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 ◽  
...  

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.

2001 ◽  
Vol 44 (10) ◽  
pp. 253-259 ◽  
Author(s):  
A.S. Vidyarthi ◽  
R.D. Tyagi ◽  
J.R. Valéro

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.


2003 ◽  
Vol 48 (8) ◽  
pp. 239-246 ◽  
Author(s):  
M.L. Tirado Montiel ◽  
R.D. Tyagi ◽  
J.R. Valero ◽  
R.Y. Surampalli

Production of Bacillus thuringiensis (Bt) based biopesticide was studied using hydrolysed or raw wastewater sludge as a raw material. The sludge hydrolysis was carried out at different pH (2, 4 and 6). The sludge after hydrolysis was sterilised at 121°C for 30 minutes. The effect of temperature, pH and agitation speed on growth and toxin production was also investigated. The pH in the shake flask was controlled by adding 0.1 M TRIS buffer. The progress of the biopesticide production process was monitored by measuring viable cell count (VC), spore count (SC) and entomotoxicity (Tx). The entomotoxicity was measured against spruce budworm. Control of pH substantially increased the entomotoxicity of the final product. Increased agitation speed resulted in higher VC, SC and Tx values.


2008 ◽  
Vol 57 (5) ◽  
pp. 639-645 ◽  
Author(s):  
J. P. Chenel ◽  
R. D. Tyagi ◽  
R. Y. Surampalli

The volume of sludge produced annually is very high and poses serious disposal problems. The traditional methods of sludge disposal produce secondary pollutants. Therefore, the alternate or suitable solution is reuse of sludge in an ecofriendly approach. Biotechnology is an interesting tool to add value to the processes involved in wastewater and wastewater sludge disposal/reuse. In this context, a study was carried out on thermophilic bacterial strains that produce thermostable proteases. The bacterial strains were first isolated from municipal wastewater sludge. In contrast to the conventional strains used in industries, like Bacillus sp., the new strains were Gram-Negative type. In semi-synthetic medium, a maximal protease activity of 5.25 IU/ml (International Unit per ml) was obtained at a pH of 8.2 and at a temperature of 60 °C, which is higher than the stability temperature of 37 °C for a similar protease obtained from the conventional producer Bacillus licheniformis. Moreover, growth and protease activity of the strains were tested in wastewater sludge. It is expected that the complexity of sludge could stimulate/enhance the protease production and their characteristics. In conclusion, reuse of wastewater sludge will help to reduce their quantity as well as the value-added products produced will replace chemical products used in industries.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 863
Author(s):  
Paweł Migdał ◽  
Agnieszka Murawska ◽  
Aneta Strachecka ◽  
Paweł Bieńkowski ◽  
Adam Roman

The effect of an artificial electromagnetic field on organisms is a subject of extensive public debate and growing numbers of studies. Our study aimed to show the effect of an electromagnetic field at 50 Hz and variable intensities on honey bee proteolytic systems and behavior parameters after 12 h of exposure. Newly emerged worker bees were put into cages and exposed to a 50 Hz E-field with an intensity of 5.0 kV/m, 11.5 kV/m, 23.0 kV/m, or 34.5 kV/m. After 12 h of exposure, hemolymph samples were taken for protease analysis, and the bees were recorded for behavioral analysis. Six behaviors were chosen for observation: walking, flying, self-grooming, contact between individuals, stillness, and wing movement. Bees in the control group demonstrated the highest number of all behavior occurrences, except flying, and had the lowest protease activity. Bees in the experimental groups showed a lower number of occurrences of walking, self-grooming, and contacts between individuals than the control bees and had significantly higher protease activity than the control bees (except that of alkaline proteases in the 23.0 kV/m group).


1965 ◽  
Vol 11 (2) ◽  
pp. 243-257 ◽  
Author(s):  
E. E. Woodside

Morphological heterogeneity in cell sizes of Escherichia coli, strains B, B/r, and BSprevents estimation of the viable cell count by the indirect turbidimetric method. The average dry weights of E. coli B, B/r, and BS, when grown in acetate synthetic medium, are 0.16, 0.10, and 0.13 picograms per cell respectively. Increased radiation sensitivity was correlated with those bacterial populations showing decreased intracellular glycogen content, decreased lipopolysaccharide–lipoprotein content, R-colony forms, and cellular elongation. The radiation-sensitive strains contained more DNA, RNA, and protein per cell than the radiation-resistant mutant; however, no significant differences were evident in the DNA, RNA, and protein contents on a dry weight basis. No qualitative differences in the monosaccharides or their derivatives were found. Intracellular glucose synthesis and accumulation preceded DNA, RNA, and protein synthesis throughout the lag and early logarithmic growth phases for all three strains. Multiple forms of intracellular glycogen complexes were present in all three strains. In addition to unbound glycogen and protein-bound glycogen, a bound form of glycogen was consistently associated with crude fractions which contained the DNA, RNA, and lipopolysaccharide constituents. Increased lability of the cold TCA-insoluble bound glycogen to hot TCA and alpha-amylase hydrolysis was correlated with increased radiosensitivities of the organisms.


Sign in / Sign up

Export Citation Format

Share Document