sortbyquote: 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/sortbyquote - from package: ncbi-tools-bin

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

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