Singh et al.

activity and therefore the initial temperature is vital (Gangadharan et al., 2006).

Temperature plays a significant role in development of the biological processes

as it influences protein denaturation, enzyme inhibition and cell growth (Balkan

et al., 2005). Varalakshmi et al. (2012) also reported 37°C for the production of

enzyme when Pseudomonas sp. 2 was used with wheat bran and further increase

of temperature decreased the enzyme production. Similar results were also found

by Ashraf et al. (2005) when Bacillus licheniformis was used with wheat bran at

40°C. Further increase in the incubation temperature there was gradual reduction

in the enzyme formation. Sameh et al. (2013) reported maximum enzyme

production at 37°C when crude millet was used as substrate with a new Bacillus

sp. UEB-S under solid state fermentation. Nagrajan et al. (2010) reported similar

results when wheat bran and rice bran were fermented with Bacillussubtilis.

Kalairasi and Paravtham (2013) obtained optimal temperature for maximum

alpha amylase production at higher temperature i.e. 50°C when Bacillus cereus

was used with wheat bran. Temperature above 50°C resulted in lesser growth

of Bacillus cereus and decreased the enzyme production. Moisture loss in solid

substrate due to increase in temperature might be the cause for lesser production

of alpha amylase. Tabassum et al. (2014) reported the enzyme production at 37°C

when wheat bran was used as substrate with Bacilluslicheniformis RTPE1. Rai

and Solanki (2014) also reported 38°C fot maximum yield of enzyme by using

Bacillusamyloliquefaciens with a mixture of wheat bran and barley bran (1:1).

El- Shishtawy et al. (2014) observed optimum temperature to be 45°C for amylase

production from wheat bran by using the Bacillus sp. In other study the optimum

temperature recorded for maximum growth and alpha amylase production by B.

subtilis was 35°C (Unakal et al., 2012).

Effect of different Incubation periods on alpha amylase production by Bacillus

licheniformis under SSF condition

In SSF, the incubation time for achieving the maximum enzyme level is governed

by the characteristics of the culture and is based on growth rate and enzyme

production. The different incubation times selected for α- amylase production

were 24, 48, 72, 96 and 120 h. There was a decreasing trend in enzyme production

from 48 to 120 h of incubation. Bacillus licheniformis produced high titers of

enzyme (155.06 IU) at 48 h of incubation. A steady decline in enzyme activity

was observed after 48 h to 120 h, with the lowest enzyme titer (83.56 IU) at 120

h (Table 6; Fig 6).

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