Correlation between entomotoxicity potency and protease activity produced by Bacillus thuringiensis var. kurstaki grown in wastewater sludge

2006 ◽  
Vol 41 (4) ◽  
pp. 794-800 ◽  
Author(s):  
A. Yezza ◽  
R.D. Tyagi ◽  
J.R. Valéro ◽  
R.Y. Surampalli
Keyword(s):  
Bacillus Thuringiensis ◽  
Protease Activity ◽  
Wastewater Sludge

Simultaneous production of biopesticide and alkaline proteases by Bacillus thuringiensis using sewage sludge as a raw material

2002 ◽  
Vol 46 (10) ◽  
pp. 247-254 ◽  
Author(s):  
R.D. Tyagi ◽  
V. Sikati Foko ◽  
S. Barnabe ◽  
A.S. Vidyarthi ◽  
J.R. Valéro ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Protease Activity ◽  
Synthetic Medium ◽  
Viable Cell ◽  
Wastewater Sludge ◽  
Raw Material ◽  
Alkaline Proteases ◽  
Ph Optimum ◽  
Simultaneous Production ◽  
Computer Controlled

The simultaneous production of Bacillus thuringiensis (Bt) based biopesticide and proteases was studied using synthetic medium and wastewater sludge as a raw material. The studies were conducted in shake flask and computer controlled 15-L capacity fermentors. Measuring viable cell and spore counts, entomotoxicity and protease activity monitored the progress of the biopesticide production process. A higher viable cell count and spore count was observed in synthetic Soya medium, however, higher entomotoxicity and protease activity were observed in wastewater sludge medium. Thus, the wastewater sludge is a better raw material than commercial Soya medium for the biopesticides and enzyme production. The maximum entomotoxicity and protease activity observed in the fermentor was 9,332 IU/μL and 4.58 IU/mL, respectively. The proteases produced by Bt were also characterised. Two types of proteases were detected; neutral proteases with pH optimum 7.0 and alkaline proteases with pH optimum 10-11. Further, two types of alkaline proteases were detected; one having a pH and temperature optimum at 10 and 50°C while the other at 11 and 70°C. The protease thermal stability was found to increase in the presence of CaCl2, indicating the proteases were metalloproteases.

Effect of surface active agents on the production of biopesticides using wastewater sludge as a raw material

2001 ◽  
Vol 44 (10) ◽  
pp. 253-259 ◽  
Author(s):  
A.S. Vidyarthi ◽  
R.D. Tyagi ◽  
J.R. Valéro
Keyword(s):  
Bacillus Thuringiensis ◽  
Shake Flask ◽  
Spruce Budworm ◽  
Tween 80 ◽  
Wastewater Sludge ◽  
Raw Material ◽  
Viable Cells ◽  
Surface Active Agents ◽  
Surface Active ◽  
Effect Of Surface

Effect of surface active agents on the production of Bacillus thuringiensis based biopesticides using secondary wastewater sludge as a raw material was studied. The experiments were conducted in a shake flask and nine different commercial surface active agents were used at a concentration of 0.2% (v/v). The sludge samples after addition of surface active agents were sterilised at 121°C for 30 min. The progress of biopesticide production was monitored by measuring viable cells and viable spores counts. The entomotoxicity was determined through bioassay against 3rd instar larvae of spruce budworm. ATPLUS 522, Tween 80 and Tween 85 increased the entomotoxicity potential in comparison to the control. The highest increase of 24% in entomotoxicity was observed when sludge was fortified with Tween 80.

Photostabilization of Bacillus thuringiensis fermented wastewater and wastewater sludge based biopesticides using additives

Acta Tropica ◽  
2009 ◽  
Vol 111 (1) ◽  
pp. 7-14 ◽  
Author(s):  
K.D. Adjalle ◽  
S.K. Brar ◽  
R.D. Tyagi ◽  
J.R. Valéro ◽  
R.Y. Surampalli
Keyword(s):  
Bacillus Thuringiensis ◽  
Wastewater Sludge

Wastewater Sludge Pre-treatment for Enhancing Entomotoxicity Produced by Bacillus thuringiensis var. kurstaki

2005 ◽  
Vol 21 (6-7) ◽  
pp. 1165-1174 ◽  
Author(s):  
Abdessalem Yezza ◽  
Rajeshwar D. Tyagi ◽  
José R. Valéro ◽  
Rao Y. Surampalli
Keyword(s):  
Bacillus Thuringiensis ◽  
Wastewater Sludge ◽  
Pre Treatment

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

2010 ◽  
Vol 34 (2) ◽  
pp. 237-246 ◽  
Author(s):  
K. D. Adjallé ◽  
K. D. Vu ◽  
R. D. Tyagi ◽  
S. K. Brar ◽  
J. R. Valéro ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Spray Drying ◽  
Wastewater Sludge ◽  
Drying Process

Molecular screening of Bacillus thuringiensis strains from wastewater sludge for biopesticide production

2006 ◽  
Vol 41 (4) ◽  
pp. 829-835 ◽  
Author(s):  
S. Mohammedi ◽  
S. Bala Subramanian ◽  
S. Yan ◽  
R.D. Tyagi ◽  
J.R. Valéro
Keyword(s):  
Bacillus Thuringiensis ◽  
Wastewater Sludge ◽  
Molecular Screening

Development of sludge based stable aqueous Bacillus thuringiensis formulations

2004 ◽  
Vol 50 (9) ◽  
pp. 229-236 ◽  
Author(s):  
S.K. Brar ◽  
M. Verma ◽  
R.D. Tyagi ◽  
J.R. Valéro ◽  
R.Y. Surampalli ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Surface Group ◽  
Tween 80 ◽  
Wastewater Sludge ◽  
Physical Parameters ◽  
Physical Factors ◽  
Viscosity Change ◽  
Sodium Metabisulphite ◽  
Secondary Sludge ◽  
Triton X

This study focuses on development of aqueous flowable (suspension) formulations for Bacillus thuringiensis (Bt) based biopesticides from wastewater sludge. Different inerts like sorbitol, sodium monophosphate, sodium metabisulphite, sorbic acid, propionic acid, Tween-80, Triton X-100 and glycerol were tested for formulations. Five different formulations for non-hydrolyzed (NH) secondary sludges were tried and the best combination selected on the basis of various physical parameters like viscosity, particle size, suspendibility, entomotoxicity, and microbiological purity tests. F5 formulations (for secondary sludge) comprising sorbitol, sodium monophosphate and sodium metabisulphite gave better physical and biological characteristics with a small effect on entomotoxicity and spore concentration after 120 days at pH 6, 6.5 and temperatures 40 and 50°C and viscosity change at 40 and 50°C. The formulations were more stable at pH 4.0 to 5.0 and temperatures 4 to 30°C whereas at pH 6.0 and 6.5 and temperatures 40 and 50°C, there was degeneration of the product. Lower proteolytic activity and physical factors like ionic strength and surface group changes at pH 6 and 6.5 were responsible for the instability of the formulation.

Sign in / Sign up

Export Citation Format

Share Document