Recovery of Bacillus licheniformis Alkaline Protease from Supernatant of Fermented Wastewater Sludge Using Ultrafiltration and Its Characterization

Abstract

Investigation on recovery of alkaline protease from B. licheniformis ATCC 21424 fermented wastewater sludge was carried out by centrifugation and ultrafiltration. Optimization of ultrafiltration parameters (transmembrane pressure (TMP) and feed flux) was carried out with 10 kDa membrane. TMP of 90 kPa and feed flux of 714 L/h/m2 gave highest recovery (83%) of the enzyme from the centrifuged supernatant. The recovered enzyme had given maximum activity at temperature of 60°C and at pH 10. It was stable between pH 8 to 10 and retained 97% activity at 60°C after 180 min of incubation. Enzyme activity was significantly augmented by metal ions like Ca2+ and Mn2+. Protease inhibitors like phenylmethyl sulphonyl fluoride (PMSF) and diisopropyl fluorophosphates (DFPs) completely inhibited the enzyme activity. The partially purified protease showed excellent stability and compatibility with various commercial detergents. The detergent (Sunlight) removed the blood stains effectively along with the enzyme as additive.

Purification and biochemical characterization of a novel thermostable serine alkaline protease from Aeribacillus pallidus C10: a potential additive for detergents

“…These results suggest that this enzyme is a thermophilic protease. Some proteases, the optimum temperature of which was 60 °C, have also been reported, which are B. licheniformis ATCC 21424 47 , B. mojavensis A21 8 , Bacillus sp. SM2014 46 , and A.veronii PG01 48 .…”

Assessment of protease activity in hydrolysed extracts from SSF of hair waste by and indigenous consortium of microorganisms

“…Additionally, protease activity was not detected in permeate as the size of alkaline proteases produced were in range between 26-100 kDa. Some studies reported that there was no protease activity detectable in all permeates due to the lost as a deposit in the membrane of the tube (Bezawada et al, 2011). However, during lyophilisation the loss of activity resulted in 21%, being this step the most critical for the recovery of protease.…”

Characterization of the Crude Alkaline Extracellular Protease of Yarrowia lipolytica YlTun15

“…It well established that pH is a key factor influencing the ionization state of the amino acid or ionization of the substrate and thereby the expression of the enzyme activity (Bezawada et al, 2011). In the present study, the relative protease activity measured at different pH ranging from 6 to 10 (Figure 3) showed maximum activities at pH 9 (88.69 ± 1.71).…”

“…The result presented in Table 1 protease activity; this may be due to the activation by the metal ions (Bezawada et al, 2011;Kumar et Takagi, 1999 showed maximum inhibition on enzyme activity up to 60%, while Hg + inhibited the enzyme activity up to 35%. Analogous results were found for the A. pullulan, A. terreus and B. subtilis , Niyonzima and More, 2015, and Alam et al, 2017.The inhibitory effect of mercury was due to the fact that it reacts with protein thiol groups and with histidine and tryptophan residues (Bezawada et al, 2011, Barth andGaillardin, 1997).…”