herein, detailed descriptions, illustrations, and phylogenetic tree are provided.

Studies on the morphology, phylogeny, and bioremediation potential of Penicillium citrinum and Paecilomyces variotii (Eurotiales) from oil-contaminated areas

Crude oil pollution is one of the most arduous issues to address, as it is hazardous to both public health and the environment. The discovery of novel biosurfactants-producing fungi and bacteria is in high demand due to their excellent properties and wide range of applications. The aim of this research is to isolate a powerful biosurfactant-producing fungus from the crude oil site near Barauni oil refinery in Bihar, India. Standard protocols were used to collect samples from the site. An integrative taxonomic approach was used, which included morphological, molecular, and phylogenetic analysis. The use of plating samples on Bushnell-Hass (BH) media aided in the isolation of a fungal strain from an enrichment culture. Two fungal strains isolated from contaminated soils, Penicillium citrinum and Paecilomyces variotti, showed potent oil degrading activity in a single culture. For preliminary biosurfactants screening, drop collapse assays, oil spreading, and emulsification activity tests were used. The results showed that the cultures performed well in the screening test and were further evaluated for degradation capacity. Different treatment periods (0, 3, 6, 9, 12, and 15 days) were used to observe degradation in single cultures. A steady drop in pH, an alteration in optical density and an increase in carbon dioxide release showed the ability of fungal strain to degrade the crude oil in a single culture. Fungi mycelia provide a larger surface area for absorption and degradation of the pollutants in contaminated environment. They produce extracellular enzymes to degrade the oil, and at the same time absorb and utilise carbon, allowing them to remove toxic substances from the oil. Thus, they could be candidates for bioremediation of a hydrocarbon-contaminated site.

New Species and Eight Undescribed Species Belonging to the Families Aspergillaceae and Trichocomaceae in Korea

During a survey of fungal diversity associated with insects, mud, soil, and freshwater niches in different areas in Korea, nine interesting fungal strains were isolated. Based on their morphological characteristics and molecular phylogeny analyses, using a combined data set of β-tubulin (BenA), calmodulin (CaM), and second largest subunit of RNA polymerase (RPB2) sequences, the strains CNUFC AM-44, CNUFC JCW3-4, CNUFC S708, CNUFC WT202, CNUFC AS1-29, CNUFC JCW3-5, CNUFC JDP37, and CNUFC JDP62 were identified as Aspergillus alabamensis, A. floridensis, A. subversicolor, Penicillium flavigenum, P. laevigatum, P. lenticrescens, Talaromyces adpressus, and T. beijingensis, respectively. The strain CNUFC JT1301 belongs to series Westlingiorum in section Citrina and is phylogenetically related to P. manginii. However, slow growth when cultivated on CYA, MEA, CREA is observed and the property can be used to easily distinguish the new species from these species. Additionally, P. manginii is known to produce sclerotia, while CNUFC JT1301 strain does not. Herein, the new fungal species is proposed as P. aquadulcis sp. nov. Eight species, A. alabamensis, A. floridensis, A. subversicolor, P. flavigenum, P. laevigatum, P. lenticrescens, T. adpressus, and T. beijingensis, have not been previously reported in Korea. The present study expands the known distribution of fungal species belonging to the families Aspergillaceae and Trichocomaceae in Korea.

Discovery and Extrolite Production of Three New Species of Talaromyces Belonging to Sections Helici and Purpurei from Freshwater in Korea

Three novel fungal species, Talaromyces gwangjuensis, T. koreana, and T. teleomorpha were found in Korea during an investigation of fungi in freshwater. The new species are described here using morphological characters, a multi-gene phylogenetic analysis of the ITS, BenA, CaM, RPB2 regions, and extrolite data. Talaromyces gwangjuensis is characterized by restricted growth on CYA, YES, monoverticillate and biverticillate conidiophores, and globose smooth-walled conidia. Talaromyces koreana is characterized by fast growth on MEA, biverticillate conidiophores, or sometimes with additional branches and the production of acid on CREA. Talaromyces teleomorpha is characterized by producing creamish-white or yellow ascomata on OA and MEA, restricted growth on CREA, and no asexual morph observed in the culture. A phylogenetic analysis of the ITS, BenA, CaM, and RPB2 sequences showed that the three new taxa form distinct monophyletic clades. Detailed descriptions, illustrations, and phylogenetic trees are provided.

Insect-fungal-interactions: A detailed review on entomopathogenic fungi pathogenicity to combat insect pests

Global food security is threatened by insect pests of economically important crops. Chemical pesticides have been used frequently for the last few decades to manage insect pests throughout the world. However, these chemicals are hazardous for human health as well as the ecosystem. In addition, several pests have evolved resistance to many chemicals. Finding environment friendly alternatives lead the researchers to introduce biocontrol agents such as entomopathogenic fungi (EPF). These fungi include various genera that can infect and kill insects efficiently. Moreover, EPFs have considerable host specificity with a mild effect on non-target organisms and can be produced in bulk quantity quickly. However, insights into the biology of EPF and mechanism of action are of prime significance for their efficient utilization as a biocontrol agent. This review focuses on EPF-mediated insect management by explaining particular EPF strains and their general mode of action. We have comprehensively discussed which criteria should be used for the selection of pertinent EPF, and which aspects can impact the EPF efficiency. Finally, we have outlined various advantages of EPF and their limitations. The article summarizes the prospects related to EPF utilization as biocontrol agents. We hope that future strategies for the management of insects will be safer for our planet.

Biocontrol Effects of Paecilomyces variotii against Fungal Plant Diseases

The genus Paecilomyces is known for its potential application in the control of pests and diseases; however, its use in agriculture is limited to few species. Research interest in new formulations based on microorganisms for the control of pathogens is growing exponentially; therefore, it is necessary to study new isolates, which may help control diseases effectively, and to examine their compatibility with established agricultural control methods. We analysed in vitro and in vivo the antagonistic capacity of Paecilomyces variotii against seven phytopathogens with a high incidence in different crops, and we examined its compatibility with 24 commercial fungicides. P. variotii was applied in the following pathosystems: B. cinereal—melon, Sclerotinia sclerotiorum—pepper, R. solani—tomato, F. solani—zucchini, P. aphanidermatum—melon, M. melonis—melon, and P. xanthii—zucchini. The results showed strong control effects on M. melonis and P. xanthii, reducing the disease severity index by 78% and 76%, respectively. The reduction in disease severity in the other pathosystems ranged from 29% to 44%. However, application of metabolites alone did not cause any significant effect on mycelial growth of phytopathogens, apart from F. solani, in which up to 12% inhibition was observed in vitro when the extract was applied at a concentration of 15% in the medium. P. variotii was compatible with most of the tested fungicides, and of the 24 fungicides tested at the maximum authorised dose, 6 acted as fungicides, 4 as fungistatics, and the remaining showed inhibition rates ranging from 18.2% to 95.8%. These results indicate that P. variotii is a potential biological control agent to be used against several aerial and soil diseases, thus it should be integrated into modern pest management strategies.

Six Newly Recorded Fungal Taxa from Freshwater Niche in Korea

Six interesting fungal strains were isolated during a survey of fungal diversity associated with freshwater; these strains were designated as CNUFC YJW2-22, CNUFC MSW11-6-2, CNUFC HRS5-3, CNUFC MSW242-6, CNUFC DMW2-2, and CNUFC CPWS-1. Based on a polyphasic approach including phylogenetic analyses of internal transcribed space (ITS), large subunit (LSU), beta-tubulin (BenA), and calmodulin (CaM) gene sequences, morphological analyses, the six strains were found to be identical to Acremonium guillematii, Cadophora novi-eboraci, Lectera nordwiniana, Mycoarthris corallina, Talaromyces siamensis, and Tetracladium globosum, respectively. To our knowledge, these are the first records of the rare Lectera, Mycoarthris, and Tetracladium genera in Korea, and the first reports of A. guillematii, C. novi-eboraci, L. nordwiniana, M. corallina, T. siamensis, and Te. globosum in a freshwater environment.

First Records of Rare Ascomycete Fungi, Acrostalagmus luteoalbus, Bartalinia robillardoides, and Collariella carteri from Freshwater Samples in Korea

The distribution and occurrence of rare ascomycete fungi within freshwater samples in Korea was investigated. Three rare fungal strains, CNUFC-YR537-1, CNUFC-CNUP1-1, and CNUFC-NDR3-1, were isolated using serial dilution method. On the basis of their morphological characteristics and phylogenetic analysis of their internal transcribed spacer regions and 28S rDNA sequences, the three isolates were identified as Acrostalagmus luteoalbus, Bartalinia robillardoides, and Collariella carteri, respectively. To our knowledge, these are the first records of rare genera Acrostalagmus, Bartalinia, and Collariella from Korea, and the first reports of A. luteoalbus, B. robillardoides, and C. carteri from freshwater samples.

New Records of Four Species Belonging to Eurotiales from Soil and Freshwater in Korea

Four strains of Penicillium and Talaromyces species are described and illustrated in an inventory of fungal species belonging to Eurotiales. The strains, CNUFC-DDS17-1, CNUFC-DDS27-1, CNUFC-PTM72-1, and CNUFC-YJW3-31, were isolated from soil and freshwater samples from South Korea. Based on their morphological characteristics and sequence analyses by the combined β-tubulin and calmodulin gene, the CNUFC-DDS17-1, CNUFC-DDS27-1, CNUFC-PTM72-1, and CNUFC-YJW3-31 isolates were identified as Penicillium pasqualense, Penicillium sanguifluum, Talaromyces apiculatus, and Talaromyces liani, respectively. The designated strains were found to represent a previously undescribed species of Korean fungal biota. In this study, detailed morphological descriptions and phylogenetic relationships of these species are provided.

Four New Records of Ascomycete Species from Korea

While evaluating fungal diversity in freshwater, grasshopper feces, and soil collected at Dokdo Island in Korea, four fungal strains designated CNUFC-DDS14-1, CNUFC-GHD05-1, CNUFC-DDS47-1, and CNUFC-NDR5-2 were isolated. Based on combination studies using phylogenies and morphological characteristics, the isolates were confirmed as Ascodesmis sphaerospora, Chaetomella raphigera, Gibellulopsis nigrescens, and Myrmecridium schulzeri, respectively. This is the first records of these four species from Korea.