GSettingsコマンドの実行エラーについて

前提・実現したいこと

centosでワークスペースごとに壁紙を変更するスクリプトを実行したときに下記のようなエラーが発生したので解決策をさがしています。

エラーメッセージ

GLib-GIO-Message: 16:39:39.273: Using the 'memory' GSettings backend.  Your settings will not be saved or shared with other applications.

該当のソースコード

#!/bin/bash
# Script to change the desktop image when switching workspaces.

IMG0='file:///home/****/picture/67861937_p0_master1200.jpg'
IMG1='file:///home/****/picture/63513874_p0_master1200.jpg'
IMG2='file:///home/****/picture/59684029_p0_master1200.jpg'
IMG3='file:///home/****/picture/58393716_p0_master1200.jpg'
IMGBG=${IMG0}
xprop -root -spy _NET_CURRENT_DESKTOP | (
   while read -r; do
      DESK=${REPLY:${#REPLY}-1:1}
      if [ "$DESK" == "0" ]; then
        IMGBG=${IMG0}
      elif [ "$DESK" == "1" ]; then
        IMGBG=${IMG1}
      elif [ "$DESK" == "2" ]; then
        IMGBG=${IMG2}
      elif [ "$DESK" == "3" ]; then
        IMGBG=${IMG3}
      else
        IMGBG=${IMG0}
      fi
      gsettings set org.gnome.desktop.background picture-uri ${IMGBG}
   done
   )