Pra-perancangan pabrik kultur sel escherichia coli BPPTCC EgRK2 dengan substrat utama tandan kosong sawit untuk produksi rekombinan endo-β-1,4-glukanase = Preliminary plant design of escherichia coli BPPTCC-EgRK2 cell culture using oil palm empty fruit bunch to produce recombinant endo-β-1,4-glucanase