run-mummer1: 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/run-mummer1 - from package: mummer

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

Error in other languages:
run-mummer1: bevel nie gevind nie
run-mummer1: comandă negăsită
run-mummer1: comando não encontrado
run-mummer1: commande introuvable
run-mummer1: command not found
run-mummer1: käsku ei ole
run-mummer1: không tìm thấy lệnh
run-mummer1: komanda nerasta
run-mummer1: Kommando nicht gefunden.
run-mummer1: kommandot finns inte
run-mummer1: komut yok
run-mummer1: nie znaleziono polecenia
run-mummer1: níor aimsíodh an t-ordú
run-mummer1: no se encontró la orden
run-mummer1: no s'ha trobat l'ordre
run-mummer1: opdracht niet gevonden
run-mummer1: parancs nem található
run-mummer1: perintah tidak ditemukan
run-mummer1: príkaz nenájdený
run-mummer1: příkaz nenalezen
run-mummer1: команда не найдена
run-mummer1: командата не е открита
run-mummer1: 命令找不到
run-mummer1: コマンドが見つかりません