Potential of a gypsum-free composting process of wheat straw for mushroom production

Abstract

Wheat straw based composting generates a selective substrate for mushroom production. The first phase of this process requires 5 days, and a reduction in time is wished. Here, we aim at understanding the effect of gypsum on the duration of the first phase and the mechanism behind it. Hereto, the regular process with gypsum addition and the same process without gypsum were studied during a 5-day period. The compost quality was evaluated based on compost lignin composition analysed by py-GC/MS and its degradability by a commercial (hemi-)cellulolytic enzyme cocktail. The composting phase lead to the decrease of the pyrolysis products 4-vinylphenol and 4-vinylguaiacol that can be associated with p-coumarates and ferulates linking xylan and lignin. In the regular compost, the enzymatic conversion reached 32 and 39% for cellulose, and 23 and 32% for xylan after 3 and 5 days, respectively. In absence of gypsum similar values were reached after 2 and 4 days, respectively. Thus, our data show that in absence of gypsum the desired compost quality was reached 20% earlier compared to the control process.

Metagenomics analysis of the effects of Agaricus bisporus mycelia on microbial diversity and CAZymes in compost

“…The straws were completely dampened and piled up for 1–3 days, and then the other materials were mixed and piled again for 2–3 days. The pre-compost was placed into the tunnel for primary fermentation (PI) ( Straatsma et al, 2000 ; Mouthier et al, 2017 ). The pile was turned three times on days 2, 4, and 7, respectively.…”

Mest en digestaat als grondstof voor alternatieve teelten

“…Dit vindt plaats in een atmosfeer met veel ammonia, bij een hoge pH (8.2) en hoge temperatuur (80 o C). Onder deze omstandigheden treden er chemische veranderingen op in de binding van lignine aan hemicellulose (Mouthier et al, 2017) waardoor er middels enzymatische werking gemakkelijk suikers kunnen worden vrijgemaakt uit het stro waarop de schimmels kunnen groeien.…”

Coprophilous fungi : Closing the loop: improving circularity with manure-loving mushrooms

“…In the first step, the compost is aerated to control temperatures between 70 and 80 o C in the presence of high levels of gaseous ammonia. In this step the carbohydrates present in the compost are made accessible for enzymes (Mouthier et al, 2017). In the second step the compost is aerated in such a way that first a 8-12 hr period of 56-58 o C is maintained after which the temperature is lowered to 45 o C. In this step, lasting about 5 days, the gaseous ammonia in the process air is slowly removed and a thermophilic microbiota, consisting of bacteria and fungi, develops in the compost.…”