scholarly journals Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sumit Kumar ◽  
S. K. Khare

Halophiles have been perceived as potential source of novel enzymes in recent years. The interest emanates from their ability to catalyze efficiently under high salt and organic solvents. Present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic Marinobacter sp. EMB8. Media ingredients and culture conditions were optimized by “one-at-a-time approach.” Starch was found to be the best carbon source at 5% (w/v) concentration. Glucose acted as catabolic repressor for amylase production. Salt proved critical for amylase production and maximum production was attained at 5% (w/v) NaCl. Optimization of various culture parameters resulted in 48.0 IU/mL amylase production, a 12-fold increase over that of unoptimized condition (4.0 IU/mL). α-Amylase was immobilized on 3-aminopropyl functionalized silica nanoparticles using glutaraldehyde as cross-linking agent. Optimization of various parameters resulted in 96% immobilization efficiency. Starch hydrolyzing efficiency of immobilized enzyme was comparatively better. Immobilized α-amylase retained 75% of its activity after 5th cycle of repeated use.

2021 ◽  
Author(s):  
Sarah I Bukhari ◽  
Mohamed H Al-Agamy ◽  
Mahmoud S Kelany ◽  
Mohammad R Al Hazani ◽  
Moaz M Hamed

Abstract Amylase is an industrial enzyme that is used in the food and biofuel industries. We screened four actinomycetes strains for amylase biosynthesis. The Streptomyces rochei strain had a larger hydrolytic zone (24 mm) on starch agar plates, than the other isolates. Plackett-Burman’s experimental design was implemented to optimize the conditions for amylase production by the selected strains. Growth under optimized culture conditions led to 1.7, 9.8, 7.7, and 3.12 -fold increases for the isolates S. griseorubens, S. rochei, S. parvus, and Streptomyces sp., respectively, in the specific activity measurement in comparison with growth under primary conditions. When applying the Box-Behnken design on S. rochei using the most significant parameters starch, K2HPO4, pH, and temperature, there was a 12.22-fold increase in the specific activity measurement: 7.37 U/mg. The optimal fermentation medium formula was kept at 30.6°C for seven days. The amylase from S. rochei was partially purified, and its molecular weight was determined using Sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight was found to be 45, 43, and 53 kDa. Amylase was particularly active at pH 6 and 65°C. The purified enzyme was most active at 65°C and a pH of 6, thermal stability of 70°C for 40 min and salt concentration of 1 M with a Km and Vmax of 6.58 mg/ml and 21.93 mg/ml/min, respectively. The amylase improved by adding Cu + 2, Zn + 2, and Fe + 2 (152.21%, 207.24%, and 111.89%). Increased production of amylase enzyme by Streptomyces rochei KR108310 attracts the production of industrially significant products.


2020 ◽  
Vol 28 (S2) ◽  
Author(s):  
Marwan Jawad Msarah ◽  
Ayesha Firdose ◽  
Izyanti Ibrahim ◽  
Wan Syaidatul Aqma

Screening of new source of novel and industrially useful enzymes is a key research pursuit in enzyme biotechnology. The study aims to report the characteristics of novel thermophilic microorganisms isolated from Sungai Klah (SK) Hot Spring, Perak, Malaysia, that can produce α-amylase. The morphological and biochemical properties were examined for SUNGC2 sample. The isolate was further screened for amylase, followed by 16S rRNA and analytical profile index (API) test. This isolate was further subjected to pH optimisation for α-amylase production. It was found that SUNGC2 was an α-amylase producer and was identified as Bacillus licheniformis SUNGC2 with NCBI accession numbers MH062901. The enzyme was found to exhibit an optimum temperature of 50°C and a pH of 7.0. The relative activity of the enzyme was obtained based on the improvement of the culture conditions. The highest amount of amylase production was 24.65 U/mL at pH 7.0, consecutively the growth was also highest at pH 7.0 with a 9.45-fold increase in specific activity by ammonium phosphate precipitation of 80% (w/v). The results showed that the bacteria isolated from the hot spring are a significant source of thermophilic enzymes that are highly promising in biotechnology.


2016 ◽  
Vol 40 (10) ◽  
pp. 8444-8450 ◽  
Author(s):  
Feng Guodong ◽  
Guan Mingming ◽  
Lai Qi ◽  
Mi Hongyu ◽  
Li Guanghua ◽  
...  

The preparation of modified silica nanoparticles with guanidine was developed and used to catalyze the Henry reaction and fix quantum dots.


2014 ◽  
Vol 2 (40) ◽  
pp. 17077-17084 ◽  
Author(s):  
Matthew J. Carnie ◽  
Cecile Charbonneau ◽  
Matthew L. Davies ◽  
Brian O' Regan ◽  
David A. Worsley ◽  
...  

Nano Letters ◽  
2016 ◽  
Vol 16 (9) ◽  
pp. 5601-5604 ◽  
Author(s):  
Travis M. Shaffer ◽  
Stefan Harmsen ◽  
Emaad Khwaja ◽  
Moritz F. Kircher ◽  
Charles Michael Drain ◽  
...  

Nanoscale ◽  
2012 ◽  
Vol 4 (15) ◽  
pp. 4680 ◽  
Author(s):  
Filipe Natalio ◽  
Anubha Kashyap ◽  
Steffen Lorenz ◽  
Hannes Kerschbaumer ◽  
Michael Dietzsch ◽  
...  

2015 ◽  
Vol 60 (3) ◽  
pp. 1226-1233 ◽  
Author(s):  
Petros Ioannou ◽  
Aggeliki Andrianaki ◽  
Tonia Akoumianaki ◽  
Irene Kyrmizi ◽  
Nathaniel Albert ◽  
...  

The modestin vitroactivity of echinocandins againstAspergillusimplies that host-related factors augment the action of these antifungal agentsin vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against variousAspergillusspecies under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P= 0. 0005). Importantly, the enhanced activity of caspofungin againstAspergillusspp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinatingAspergillushyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin withAspergillushyphae (P< 0.0001). Collectively, we found a novel synergistic interaction between albumin and caspofungin, with albumin acting as a potential carrier molecule to facilitate antifungal drug delivery toAspergillushyphae.


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