B.S., Zoology, Eastern Illinois University
M.S., Botany, Eastern Illinois University
Ph.D., Plant Pathology, University of Illinois

My research program is directed toward improving the production efficiency and quality of edible mushrooms to help minimize production costs and maximize farm profits. My research efforts are focused on the species as follows:

Agaricus bisporus (Button mushroom, Portobello, Crimini)
One emphasis of our work on A. bisporus is to develop alternative substrates to eliminate environmental problems such as odor generation and surface and ground water contamination associated with traditional composting. Another area of interest is to identify specific nutrients, such as polypeptides and micronutrients, that are depleted during the production cycle and that limit mushroom yield. Our work is focused on re-supplementing and re-casing “spent” mushroom compost for the production of a second crop of mushrooms. We are also cooperating with faculty in the Department of Food Science to improve the nutritional and medicinal qualities of these mushrooms.

Grifola frondosa (Maitake)
We have assembled a large collection of cultures of this species from worldwide sources and are evaluating them for yield potential and quality characteristics. We are also investigating the influence of various micronutrients and supplements on mushroom yield.

Lentinula edodes (Shiitake)
Our work on this species focuses on the development of improved synthetic substrates and utilization of “spent” shiitake logs for animal feed. We are investigating alternative materials, such as wheat straw, as a replacement for wood chips in substrate formulae. We also are evaluating the interactive effects of substrate moisture content, log weight and bag filtration porosity on mushroom yield and quality.

Pleurotus spp. (Oyster mushrooms)
Our research efforts on various species of these mushrooms include genetic improvement though selective breeding, based on a better understanding of the genetic life history of the mushroom. Standard methodologies used in these studies include PCR, DNA sequencing, determinations of phylogenic relationships, and assessments of genetic diversity and population structure.

Mamiro, D. P., and D. J. Royse. 2008.  The influence of spawn type and strain on yield, size and mushroom solids content of Agaricus bisporus produced on non-composted and spent mushroom compost.  Bioresource Technol., in press.

Sanchez, J. E., L. Mejia and D. J. Royse. 2008. Pangola grass colonized with Scytalidium thermophilum for the production of Agaricus bisporus. Bioresource Technology, in press.

Dubost, N. J., R. B. Beelman, and D. J. Royse. 2007. Influence of selected cultural factors and postharvest storage on ergothioneine content of common button mushrooms (Agaricus bisporus). International J. Medicinal Mushrooms 9:163-176.

Mamiro, D. P., D. J. Royse and R. B. Beelman. 2007.  Yield, size and mushroom solids content of Agaricus bisporus produced on non-composted and spent mushroom compost.  World J. Microbiology Biotechnology 23:1289-1296.

Rodriguez Estrada, A. E. and D. J. Royse. 2007. Yield, size and bacterial blotch resistance of Pleurotus eryngii grown on cottonseed hulls/oak sawdust supplemented with manganese, copper and whole ground soybean. Bioresource Technol. 98:1898-1906.

Royse, D. J., and J. E. Sanchez. 2007. Ground wheat straw as a substitute for portions of oak wood chips used in shiitake (Lentinula edodes) substrate formulae. Bioresource Technol. 98:2137-2141.

Beelman, R. B. and D. J. Royse. 2006. Selenium enrichment of Pleurotus cornucopiae (Paulet) Rolland and Grifola frondosa (Dicks.:Fr.) S. F. Gray mushrooms. International J. Medicinal Mushrooms 8:77-84.

Dubost, N. J., R. B. Beelman, D. Peterson, and D. J. Royse. 2006. Identification and quantification of ergothioneine in cultivated mushrooms by liquid chromatography-mass spectroscopy. International J. Medicinal Mushrooms 8:215-222.

Collopy, P. D., and D. J. Royse. 2004. Characterization of phytase activity from cultivated edible mushrooms and their production substrates. J. Agricultural Food Chemistry 52:7518-7524.

Geml, J., D. M. Geiser and D. J. Royse. 2004. Molecular evolution of Agaricus species based on ITS and LSU rDNA sequences. Mycological Progress 3:157-176.

Ohga, S., and D. J. Royse. 2004. Cultivation of Pleurotus eryngii on umbrella plant (Cyperus alternifolius) substrate. J. Wood Science 50:466-469.

Romaine, C. P., C. B. Keil, D. L. Rinker and D. J. Royse (Eds.). 2004. Science and Cultivation of Edible and Medicinal Fungi . Mushroom Science, Vol. 16. The Pennsylvania State University Press, University Park, Pennsylvania, U.S.A.

Royse, D. J., S. Ohga, and J. E. Sanchez-Vazquez. 2004. Yield, mushroom size and time to production of Pleurotus cornucopiae (oyster mushroom) grown on switch grass substrate spawned and supplemented at various rates. Bioresource Technology 91:85-91.