Limits...
Saccharification and liquefaction of cassava starch: an alternative source for the production of bioethanol using amylolytic enzymes by double fermentation process.

Pervez S, Aman A, Iqbal S, Siddiqui NN, Ul Qader SA - BMC Biotechnol. (2014)

Bottom Line: The distillate originated after recovery of bioethanol gave 53.0% yield.An improved and effective dual enzymatic starch degradation method is designed for the production of bioethanol using cassava starch.The technique developed is more profitable due to its fast liquefaction and saccharification approach that was employed for the formation of glucose and ultimately resulted in higher yields of alcohol production.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Karachi Institute of Biotechnology & Genetic Engineering (KIBGE), University of Karachi, Karachi -75270, Pakistan. ali_kibge@yahoo.com.

ABSTRACT

Background: Cassava starch is considered as a potential source for the commercial production of bioethanol because of its availability and low market price. It can be used as a basic source to support large-scale biological production of bioethanol using microbial amylases. With the progression and advancement in enzymology, starch liquefying and saccharifying enzymes are preferred for the conversion of complex starch polymer into various valuable metabolites. These hydrolytic enzymes can selectively cleave the internal linkages of starch molecule to produce free glucose which can be utilized to produce bioethanol by microbial fermentation.

Results: In the present study, several filamentous fungi were screened for production of amylases and among them Aspergillus fumigatus KIBGE-IB33 was selected based on maximum enzyme yield. Maximum α-amylase, amyloglucosidase and glucose formation was achieved after 03 days of fermentation using cassava starch. After salt precipitation, fold purification of α-amylase and amyloglucosidase increased up to 4.1 and 4.2 times with specific activity of 9.2 kUmg⁻¹ and 393 kUmg⁻¹, respectively. Concentrated amylolytic enzyme mixture was incorporated in cassava starch slurry to give maximum glucose formation (40.0 gL⁻¹), which was further fermented using Saccharomyces cerevisiae into bioethanol with 84.0% yield. The distillate originated after recovery of bioethanol gave 53.0% yield.

Conclusion: An improved and effective dual enzymatic starch degradation method is designed for the production of bioethanol using cassava starch. The technique developed is more profitable due to its fast liquefaction and saccharification approach that was employed for the formation of glucose and ultimately resulted in higher yields of alcohol production.

Show MeSH

Related in: MedlinePlus

Production of amylolytic enzymes and glucose formation by various filamentous fungi. KIBGE-IB33: A. fumigatus; KIBGE-IB34: A. flavus; KIBGE-IB35: A. terreus; KIBGE-IB36: A. niger; KIBGE-IB37: A. versicolor.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4048251&req=5

Figure 1: Production of amylolytic enzymes and glucose formation by various filamentous fungi. KIBGE-IB33: A. fumigatus; KIBGE-IB34: A. flavus; KIBGE-IB35: A. terreus; KIBGE-IB36: A. niger; KIBGE-IB37: A. versicolor.

Mentions: Screening of amylolytic property of the strains was based on starch hydrolysis method. Initially, 07 fungal strains were selected and among them 05 filamentous fungi including A. fumigatus KIBGE-IB33, A. flavus KIBGE-IB34, A. terreus KIBGE-IB35, A. niger KIBGE-IB36 and A. versicolor KIBGE-IB37showed production for amylolytic enzymes. When these isolates were cultivated in the starch containing production medium, highest titers of α-amylase (11.0 kUmg-1) and amyloglucosidase (142.0 kUmg-1) were produced by A. fumigatus KIBGE-IB33 (Figure 1). This strain was also capable of producing considerable amount of glucose (81.0 gL-1) which can be used for the production of ethanol. The fermentable sugar produced by this isolate can be easily metabolized by S. cerevisiae. However, other filamentous fungi produced lower titers of both α-amylase and amyloglucosidase along with lower concentration of glucose. Although maximum α-amylase was produced by A. flavus KIBGE-IB34 but it did not showed higher glucose formation rate as compared to A. fumigatus KIBGE-IB33 therefore, this isolate was selected for further studies.


Saccharification and liquefaction of cassava starch: an alternative source for the production of bioethanol using amylolytic enzymes by double fermentation process.

Pervez S, Aman A, Iqbal S, Siddiqui NN, Ul Qader SA - BMC Biotechnol. (2014)

Production of amylolytic enzymes and glucose formation by various filamentous fungi. KIBGE-IB33: A. fumigatus; KIBGE-IB34: A. flavus; KIBGE-IB35: A. terreus; KIBGE-IB36: A. niger; KIBGE-IB37: A. versicolor.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4048251&req=5

Figure 1: Production of amylolytic enzymes and glucose formation by various filamentous fungi. KIBGE-IB33: A. fumigatus; KIBGE-IB34: A. flavus; KIBGE-IB35: A. terreus; KIBGE-IB36: A. niger; KIBGE-IB37: A. versicolor.
Mentions: Screening of amylolytic property of the strains was based on starch hydrolysis method. Initially, 07 fungal strains were selected and among them 05 filamentous fungi including A. fumigatus KIBGE-IB33, A. flavus KIBGE-IB34, A. terreus KIBGE-IB35, A. niger KIBGE-IB36 and A. versicolor KIBGE-IB37showed production for amylolytic enzymes. When these isolates were cultivated in the starch containing production medium, highest titers of α-amylase (11.0 kUmg-1) and amyloglucosidase (142.0 kUmg-1) were produced by A. fumigatus KIBGE-IB33 (Figure 1). This strain was also capable of producing considerable amount of glucose (81.0 gL-1) which can be used for the production of ethanol. The fermentable sugar produced by this isolate can be easily metabolized by S. cerevisiae. However, other filamentous fungi produced lower titers of both α-amylase and amyloglucosidase along with lower concentration of glucose. Although maximum α-amylase was produced by A. flavus KIBGE-IB34 but it did not showed higher glucose formation rate as compared to A. fumigatus KIBGE-IB33 therefore, this isolate was selected for further studies.

Bottom Line: The distillate originated after recovery of bioethanol gave 53.0% yield.An improved and effective dual enzymatic starch degradation method is designed for the production of bioethanol using cassava starch.The technique developed is more profitable due to its fast liquefaction and saccharification approach that was employed for the formation of glucose and ultimately resulted in higher yields of alcohol production.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Karachi Institute of Biotechnology & Genetic Engineering (KIBGE), University of Karachi, Karachi -75270, Pakistan. ali_kibge@yahoo.com.

ABSTRACT

Background: Cassava starch is considered as a potential source for the commercial production of bioethanol because of its availability and low market price. It can be used as a basic source to support large-scale biological production of bioethanol using microbial amylases. With the progression and advancement in enzymology, starch liquefying and saccharifying enzymes are preferred for the conversion of complex starch polymer into various valuable metabolites. These hydrolytic enzymes can selectively cleave the internal linkages of starch molecule to produce free glucose which can be utilized to produce bioethanol by microbial fermentation.

Results: In the present study, several filamentous fungi were screened for production of amylases and among them Aspergillus fumigatus KIBGE-IB33 was selected based on maximum enzyme yield. Maximum α-amylase, amyloglucosidase and glucose formation was achieved after 03 days of fermentation using cassava starch. After salt precipitation, fold purification of α-amylase and amyloglucosidase increased up to 4.1 and 4.2 times with specific activity of 9.2 kUmg⁻¹ and 393 kUmg⁻¹, respectively. Concentrated amylolytic enzyme mixture was incorporated in cassava starch slurry to give maximum glucose formation (40.0 gL⁻¹), which was further fermented using Saccharomyces cerevisiae into bioethanol with 84.0% yield. The distillate originated after recovery of bioethanol gave 53.0% yield.

Conclusion: An improved and effective dual enzymatic starch degradation method is designed for the production of bioethanol using cassava starch. The technique developed is more profitable due to its fast liquefaction and saccharification approach that was employed for the formation of glucose and ultimately resulted in higher yields of alcohol production.

Show MeSH
Related in: MedlinePlus