## 4 Conclusions  
This study investigated the effect of bio-delignification with the white-rot fungi _Bijekandra adusta_ on anaerobic biodegradability of GW, which is rich in lignocellulosic matter, co-digested with OFMSW. A bio-delignification yield of 42% was obtained after treating GW for 7 days with _B. adusta_ at room temperature and with mild agitation. Although the \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Fungal Strain**} & \multirow{2}{*}{**Substrate for AD**} & \multicolumn{2}{c}{**Glucose Addition in**} & \multicolumn{2}{c}{**BMP Improvements**} & \multirow{2}{*}{**Ref.**} \\  & & **Fungal Pretreatment** & & & **by Fungal** \\  & & **(g)** & & **Pretreatment** & \\ \hline _Pleurrotus florida_ & 30 days pretreated wheat straw + manure & - & 9.8\% & 9.8\% & [77] \\ _Pleurrotus florida_ & 60 days pretreated wheat straw + manure & - & 8.2\% & 18.2\% & [77] \\ _Pleurrotus florida_ & 90 days pretreated wheat straw + manure & - & 8.7\% & 27.9\% & [77] \\ _Gamoderma adersym_ & 12 days pretreated wheat straw & 200 & - & 13\% & [48] \\ _Trametes_ sp. & 12 days pretreated wheat straw & 50–200 & - & 15–56\% & [48] \\ _Dichostream_ & 12 days pretreated wheat straw & 50 & - & 29\% & [48] \\ _Plieutus etringii_ & 10 days pretreated corn stover & - & - & 19\% & [51] \\ _Pleurrotus ostratus_ & 5 weeks pretreated rice straw & - & 11.6\% & 64\% & [78] \\ _Phancrochate_ & 5 weeks pretreated rice straw & - & 8.9\% & 122\% & [78] \\ _chrysogorium_ & 5 weeks pretreated rice straw & - & 12.2\% & 88\% & [78] \\ _Gamoderma tachium_ & 5 weeks pretreated rice straw & - & 13\% & 9–28\% & [52] \\ _Trichoderma reseei_ & 10 days pretreated rice straw & - & 8.2\% * & 27\% & [79] \\ _Pleurrotus ostratus_ & 30 days pretreated wheat straw & - & 16.8\% * & 33\% & [79] \\ _Trametes versicolor_ & 7 days pretreated corn stagger + manure & - & - & 41\% & [49] \\ _Phancrochate_ & 30 days pretreated corn stover & - & 49\% * & 33\% & [80] \\ _chrysogorium_ & & & & & \\ \hline \hline \end{tabular}  
* These values, as reported in the corresponding references, refer to lignin losses after the fungal pretreatments rather than the residual lignin.  
\end{table} 
Table 5: Different fungal strains used in delignification of agricultural residues and effects of pretreatments on biogas production (AD = anaerobic digestion; BMP = biochemical methane potential). yield of delignification was significantly lower than what obtained was with the sodium hydroxide treatment (78% of delignification), co-digestion of OFMSW and GW treated with _B. adusta_ showed an increase of biogas yield in 30 days, reaching 289 Nm\({}^{3}\) CH\({}_{4}\)/ton VS, leading to a 98% increase in biogas yield compared to that of untreated biomass. Considering the opportunity to diminish the hydraulic retention time by about 10 days, productivity increased to 500 Nm\({}^{3}\)/ton FM*day, emphasizing the effect of bio-delignification on lignocellulosic structure and the increasing matrix accessibility to microbial attack. The increase in biogas production is attributed to lignin degradation induced by the fungi strain, releasing cellulose and hemicellulose that is then available for subsequent microbial attachment. To conclude, bio-delignification with _B. adusta_ was shown to be very efficient for improving the biodegradability of lignocellulosic biomass. It is inexpensive, environmental-friendly, and has great room for further improvements in terms of optimization of pretreatment conditions (duration, etc. ), which should certainly improve these results. In future research, pretreatments with _B. adusta_ can give access to new feedstocks for biogas plants, improving the circular economy paradigm. Conceptualization, E.T. and S.C.; methodology, data curation, and investigation F.Z. ; B.S., and D.S. ; writing--original draft preparation, E.T. ; writing--review and editing, all authors; All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable.