Growth and proximate composition of Pleurotus ostreatuscultivated on green bocaiuva pulp substrates with different nitrogen sources

The aim of this work was to evaluate the growth and the proximate compositionof the mycelium-based bocaiuva pulp with the edible mushroom Pleurotusostreatuson green bocaiuva flour added with different sources of nitrogen (urea, ammonium nitrate and sulfate ammonia). Growth was monitored by kinectics. At the end, the proximate composition of the best three treatments (dehydrated green bocaiuva pulp and water, T1; dehydrated green bocaiuva pulp and ammonium nitrate, T3; and green bocaiuva pulp/wheat bran and ammonium nitrate, T7) was determined. Ammonium nitrate was the nitrogen source that showed the greatest growth in both substrates (T3:8.33 cm and T7:7.67 cm) in relation to the other treatments (4.67 to 7.17 cm), with emphasis on the green bocaiuva pulp. The substrate with green bocaiuva pulp and water was the one that showed the highest growth (7.50 cm), which was close to the treatment with mixed substrate and ammonium nitrate (7.67 cm). The treatment with the green bocaiuva pulp and ammonium nitrate (T3) was highlighted due to its significant increase in proteins (9.42 g 100 g-1) and fibers (5.21 g 100 g-1), and decrease in carbohydrates (9.52 g 100 g-1), in comparison to the other treatments T7 (8.94, 2.16, and 5.99 g 100 g-1, respectively) and T1 (2.78, 4.33, and 2.28 g 100 g-1, respectively). The product obtained from the growth of P. ostreatusin green bocaiuva pulp presents promising perspectives to be utilized as raw material for the development of new food products with added nutritional value.

Genome-wide gene expression patterns in dikaryon of the basidiomycete fungus Pleurotus ostreatus

Abstract Dikarya is a subkingdom of fungi that includes Ascomycota and Basidiomycota. The gene expression patterns of dikaryon are poorly understood. In this study, we bred a dikaryon DK13 × 3 by mating monokaryons MK13 and MK3, which were from the basidiospores of Pleurotus ostreatus TD300. Using RNA-Seq, we obtained the transcriptomes of the three strains. We found that the total transcript numbers in the transcriptomes of the three strains were all more than ten thousand, and the expression profile in DK13 × 3 was more similar to MK13 than MK3. However, the genes involved in macromolecule utilization, cellular material synthesis, stress-resistance and signal transduction were much more up-regulated in the dikaryon than its constituent monokaryons. All possible modes of differential gene expression, when compared to constituent monokaryons, including the presence/absence variation, and additivity/nonadditivity gene expression in the dikaryon may contribute to heterosis. By sequencing the urease gene poure sequences and mRNA sequences, we identified the monoallelic expression of the poure gene in the dikaryon, and its transcript was from the parental monokaryon MK13. Furthermore, we discovered RNA editing in the poure gene mRNA of the three strains. These results suggest that the gene expression patterns in dikaryons should be similar to that of diploids during vegetative growth.

Applicability of the use of waste from different banana cultivars for the cultivation of the oyster mushroom

The objective of this research was to evaluate the oyster mushroom Pleurotus ostreatus- (Jacq.: Fr.) Kumm. cultivation in substrates based on different combinations of wastes (leaf, pseudo-stem and pseudo-stem + leaf) and banana cultivars - Musa spp. (Thap Maeo, Prata Anã, Pelipita and Caipira) during 49 days. Organic matter loss in the substrate by action of the fungus was also evaluated during that period. It was verified that the pseudo-stem waste provided the best averages of biological efficiency among all cultivars tested and best rates were obtained by Thap Maeo (61.5%). The highest organic matter loss (OML) was obtained from pseudo-stem + leaf wastes (Prata Anã - 78.6%; Thap Maeo - 67.6%; Pelipita - 64.8%; Caipira - 60.6%). Therefore, the use of those wastes showed itself viable for P. ostreatus cultivation due to its availability and low cost, besides decreasing discards to environment.

Pleurotus sajor-caju HSP100 complements a thermotolerance defect in hsp104 mutant Saccharomyces cerevisiae.

A putative Hsp100 gene was cloned from the fungus Pleurotus sajor-caju. mRNA expression studies demonstrated that this gene (designated PsHsp100) is highly induced by high temperature,induced less strongly by exposure to ethanol, and not induced by drought or salinity. Heat shock induction is detectable at 37 degrees C and reaches a maximum level at 42 degrees C. PsHsp100 mRNA levels sharply increased within 15 min of exposure to high temperature, and reached a maximum expression level at 2 h that was maintained for several hours. These results indicate that PsHsp100 could work at an early step in thermotolerance. To examine its function, PsHsp100 was transformed into a temperature-sensitive hsp104 deletion mutant Saccharomycetes cerivisiae strain to test the hypothesis that PsHSP100 is an protein that functions in thermotolerance. Overexpression of PsHSP100 complemented the thermotolerance defect of the hsp104 mutant yeast, allowing them being survive even at 50 degree C for 4 h. These results indicate that PsHSP100 protein is functional as an HSP100 in yeast and could play and important role in thermotolerance in P. sajor-caju.