Hypomyces lactifluorum
1. Classification
Lineage in full : cellular organisms; Eukaryota; Opisthokonta; Fungi; Dikarya; Ascomycota; saccharomyceta; Pezizomycotina; leotiomyceta; sordariomyceta; Sordariomycetes; Hypocreomycetidae; Hypocreales; Hypocreaceae; Hypomyces (1)
2. Description and significance
Hypomyces lactifluorum, commonly known as the lobster mushroom, is a parasitic fungus of fungi in the genera Lactarius or Russula. The organism’s nickname was coined due to the mushroom’s bright red color and lobster-tail shape (2). Hypomyces lactifluorum is of interest to the public due to its prominence in the field of commerce as well as its importance in a culinary setting as the mushroom is consumed widely (3). In Mexico, particularly Uruapan, Michoacan, Hypomyces lactifluorum is important in various aspects of the lives of citizens (3). After being parasitized, the mushrooms affected are sold then consumed (8). H. lactifluorum increases the vendor's profit by more than half, as determined by the Economic Profit Index (3). Those who consume H. lactifluorum in this region have stated that their main method of determining edibility is by various criteria such as odor, presence of worms, and taste (4).
3. Genome structure
The genome Hypomyces lactifluorum has not been completely sequenced. However, partial sequencing of internal transcribed spacers have been recorded as well as 5.8S and 28S ribosomal RNA genes (12). This partial sequencing was done from 550 base pairs in which internalized transcribed spacer 1 partial sequence, 5.8S rRNA complete sequence, and partially internal transcribed spacer 2 was sequenced (12). When comparing samples of the DNA of the host and Hypomyces lactifluorum, H. lactifluorum contained a higher amount of base pairs than its host. Comparing a sample of DNA of Russula brevipes, a common host species, with the DNA of H. lactifluorum, there are 164 and 207 base pairs respectively (5). The chromosome number for Hypomyces lactifluorum is assumed to be 5 based on this sample(5).
4. Cell structure
Hypomyces lactifluorum infects its host cells through its spores. H. lactifluorum develops a true perithecium over its host, containing pseudoparaphyses that grow downward (6). It contains asci and ascogenous cells that are placed close together. Ascocarps have a spiral and coiled appearance, growing in size and developing to be multinucleate (6). Ascospores are made of hyaline, are two-celled, and have a size of 35-40 x 4.5-7 μm which are forcibly released. The ascospores are formed in the asci, which are long and cylindrical, and 200-260 x 5-10 μm (7).
5. Metabolic processes
Hypomyces lactifluorum parasitizes mushrooms of its host fungi in order to grow (8). The metabolites within the Hypomyces lactifluorum are altered via transformation, specifically the lipid and terpene compounds to reflect that of the host (5). Hypomyces lactifluorum attacks its host, causing agaric carpophores to form at the infection site and eventually, the parasite spreads to the entire host (6).
6. Ecology
The exact conditions for growth of Hypomyces lactifluorum are unknown, but they are typically found in areas with heavy forestation, and alongside trail routes (9). In eastern Canada, they are often found in boreal forests, away from the canopies, within a jack pine stand where fresh sporocarp biomass and density were present (10). In Mexico, H. lactiflourum are often found in temperate, pine-oak forests (11).
7. Pathology
There is no evidence that Hypomyces lactifluorum causes severe health conditions for humans, but there is evidence for positive benefits after consumption. H. lactiflourum has a higher concentration of protein amino acids, than the typical store bought mushroom (9). Similarly, the presence of phenol concentrations in Hypomyces lactifluorum increases health benefits, especially in reducing the risk of cancer, diabetes, and cardiovascular disease (9). The most common host mushroom parasitized by the Hypomyces lactifluorum is the Russula brevipes, which was determined by the presence of DNA from both species in the edible H. lactiflourum (5). As the infection progresses, the DNA of the host organism declines as the DNA of Hypomyces lactifluorum grows (5).
8. Current Research
While the health benefits and potential negative effects of lobster mushrooms are still being researched, current research has shown nutritional value of Hypomyces lactifluorum. Hypomyces lactifluorum had the lowest level of crude protein compared to the other types of wild edible mushrooms tested (9), but still had higher levels of protein compared to common mushrooms sold at grocery stores. Hypomcyes lactifluorum also had the highest rate of degradation compared to other wild edible mushrooms, yet the nutritional benefits of Hypomyces lactifluorum are still higher than that of a common mushroom at a grocery store (9).
9. References
(1) U.S. National Library of Medicine. (n.d.). Taxonomy browser (hypomyces lactifluorum). National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=557406
(2) Rogerson, C. T., & Samuels, G. J. (1994). Agaricicolous Species of Hypomyces. Mycologia, 86(6), 839–866. https://doi.org/10.2307/3760597
(3) Larios-Trujillo, C., Ruan-Soto, F., Herrerías-Diego, Y. et al. Local Knowledge and Economical Significance of Commercialized Wild Edible Mushrooms in the Markets of Uruapan, Michoacan, Mexico. Econ Bot 73, 200–216 (2019). https://doi-org.ezproxy.bu.edu/10.1007/s12231-019-09458-z
(4) Montoya, A., Hernández-Totomoch, O., Estrada-Torres, A., Kong, A., & Caballero, J. (2003). Traditional Knowledge about Mushrooms in a Nahua Community in the State of Tlaxcala, México. Mycologia, 95(5), 793–806. https://doi.org/10.2307/3762007
(5) Laperriere, G., Desgagné-Penix, I., Germain, H., & Xu, J. (2018). DNA distribution pattern and metabolite profile of wild edible lobster mushroom ( Hypomyces lactifluorum/ Russula brevipes). Genome, 61(5), 329–336. https://doi-org.ezproxy.bu.edu/10.1139/gen-2017-0168
(6) Hanlin, R. T. (1963). Morphology of Hypomyces lactifluorum. Botanical Gazette, 124(6), 395–404. http://www.jstor.org/stable/2473206
(7) Yu, F. M., Jayawardena, R. S., Liu, J., Hyde, K. D., & Zhao, Q. (2020). Hypomyces pseudolactifluorum sp. nov.(Hypocreales: Hypocreaceae) on Russula sp. from Yunnan, PR China. Biodiversity Data Journal, 8.
(8) Elkhateeb, A.W., Daba, G.M. (2021). Fungi over fungi, endophytic fungi associated with mushroom fruiting bodies and lichens. Pharmaceutics and Pharmacology Research, 4(2), 01–04. https://doi.org/10.31579/2693-7247/028
(9) Espejel-Sánchez, KI, Espinosa-Solares, T., Reyes-Trejo, B., Hernández-Rodríguez, G., Cunill-Flores, JM, & Guerra-Ramírez, D. (2021). Nutritional value and thermal degradation of bioactive compounds in wild edible mushrooms. Chapingo Magazine Forestry and Environmental Sciences Series, 27 (3), 337–354. https://doi.org/10.5154/r.rchscfa.2020.12.078
(10) Rochon, C., Pare, D., Khasa, D. P., & Fortin, J. A. (2009). Ecology and management of the lobster mushroom in an eastern Canadian jack pine stand. Canadian journal of forest research, 39(11), 2080-2091.
(11) Torres-Gómez, M., Garibay-Orijel, R., Pérez-Salicrup, D., et. al. (2022). Wild edible mushroom knowledge and use in five forest communities in central México. Canadian Journal of Forest Research. 53(1): 25-37. https://doi-org.ezproxy.bu.edu/10.1139/cjfr-2022-0043
(12) Berbee, M., Bazzicalupo, A., Schwartz, C., van der Meer, B., & Kroeger, P. (2016, December 12). Hypomyces lactifluorum isolate PK7615A voucher F28785 internal TRANSCR - nucleotide - NCBI. National Center for Biotechnology Information. https://www.ncbi.nlm.nih.gov/nuccore/MH718202.1
