## 4 Conclusions  
This research highlights the significant potential of MBCs as sustainable, high-performance alternatives to conventional materials. By utilizing renewable agricultural and essential oil by-products, we demonstrated that MBCs can achieve competitive thermal insulation and mechanical properties while maintaining biodegradability, thus supporting the principles of a circular economy. Although challenges such as high water absorption remain, the promising balance between structural stability and environmental responsibility obligations MBCs as a transformative solution for sustainable construction and material innovation. Moreover, due to their high porosity and biodegradability, these composites show great promise as support for the immobilization of carbonic anhydrase, offering an innovative pathway for direct carbon capture technologies.  
Conceptualization, G.A., H.Y., R.Z., P.S. and A.K.; Data curation, M.B.; Formal analysis, R.Z., R.K., P.S. and R.B.; Funding acquisition, A.K.; Investigation, V.V.; Methodology, G.A., H.Y., R.Z., M.B., R.K., R.B. and V.V.; Project administration, A.K.; Resources, V.V.; Software, M.B.; Supervision, G.A.; Visualization, R.B.; Writing--original draft, G.A., H.Y., R.Z. and R.K.; Writing--review and editing, M.B., V.V., and A.K. All authors have read and agreed to the published version of the manuscript.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Sample** & & & & & & & & \\
**Period for** & **HERF** & **SDLS** & **WS** & **BLS:** & **WS** & **PS** & **BC** & **AC** \\
**Degradation** & & & & & & & & \\ \hline
28 days & 72 & 125 & 113 & 161 & 114 & 106 & 57 & 18 \\ \hline
56 days & 99 & 149 & 141 & 192 & 133 & 122 & 49 & 18 \\ \hline Oxygen consumption as \% of the ThOD \({}^{*}\) & 14.9 & 27.1 & 24.1 & 46.4 & 30.2 & 15.1 & - & - \\ \hline \hline \end{tabular}  
* for the calculation of the oxygen consumption for biological degradation, the amount of oxygen consumed by the BC (Blank control) is not taken into account, based on the assumption that microbial autolysis, a process, has not yet taken place at this stage of the degradation process.  
\end{table}
Table 3: Oxygen consumption during the biodegradation tests for 28- and 56-day incubation periods and the decomposition degree reached compared to ThOD.  
Funding: This research was funded by THE NATIONAL SCIENCE FUND OF BULGARIA, under contract No. KTI-06-H77/10 from 6 December 2023 \"An enzyme-based biomimetic approach to develop engineered biomaterials for direct carbon capture\". Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable. Data Availability Statement: The raw data supporting the conclusions of this article will be made available by the authors on request. Conflicts of Interest: The authors declare no conflicts of interest. Abbreviations The following abbreviations are used in this manuscript: MBCs Mycelium-based composites HERF Hexane-extracted rose flower SDLS Steam-distilled lavender straw WS Wheat straw PS Pine sawdust WHO World Health Organization SDGs Sustainable development goals FAO Food and agriculture organization ThOD Theoretical oxygen demand COD Chemical oxygen demand BOD Biological oxygen demand WWTP Wastewater treatment plant