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Table 2 Comparison of cell growth, sporulation, and δ-endotoxin production by Bacillus thuringiensis MPK13 in fed-batch cultivation with the optimal DOT control strategy

From: Effect of different fermentation strategies on Bacillus thuringiensis cultivation and its toxicity towards the bagworm, Metisa plana Walker (Lepidoptera: Psychidae)

Fed-batch with aeration strategyMax cell count (× 1011 CFU/ml)Max spore count (× 1011 spore/ml)Increase in cell count (%)aIncrease in spore count (%)bδ-endotoxinMax percentage of sporulation (%)Max cell productivity (× 1011 CFU/l/h)Max spore productivity (× 1011 spore/l/h)
Medium feeding at lag growth phase (2 h) (DOT was switched from 80% to 40% at 8 h of cultivation)14.7 (48 h)6.6 (48 h)5.826.9Yes (24–48 h)45.9 (48 h)76.630.2
Medium feeding at exponential growth phase (6 h) (DOT was switched from 80% to 40% at 12 h of cultivation)14.5 (48 h)7.1 (48 h)4.336.5Yes (28–48 h)49.0 (48 h)75.537.0
  1. aThe increase (%) was calculated based on batch fermentation
  2. bThe decrease (%) was calculated in comparison with batch cultivation data