Enhancement of xylanase expression by Komagataella phaffii through pexophagy inhibition

• Published in: Biotechnology, biotechnological equipment Vol. 33; no. 1; pp. 855 - 862
• Main Authors: Liu, Taiyu, Zhao, Yixin, Zhang, Jianguo, Zhang, Jining
• Format: Journal Article
• Language: English
• Published: Sofia Taylor & Francis 01-01-2019; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Carbon; Carbon sources; Food industry; Food processing industry; Gene knockout; Homologous recombination; Homology; Komagataella phaffii; Methanol; mixed carbon source feeding; Pexophagy; Sorbitol; Xylanase; Yeasts
• ISSN: 1310-2818; 1314-3530
• DOI: 10.1080/13102818.2019.1623717

Xylanase is widely used in agriculture and food industry. To increase heterologous xylanase expression by Komagataella phaffii under the condition of mixed carbon source feeding, the atg30 gene was knocked out from this yeast to inhibit pexophagy for increasing sorbitol consumption. Komagataella phaffii atg30Δ was constructed through homologous recombination that resulted in the inhibition of pexophagy. When compared with the control, the yield of secretory xylanase increased by 4.1 ± 0.2%, 5.7 ± 0.5%, 11.8 ± 0.4% and 11.4 ± 0.7% under the conditions of 1.5% methanol and 0.5, 1, 1.5 and 2% sorbitol addition, respectively. The residual sorbitol analysis showed that sorbitol consumed by Komagataella phaffii atg30Δ increased by 121.3 ± 9.3%, 66.8 ± 15.2% and 31.2 ± 3.2% following 1, 1.5 and 2 sorbitol addition, respectively. Thus, non-methanol carbon source, co-feeding with methanol, provided more energy without pexophagy by atg30 gene knockout. Pexophagy inhibition increased the heterologous protein expression by Komagataella phaffii, which provided basis for increased yield of xylanase through pexophagy monitoring.