ISSN: 0973-7510

E-ISSN: 2581-690X

Research Article | Open Access
Hala A. Salah1, Hanan A. Temerk2, Nivin A. Salah3, Saeed Rafa Zara Alshehri4,
Jazi A. Al-Harbi5, Asmaa M.M. Mawad6, Khaled A. M. Khaled7, Abd El-Latif Hesham7 and Karam A. Amein8
1Molecular Biology Department, National Research Centre, Cairo, Egypt.
2Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt.
3Biochemistry Division, Department of Chemistry, Faculty of Science, Mansoura, University, Mansoura, Egypt.
4College of Technology, Khamis Mushait, Saudi Arabia.
5Ministry of Health, Saudi Arabia.
6Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut – 71516,Egypt.
7Genetics Department, Faculty of Agriculture, Beni-Suef University, Beni-Suef – 62511, Egypt.
8Genetics Department, Faculty of Agriculture, Assiut University, Egypt.
J Pure Appl Microbiol. 2021;15(1):452-461 | Article Number: 6783
https://doi.org/10.22207/JPAM.15.1.43 | © The Author(s). 2021
Received: 05/11/2020 | Accepted: 13/02/2021 | Published: 01/03/2021
Abstract

The xylanolytic and amylolytic yeasts were qualitatively determined by Cong red xylan agar and soluble starch agar plates, respectively. The most xylanase and α-amylase inducible strain (AUN-02) was selected and identified using PCR amplification of 26S rRNA gene and sequence analysis. The comparison of the alignment results and phylogenetic analysis of the sequences of the isolated yeast to published rRNA gene sequences in GenBank, confirmed the identification of the isolate as Pichia membranifaciens. Xylanase and α-amylase production by isolated P. membranifaciens were investigated at different pH values (4-8), temperature degrees (20-45°C), incubation time (1-7 days) and various substrates.A higher production of xylanase (38.8 U/mL) and a-amylase (28.7 U/mL) was obtained after 4 days of fermentation of P. membranifaciens. Higher activity of xylanase (36.83 U/mL) and a-amylase (27.7 U/mL) was obtained in the fermentation of P. membranifaciens in a culture medium adjusted to pH 7.0. The optimum temperature showed maximum xylanase and a-amylase activity (42.6 and 32.5 units/mL, respectively) was estimated at 35 °C. The xylanase and a-amylase activities of P. membranifaciens were estimated and compared for the different substrates tested. The strain revealed 100% relative activity of xylanase and a-amylase on beechwood and potato starch, respectively. The affinity of enzymes towards substrate was estimated using Km values. The Km values of xylanase and α-amylase increased in the order of pH’s 7.0, 6.0 and 4.5 (0.85, 1.6 and 3.4 mg xylan/mL and 0.22, 0.43 and 2.8 mg starch/mL, respectively). the yeast P. membranifaciensis is suitable for produce neutral xylanase and α-amylase enzymes. So, it could be used as a promising strain for production of these enzymes in industrial field.

Keywords

Amylase, neutral, Pichia membranifaciens, xylanase, yeast

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