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Molecular Identification of a Newly Isolated Bacillus subtilis BI19 and Optimization of Production Conditions for Enhanced Production of Extracellular Amylase.

Dash BK, Rahman MM, Sarker PK - Biomed Res Int (2015)

Bottom Line: Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly.Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively.These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time.

View Article: PubMed Central - PubMed

Affiliation: Department of Biotechnology and Genetic Engineering, Faculty of Applied Science and Technology, Islamic University, Kushtia 7003, Bangladesh ; Department of Genetic Engineering and Biotechnology, Faculty of Biological Science and Technology, Jessore University of Science and Technology, Jessore 7408, Bangladesh.

ABSTRACT
A study was carried out with a newly isolated bacterial strain yielding extracellular amylase. The phylogenetic tree constructed on the basis of 16S rDNA gene sequences revealed this strain as clustered with the closest members of Bacillus sp. and identified as Bacillus subtilis BI19. The effect of various fermentation conditions on amylase production through shake-flask culture was investigated. Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly. A combination of peptone and tryptone as organic and ammonium sulfate as inorganic nitrogen sources gave highest yield. Maximum production was obtained after 24 h of incubation at 37 °C with an initial medium pH 8.0. Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively. Amylase production was 3.06 times higher when optimized production conditions were used. Optimum reaction temperature and pH for crude amylase activity were 50 °C and 6.0, respectively. The crude enzyme showed activity and stability over a fair range of temperature and pH. These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time.

No MeSH data available.


Related in: MedlinePlus

The production of amylase by Bacillus subtilis BI19 in shake flask fermentation. (a) Effect of different inorganic nitrogen sources and (b) effect of different concentrations of ammonium sulfate.
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Related In: Results  -  Collection


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fig3: The production of amylase by Bacillus subtilis BI19 in shake flask fermentation. (a) Effect of different inorganic nitrogen sources and (b) effect of different concentrations of ammonium sulfate.

Mentions: The nature and relative concentration of different complex nitrogenous sources in the growth medium are both important in the synthesis of amylase. Like lower levels, higher levels of nitrogen are equally detrimental causing enzyme inhibition [27]. Various complex nitrogen sources were added separately and in combination as replacement of peptone (1%) to the original medium to assess their effects on the final production (Figure 2(a)). It has been previously found that organic nitrogen sources like peptone and yeast extract usually have stimulating effects [28] and our findings are similar to them. Yeast extract also reported to serve as good organic nitrogen source for α-amylase synthesis from B. amyloliquefaciens [27]. Bozic et al. (2011) [29] found casein to be the best nitrogen source for α-amylase production from B. subtilis IP 5832. Albeit peptone as single replacement was significant; all the combination of peptone, tryptone, and yeast extract gave better results for amylase production in this experiment. Nusrat and Rahman (2007) [21] reported similar results for α-amylase production by B. licheniformis and B. subtilis. As a single organic nitrogen source, 1.2% of peptone was found to produce maximum amylase (7.82 U/mL/min) (Figure 2(b)). Inorganic nitrogen sources likely ammonium salts have been reported to induce amylase production [4]. Our findings are in good agreement with these studies. Presence of 1% (NH4)2SO4 was found to give maximum yield (7.31 U/mL/min) of amylase in this experiment (Figures 3(a) and 3(b)). The decline in amylase production at increased nitrogen concentration could be due to the lowering of pH of the production medium or induction of protease, which suppresses the amylolytic activity [23]. Swain et al. (2006) [30] reported to find suppressed α-amylase production by newly isolated B. subtilis when 1% ammonium sulphate was used in the fermentation medium which is contrary with our findings.


Molecular Identification of a Newly Isolated Bacillus subtilis BI19 and Optimization of Production Conditions for Enhanced Production of Extracellular Amylase.

Dash BK, Rahman MM, Sarker PK - Biomed Res Int (2015)

The production of amylase by Bacillus subtilis BI19 in shake flask fermentation. (a) Effect of different inorganic nitrogen sources and (b) effect of different concentrations of ammonium sulfate.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4477212&req=5

fig3: The production of amylase by Bacillus subtilis BI19 in shake flask fermentation. (a) Effect of different inorganic nitrogen sources and (b) effect of different concentrations of ammonium sulfate.
Mentions: The nature and relative concentration of different complex nitrogenous sources in the growth medium are both important in the synthesis of amylase. Like lower levels, higher levels of nitrogen are equally detrimental causing enzyme inhibition [27]. Various complex nitrogen sources were added separately and in combination as replacement of peptone (1%) to the original medium to assess their effects on the final production (Figure 2(a)). It has been previously found that organic nitrogen sources like peptone and yeast extract usually have stimulating effects [28] and our findings are similar to them. Yeast extract also reported to serve as good organic nitrogen source for α-amylase synthesis from B. amyloliquefaciens [27]. Bozic et al. (2011) [29] found casein to be the best nitrogen source for α-amylase production from B. subtilis IP 5832. Albeit peptone as single replacement was significant; all the combination of peptone, tryptone, and yeast extract gave better results for amylase production in this experiment. Nusrat and Rahman (2007) [21] reported similar results for α-amylase production by B. licheniformis and B. subtilis. As a single organic nitrogen source, 1.2% of peptone was found to produce maximum amylase (7.82 U/mL/min) (Figure 2(b)). Inorganic nitrogen sources likely ammonium salts have been reported to induce amylase production [4]. Our findings are in good agreement with these studies. Presence of 1% (NH4)2SO4 was found to give maximum yield (7.31 U/mL/min) of amylase in this experiment (Figures 3(a) and 3(b)). The decline in amylase production at increased nitrogen concentration could be due to the lowering of pH of the production medium or induction of protease, which suppresses the amylolytic activity [23]. Swain et al. (2006) [30] reported to find suppressed α-amylase production by newly isolated B. subtilis when 1% ammonium sulphate was used in the fermentation medium which is contrary with our findings.

Bottom Line: Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly.Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively.These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time.

View Article: PubMed Central - PubMed

Affiliation: Department of Biotechnology and Genetic Engineering, Faculty of Applied Science and Technology, Islamic University, Kushtia 7003, Bangladesh ; Department of Genetic Engineering and Biotechnology, Faculty of Biological Science and Technology, Jessore University of Science and Technology, Jessore 7408, Bangladesh.

ABSTRACT
A study was carried out with a newly isolated bacterial strain yielding extracellular amylase. The phylogenetic tree constructed on the basis of 16S rDNA gene sequences revealed this strain as clustered with the closest members of Bacillus sp. and identified as Bacillus subtilis BI19. The effect of various fermentation conditions on amylase production through shake-flask culture was investigated. Rice flour (1.25%) as a cheap natural carbon source was found to induce amylase production mostly. A combination of peptone and tryptone as organic and ammonium sulfate as inorganic nitrogen sources gave highest yield. Maximum production was obtained after 24 h of incubation at 37 °C with an initial medium pH 8.0. Addition of surfactants like Tween 80 (0.25 g/L) and sodium lauryl sulfate (0.2 g/L) resulted in 28% and 15% increase in enzyme production, respectively. Amylase production was 3.06 times higher when optimized production conditions were used. Optimum reaction temperature and pH for crude amylase activity were 50 °C and 6.0, respectively. The crude enzyme showed activity and stability over a fair range of temperature and pH. These results suggest that B. subtilis BI19 could be exploited for production of amylase at relatively low cost and time.

No MeSH data available.


Related in: MedlinePlus