The Experts below are selected from a list of 7623 Experts worldwide ranked by ideXlab platform
J.r. Valéro - One of the best experts on this subject based on the ideXlab platform.
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production of biopesticides using wastewater sludge as a raw material effect of process parameters
Water Science and Technology, 2003Co-Authors: M Tirado L Montiel, J.r. Valéro, R D Tyagi, Rao Y. SurampalliAbstract: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.
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simultaneous production of biopesticide and alkaline proteases by bacillus thuringiensis using sewage sludge as a raw material
Water Science and Technology, 2002Co-Authors: R D Tyagi, Sikati V Foko, Simon Barnabé, A S Vidyarthi, J.r. Valéro, Rao Y. SurampalliAbstract: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 CaCl 2 , indicating the proteases were metalloproteases.
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wastewater treatment sludge as a raw material for the production of bacillus thuringiensis based biopesticides
Water Research, 2001Co-Authors: Maria De Lourdes Tirado Montiel, R D Tyagi, J.r. ValéroAbstract:Abstract Seven wastewater sludges of different origins and types were used as an alternate culture medium for producing Bacillus thuringiensis variety kurstaki HD-1. The sludge samples were used under three different preparations: without pre-treatment, with acid treatment (hydrolysed sludge) and the supernatant obtained after centrifugation of the hydrolysed sludge. The sludge composition varied widely with origin and the type of sludge. Growth and sporulation were evaluated by the total Viable Cell Count and spore Count of the preparations. Growth, sporulation and endotoxin production were affected by the sludge origin. Hydrolysed sludge gave the highest Viable Cell and spore Counts while the liquid phase (supernatant) gave the lowest. Non-hydrolysed primary sludge from Valcartier was unable to sustain bacterial growth because of its low pH. Bioassays were conducted against larvae of spruce budworm to evaluate entomotoxic potential of the preparations obtained. In general, sludge hydrolysis increased the entomotoxicity yields. Similar entomotoxicity was observed in Black Lake secondary sludge (4100 IU/μL) as that obtained in the reference soya medium (3800 IU/μL). The use of the sludge supernatant (liquid phase) was not recommended due to the low entomotoxic potential obtained.
S.-q. Liu - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of bifidobacteria survival by Williopsis saturnus var. saturnus in milk.
Beneficial microbes, 2015Co-Authors: A.y.y. Yeo, Mingzhan Toh, S.-q. LiuAbstract:The viability of three strains of probiotic Bifidobacterium lactis that were inoculated into UHT milk was examined with and without the presence of the yeast, Williopsis saturnus var. saturnus NCYC 22, in polypropylene tubes at 30 °C. The B. lactis Viable Cell Count for strains HN019 and BB-12 remained above 6.0 Log cfu/ml, while strain B94 had 5.7 Log cfu/ml after six weeks of incubation in the presence of the co-inoculated yeast. Incubating the bifidus milk without added yeast under anaerobic condition did not improve the survival of B. lactis HN019, indicating that oxygen removal may not be responsible for W. saturnus NCYC 22’s viability enhancing property. The addition of yeast supernatant or non-Viable yeast also did not show any stabilising effects, suggesting that physical contact and/or interaction between Viable W. saturnus and B. lactis plays an important role in sustaining the viability of the probiotic. W. saturnus NCYC 22 could increase the survival of B. lactis in bifidus milk under ambient ...
Mono Mohan Singh - One of the best experts on this subject based on the ideXlab platform.
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Toxicity Assay Using Bacterial Growth
Environmental Chemistry, 2008Co-Authors: Jorge G. Ibanez, Margarita Hernandez-esparza, Carmen Doria-serrano, Arturo Fregoso-infante, Mono Mohan SinghAbstract:After performing the experiment, the student shall be able to: Use the Viable Cell Count of a mixed bacterial culture present in spent water to assess the toxicity of sodium azide, chromium (VI), and chromium (III) as examples of inorganic toxic compounds.
R D Tyagi - One of the best experts on this subject based on the ideXlab platform.
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production of biopesticides using wastewater sludge as a raw material effect of process parameters
Water Science and Technology, 2003Co-Authors: M Tirado L Montiel, J.r. Valéro, R D Tyagi, Rao Y. SurampalliAbstract: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.
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simultaneous production of biopesticide and alkaline proteases by bacillus thuringiensis using sewage sludge as a raw material
Water Science and Technology, 2002Co-Authors: R D Tyagi, Sikati V Foko, Simon Barnabé, A S Vidyarthi, J.r. Valéro, Rao Y. SurampalliAbstract: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 CaCl 2 , indicating the proteases were metalloproteases.
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wastewater treatment sludge as a raw material for the production of bacillus thuringiensis based biopesticides
Water Research, 2001Co-Authors: Maria De Lourdes Tirado Montiel, R D Tyagi, J.r. ValéroAbstract:Abstract Seven wastewater sludges of different origins and types were used as an alternate culture medium for producing Bacillus thuringiensis variety kurstaki HD-1. The sludge samples were used under three different preparations: without pre-treatment, with acid treatment (hydrolysed sludge) and the supernatant obtained after centrifugation of the hydrolysed sludge. The sludge composition varied widely with origin and the type of sludge. Growth and sporulation were evaluated by the total Viable Cell Count and spore Count of the preparations. Growth, sporulation and endotoxin production were affected by the sludge origin. Hydrolysed sludge gave the highest Viable Cell and spore Counts while the liquid phase (supernatant) gave the lowest. Non-hydrolysed primary sludge from Valcartier was unable to sustain bacterial growth because of its low pH. Bioassays were conducted against larvae of spruce budworm to evaluate entomotoxic potential of the preparations obtained. In general, sludge hydrolysis increased the entomotoxicity yields. Similar entomotoxicity was observed in Black Lake secondary sludge (4100 IU/μL) as that obtained in the reference soya medium (3800 IU/μL). The use of the sludge supernatant (liquid phase) was not recommended due to the low entomotoxic potential obtained.
A.y.y. Yeo - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of bifidobacteria survival by Williopsis saturnus var. saturnus in milk.
Beneficial microbes, 2015Co-Authors: A.y.y. Yeo, Mingzhan Toh, S.-q. LiuAbstract:The viability of three strains of probiotic Bifidobacterium lactis that were inoculated into UHT milk was examined with and without the presence of the yeast, Williopsis saturnus var. saturnus NCYC 22, in polypropylene tubes at 30 °C. The B. lactis Viable Cell Count for strains HN019 and BB-12 remained above 6.0 Log cfu/ml, while strain B94 had 5.7 Log cfu/ml after six weeks of incubation in the presence of the co-inoculated yeast. Incubating the bifidus milk without added yeast under anaerobic condition did not improve the survival of B. lactis HN019, indicating that oxygen removal may not be responsible for W. saturnus NCYC 22’s viability enhancing property. The addition of yeast supernatant or non-Viable yeast also did not show any stabilising effects, suggesting that physical contact and/or interaction between Viable W. saturnus and B. lactis plays an important role in sustaining the viability of the probiotic. W. saturnus NCYC 22 could increase the survival of B. lactis in bifidus milk under ambient ...
