## 3 Results
### Degradation of Cellulose and Lignin by Isolated Bacterial Strains  
All isolated strains were cultured on a medium containing carboxymethylcellulose (CMC) to determine whether they could degrade cellulose. These strains were cultured on CMC plates at 28 \({}^{\circ}\)C for 4 days (Shown in Figure S2). As shown in Figure 2, after flooding the plates with Congo red for 15-20 min and eluting with NaCl solution for 20 min, _Microbacterium_ sp. NK-NH4, _Ochroactrum_ sp. NK-NH9, and _Bacillus megaterium_ NK-NH10 barely grew and almost did not show degradation circles. The rest of the cultured bacteria showed different sizes of degradation circles. _Bacillus tequilensis_ NK-NH5 and _Bacillus velexensis_ NK-NH11 had the highest capacity for cellulose degradation (H/D > 3.0). _Stentotrophomonas_ sp. NK-NH14 also showed a high capacity for cellulose degradation (H/D > 2.0). _Bacillus subtilis_ NK-NH6, _Pseudomonas_ sp. NK-NH7, and _Bacillus_ sp. NK-NH8 had a relatively lower capacity for cellulose degradation (H/D < 2.0), even though these genera grew more vigorously on the plates. \begin{table}
\begin{tabular}{c c c c c c} \hline \multicolumn{6}{c}{**Molecular Identification of Strains Isolated from the Water Samples**} \\ \hline
**Bacteria** & **Accession** & **Closet Relative** & **Accession** & **Similarity** & **Source** \\
**Number** & **Strain** & **Number** & **(\%)** & **Source** \\ \hline NK-NH4 & MH997669 & _Microbacterium_ sp. & DQ658916.1 & 99\% & water samples \\ NK-NH5 & MH997670 & _Bacillus tequilensis_ & MG519475.1 & 93\% & water samples \\ NK-NH6 & MH997671 & _Bacillus subtilis_ & KY510927.1 & 99\% & water samples \\ NK-NH7 & MH997672 & _Pseudomonas_ sp. & MF436694.1 & 99\% & water samples \\ NK-NH8 & MH997673 & _Bacillus_ sp. & MG827113.1 & 99\% & water samples \\ NK-NH9 & MH997674 & _Ochrobactrum_ sp. & MF442305.1 & 99\% & water samples \\ NK-NH10 & MH997675 & _Bacillus megaterium_ & MG818943.1 & 99\% & water samples \\ NK-NH11 & MH997676 & _Bacillus velexensis_ & MH014956.1 & 99\% & water samples \\ NK-NH14 & MH997679 & _Stentotrophomonas_ sp. & MH144251.1 & 99\% & water samples \\ \hline \end{tabular}
\end{table} 
Table 1: Similarity in partial 16S rDNA sequences of clones to sequences of their closest bacterial relatives available in the Genbank nucleotide sequence database. Next, all strains isolated from the water samples collected in December 2017 were first cultured on a medium containing sodium lignocellulosic at 28 \({}^{\circ}\)C for 5 days. All strains could grow colonies on the plates. Then, these strains were cultured on a medium with azure and Remazol brilliant blue at 28 \({}^{\circ}\)C for 4 days. On the medium with azure, none of the strains presented clear and distinct degradation zones, indicating that they had little capacity to produce lignin peroxidase (LiP) and manganese peroxidase (MnP). Among them, _Microbacterium_ sp. NK-NH4 and _Ochrobactrum_ sp. NK-NH9 barely grew. As shown in Figure 3, on the medium with Remazol brilliant blue, _Pseudomonas_ sp. NK-NH7, _Bacillus_ sp. NK-NH8, _Ochrobactrum_ sp. NK-NH9, and _Stenotrophomonas_ sp. NK-NH14 did not show degradation zones. The rest of the cultured bacteria showed different sizes of decolorized circles, indicating that they had the ability to produce lactose; however, the enzyme production was weak (H/D \(<\) 2.0). _Bacillus megaterium_ NK-NH10 had the most distinct degradation circle and presented a relatively high ability to produce lactose together with _Microbacterium_ sp. NK-NH4. _Bacillus tequilensis_ NK-NH5, _Bacillus subtilis_ NK-NH6, and _Bacillus velezensis_ NK-NH11 showed degradation zones; however, these zones were not clear, and the ratio of H and D was lower than 1.5. Figure 2: Photograph showing cellulolytic enzymatic activity of each bacterial colony. (**A**) The colonies of nine strains grown on carboxymethylcellulose (CMC) plates at 28 \({}^{\circ}\)C for 4 days. Different transparent circles are shown after flooding with Congo red, indicating different degrees of cellulose degradation: (**a**) _Microbacterium_ sp.