Use multiple local strategies in PassportJS

You can name your local strategies to separate them.

// use two LocalStrategies, registered under user and sponsor names

      // add other strategies for more authentication flexibility
  passport.use('user-local', new LocalStrategy({
      usernameField: 'email',
      passwordField: 'password' // this is the virtual field on the model
    },
    function(email, password, done) {
      User.findOne({
        email: email
      }, function(err, user) {
        if (err) return done(err);

        if (!user) {
          return done(null, false, {
            message: 'This email is not registered.'
          });
        }
        if (!user.authenticate(password)) {
          return done(null, false, {
            message: 'This password is not correct.'
          });
        }
        return done(null, user);
      });
    }
  ));

    // add other strategies for more authentication flexibility
    passport.use('sponsor-local', new LocalStrategy({
            usernameField: 'username',
            passwordField: 'password' // this is the virtual field on the model
        },
        function(username, password, done) {
            Sponsor.findOne({
                'primaryContact.username': username
            }, function(err, sponsor) {
                if (err) return done(err);

                if (!sponsor) {
                    return done(null, false, {
                        message: 'This email/username is not registered.'
                    });
                }
                if (!sponsor.authenticate(password)) {
                    return done(null, false, {
                        message: 'This password is not correct.'
                    });
                }
                return done(null, sponsor);
            });
        }
    ));

Later controller code refer to them by name.

/**
 * User Login
 */
exports.loginUser = function (req, res, next) {
    passport.authenticate('user-local', function(err, user, info) {
        var error = err || info;
        if (error) return res.json(401, error);

        req.logIn(user, function(err) {

            if (err) return res.send(err);
            res.json(req.user.userInfo);
        });
    })(req, res, next);
};

/**
 * Sponsor Login
 */
exports.loginSponsor = function (req, res, next) {
    passport.authenticate('sponsor-local', function(err, sponsor, info) {
        var error = err || info;
        if (error) return res.json(401, error);

        req.logIn(sponsor, function(err) {
            if (err) return res.send(err);
            res.json(req.sponsor.profile);
        });
    })(req, res, next);
};

Later when it comes time to serialize you user, you may want to do something like this.

// serialize
passport.serializeUser(function(user, done) {            
  if (isUser(user)) {
    // serialize user
  } else if (isSponsor(user)) {
    // serialize company
  }
});