Production and partial characterization of dehairing alkaline protease from Bacillus subtilis AKAL7 and Exiguobacterium indicum AKAL11 by using organic municipal solid wastes

Abstract

Alkaline proteases have applications in numerous industries. In this study, we have isolated and screened proteolytic bacteria from poultry wastes mixed soil and identified two bacterial isolates as Bacillus subtilis AKAL7 and Exiguobacterium indicum AKAL11 based on 16S rDNA sequencing. Maximum level of protease production was achieved after 24 h of fermentation in a basal medium. The optimal temperature, initial pH of the media and agitation for alkaline protease production by these two isolates were 30 °C, pH 9.0 and 120 rpm, respectively. The both bacterial isolates produced maximum level of protease with 3.0% organic municipal solid wastes (OMSW) as the sole source of carbon and nitrogen under previously optimized fermentation conditions. In comparison with the shake flask, protease production increased about 2.5-fold in the bioreactor with reduction in fermentation period. The partial purification of protease resulted in a final 45.67 and 34.86-fold purified protease with a specific activity of 8335.34 and 9918.91 U/mg protein and a typical yield of 9.75 and 9.41% from B. subtilis and E. indicum, respectively. The optimum temperature and pH of the partially purified protease from the both sources was 40 °C and pH 9.0, respectively. Protease from the both isolates was stable at pH 7.0–12.0 and at temperatures up to 50 °C. The effects of protease inhibitors indicated that the protease from B. subtilis might be serine and cysteine type and from E. indicum might be cysteine type. Mg2+, K+ and Ca2+ stimulated but Zn2+, Hg2+, Co2+ and Fe3+ strongly inhibited the protease activity. The partially purified protease from B. subtilis substantially dehaired cow skin and decomposed gelatinous compound from X-ray film. Our study revealed that OMSW can be used as raw material for production of bacterial extracellular protease and alkaline protease from B. subtilis might be potential for industrial and biotechnological applications.

HEAT AND pH STABLE PROTEASE PRODUCED BY A BACTERIUM ISOLATED FROM FIELDS WITH HIGH BORON

“…Cu 2+ ions may be important for catalysis. It is reported that the activity of alkaline protease from Bacillus sp., Bacillus subtilis, and Bacillus megaterium RRM2 was decreased by Fe 3+ , Hg 2+ , Zn 2+ and Co 2+ (Venugopal and Saramma, 2007;Olajuyigbe and Falade, 2014;Hakim et al, 2018).…”

“…DB14 protease exhibited interestingly stability in the temperature range of 20 °C and 50 °C. Similarly, Lakshmi et al (2018) reported thermostability of protease from Bacillus cereus strain S8 exhibiting in the temperature range of 30-80 °C, while Hakim et al (2018) showed that Bacillus subtilis AKAL7 protease was stable from 30 °C to 50 °C. Jaouadi et al (2008) determined that the protease of Bacillus pumilus CBS was stable in the temperature range 30-55 °C.…”

“…Proteases (EC 3.4.2124) which breaks the peptide bonds in amino acid residues of other enzymes are member of the class of hydrolases. They are utilized in the large industrial applications such as detergent, leather, pharmaceutical, protein processing, foods (Hakim et al, 2018;Lakshmi et al, 2018). The proteases are one of the vital enzymes which account 40%-60% of the total worldwide enzymes sales (Harer et al, 2018;Hakim et al, 2018).…”

“…They are utilized in the large industrial applications such as detergent, leather, pharmaceutical, protein processing, foods (Hakim et al, 2018;Lakshmi et al, 2018). The proteases are one of the vital enzymes which account 40%-60% of the total worldwide enzymes sales (Harer et al, 2018;Hakim et al, 2018). Microbial enzymes are more efficient compared to enzymes of other organisms such as plant and animal (Banerjee et al, 1999).…”

Purification and characterization of cysteine protease from miswak Salvadora persica

“…Papaya proteases had pharmaceutical applications such as antitumorals, anti-inflammatory, wound healing and digestive disorder [ 13 ]. The partially purified protease from B. subtilis substantially dehaired cow skin [ 14 ].…”