Category Archives: Volume 16 1976

On the composition of nutriens in wild and cultivated mushrooms

Authors: Kreula, Matti & Saarivirta, Maija & Karanko, Sirkka-Liisa
Journal: Karstenia, Volume 16 (1976), pages 10-14.
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Abstract:  The basic composition and the contents of amino acids and fatty acids and eight minerals of nine wild and two cultivated mushrooms were investigated. On a dry matter basis, the protein content of the mushrooms studied (Total N x 6.25) varied between 12 %and 31 %, the fat content between 1.2% and 8.9% and the ash content between 5.7% and 12.8 %. The amount of essential amino acids (excluding Try) varied between 2.6 % and 7.6% of the dry matter. The fat content of the mushrooms, which in fresh mushroom is 0.2 – 0.5 ·%, was on the average 4.5% of the dry material. The fatty acid composition resembled the general composition of vegetable fats, because there was plenty of oleic and linoleic acid. The mineral composition of the mushrooms studied was complex. It seems that they are good sources of Cu and fairly good sources of Zn as compared with other foodstuffs, provided that there are no remarkable differences in their availability.

Scanning electron microscopy of the spores of Gyromitra subg. Gyromitra and subg. Discina (Pezizales) 

Authors: Harmaja, Harri
Journal: Karstenia, Volume 16 (1976), pages 6-9.
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Abstract:  The spore surface was studied with the SEM in three species of Gyromitra Fr. subg. Gyromitra, viz. G. ambigua (Karst.) Harmaja, G. esculenta (Pers.) Fr. and G. infula (Fr.) Quél., and in two species of Gyromitra subg. Discina (Fr.) Harmaja, viz. G. gigas (Krombh.) Quél. and G. montana Harmaja. G. ambigua and G. esculenta have not been examined with the SEM before. The spores were found to be ornamented in all the species studied, having a fairly regular pattern with ridges running in different directions. The relief of the ornamentation varies with the species, being lowest in G. esculenta and highest in G. gigas. No differences in kind exist between the spore surfaces of the two subgenera, and the difference in degree is almost negligible between the ornamentation with the highest relief in subg. Gyromitra (in G. ambigua) and that with the lowest relief in subg. Discina (in G. montana). The difference between ‘smooth’ and rough spores can no longer be used as the basic generic character. Thus the present results justify the author’s earlier proposal that the genus Discina (Fr.) Fr. sensu Eckblad (i.e., including Maublancomyces Herter and Neogyromitra Imai) should be merged in Gyromitra.

Effect of temperature and light on the mycelial growth of Gyromitra esculenta in pure culture

Authors: Raudaskoski, Marjatta & Pohjola, Kalevi & Saarvanto, Irmeli
Journal: Karstenia, Volume 16 (1976), pages 1-5.
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Abstract:  “The mycelial growth of Gyromitra esculenta (Pers.) Fr. was studied on four different culture media, complete medium, Hagem’s medium, minimal medium and Czapek’s medium. The mycelium was found to grow best on complete medium. One strain was subsequently cultured on complete medium at temperatures ranging from 6 to 27° C. The optimum temperature for mycelial growth was 15-23° C. At 25° C and 27° C the vegetative growth was slower and some morphological changes were observed in the mycelium.
The mycelium started to grow within 24 hours after cold treatment of one two and three weeks at -4 C. After cold treatment of one, two and three weeks at -15° C and -25° C, no growth was observed within 24 hours. At -15° C the duration of the cold treatment was significant for the recovery of the mycelium; it clearly grew better after one than two or three weeks in cold. The same tendency was observable after cold treatment at -25° C.”