## 3 Results
### Bacterial Community  
Across all variants, bacteria (EUB338) accounted for the largest share of microbes, which fell within the narrow range of 69 \(\pm\) 4 in Variant 4 (MA40 + MS60) to 72 \(\pm\) 2 in Variant 1 (MA100+MS0) (Table 4). Archaea (ARC915) were also quite populous, accounting for \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multirow{2}{*}{**Unit**} & \multicolumn{6}{c}{**Variant**} \\ \cline{3-8}  & & **1—MA100+MS0** & **2—MA80+MS20** & **3—MA60+MS40** & **4—MA40+MS60** & **5—MA20+MS80** & **6—MA0 + MS100** \\ \hline \multirow{4}{*}{Biogas production} & cm\({}^{3}\)/gTS & 384.72 \(\pm\) 22.11 & 453.06 \(\pm\) 26.05 & 511.42 \(\pm\) 28.11 & 573.83 \(\pm\) 12.54 & 567.11 \(\pm\) 17.66 & 534.29 \(\pm\) 7.74 \\  & cm\({}^{3}\)/gVS & 483.73 \(\pm\) 25.21 & 509.53 \(\pm\) 11.71 & 567.32 \(\pm\) 22.31 & 628.00 \(\pm\) 20.05 & 612.42 \(\pm\) 19.07 & 569.42 \(\pm\) 8.25 \\  & cm\({}^{3}\)/d & 3509.82 \(\pm\) 20.17 & 4076.91 \(\pm\) 114.24 & 458.39 \(\pm\) 125.73 & 502.04 \(\pm\) 185.64 & 4899.33 \(\pm\) 152.57 & 4655.39 \(\pm\) 65.99 \\  & cm\({}^{3}\)/gVS\({}_{\text{smooth}}\) & 2290.00 \(\pm\) 99.73 & 2117.10 \(\pm\) 149.14 & 2122.07 \(\pm\) 152.22 & 2608.32 \(\pm\) 193.44 & 2206.65 \(\pm\) 125.16 & 1780.97 \(\pm\) 100.64 \\  & cm\({}^{3}\)/gTS & 2505.03 \(\pm\) 18.15 & 289.60 \(\pm\) 20.01 & 317.44 \(\pm\) 24.512 & 347.86 \(\pm\) 25.55 & 325.41 \(\pm\) 31.06 & 274.36 \(\pm\) 19.36 \\  & cm\({}^{3}\)/gVS & 285.70 \(\pm\) 18.69 & 325.69 \(\pm\) 25.88 & 352.14 \(\pm\) 29.46 & 308.69 \(\pm\) 28.55 & 351.40 \(\pm\) 33.54 & 292.40 \(\pm\) 20.64 \\  & cm\({}^{3}\)/gVS\({}_{\text{smooth}}\) & 288.59 \(\pm\) 19.46 & 266.05 \(\pm\) 27.24 & 2817.10 \(\pm\) 256.62 & 3045.56 \(\pm\) 274.06 & 2811.24 \(\pm\) 268.35 & 2339.19 \(\pm\) 165.09 \\  & cm\({}^{3}\)/gVS\({}_{\text{smooth}}\) & 1491.25 \(\pm\) 54.62 & 1353.25 \(\pm\) 40.62 & 1317.17 \(\pm\) 39.99 & 1581.16 \(\pm\) 69.46 & 1266.18 \(\pm\) 55.94 & 914.53 \(\pm\) 50.35 \\  & \% & 65.12 \(\pm\) 1.94 & 639.2 \(\pm\) 3.02 & 62.07 \(\pm\) 2.76 & 60.62 \(\pm\) 4.13 & 57.38 \(\pm\) 3.69 & 51.35 \(\pm\) 2.88 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Performance of microalgal biomass co-digestion with giant miscanthus silage. \(23\pm 3\) (Variant 6: MA0 + MS100) to \(27\pm 3\) (Variant 4: MA40+MS60) of all microbes (Table 4). The highest share of methanogenic bacteria from the _Methanosarcinaceae_ and _Methanoseta_ groups in the anaerobic bacterial community structure was found for the substrates with the share of microalgae at the level of 20% and 40%. These were, respectively, 15 \(\pm\) 2% and 10 \(\pm\) 1% for _Methanosarcinaceae_, and 14 \(\pm\) 2% and 11 \(\pm\) 1% for _Methanoseta_ (Table 4). Other researchers also determined the impact of the substrate used and the technological parameters of anaerobic digestion on the anaerobic bacterial community. [PERSON] et al. [56] proved that _Methanoseta_ dominated in the silage and dry cornstalks co-fermentation process. In the study of [PERSON] et al. [57], it was observed that the type of substrate had a significant impact on the formation of the bacterial community. In the study of [PERSON] et al., pig manure and rice straw were co-fermented in various proportions (95:5; 78:22 and 65:35 \(w/w\)), which corresponded to C/N ratios of 10:1, 20:1 and 30:1, respectively. The hydrotrophic methanogenic species _Methanothermobacter_ was predominant, but at higher C/N ratios, sequences related to the genus _Methanosarcina_ were also detected. In contrast, [PERSON] et al. [58], in a co-fermentation of polyhydroxybutyrate (PHB) with primary sludge, found that the bacterial communities were changed, but no changes were observed in the archaea community in different variants of the process. This research proved that the C/N ratio can be a factor significantly affecting the taxonomic structure of anaerobic bacteria in fermentation reactors, which directly translates into the methane fermentation efficiency achieved [59]. According to [PERSON] et al.