Substrate disinfection methods on the production and nutritional composition of a wild oyster mushroom from the Amazon

Abstract

One of the most expensive steps in mushroom production is the disinfection of the substrate. This study aimed to evaluate different methods of disinfecting various substrates used in the cultivation of Pleurotus ostreatus from the Amazon. P. ostreatus was grown under uncontrolled temperature conditions in a greenhouse (at approximately 30 °C) on substrates formulated with residues (seeds) of açaí and tucumã palm trees, Brazil nuts shell and pine sawdust. The different substrate disinfection treatments comprised autoclaving, immersion in hot water or immersion in calcium hydroxide (2%). The chemical composition of residues, substrates, and mushrooms was analyzed. During cultivation, it was found that in the treatment with hot water, all the bags were contaminated, and treatment with calcium hydroxide inhibited the colonization and growth of the mushrooms. P. ostreatus grown on the autoclaved açaí substrate supplemented with tucumã had higher production. The highest percentage of fiber content was obtained when the mushrooms were cultivated in the pine substrate supplemented with Brazil nuts (32.68 to 33.65%), and the highest protein content (20.03 to 20.88%) was found in the mushrooms grown on açaí-based substrates. Considering that P. ostreatus showed higher productivity in autoclaved substrates, further studies should be performed to develop alternative methods of disinfecting substrates for the cultivation of mushrooms in the Amazon region, as well as, in other regions with a tropical climate. However, the cultivation of this mushroom is promising using some regional substrates, especially with açaí, which is one of the important natural products of the Amazon.

Screening of ligninolytic enzymes produced by Ganoderma lucidum in solid residues from the Amazon

“…On other hand, in the substrate based on marupá sawdust without supplementation, no fungal colonization was observed; therefore, there was no growth of G. lucidum, and it was not possible to determine the enzymatic activities for this substrate (Figure 1). The inhibition of fungal development may be associated with the low nitrogen content in the residue, which results from the low protein value that is characteristic of woody material (0.03 -1%) and requires supplementation to achieve greater biological efficiency of the macrofungi (Chang & Miles, 1989;Sales-Campos et al, 2010a;Pedri et al, 2015;Aguiar et al, 2021;Aguiar et al, 2022).…”

“…As a substrate for mushroom development and obtaining enzymes for industrial application, the use of easily accessible residues that are available in the Amazon region, becomes promising, since the raw material is low cost, in addition to reducing the environmental impacts resulting from the inadequate disposal of this biomass (Sadh et al, 2018;Aguiar et al, 2021;Aguiar et al, 2022). Among the Amazonian residues, sawdust from marupá (Simarouba amara) has already been reported as an efficient substrate for mushroom development (Sales-Campos et al, 2010a;Sales-Campos et al, 2011;Aguiar et al, 2022).…”

“…The seeds correspond to 93% of the fruit and are discarded without further use (Maranho & Paiva, 2012;Lima et al, 2021). Studies have already reported the use of açaí seed-based residue in biorefinery and anaerobic digestion processes, with the aim of production of mushrooms and lignocellulolytic enzymes (Santos & Cavallazzi, 2017;Lima et al, 2021;Aguiar et al, 2021;Aguiar et al, 2022).…”

Metaprofiling of the Bacterial Community in Colonized Compost Extracts by Agaricus subrufescens

“…The inoculum was produced from sorghum grains ( Sorghum bicolor ) cooked for approximately 40 min in boiling water. After cooking, excess water was drained and 2% calcite was added to the grains based on their wet weight to provide calcium and raise the pH [ 20 ]. After homogenization with calcite, the grains were autoclaved for a period of 4 h at 121 °C.…”