The glucose RQ-feedback control leading to improved erythromycin production by a recombinant strain Saccharopolyspora erythraea ZL1004 and its scale-up to 372-m3 fermenter

Abstract

In this paper, glucose respiratory quotient (RQ)-feedback control was developed for erythromycin production with a recombinant strain Saccharopolyspora erythraea ZL1004. RQ was confirmed to be an ideal online parameter for regulating glucose feed rate. Through feeding glucose to control RQ at 0.85 during 45-100 h and 0.95 during 100-185 h, erythromycin titer and erythromycin A concentration were reached 11.88 and 8.82 g l(-1) in 50 l fermenter, which were increased by 8.3 and 6.1 % as compared to that with glucose pH-feedback control, respectively. When glucose RQ-feedback control was scaled up to 372-m(3) fermenter, erythromycin titer and erythromycin A concentration at 155 h were reached 9.12 and 7.12 g l(-1), respectively, which were 10.5 and 9.4 % higher than that with the original technology (glucose pH-feedback control). To the best of our knowledge, this is the first report on the successful application of glucose RQ-feedback control in erythromycin production, especially in 372-m(3) fermenter.