Valorization of Spent Coffee Grounds as a Substrate for Fungal Laccase Production and Biosorbents for Textile Dye Decolorization

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Spent coffee grounds (SCG) are a widely available agro-industrial residue rich in carbon and phenolic compounds, presenting significant potential for biotechnological valorization. This study evaluated the use of SCG as a suitable substrate for fungal laccase production and the application of the resulting fermented biomass (RFB), a mixture of fermented SCG and fungal biomass as a biosorbent for textile dye removal. Two fungal strains, namely Lentinus crinitus UCP 1206 and Trametes sp. UCP 1244, were evaluated in both submerged (SmF) and solid-state fermentation (SSF) using SCG. L. crinitus showed superior performance in SSF, reaching 14.62 U/g of laccase activity. Factorial design revealed that a lower SCG amount (5 g) and higher moisture (80%) and temperature (30 °C ± 0.2) favored enzyme production. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analyses confirmed significant structural degradation of SCG after fermentation, especially in SSF. Furthermore, SCG and RFB were chemically activated and evaluated as biosorbents. The activated carbon from SCG (ACSCG) and RFB (ACRFB) exhibited high removal efficiencies for Remazol dyes, comparable to commercial activated carbon. These findings highlight the potential of SCG as a low-cost, sustainable resource for enzyme production and wastewater treatment, contributing to circular bioeconomy strategies.
Funding Information
  • Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (IBPG-1590-2.00/21, 312242/2022-4, 308824/2022-9)
  • CNPq (National Council for Scientific and Technological Development) (IBPG-1590-2.00/21, 312242/2022-4, 308824/2022-9)

This publication has 58 references indexed in Scilit: