Low-cost and low maintenance preservation of Agaricus brasiliensis cultures

Abstract

Agaricus brasiliensis cultures quickly lose viability when stored at cool temperatures, even for a short period of time. We evaluated several low-cost preservation methods using varied substrates, preservation solutions, and storage temperatures. Agaricus brasiliensis was intolerant to freezing temperatures, making liquid nitrogen use and deep-freezing methods impossible for its preservation. The best preservation conditions for the A. brasiliensis CS1 strain tested in this study were obtained by using rice as substrate and water as preservation solution, with storage at room temperature or when using soil, mushroom cultivation compost, or rice and stored at 10 °C without preservation solution. Those cultures that were reactivated showed the same productivity attributes as the control. In addition, no effect on productivity or biological efficiency was observed through successive subculturing of the strain (CS1). Parboiled rice was successfully used for other A. brasiliensis strains (CS2, CS5, CS7, CS9, and CS10), and also for Pleurotus ostreatus, P. sajor-caju, and Lentinula edodes.

Long-term cryopreservation of basidiomycetes

“…PDA cultivation medium is the most utilized in frozen basidiomycete recovery. 27 , 47 , 48 , 52 The second most utilized cultivation medium is MEA, 41 , 43 , 45 , 56 followed by other agar-based culture media such as wort-agar, 24 , 53 MEYA (malt extract, yeast extract, glycerol and agar) 53 and MGL1 (barley flour, yeast extract, sucrose and agar). 49 Tanaka et al (unpublished data) verified differences in the mycelial viability of A. subrufescens after 5 years of cryopreservation at −70 °C in MEA with different concentrations of agar and verified that the water activity in the cultivation medium affects the recovery of mycelial viability.…”

“…The expansion of the biotechnological applications of basidiomycetes requires maintenance of the physiological, morphological and therapeutic characteristics, and the genomic stability after thawing of the biological material, besides the long-term preservation of the mycelial viability. All articles in this review evaluated the mycelial viability of basidiomycetes after thawing, 23.5% of them also evaluated characteristics like the production of enzymes such as laccase and peroxidase manganese, 24 , 53 , 54 , 55 29.4% of them characteristics like mushroom production, 27 , 43 , 47 , 48 , 56 11.7% of them characteristics such as the genetic stability with the utilization of molecular markers 43 , 55 and 17.6% of them macro and micromorphological characteristics such as texture, coloring and density of mycelium, presence or absence of connection clamps among others. 24 , 54 , 55 Only one article analyzed biomass production, exopolysaccharides and intrapolysaccharides.…”

Semisolid culture medium improves mycelial recovery of Agaricus subrufescens cryopreserved in cereal grains

“…The solid culture medium, conventionally utilized in the recovery of cryopreserved A. subrufescens mycelial viability [13,[16][17][18][19]25], was not effective to recover the mycelial viability (< 75%) of all treatments after 5-year cryopreservation of the fungus (Fig. 1).…”

“…Most basidiomycete cryopreservation studies evaluate the cryopreservation effect of temperature [12][13][14], substrates for fungal growth before cryopreservation [15][16][17], class and concentration of cryoprotectants [18,19], and maintenance period [18,[20][21][22]. However, few studies assess the effect of cereal grains for cryopreservation and the consistency of recovery culture medium on the mycelial viability after cryopreservation.…”

Agaricus subrufescens en México: un recurso forestal no maderable, comestible, medicinal y potencialmente cultivable

“…Para la propagación de cepas, se aisló tejido miceliar a partir del contexto del píleo de los basidiomas frescos, usando como medios de cultivo papa-dextrosa-agar (PDA) y medio completo básico (CMB, descrito en Maia et al, 2012). Las cepas aisladas se incubaron a 25 °C, se observaron y caracterizaron en fresco haciendo preparaciones temporales para microscopía óptica usando KOH al 5%, Rojo Congo y reactivo de Melzer (Largent et al, 1977).…”