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Amylascusis a genus of ectomycorrhizal truffles withinPezizaceaethat is known from Australia and contains only two described species,A. herbertianusandA. tasmanicus. Species ofAmylascusare closely related to truffles (Pachyphlodes,Luteoamylascus) and cup fungi (Plicariella) from the Northern Hemisphere. Here we reevaluate the species diversity ofAmylascusand related taxa from southern South America and Australia based on new morphological and molecular data. We identify previously undocumented diversity and morphological variability in ascospore color, ascospore ornamentation, hymenial construction, epithecium structure and the amyloid reaction of the ascus in Melzer’s reagent. We redescribe twoAmylascusspecies from Australia and describe seven newAmylascusspecies, five from South America and two from Australia. This is the first report ofAmylascusspecies from South America. We also describe the new South American genusNothoamylascusas sister lineage to thePachyphlodes-Amylascus-Luteoamylascusclade (includingAmylascus,Luteoamylascus,Pachyphlodes, andPlicariella). We obtained ITS sequences of mitotic spore mats fromNothoamylascus erubescensgen. & sp. nov. and four of the seven newly describedAmylascusspecies, providing the first evidence of mitotic spore mats inAmylascus. Additional ITS sequences from mitotic spore mats reveal the presence of nine additional undescribedAmylascusand oneNothoamylascusspecies that do not correspond to any sampled ascomata. We also identify three additional undescribedAmylascusspecies based on environmental sequences from the feces of two ground-dwelling bird species from Chile,Scelorchilus rubeculaandPteroptochos tarnii. Our results indicate that ascomata fromAmylascusandNothoamylascusspecies are rarely collected, but molecular data from ectomycorrhizal roots and mitotic spore mats indicate that these species are probably common and widespread in southern South America. Finally, we present a time-calibrated phylogeny that is consistent with a late Gondwanan distribution. The time since the most recent common ancestor of: 1) the familyPezizaceaehad a mean of 276 Ma (217–337 HPD); 2) theAmylascus-Pachyphlodes-Nothoamylascus-Luteoamylascusclade had a mean of 79 Ma (60–100 HPD); and 3) theAmylascus-Pachyphlodesclade had a mean of 50 Ma (38–62 HPD). The crown age ofPachyphlodeshad a mean of 39 Ma (25–42 HPD) andAmylascushad a mean age of 28 Ma (20–37 HPD), falling near the Eocene-Oligocene boundary and the onset of the Antarctic glaciation (c. 35 Ma).

 

Tuber luomae, a new truffle species known only from the Pacific Northwest, USA, is distinguished by spiny, nonreticulate spores and a two-layered peridium — the outermost layer (pellis) consists of inflated, globose to subpolygonal cells and the inner (subpellis) of narrow hyphae. ITS sequence analyses show that it has phylogenetic affinity to other Tuber species in the Rufum clade. The only other members of the Rufum clade with a strongly developed peridiopellis of large, inflated cells are the southern European T. malacodermum and T. pustulatum and the northern Mexican T. theleascum . We find it interesting that this peridial structure that is uncommon in the Rufum clade has been found in geographically disjunct species. 

Many unicellular microorganisms including yeasts, fungi, microalgae, and to a lesser extent bacteria (Fig. 1), can produce intra- cellular edible oils under normal and specialized conditions (Papanikolaou and Aggelis, 2011). Most of these organisms can accumulate microbial lipids, or single-cell oils (SCOs), to 20%–90% (w/w) of their dry cell biomass. For example, fungi in the genus Mortierella and Umbelopsis can accumulate lipids at concentrations that exceed 86% of their dry weight (Meng et al., 2009). Microbial lipids can be produced using low-priced organic materials, including waste-streams from the food industry, as growth substrate. The fatty acid of microbial lipids is very similar to the conventional vegetable oils in type and composition (Madani et al., 2017). Furthermore, microbial lipids have many potential applications, including human food additives, nutraceuticals, pharmaceuticals, cosmetics, biopolymers and feed ingredients for aquaculture, and as an alternative feedstock for the production of biofuel (Lewis et al., 2000). Due to the reduced availability of cultivable land and increasing human population growth, producing lipids via traditional methods will not satisfy the rapidly growing global demand. Therefore, microbial lipids accu- mulated from microorganisms, especially oleaginous fungi, are considered as a vital and renewable oil resource and have been regarded as an alternative to animal and plant lipids in recent years, given their unique characteristics and functions in energy, chemical, and food industries (Huang et al., 2017). The production of microbial lipids is particularly attractive when low or negative cost substrates are used as the feedstock. 

ABSTRACT Mycoviruses are widespread and purportedly common throughout the fungal kingdom, although most are known from hosts in the two most recently diverged phyla, Ascomycota and Basidiomycota, together called Dikarya. To augment our knowledge of mycovirus prevalence and diversity in underexplored fungi, we conducted a large-scale survey of fungi in the earlier-diverging lineages, using both culture-based and transcriptome-mining approaches to search for RNA viruses. In total, 21.6% of 333 isolates were positive for RNA mycoviruses. This is a greater proportion than expected based on previous taxonomically broad mycovirus surveys and is suggestive of a strong phylogenetic component to mycoviral infection. Our newly found viral sequences are diverse, composed of double-stranded RNA, positive-sense single-stranded RNA (ssRNA), and negative-sense ssRNA genomes and include novel lineages lacking representation in the public databases. These identified viruses could be classified into 2 orders, 5 families, and 5 genera; however, half of the viruses remain taxonomically unassigned. Further, we identified a lineage of virus-like sequences in the genomes of members of Phycomycetaceae and Mortierellales that appear to be novel genes derived from integration of a viral RNA-dependent RNA polymerase gene. The two screening methods largely agreed in their detection of viruses; thus, we suggest that the culture-based assay is a cost-effective means to quickly assess whether a laboratory culture is virally infected. This study used culture collections and publicly available transcriptomes to demonstrate that mycoviruses are abundant in laboratory cultures of early-diverging fungal lineages. The function and diversity of mycoviruses found here will help guide future studies into mycovirus origins and ecological functions. IMPORTANCE Viruses are key drivers of evolution and ecosystem function and are increasingly recognized as symbionts of fungi. Fungi in early-diverging lineages are widespread, ecologically important, and comprise the majority of the phylogenetic diversity of the kingdom. Viruses infecting early-diverging lineages of fungi have been almost entirely unstudied. In this study, we screened fungi for viruses by two alternative approaches: a classic culture-based method and by transcriptome-mining. The results of our large-scale survey demonstrate that early-diverging lineages have higher infection rates than have been previously reported in other fungal taxa and that laboratory strains worldwide are host to infections, the implications of which are unknown. The function and diversity of mycoviruses found in these basal fungal lineages will help guide future studies into mycovirus origins and their evolutionary ramifications and ecological impacts. 

Background: Although microalgal biofuels have potential advantages over conventional fossil fuels, high production costs limit their application in the market. We developed bio-flocculation and incubation methods for the marine alga Nannochloropsis oceanica CCMP1779 and the oleaginous fungus Mortierella elongata AG77 resulting in increased oil productivity. Results: Grown separately and then combining the cells the M. elongata mycelium could efficiently capture N. oceanica due to an intricate cellular interaction between the two species leading to bio-flocculation. Use of a high-salt culture medium induced accumulation of triacylglycerol (TAG) and enhanced the content of polyunsaturated fatty acids (PUFAs) including arachidonic acid (ARA) and docosahexaenoic acid (DHA) in M. elongata. To increase TAG productivity in the alga, we developed an effective reduced nitrogen supply regime based on ammonium in environmental photobioreactors (ePBRs). Under optimized conditions, N. oceanica produced high levels of TAG that could be indirectly monitored by following chlorophyll content. Combining N. oceanica and M. elongata to initiate bio-flocculation yielded high levels of TAG and total fatty acids, ~15% and 22% of total dry weight (DW), respectively, as well as high levels of PUFAs. Genetic engineering N. oceanica for higher TAG content in nutrient-replete medium was accomplished by overexpressing DGTT5, a gene encoding the type II acyl-CoA:diacylglycerol acyltransferase 5. Combined with bioflocculation this approach led to increased production of TAG under nutrient replete conditions (~10% of DW) compared to the wild type (~6% of DW). Conclusions: The combined use of M. elongata and N. oceanica with available genomes and genetic engineering tools for both species opens up new avenues to improve bio-fuel productivity and allows the engineering of polyunsaturated fatty acids. Keywords: Microalgae, Filamentous fungi, Flocculation, Cell wall interaction, Biofuel, Nitrogen starvation, Polyunsaturated fatty acid, Triacylglycerol