The choise of the blast result for taxonomy assign

Question

[hua.peng1314]

Hi,I am dealing with some nifH gene. I translated the sequence into protein sequences and cluster them at 92% similarity.

A part of result of BLASTp of the representative sequences is shown below.

Query id, Subject id, % identity, alignment length,
OTU_64;size=38;    gi|563439003|gb|AHB60519.1| 90.18 112 Bacteria{superkingdom}(100);Proteobacteria{phylum}(100);Alphaproteobacteria{class}(100);Rhizobiales{order}(100);Bradyrhizobiaceae{family}(100);Rhodoblastus{genus}(100);Rhodoblastus_acidophilus{species}(100);
OTU_1;size=712055;   gi|70672909|gb|AAZ06688.1| 94.55 110 Bacteria{superkingdom}(100);environmental_samples{no_rank}(100);uncultured_nitrogen-fixing_bacterium{species}
OTU_1;size=712055;   gi|147743755|gb|ABQ50812.1| 94.55 110 environmental_samples{no_rank}(100);uncultured_microorganism{species}
OTU_1;size=712055;   gi|208970345|gb|ACI32157.1| 93.64 110  Bacteria{superkingdom}(100);environmental_samples{no_rank}(100);uncultured_bacterium{species}
OTU_1;size=712055;    gi|208970541|gb|ACI32252.1| 95.45 110 Bacteria{superkingdom}(100);environmental_samples{no_rank}(100);uncultured_bacterium{species}
OTU_1;size=712055;    gi|330506826|ref|YP_004383254.1| 93.64 110 Archaea{superkingdom}(100);Euryarchaeota{phylum}(100);Methanomicrobia{class}(100);Methanosarcinales{order}(100);Methanosaetaceae{family}(100);Methanosaeta{genus}(100);Methanosaeta_concilii{species}(100);Methanosaeta_concilii_GP6{no_rank}

I know the closest-match result will be chose as the assigned taxonomy and OTU_64;size=38; has no problem.I wonder if I can pick the last match result for the OTU_1;size=712055;. Is there any problem for my choice?