blastdbcmd: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/blastdbcmd - from package: ncbi-blast+

You may install the required package with command apt-get install {package}

Error in other languages:
blastdbcmd: bevel nie gevind nie
blastdbcmd: comandă negăsită
blastdbcmd: comando não encontrado
blastdbcmd: commande introuvable
blastdbcmd: command not found
blastdbcmd: käsku ei ole
blastdbcmd: không tìm thấy lệnh
blastdbcmd: komanda nerasta
blastdbcmd: Kommando nicht gefunden.
blastdbcmd: kommandot finns inte
blastdbcmd: komut yok
blastdbcmd: nie znaleziono polecenia
blastdbcmd: níor aimsíodh an t-ordú
blastdbcmd: no se encontró la orden
blastdbcmd: no s'ha trobat l'ordre
blastdbcmd: opdracht niet gevonden
blastdbcmd: parancs nem található
blastdbcmd: perintah tidak ditemukan
blastdbcmd: príkaz nenájdený
blastdbcmd: příkaz nenalezen
blastdbcmd: команда не найдена
blastdbcmd: командата не е открита
blastdbcmd: 命令找不到
blastdbcmd: コマンドが見つかりません