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

1977 ◽  
Vol 41 (7) ◽  
pp. 1309-1310 ◽  
Author(s):  
Gunki FUNATSU ◽  
Masaru FUNATSU
2009 ◽  
Vol 191 (9) ◽  
pp. 3050-3058 ◽  
Author(s):  
Sadanobu Abe ◽  
Ayako Yasumura ◽  
Teruo Tanaka

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hamid Mukhtar ◽  
Ikramul Haq

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.


2006 ◽  
Vol 188 (21) ◽  
pp. 7609-7616 ◽  
Author(s):  
Alicia Monroe ◽  
Peter Setlow

ABSTRACT The Bacillus subtilis spore coat protein GerQ is necessary for the proper localization of CwlJ, an enzyme important in the hydrolysis of the peptidoglycan cortex during spore germination. GerQ is cross-linked into high-molecular-mass complexes in the spore coat late in sporulation, and this cross-linking is largely due to a transglutaminase. This enzyme forms an ε-(γ-glutamyl) lysine isopeptide bond between a lysine donor from one protein and a glutamine acceptor from another protein. In the current work, we have identified the residues in GerQ that are essential for transglutaminase-mediated cross-linking. We show that GerQ is a lysine donor and that any one of three lysine residues near the amino terminus of the protein (K2, K4, or K5) is necessary to form cross-links with binding partners in the spore coat. This leads to the conclusion that all Tgl-dependent GerQ cross-linking takes place via these three lysine residues. However, while the presence of any of these three lysine residues is essential for GerQ cross-linking, they are not essential for the function of GerQ in CwlJ localization.


2021 ◽  
Vol 16 (7) ◽  
pp. 84-91
Author(s):  
Maslinda Alias ◽  
Hakim Che Harun Mohammad ◽  
Ashraf Razali Nurul ◽  
Jasnizat Saidin ◽  
Nazaitulshila Rasit ◽  
...  

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.


2014 ◽  
Vol 14 (7) ◽  
pp. 472-479
Author(s):  
O.M. Ajunwa ◽  
O.A. Odeniyi ◽  
A.J. Adeleke ◽  
F.A. Orji ◽  
J.U. Ewansiha ◽  
...  

2001 ◽  
Vol 183 (16) ◽  
pp. 4886-4893 ◽  
Author(s):  
Madan Paidhungat ◽  
Katerina Ragkousi ◽  
Peter Setlow

ABSTRACT Dormant Bacillus subtilis spores can be induced to germinate by nutrients, as well as by nonmetabolizable chemicals, such as a 1:1 chelate of Ca2+ and dipicolinic acid (DPA). Nutrients bind receptors in the spore, and this binding triggers events in the spore core, including DPA excretion and rehydration, and also activates hydrolysis of the surrounding cortex through mechanisms that are largely unknown. As Ca2+-DPA does not require receptors to induce spore germination, we asked if this process utilizes other proteins, such as the putative cortex-lytic enzymes SleB and CwlJ, that are involved in nutrient-induced germination. We found that Ca2+-DPA triggers germination by first activating CwlJ-dependent cortex hydrolysis; this mechanism is different from nutrient-induced germination where cortex hydrolysis is not required for the early germination events in the spore core. Nevertheless, since nutrients can induce release of the spore's DPA before cortex hydrolysis, we examined if the DPA excreted from the core acts as a signal to activate CwlJ in the cortex. Indeed, endogenous DPA is required for nutrient-induced CwlJ activation and this requirement was partially remedied by exogenous Ca2+-DPA. Our findings thus define a mechanism for Ca2+-DPA-induced germination and also provide the first definitive evidence for a signaling pathway that activates cortex hydrolysis in response to nutrients.


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