scholarly journals Enhancement of Alkaline Protease Activity and Stability via Covalent Immobilization onto Hollow Core-Mesoporous Shell Silica Nanospheres

2016 ◽  
Vol 17 (2) ◽  
pp. 184 ◽  
Author(s):  
Abdelnasser Ibrahim ◽  
Ali Al-Salamah ◽  
Ahmed El-Toni ◽  
Khalid Almaary ◽  
Mohamed El-Tayeb ◽  
...  
Keyword(s):  
Alkaline Protease ◽  
Protease Activity ◽  
Covalent Immobilization ◽  
Hollow Core ◽  
Silica Nanospheres ◽  
Mesoporous Shell

Resistance of Phlebotomus papatasi to infection with Leishmania donovani is modulated by components of the infective bloodmeal

Parasitology ◽  
1998 ◽  
Vol 117 (5) ◽  
pp. 467-473 ◽  
Author(s):  
Y. SCHLEIN ◽  
R. L. JACOBSON
Keyword(s):  
Proteolytic Activity ◽  
Trypsin Inhibitor ◽  
Alkaline Protease ◽  
Protease Activity ◽  
Leishmania Donovani ◽  
Blood Feeding ◽  
Growth Conditions ◽  
Enzymatic Activities ◽  
Phlebotomus Papatasi ◽  
Proteolytic Activities

The circumstances which permit the establishment of Leishmania infections in sandflies were investigated by altering the growth conditions for L. donovani parasites in the unsuitable vector Phlebotomus papatasi. Only 5·0% of the sandflies harboured a few parasites 3 days after feeding on promastigotes in defibrinated blood. Heparinized blood or the addition of trypsin inhibitor to the meals allowed persistence of infections (day 6) in 9·9% and 25·8% of the flies respectively. Meals of erythrocytes, saline and amastigotes produced 44·4% fly infection on day 6, while similar promastigote-initiated infections remained in 70·3% of the flies. Proteolytic activities in the guts of sandflies fed on the above meals without parasites, were the highest after defibrinated bloodmeals. Erythrocytes with saline decreased the maximal alkaline protease level from 20·8 U to 13·5 U/fly; that of trypsin from 3·9 U to 1·8 U/fly and that of the aminopeptidase from 5·5 U to 3·9 U/fly. After meals of heparinized blood, the maximal alkaline protease activity (12·0 U/fly) was also much lower than after defibrinated blood-feeding. The different diets which resulted in comparatively low enzymatic activities, including blood with trypsin inhibitor, also promoted the survival of infections. This implies that the proteolytic activity in the sandfly gut modulates the vector susceptibility.

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

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.

scholarly journals Sporulation and Extracellular Alkaline Protease Activity of Bacillus subtilis 168 Grown in the Presence of Tween

1988 ◽  
Vol 3 (4) ◽  
pp. 22-24
Author(s):  
Svetla Baykousheva ◽  
Konstantina Ilieva ◽  
Св. Байкушева ◽  
К Илиева ◽  
С. Байкушева ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Alkaline Protease ◽  
Protease Activity ◽  
Bacillus Subtilis 168
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