Production, purification and Characterization of thermostable bacterial α– amylase by solid state fermentation of agro-byproducts
KrishiKosh
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Title |
Production, purification and Characterization of thermostable bacterial α– amylase by solid state fermentation of agro-byproducts
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Creator |
Singh, Ajay Kumar
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Contributor |
Ramteke, P. W.
Masih, Harison |
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Subject |
oils, oilseeds, marketing, markets, sales, productivity, plant oils, retail marketing, groundnuts, accounts
Bacillus amyloliquefaciens, Bacillus licheniformis, SSF, Enzyme activity |
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Description |
A Thesis Entitled “Production, Purification and Characterization of Thermostable Bacterial Α–Amylase by Solid State Fermentation of Agro-Byproducts” was submitted in partial fulfillment of the requirement for the award of the degree of Doctor of Philosophy in Biotechnology by Ajay Kumar Singh.
The production of extracellular α-amylase by thermotolerant Bacillus amyloliquefaciens and Bacillus licheniformis was studied under solid state fermentation (SSF). Various agro- byproducts namely Wheat flour, Barley flour, Corn flour, Gram flour, Moong husk, Arhar husk, Mustard oil cake, coconut oil cake, Banana peel, Potato peel, Sweet Potato peel, Soybean hull, Wheat bran, Rice bran, and Sugarcane baggase were examined for α- amylase production. Among all the substrates wheat flour was found to be best substrate for α-amylase production (145.56 IU/ml) in phosphate buffer as extracting medium for Bacillus amyloliquefaciens, but in case of Bacillus licheniformis, wheat bran supported maximum growth and produced maximum α- amylase (154.17 IU/ml) with Triton –X as extraction medium. Process optimization was conducted using wheat flour and wheat bran in a single parameter mode showing enhanced enzyme titre. Further, the appropriate incubation period, moisture level, incubation temperature and inoculum concentration were determined. Maximum yields of 149.62 IU/ml, 144.64 IU/ml, 173.28 IU/ml, 164.48 IU/ml were achieved by employing wheat flour as substrates with Bacillus amyloliquefaciens at temperature 37°C, pH 7, moisture content 80% and incubation period 72 h whereas Bacillus licheniformis was found to produce optimum α- amylase at temperature 40°C (168.78 IU/ml), pH 6 (170.34 IU/ml), moisture content 80% (171.89 IU/ml) and incubation period 48 h (155.06 IU/ml). The phosphate concentration was also found to enhance α- amylase yield. Media supplementation with carbon source as (1%) maltose and (0.15 M) inorganic source (ammonium chloride) in SSF medium increased amylase enzyme yield (167.44 IU/ml, 167.11 IU/ml) for Bacillus amyloliquefaciens and (178.46 IU/ml and 172.36 IU/ml) for Bacillus licheniformis, respectively. The effect of addition of external organic nitrogenous compounds further showed a positive impact on enzyme synthesis by both the culture. Increase in the enzyme activity was obtained when tryptone and soy peptone at 1% concentration was added to the fermentation medium. The enzyme was partially purified to 2.40 and 2.18 fold by ammonium sulphate precipitation and ion exchange chromatography. The stability profile of the partially purified enzyme from both strains exhibited maximum activity at 65°C and pH 6-7. The enzyme exhibited marked increase in activity in presence of metal ions (Ca2+, Fe+++, Mn2+). On the basis of comparative production optimization parameters the molecular weight of purified alpha amylase enzyme from Bacillus licheniformis was determined and estimated as 71 kDa on SDS Polyacrylamide gel electrophoresis. The apparent Km and Vmax of alpha amylase enzyme from Bacillus amyloliquefaciens for soluble starch were estimated to be 0.085 mg/ml and 212.76 IU/ml respectively whereas from Bacillus licheniformis were found to be 0.074 mg/ml and185.87 IU/ml, respectively. |
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Date |
2016-12-16T10:37:13Z
2016-12-16T10:37:13Z 2016 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/90459
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Language |
en
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Format |
application/pdf
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Publisher |
Sam Higginbottom Institute of Agriculture, Technology & Sciences (SHIATS)
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