interest in the economic production of bio-insecticides with low-cost materials,
industrial by-products and even waste materials (Shojaaddini et al. 2010).
Shojaaddini et al. (2010) focused on the economic production of Bt based insecticide
by developing fermentation media based on food barley as a substitution of commercial starch. They investigated different carbon and nitrogen sources; hull-less
barley grain, commercial soybean cake, and groundnut, for fermentation of newly
isolated Iranian Bt strain and B. thuringiensis subsp. kurstaki HD-1 as a reference.
To determine the best substitution, different parameters such as biomass,
δ-endotoxin concentration and the number of Bt spores (CFU/ml) were estimated.
The use of barley in Bt fermentation media led to faster sporulation, similar final
biomass, shorter fermentation time and more importantly economic production.
Previously it was reported that KH4 Bt strain from the Bt collection of Agricultural Biotechnology Research Institute of Iran (ABRII) is highly toxic for coleopteran species namely X. luteola and Leptinotarsa decemlineata (Nazarian et al. 2009;
Salehi Jouzani et al. 2015a). Due to the great potential of this Bt strain Salehi Jouzani
et al. (2015a) attempted to optimize the growth condition and develop a costeffective medium for its mass production. Different temperatures and pH conditions
were examined to determine the appropriate growth conditions. A pH of 6.5 and
temperature of 30
C were found to be the optimum. Available agricultural waste
sources were used as carbon and nitrogen sources, and sea salt was utilized as a
cheap source of minerals. Molasses and corn steep liquor were the appropriate
sources of carbon and nitrogen. These findings (Salehi Jouzani et al. 2015a) could
be used to successfully develop an appropriate fermentation condition and design a
cost-effective medium for mass production of a local high potent Bt strain. An
economic fermentation medium and an appropriate condition for mass production
of YD5 Bt strain toxic for lepidopterans was designed and examined by Salehi
Jouzani et al. (2015b). The optimum reported pH and temperature for mass production of YD5 Bt strain were estimated at 7 and 30
C. The utilization of different costeffective materials from wastes of agriculture and industry led to discovery of an
economical medium for mass production of YD5 Bt strain. The highest number of
spores and crystals were obtained in the medium containing 3% hydrolyzed starch,
3% corn steep liquor and 0.003% sea minerals (Salehi Jouzani et al. 2015b).
It is important to recover Bt spores and crystals from the fermentation medium as
the last step of Bt mass production. Several methods such as precipitation, absorption, evaporation and centrifugation (Brar et al. 2006a, b; Adjalle et al. 2007; Naseri
Rad et al. 2016), have been suggested and indeed used for recovery of the Bt spores
and crystals. Amongst them, Marzban et al. (2014, 2016) investigated the
membrane-based filtration method. Based on their observation, microfiltration and
ultrafiltration were found to be effective for the separation of Bt spores and crystals
from the medium.
10 Progress on the Bacterium Bacillus thuringiensis and Its. . .
419
industrial by-products and even waste materials (Shojaaddini et al. 2010).
Shojaaddini et al. (2010) focused on the economic production of Bt based insecticide
by developing fermentation media based on food barley as a substitution of commercial starch. They investigated different carbon and nitrogen sources; hull-less
barley grain, commercial soybean cake, and groundnut, for fermentation of newly
isolated Iranian Bt strain and B. thuringiensis subsp. kurstaki HD-1 as a reference.
To determine the best substitution, different parameters such as biomass,
δ-endotoxin concentration and the number of Bt spores (CFU/ml) were estimated.
The use of barley in Bt fermentation media led to faster sporulation, similar final
biomass, shorter fermentation time and more importantly economic production.
Previously it was reported that KH4 Bt strain from the Bt collection of Agricultural Biotechnology Research Institute of Iran (ABRII) is highly toxic for coleopteran species namely X. luteola and Leptinotarsa decemlineata (Nazarian et al. 2009;
Salehi Jouzani et al. 2015a). Due to the great potential of this Bt strain Salehi Jouzani
et al. (2015a) attempted to optimize the growth condition and develop a costeffective medium for its mass production. Different temperatures and pH conditions
were examined to determine the appropriate growth conditions. A pH of 6.5 and
temperature of 30
C were found to be the optimum. Available agricultural waste
sources were used as carbon and nitrogen sources, and sea salt was utilized as a
cheap source of minerals. Molasses and corn steep liquor were the appropriate
sources of carbon and nitrogen. These findings (Salehi Jouzani et al. 2015a) could
be used to successfully develop an appropriate fermentation condition and design a
cost-effective medium for mass production of a local high potent Bt strain. An
economic fermentation medium and an appropriate condition for mass production
of YD5 Bt strain toxic for lepidopterans was designed and examined by Salehi
Jouzani et al. (2015b). The optimum reported pH and temperature for mass production of YD5 Bt strain were estimated at 7 and 30
C. The utilization of different costeffective materials from wastes of agriculture and industry led to discovery of an
economical medium for mass production of YD5 Bt strain. The highest number of
spores and crystals were obtained in the medium containing 3% hydrolyzed starch,
3% corn steep liquor and 0.003% sea minerals (Salehi Jouzani et al. 2015b).
It is important to recover Bt spores and crystals from the fermentation medium as
the last step of Bt mass production. Several methods such as precipitation, absorption, evaporation and centrifugation (Brar et al. 2006a, b; Adjalle et al. 2007; Naseri
Rad et al. 2016), have been suggested and indeed used for recovery of the Bt spores
and crystals. Amongst them, Marzban et al. (2014, 2016) investigated the
membrane-based filtration method. Based on their observation, microfiltration and
ultrafiltration were found to be effective for the separation of Bt spores and crystals
from the medium.
10 Progress on the Bacterium Bacillus thuringiensis and Its. . .
419