Concomitant production of two proteases and alpha-amylase by a novel strain of Bacillus subtilis in a microprocessor controlled bioreactor

Abstract

We describe the simultaneous production of Bacillus subtilis based proteases and alpha amylase using a computer controlled laboratory scale 7.5 L batch bioreactor. The present strain is the first to be reported that concomitantly produces these two industrially important enzymes. The growth and sporulation of Bacillus subtilis was monitored and maximum production of alkaline protease and alpha amylase was found to coincide with maximum sporulation. Two types of proteases were detected in the fermentation broth; a neutral and an alkaline protease most active in a pH range of 7.0-8.0 and 8.0-10, respectively. Maximum production of proteases was observed at an incubation temperature of 37°C while that of alpha amylase was observed at 40°C. The optimum aeration and agitation levels for protease production were 0.6 L/L/min and 200rpm, respectively, and for alpha amylase were 0.6 L/L/min and 150 rpm. The kinetic parameters Y p/x and qp were also found to be significant at the given fermentation conditions.

Optimization of Solid State Fermentation Conditions and Characterization of Thermostable Alpha Amylase from Bacillus subtilis (ATCC 6633)

“…The value can be correlated with the results of other workers supporting highest amylase production after 48 hours fermentation period [20]. Earlier study depicts that a clear correlation exists between bacterial growth and alpha amylase production [23]. The activity or production of amylase rises linearly with time up to 42 hours that merges with the sporulation pattern of Bacillus subtilis [23].…”

“…Earlier study depicts that a clear correlation exists between bacterial growth and alpha amylase production [23]. The activity or production of amylase rises linearly with time up to 42 hours that merges with the sporulation pattern of Bacillus subtilis [23]. The fall in activity of amylase beyond 48 hours may be due to the denaturation or degradation of alpha amylase in presence of other components in the fermentation medium like protease etc.…”

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“…Higher agitation rates could increase the oxygen pressure of the system, but did not provide the increase in enzyme production, probably because at a high agitation rate, the structure of enzyme would be altered (Roychoudhury et al 1989). A similar profile was determined for the effect of agitation speed on α-amylase production by Bacillus subtilis (Mukhtar and Ikram ul 2012). Some researchers reported various agitation rates (100-200 rpm) for enzymes production by different microorganisms (Dahot 1986, Mamma et al 2008, Sharma and Satyanarayana 2011.…”

“…The maximum production of α-amylase was obtained at 40 °C for Bacillus sp. and Bacillus cereus (Mukhtar and Ikram ul 2012, Singh et al 2015, Sivakumar et al 2011. The higher temperatures, the enzyme production decreased which might be due to growth reduction and enzyme inactivation or suppression of cell viability (Goes and Sheppard 1999).…”

Simultaneous production of commercial enzymes using agro industrial residues by statistical approach

“…The interaction between these bioprocess variables becomes the vital aspect for evaluating multienzyme production in SSF. Simultaneous production of enzymes, including amylase and protease, lipase and protease, protease and cellulase were reported. However, reports on simultaneous production of amylase and pectinase from Bacillus sp.…”