Production and partial characterization of thermostable and calcium-independent alpha-amylase of an extreme thermophile Bacillus thermooleovorans NP54

Malhotra, Rajni; Noorwez, Syed M.; Satyanarayana, T.

doi:10.1046/j.1472-765x.2000.00830.x

Cited by 131 publications

(90 citation statements)

References 26 publications

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“…The pH of 6 and 7 has been reported for normal growth and enzyme activity in Bacillus strain isolated from soil [12]- [24]. Neutral pH was found to be optimal for amylase production as also reported in B. thermooleovorans NP54 [25], B.…”

Section: Resultsmentioning

confidence: 56%

Isolation and Characterization of Bacillus Subtilis KC3 for Amylolytic Activity

VIJAYALAKSHMI¹,

Sushma²,

Abha³

et al. 2012

IJBBB

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Abstract-Microbial α-amylase is a highly demanded industrial enzyme with extensive commercial applications in various sectors. Studies were carried out with a bacterial strain producing extracellular α-amylase, isolated from rhizospheric soil of Euphorbia hirta. The isolate was gram positive, motile rod, bearing terminal endospore. It exhibited >98% similarity with the reference strains in the GenBank. The phylogenetic tree constructed on the basis of 16S rRNA gene sequences revealed that it clustered with the closest members of Bacillus subtilis and identified as Bacillus subtilis KC3. Furthermore, the effects of incubation period, temperature, pH, different carbon and nitrogen sources, metal salts and different substrate concentrations of the medium were optimized. The maximum enzyme production was found after 48 h (22.92 U/ml) of incubation at temperature 40°C and pH 7. The optimal temperature and pH for enzyme activity were 50°C and 6.5 respectively. Barley starch (27.27 U/ml) was observed to be the best inducer followed by corn starch (24.30 U/ml) and maltose (19.10 U/ml). The addition of glucose to the culture medium greatly reduced the synthesis of α-amylase (5.45 U/ml) which demonstrates that a classical glucose effect is operative in this organism. The effects of different metal ions (Ca 2+, Fe 2+ , Mg 2+ , Zn 2+ and Cu 2+ ) on amylolytic activity were investigated and it was found that 0.1% of Ca 2+ increased enzyme production (28.83U/ml), whereas other metal ions exhibited inhibitory effects. The enzyme production was maximum at 2% substrate (starch) concentration, which declined beyond it. These characteristics of Bacillus subtilis KC3, suggest that this is a promising isolate which merits further investigations for potential applications in various biotechnological processes.Index Terms-α-amylase, bacillus subtilis KC3, euphorbia hirta, rhizospheric soil

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Section: Resultsmentioning

confidence: 56%

Isolation and Characterization of Bacillus Subtilis KC3 for Amylolytic Activity

VIJAYALAKSHMI¹,

Sushma²,

Abha³

et al. 2012

IJBBB

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“…Calcium-independent enzymes have also been reported. Malhotra et al [29] reported that the amylase from Bacillus Thermoleovorans NP54 did not require calcium ions for its activity or production. Similar result was reported by Najafi et al [30] for amylase from Bacillus subtilis AX20.…”

Section: Resultsmentioning

confidence: 99%

Characteristics of a Novel Highly Thermostable and Extremely Thermophilic Alkalitolerant Amylase from Hyperthermophilic Bacillus Strain HUTBS71

Al-Quadan¹,

Akel²,

Natshi³

2009

OnLine J. of Biological Sciences

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Problem statement:This study reported the purification and characterization of a novel highly thermostable alkaline amylase from a newly isolated Bacillus strain HUTBS71. Approach: The enzyme was purified using ammonium sulfate precipitation, ion exchange and gel filtration chromatography. Results: Maximum amylase activity (72 U mL −1 ) was obtained at 100°C after 10 min of incubation. The enzyme was purified 24 fold with 12.5% yield and showed a monomer band with a molecular weight of 58.8 kDa by SDS-PAGE. This enzyme exhibited maximum activity at pH and temperature, 7.8 and 100°C, respectively. It performed stability over a broad range of pH and temperature, 5.2-10.0 and 80-115°C, respectively. The half-life of the enzyme at 90 and 100°C was estimated to be 3 h. The activation energy of denaturation of purified enzyme was 2.53 kJ moL −1 . The enzyme was activated by 5 mM of CoCl 2 , MgSO 4 , MnCl 2 , ZnSO 4 and MnSO 4 (relative activity was 133, 126, 133, 106.6 and 103%, respectively). It was strongly inhibited by CuSO 4 and CdCl 2 but less affected by NaCl, CaCl 2 , FeCl 3 , ZnCl 2 and EDTA. Conclusion: The present purified amylase therefore could be defined as a highly thermostable, extremely hyperthermophilic and alkalitolerant with new properties make the present enzyme applicable for many starch processing and food industries.

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“…However, a similar inhibitory effect of heavy metal ions such as Cu 2+ and Zn 2+ on amylase activity of Bacillus sp. strain TS-23 (Lin et al, 1998), B. subtilis (Sarikaya and Gürgün, 2000), B. thermooleovorans NP54 (Malhotra et al, 2000) and Bacillus sp. strain L1711 (Bernhanrdsdotter et al, 2005) has been reported.…”

Section: +mentioning

confidence: 99%