javascript – How to use recursion to turn object into string?

EDIT

To me JSON.stringify is not the solution here, as it is much slower than recursion

    JSON.stringify(fakeData)
        .replace(/,/g, ';')
        .replace(/:(?={)/g, '')
        .replace(/"/g, '')

//Result
Recursion with reduce x 816,321 ops/sec ±7.38% (80 runs sampled)
JSON.stringify x 578,221 ops/sec ±1.72% (92 runs sampled)
Fastest is Recursion with reduce

I am making a css-in-js library, and I need to use recursion to turn object into string like this:

Input:

const fakeData = {
  a: {
    b: 'c',
    d: 'e'
  }
}

Output:

a{b:c;d:e;}

My recursion function:

const buildKeyframe = (obj) => {
    return Object.entries(obj).reduce((acc, (prop, value)) => {
        if (typeof value === 'string') {
            return `${acc}${prop}:${value};`
        }

        return `${acc}${prop}:{${buildKeyframe(value)}}`
    }, '')
}

This function works, but I think there is room for improvement(e.g. use TCO, avoid using reduce)… How can I write a better function to recurse this data structure?