Hyper-production of Alkaline Protease by Mutagenic Treatment of Bacillus subtilis M-9 using Agroindustrial Wastes in Submerged Fermentation

ABSTRACT Expression of the gene for the extracellular alkaline protease (aprE) of Bacillus subtilis is subject to regulation by many positive and negative regulators. We have found that aprE expression was increased by disruption of the glutamine synthetase gene glnA. The increase in aprE expression was attributed to a decreased in expression of scoC, which encodes a negative regulator of aprE expression. The glnA effect on scoC expression was abolished by further disruption of tnrA, indicating that aprE expression is under global regulation through TnrA. In the scoC background, however, aprE expression was decreased by glnA deletion, and it was shown that the decrease was due to a defect in positive regulation by DegU. Among the genes that affect aprE expression through DegU, the expression of degR, encoding a protein that stabilizes phosphorylated DegU, was inhibited by glnA deletion. It was further shown that the decrease in degR expression by glnA deletion was caused by inhibition of the expression of sigD, encoding the σD factor, which is required for degR expression. In accordance with these findings, the expression levels of aprE-lacZ in glnA scoC degR and scoC degR strains were identical. These results led us to conclude that glnA deletion brings about two effects on aprE expression, i.e., a positive effect through inhibition of scoC expression and a negative effect through inhibition of degR expression, with the former predominating over the latter.

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Comparative Evaluation of Agroindustrial Byproducts for the Production of Alkaline Protease by Wild and Mutant Strains ofBacillus subtilisin Submerged and Solid State Fermentation

The Scientific World JOURNAL ◽

10.1155/2013/538067 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Hamid Mukhtar ◽

Ikramul Haq

Keyword(s):

Bacillus Subtilis ◽

Solid State ◽

Wheat Bran ◽

Solid State Fermentation ◽

Soybean Meal ◽

Alkaline Protease ◽

Enzyme Production ◽

Enhanced Production ◽

Industrial Byproducts ◽

Agroindustrial Byproducts

The present study describes the screening of different agroindustrial byproducts for enhanced production of alkaline protease by a wild and EMS induced mutant strain ofBacillus subtilisIH-72EMS8. During submerged fermentation, different agro-industrial byproducts were tested which include defatted seed meals of rape, guar, sunflower, gluten, cotton, soybean, and gram. In addition to these meals, rice bran, wheat bran, and wheat flour were also evaluated for protease production. Of all the byproducts tested, soybean meal at a concentration of 20 g/L gave maximum production of the enzyme, that is, 5.74 ± 0.26 U/mL from wild and 11.28 ± 0.45 U/mL from mutant strain, during submerged fermentation. Different mesh sizes (coarse, medium, and fine) of the soybean meal were also evaluated, and a finely ground soybean meal (fine mesh) was found to be the best. In addition to the defatted seed meals, their alkali extracts were also tested for the production of alkaline protease byBacillus subtilis, but these were proved nonsignificant for enhanced production of the enzyme. The production of the enzyme was also studied in solid state fermentation, and different agro-industrial byproducts were also evaluated for enzyme production. Wheat bran partially replaced with guar meal was found as the best substrate for maximum enzyme production under solid state fermentation conditions.

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Xylanase Production by Bacillus subtilis Using Carbon Source of Inexpensive Agricultural Wastes in Two Different Approaches of Submerged Fermentation (SmF) and Solid State Fermentation (SsF)

Journal of Food Processing & Technology ◽

10.4172/2157-7110.1000437 ◽

2015 ◽

Vol 06 (04) ◽

Cited By ~ 2

Keyword(s):

Bacillus Subtilis ◽

Solid State ◽

Carbon Source ◽

Solid State Fermentation ◽

Submerged Fermentation ◽

Agricultural Wastes ◽

Xylanase Production

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Biochemical studies on ricin. XV. Limited hydrolysis of ricin D with alkaline protease from Bacillus subtilis.

Agricultural and Biological Chemistry ◽

10.1271/bbb1961.41.1309 ◽

1977 ◽

Vol 41 (7) ◽

pp. 1309-1310 ◽

Cited By ~ 4

Author(s):

Gunki FUNATSU ◽

Masaru FUNATSU

Keyword(s):

Bacillus Subtilis ◽

Alkaline Protease ◽

Biochemical Studies ◽

Hydrolysis Of

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Production and characterisation of thermostable alkaline protease from Bacillus subtilis isolated from LA hot spring, Terengganu

Research Journal of Biotechnology ◽

10.25303/167rjbt8421 ◽

2021 ◽

Vol 16 (7) ◽

pp. 84-91

Author(s):

Maslinda Alias ◽

Hakim Che Harun Mohammad ◽

Ashraf Razali Nurul ◽

Jasnizat Saidin ◽

Nazaitulshila Rasit ◽

...

Keyword(s):

Bacillus Subtilis ◽

Alkaline Protease ◽

Protease Activity ◽

Hot Spring ◽

Skim Milk ◽

Industrial Applications ◽

Protease Production ◽

Significant Activity ◽

Original Activity ◽

Optimum Ph

This research aims to produce thermostable alkaline protease from Bacillus subtilis isolated from La Hot Spring, Terengganu, Malaysia. The study was also conducted to determine the optimum conditions for protease production and stability by considering several parameters including pH, temperature and salt concentration. All seven bacteria were screened on skim milk agar overnight at 37 °C. Three strains with the highest proteolytic activity were identified in protease specific medium. The thermostable alkaline protease had an optimum temperature of 60 °C which achieved 85.73, 82.90 and 83.05 U/mL of protease activity for the three strains respectively. Furthermore, the strains exhibited significant activity of more than 90% from their original activity. Meanwhile, the optimum pH for protease production was pH 9 with the protease activity of 76.76, 79.71 and 88.39 U/mL for TB4, TB6 and TB9 strains, respectively. Proteases were found stable at pH 9 where the loss did not exceed 30% of its original activity. Collectively, all of the data emphasised that proteases from B. subtilis were alkaline thermostable proteases in accordance with a recent report. The finding highlights the viability of the proteases for biotechnological and industrial applications.

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