1. High level expression of a xyloglucanase from Rhizomucor miehei in Pichia pastoris for production of xyloglucan oligosaccharides and its application in yoghurt
- Author
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Chun-hua Zhu, Li Yanxiao, Miao Miao, Nan-nan Wang, Qiaojuan Yan, and Zhengqiang Jiang
- Subjects
Time Factors ,Glycoside Hydrolases ,Oligosaccharides ,Rhizomucor miehei ,Biochemistry ,Pichia pastoris ,Hydrolysis ,chemistry.chemical_compound ,Structural Biology ,Lactobacillus ,Enzyme Stability ,Tamarindus ,Food science ,Rhizomucor ,Glucans ,Molecular Biology ,Lactobacillus delbrueckii ,biology ,Thermophile ,Temperature ,Streptococcus ,food and beverages ,General Medicine ,Hydrogen-Ion Concentration ,Yogurt ,biology.organism_classification ,Molecular Weight ,Xyloglucan ,chemistry ,Saccharomycetales ,Xylans ,Specific activity ,Fermentation - Abstract
The xyloglucanase gene (RmXEG12A) from Rhizomucor miehei CAU432 was successfully expressed in Pichia pastoris. The highest xyloglucanase activity of 25,700 U mL−1 was secreted using high cell density fermentation. RmXEG12A was optimally active at pH 7.0 and 65 °C, respectively. The xyloglucanase exhibited the highest specific activity towards xyloglucan (7915.5 U mg−1). RmXEG12A was subjected to hydrolyze tamarind powder to produce xyloglucan oligosaccharides with the degree of polymerization (DP) 7–9. The hydrolysis ratio of xyloglucan in tamarind powder was 89.8%. Moreover, xyloglucan oligosaccharides (2.0%, w/w) improved the water holding capacity (WHC) of yoghurt by 1.1-fold and promoted the growth of Lactobacillus bulgaricus and Streptococcus thermophiles by 2.3 and 1.6-fold, respectively. Therefore, a suitable xyloglucanase for tamarind powder hydrolysis was expressed in P. pastoris at high level and xyloglucan oligosaccharides improved the quality of yoghurt.
- Published
- 2021