Development of a solid-state fermentation process for production of bacterial

extract.After 10 min of incubation at 37°C, 3 ml of 3, 5-dinitrosalicylic acid (DNS)

reagent was added and boiled for 5 minutes to stop the reaction. The liberated

reducing sugars (glucose equivalents) were estimated by glucose standard curve

using the 3, 5- dinitrosalicylic acid (DNS) (Miller, 1959).The colour developed

was read at 510 nm using a UV- spectrophotometer. Enzyme activity (IU) was

calculated as the amount of enzyme releasing one µmol of glucose equivalents per

minute under the assay conditions”. The enzyme activities used for representations

were the average values of three independent experiments.

Amount of reducing sugars (X) ×

Dilution factor

Enzyme activity (U/ml) = ----------------------------------------

Molecular weight of glucose ×

time of incubation ×

volume of enzyme

Evaluation of various agrobased substrates for production of alpha amylase

by using Bacillus licheniformis

In an attempt to choose a potential substrate for solid state fermentation which

supports amylase production, various agro residues like Wheat flour, Moong

husk, Barley flour, Corn flour, Gram flour, Arhar husk, Mustard oil cake, Coconut

oil cake, Rice bran, wheat bran, Potato peel, Sweet potato peel, Banana peel,

Sugarcane baggase, Soybean husk were evaluated individually. SSF was carried

out at 37°C for 48 h and crude enzyme was extracted by centrifugation at 8000

rpm for 10 minutes. The supernatant so obtained after centrifugation was used

for enzyme assay. The substrate showing highest enzyme activity was considered

potential substrate for production of alpha amylase

Optimization of fermentation process parameters for production of alpha

amylase

Best substrate was employed for further optimization of production process

parameters namely initial moisture content (55, 60, 65, 70, 75, 80, 85 and 90 %),

incubation time (24, 48, 72, 96, and 120 h), incubation temperature (35, 40, 45, 50,

and 55°C), initial pH (4, 5, 6, 7, 8, 9, and 10) of the medium, inoculums size (0.5,

1, 2, 4, 6, and 8 x 106 CFU/ml).

Optimization of medium components for production of alpha amylase in SSF

To study the efficacy of various inducers the fermentation medium was

supplemented independently with 1% carbon sources (glucose, lactose, maltose

and soluble starch), inorganic nitrogen sources (0.15M) (Ammonium nitrate,

International Journal of Bioinformatics and Biological Sciences : v.2 n.3&4. Dec. 2014

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