title: Pellet-dispersion strategy to simplify the seed cultivation of Aspergillus niger and optimize citric acid production.
abstract: Citric acid (CA) as an extremely important platform compound has attracted intense attention due to wide applications and huge markets. Here, we proposed a novel method, using pellet inoculation to replace spores, and constructed the seed recycling cultivation process, effectively avoided the longtime (spore preparation 30 days) of seed culture (including spores germination 12 h) in the traditional batch-fermentation. On this basis, using pellet-dispersion strategy, the bottleneck caused by the mycelium structure was overcome, with the seed restoring high cell-viability with CA titer (11.0 g/L) even in the eighth batch compared to that in the control (4.6 g/L). The optimum morphology of these recycling cultured seeds for CA production was dispersed pattern rather than pellets. And the CA production was 130.5 g/L on average in 5 L five-conjoined-fermenters recycling eight batches, especially increasing 3.1 g/L compared with the control. To our knowledge, this is the first that reported the application of these strategies in effective production of CA. Our fermentation strategies not only significantly enhanced CA productivity, but also severed as a promising stepping-stone for other fermentations dominated with the filamentous fungi.
authors: National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, 214122, China.|School of Biotechnology, Jiangnan University, Wuxi, 214122, China.|Jiangsu Guoxin Union Energy Co., Ltd., Wuxi, 214203, China.
authors: Baoshi
authors: B
authors: Wang
authors: National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, 214122, China.
authors: Jian
authors: J
authors: Chen
authors: National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, 214122, China.
authors: Hua
authors: H
authors: Li
authors: Jiangsu Guoxin Union Energy Co., Ltd., Wuxi, 214203, China.
authors: Fuxin
authors: F
authors: Sun
authors: National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, 214122, China.|School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors: Youran
authors: Y
authors: Li
authors: National Engineering Laboratory for Cereal Fermentation Technology, Wuxi, 214122, China. gyshi@jiangnan.edu.cn.|School of Biotechnology, Jiangnan University, Wuxi, 214122, China. gyshi@jiangnan.edu.cn.
authors: Guiyang
authors: G
authors: Shi
mesh_terms: D001234:Aspergillus niger / Q000254:growth & development*; D019343:Citric Acid / Q000378:metabolism*; D025282:Mycelium / Q000254:growth & development*; D013172:Spores, Fungal / Q000378:metabolism*
chemical_list: D019343:Citric Acid
keywords: Aspergillus niger; Citric acid; Pellet dispersion; Recycling cultivation; Seed morphology