Use of agave bagasse for production of an organic fertilizer by pretreatment with <i>Bjerkandera adusta</i> and vermicomposting with <i>Eisenia fetida</i>

<p><i>Agave tequilana</i> Weber is used in tequila and fructans production, with agave bagasse generated as a solid waste. The main use of bagasse is to produce compost in tequila factories with a long traditional composting that lasts 6–8 months. The aim of this study was to evaluate the degradation of agave bagasse by combining a pretreatment with fungi and vermicomposting. Experiments were carried out with fractionated or whole bagasse, sterilized or not, subjecting it to a pretreatment with <i>Bjerkandera adusta</i> alone or combined with native fungi, or only with native bagasse fungi (non-sterilized), for 45 days. This was followed by a vermicomposting with <i>Eisenia fetida</i> and sewage sludge, for another 45 days. Physicochemical parameters, lignocellulose degradation, stability and maturity changes were measured. The results indicated that up to 90% of the residual sugars in bagasse were eliminated after 30 days in all treatments. The highest degradation rate in pretreatment was observed in non-sterilized, fractionated bagasse with native fungi plus <i>B. adusta</i> (BNFns) (71% hemicellulose, 43% cellulose and 71% lignin) at 45 days. The highest total degradation rates after vermicomposting were in fractionated bagasse pre-treated with native fungi (94% hemicellulose, 86% cellulose and 91% lignin). However, the treatment BNFns showed better maturity and stability parameters compared to that reported for traditional composts. Thus, it seems that a process involving vermicomposting and pretreatment with <i>B. adusta</i> could reduce the degradation time of bagasse to 3 months, compared to the traditional composting process, which requires from 6 to 8 months.