Taxonomy, comparative genomics and evolutionary insights of Penicillium ucsense: a novel species in series Oxalica

Regulation of genes encoding polysaccharide-degrading enzymes in Penicillium

Penicillium fungi, including Penicillium oxalicum, can secrete a range of efficient plant-polysaccharide-degrading enzymes (PPDEs) that is very useful for sustainable bioproduction, using renewable plant biomass as feedstock. However, the low efficiency and high cost of PPDE production seriously hamper the industrialization of processes based on PPDEs. In Penicillium, the expression of PPDE genes is strictly regulated by a complex regulatory system and molecular breeding to modify this system is a promising way to improve fungal PPDE yields. In this mini-review, we present an update on recent research progress concerning PPDE distribution and function, the regulatory mechanism of PPDE biosynthesis, and molecular breeding to produce PPDE-hyperproducing Penicillium strains. This review will facilitate future development of fungal PPDE production through metabolic engineering and synthetic biology, thereby promoting PPDE industrial biorefinery applications. KEY POINTS: • This mini review summarizes PPDE distribution and function in Penicillium. • It updates progress on the regulatory mechanism of PPDE biosynthesis in Penicillium. • It updates progress on breeding of PPDE-hyperproducing Penicillium strains.

New colours for old in the blue-cheese fungus Penicillium roqueforti

Penicillium roqueforti is used worldwide in the production of blue-veined cheese. The blue-green colour derives from pigmented spores formed by fungal growth. Using a combination of bioinformatics, targeted gene deletions, and heterologous gene expression we discovered that pigment formation was due to a DHN-melanin biosynthesis pathway. Systematic deletion of pathway genes altered the arising spore colour, yielding white to yellow-green to red-pink-brown phenotypes, demonstrating the potential to generate new coloured strains. There was no consistent impact on mycophenolic acid production as a result of pathway interruption although levels of roquefortine C were altered in some deletants. Importantly, levels of methyl-ketones associated with blue-cheese flavour were not impacted. UV-induced colour mutants, allowed in food production, were then generated. A range of colours were obtained and certain phenotypes were successfully mapped to pathway gene mutations. Selected colour mutants were subsequently used in cheese production and generated expected new colourations with no elevated mycotoxins, offering the exciting prospect of use in future cheese manufacture.

Seven New Species of Eurotiales (Ascomycota) Isolated from Tidal Flat Sediments in China

Tidal flats have been reported to contain many microorganisms and play a critical role in maintaining biodiversity. In surveys of filamentous fungi from tidal flat sediments in China, seven new species of Eurotiales were discovered and described. Morphological characteristics and DNA sequence analyses of combined datasets of the BenA, CaM, and RPB2 regions support their placements and recognition as new species. Aspergillus liaoningensis sp. nov. and A. plumeriae sp. nov. belong to sections Candidi and Flavipedes of subgenus Circumdati, and A. subinflatus sp. nov. is a member of section Cremei of subgenus Cremei. Penicillium danzhouense sp. nov., P. tenue sp. nov., and P. zhanjiangense sp. nov. are attributed to sections Exilicaulis and Lanata-Divaricata of subgenus Aspergilloides. Talaromyces virens sp. nov. is in section Talaromyces. Detailed descriptions and illustrations of these novel taxa are provided. Their differences from close relatives were compared and discussed.