RESUMO
The optimization of submerged culture conditions for mycelial growth and exopolysaccharide (EPS) production in an edible mushroom Tremella fuciformis was studied in shake flasks and bioreactors. The temperature of 28 degrees C and pH 8 in the beginning of fermentation in agitated flasks was the most efficient condition to obtain maximum mycelial biomass and EPS. The optimal medium constituents were as follows (gL(-1)): glucose 20, tryptone 2, KH(2)PO(4) 0.46, K(2)HPO(4) 1 and MgSO(4).7H(2)O 0.5. The fungus was cultivated under various agitation and aeration conditions in a 5L stirred-tank bioreactor. The maximum cell mass and EPS production were obtained at a relatively high agitation speed of 200 rpm and at an aeration rate of 2 vvm. The flow behavior of the fermentation broth was Newtonian and the maximum apparent viscosity (35 cP) was observed at a highly aerated condition (2 vvm). The EPS productivity in an airlift reactor was higher than that in the stirred-tank reactor. The morphological study revealed that the fungus grows in mainly three different yeast-like forms: ovoid, elongated, and double yeast forms. The high population of the elongated yeast has a very close relationship to high EPS production. The EPS were protein-bound polysaccharides consisted of mainly mannose, xylose, and fucose. The molecular weights of EPS were determined to be (1.3-1.5)x10(6).
Assuntos
Basidiomycota/metabolismo , Fermentação/fisiologia , Micélio/metabolismo , Polissacarídeos Bacterianos/biossíntese , Basidiomycota/citologia , Reatores Biológicos , Meios de Cultura/química , Cinética , ReologiaRESUMO
To obtain basic information on the biochemical property of basidiospores of shiitake mushroom (Lentinula edodes), the ability of producing extracellular enzyme was assessed using a chromogenic plate-based assay. For the aim, amylase, avicelase, beta-glucosidase, CM-cellulase, pectinase, proteinase, and xylanase were tested against monokaryotic strains generated from forty basidiospores of two different parental dikaryotic strains of shiitake mushroom, Sanjo-101Ho and Sanjo-108Ho. These two parental strains showed different degree of extracellular enzyme activity. No identical patterns of the degree of enzyme activity were observed between monokaryotic strains and parental strains of the two shiitake cultivars. The degree of extracellular enzyme activity also varied among monokaryotic strains of the two shiitake cultivars. Our results showed that dikaryotic parental strains of shiitake mushroom produce monokaryotic basidiospores having very diverse biochemical properties.
Assuntos
Humanos , Amilases , beta-Glucosidase , Celulases , Pais , Poligalacturonase , Cogumelos ShiitakeRESUMO
White and brown strains of Flammulina velutipes were inter-crossed. All F1 showed light-brown fruitbody, suggesting that a gene for the brown fruitbody was incompletely dominant against the white one. And backcross experiment showed that more than two genes were involved in color determination. To isolate a molecular marker linked to fruitbody color, a set of primers was designed from a sequence of clones derived by a bulked segregant analysis. These markers showed a specific band which co-segregated with brown fruitbody forming strains.
Assuntos
Células Clonais , Flammulina , Genes vifRESUMO
Cultural characteristics and phylogenic relationships were investigated and classified among collected strains in Pholiota spp. which contain P. adiposa, P. squarrosa, P. nameko etc. They were tested on the four different media (PDA, MCM, YM, MEA) and sawdust (Alder, Oak, Pine, Popular) substrates. There was a little variation according to the media and sawdust substrates, although PDA and popular sawdust substrate seemed to be better. Most strains showed white colonies, but some strains were brown. Mycelial growth length differed according to the strains. To classify species, the internal transcribed spacer regions (ITS) of the ribosomal DNA (rDNA) repeats from Pholiota spp. were amplified using polymerase chain reaction (PCR) and then sequenced. According to the analysis of ITS sequences, they were classified into five clusters. Their spacer regions were 644~700 nucleotides in length. The reciprocal homologies of each ITS region among these strains were ranged from 49.6~99.9%. The phylogenic analysis might give a criterion to classify species in the collected strains.
Assuntos
Características Culturais , DNA Ribossômico , Nucleotídeos , Pholiota , Reação em Cadeia da PolimeraseRESUMO
URP primers of 20 mer derived from repetitive sequence of rice were used to assess genetic variation of oyster mushroom consisting of 10 cultivars of Pleurotus ostreatus, two cultivars of P. florida and two cultivars of P. sajor-caju which were registered in Korea. URP2F and URP38F primers produced cultivar-specific PCR polymorphic bands in the Pleurotus species. UPGMA cluster analysis using the URP-PCR data showed that 14 Pleurotus cultivars are genetically clustered into large three groups. The URP-PCR data provided important information for more efficient breeding strategies of Pleurotus cultivars.