Optimization of spray drying process for Bacillus thuringiensis fermented wastewater and wastewater sludge

Abstract

Response surface methodology was used to optimize spray drying process for producing biopesticide powders of Bacillus thuringiensis by using fermented broth of starch industry wastewater and wastewater sludge. Analysis of variance was carried out using number of viable spores in the powder as dependent variable. The determination coefficients of models were 92 and 94% for fermented broth of starch industry wastewater and wastewater sludge, respectively. Under the optimal conditions of the operational parameters of spray drying, the numbers of viable spores were 2.2 × 10(8) and 1.3 × 10(8) CFU/mg in the dry powders for starch industry wastewater and wastewater sludge respectively, with a loss of viable spores of 18 and 13% when compared with their respective fermented broths. The entomotoxicity (measured by the bioassay method) of the powders obtained under optimal conditions showed a loss of 28 and 18% when compared with the fermented broth of starch industry wastewater and wastewater sludge, respectively. The optimized results of spray drying were used for field application calculations. The volume of fermented broth required to produce powder formulated product when compared with the volume required for liquid formulation product in order to treat 1 ha of balsam fir was less and offered several advantages.

Formulation development of the biocontrol agent Bacillus subtilis strain CPA-8 by spray-drying

“…2006). However, shelf‐stable and effective products of well‐known pest control agent B. thuringiensis (Prabakaran and Hoti 2008; Adjallé et al. 2011) can be obtained by spray‐drying and currently it is reported as an economical process for formulation of probiotic bacteria (Chávez and Ledeboer 2007; Golowczyc et al.…”

Optimization of Spray Drying Conditions for Yield, Particle Size and Biological Activity of Thermally Stable Viral Vectors

“…Earlier studies related to the present work have specifically optimized the yield and particle size of spray dried particles [23][24][25][26]. Further work has examined the effects of spray drying process parameters on various species of bacteria [27][28][29]. Understandably, viral vectors, as considered in the present work, exhibit different stabilizing profiles than that of bacterial biologics and have not been included in previously published optimization studies.…”

Biphasic Fermentation Is an Efficient Strategy for the Overproduction of δ-Endotoxin from Bacillus thuringiensis

“…According to Schnepf et al [32], depending on the protoxin composition, the crystals would assume various forms such as bipyramidal (Cry1), cuboidal (Cry2), flat rectangular (Cry3A), irregular (Cry3B), spherical (Cry4A and Cry4B), or rhomboidal (Cry11A) shapes. Employing response surface methodology, Adjalle et al [33] demonstrated a spray drying process for the raw solid-fermented matter from starch industry wastewater and wastewater sludge (after proper dilution) and showed that optimum solid particles in these media were 15 and 25 g/L, respectively, for maximum efficiency of drying. Since raw product (crystals, spores, and vegetative cells) is sufficient for field applications, without going through purification protocols, the filtrate of the fermented matter could directly be dried employing the method of Adjalle et al [33].…”

“…Employing response surface methodology, Adjalle et al [33] demonstrated a spray drying process for the raw solid-fermented matter from starch industry wastewater and wastewater sludge (after proper dilution) and showed that optimum solid particles in these media were 15 and 25 g/L, respectively, for maximum efficiency of drying. Since raw product (crystals, spores, and vegetative cells) is sufficient for field applications, without going through purification protocols, the filtrate of the fermented matter could directly be dried employing the method of Adjalle et al [33]. This would benefit the farmers, especially from third world countries as envisaged by Anilkumar et al [7].…”