Batch and fed-batch fermentation of Bacillus thuringiensis using starch industry wastewater as fermentation substrate

Abstract

Bacillus thuringiensis var. kurstaki biopesticide was produced in batch and fed-batch fermentation modes using starch industry wastewater as sole substrate. Fed-batch fermentation with two intermittent feeds (at 10 and 20 h) during the fermentation of 72 h gave the maximum delta-endotoxin concentration (1,672.6 mg/L) and entomotoxicity (Tx) (18.5 x 10(6) SBU/mL) in fermented broth which were significantly higher than maximum delta-endotoxin concentration (511.0 mg/L) and Tx (15.8 x 10(6) SBU/mL) obtained in batch process. However, fed-batch fermentation with three intermittent feeds (at 10, 20 and 34 h) of the fermentation resulted in the formation of asporogenous variant (Spo-) from 36 h to the end of fermentation (72 h) which resulted in a significant decrease in spore and delta-endotoxin concentration and finally the Tx value. Tx of suspended pellets (27.4 x 10(6) SBU/mL) obtained in fed-batch fermentation with two feeds was the highest value as compared to other cases.

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

“…The absence of δ-endotoxin in intermittent fed-batch cultivation has also been reported. Although intermittent fed-batch cultivation enhanced the growth of Bt cell, the sporulation and δ-endotoxin synthesis were significantly reduced (Vu et al 2010). Sasaki et al (1998) claimed that high cell concentration (16.1 g/l) could be obtained in fed-batch cultivation, using sodium acetate-yeast extract (AYE) as a feeding medium, which was fed twice during the cultivation.…”

“…The final spore concentrations obtained in batch cultivation of Bt were relatively low and not exceeded 10 11 spores/ml (Sarrafzadeh et al 2005;Khodair et al 2008;Vu et al 2010). A mixture of Bt spores and crystals can be produced using different modes of cultivation (Aronson and Yechiel 2001).…”

Bacillus sphaericus and Bacillus thuringiensis to Insect Control: Process Development of Small Scale Production to Pilot-Plant-Fermenters

“…Batch fermentation is currently used to Bacillus thuringiensis cultivation (Rivera et al, 1999;Silva et al, 2011;Vu et al, 2010). However, there are studies about cultivation in continuous (Selinger et al, 1988;Mignone & Avignone-Rossa, 1996) and fed-batch (Jong et al, 1994;Jong et al, 1995;Jing-Wen et al, 2007) conditions.…”

Poplar growth and wood production on a grassland irrigated for decades with potato starch wastewater

“…PSW is rich in organic substances, inorganic suspensions and macronutrients (Arienzo et al 2009). Because of the high concentrations of organic substances and nutrients, attempts were made to use PSW as substrate for production of microorganisms (Chang et al 2008;Vu et al 2010) and electricity (Lu et al 2009). However, most often PSW is used to irrigate and fertilize fields (Rosenwinkel et al 2005).…”