This application relates to the field of
biotechnology, specifically disclosing a *
Pichia pastoris*
yeast, its construction method, and its applications. This application involves knocking out the *gas1*
gene, which is related to β-
glucan synthesis, in *
Pichia pastoris*. By deleting the *gas1*
gene, which encodes β-
glucan in the
cell wall of *
Pichia pastoris*, this application reduces
cell size, decreases the transfer distance from the
cell surface to the
nucleus, improves
oxygen transfer and product
secretion during high-density culture, and enhances
fermentation efficiency. Furthermore, the *
Pichia pastoris*
yeast constructed using this application enhances the synthesis of the
intracellular product
bisabolol and also enhances its
secretion capacity. This application, by reducing
cell size and decreasing the
carbon flow to
cell wall polysaccharide synthesis while increasing the
carbon source flow to target product synthesis, has significant implications for industrial production.