Sorry to see that your question hasn't received an answer yet. Unfortunately, without more information, it is unlikely an answer for this specific question will be provided. To answer the more general question: Yes, it is possible, but there should be no difference between the two. In fact, for the version of the MEAN stack you are using, npm start simply calls grunt From the package.json file:

  "scripts": {
    "start": "grunt",
    "test": "grunt test",
    "postinstall": "bower install --config.interactive=false"
  },

More recently, the MEAN stack has moved from using grunt to using gulp. The current package.json now calls gulp when you run npm start:

    "start": "gulp",