Y-M Tzeng1, Y K Rao, K-J Tsay, W-S Wu. 1. Institute of Biotechnology, Chaoyang University of Technology, Wufeng, Taiwan, Republic of China. ymtzeng@cyut.edu.tw
Abstract
AIMS: To maximize spore production by Bacillus amyloliquefaciens B128, and its antagonism to the fungal pathogen Botrytis elliptica B061. METHODS AND RESULTS: In the 5-l stirred-tank bioreactor (STR), with the 0.5 vvm aeration rate, an agitation rate of 200 rev min(-1) significantly enhanced the spore yield compared to the same in 300 rev min(-1) cultivations. In a 20-l airlift bioreactor (ALR) the maximal spore production was further increased with a controlled aeration rate of 2.5 vvm operated in a 24-mesh net-draft tube mode, and no pH control cultivation. This spore yield in the 20-l ALR was five- and eightfold higher; in addition the cultivation period was 19 h shorter, compared to that obtained from shaker flask and in the 5-l STR cultivations respectively. CONCLUSIONS: Although culture conditions are still to be optimized, by using an ALR with net-draft tube, a scaling up from shaker flasks and STR to ALR of spore production by the strain B128 is technically feasible. SIGNIFICANCE AND IMPACT OF THE STUDY: The spore yields obtained using bioreactors were much higher than those previously reported. The freshly produced spore preparations from the B128 strain significantly antagonized the grey mould pathogen B. elliptica.
AIMS: To maximize spore production by Bacillus amyloliquefaciens B128, and its antagonism to the fungal pathogen Botrytis elliptica B061. METHODS AND RESULTS: In the 5-l stirred-tank bioreactor (STR), with the 0.5 vvm aeration rate, an agitation rate of 200 rev min(-1) significantly enhanced the spore yield compared to the same in 300 rev min(-1) cultivations. In a 20-l airlift bioreactor (ALR) the maximal spore production was further increased with a controlled aeration rate of 2.5 vvm operated in a 24-mesh net-draft tube mode, and no pH control cultivation. This spore yield in the 20-l ALR was five- and eightfold higher; in addition the cultivation period was 19 h shorter, compared to that obtained from shaker flask and in the 5-l STR cultivations respectively. CONCLUSIONS: Although culture conditions are still to be optimized, by using an ALR with net-draft tube, a scaling up from shaker flasks and STR to ALR of spore production by the strain B128 is technically feasible. SIGNIFICANCE AND IMPACT OF THE STUDY: The spore yields obtained using bioreactors were much higher than those previously reported. The freshly produced spore preparations from the B128 strain significantly antagonized the grey mould pathogen B. elliptica.
Authors: Tamar Khardziani; Eva Kachlishvili; Kakha Sokhadze; Vladimir Elisashvili; Richard Weeks; Michael L Chikindas; Vladimir Chistyakov Journal: Probiotics Antimicrob Proteins Date: 2017-12 Impact factor: 4.609