Crucial part in medicine, cosmetics, and business [1]. Nonetheless, natural merchandise normally have complex chemical structures and are extracted from sources with extended development periods and extremely low P/Q-type calcium channel drug abundance, resulting in quick supply and high price, specifically these with plant origins [2]. With the improvement of synthetic biology, numerous microorganisms like Pichia pastoris (a.k.a. Komagataella phaffii) have been created as cell factories to make natural goods [3]. Compared with bacterial cell factories (i.e. Escherichia coli), the ability of post-translational modifications along with the presence of inner membrane systems make yeasts which includes P. pastoris preferred hosts to express eukaryotic complicated proteins, for example cytochrome P450s (CYPs), that are usually involved in the biosynthesis of all-natural products [6]. When compared with all the model yeast Saccharomyces cerevisiae, P. pastoris has the advantage of robust and tightly regulated promoters for higher level expression of recombinant proteins [7]. By way of example, theexpression degree of the target gene can account for more than 30 on the total proteins of P. pastoris, which is a great deal larger than that in S. cerevisiae [8]. Furthermore, hyperglycosylation is a further concern for expressing eukaryotic proteins inside the S. cerevisiae expression program [9]. Organic product biosynthetic pathway enzymes (i.e. polyketide synthases and CYPs) are commonly identified to have fairly low catalytic activities, which really should be expressed at high levels to achieve effective biosynthesis. As a result, P. pastoris is often a promising host for large-scale production of all-natural items, specifically these with eukaryotic origins. Despite the fact that normally thought of as a non-conventional yeast, genetics, physiology, and cell biology of P. pastoris have already been studied in-depth [4]. The genomes of P. pastoris GS115 and CBS7435 have been PKCη Source sequenced and annotated, and genome-scale metabolic models have already been constructed by analyzing the metabolic patterns [10]. Metabolomics studies indicate that the intermediate metabolites of P. pastoris and S. cerevisiae are very comparable, with identical metabolites up to 90 [11]. The exploration on the genetic background of P. pastoris has laid a strong foundation for customized modification of P. pastoris. Currently, besides therapeutic proteins and enzymes [12], P. pastoris has beenPeer assessment below duty of KeAi Communications Co., Ltd. Corresponding author. Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China. E-mail address: [email protected] (J. Lian). https://doi.org/10.1016/j.synbio.2021.04.005 Received 27 January 2021; Received in revised type 13 March 2021; Accepted 26 April 2021 2405-805X/2021 The Authors. Publishing solutions by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access write-up below the CC BYlicense (http://creativecommons.org/licenses/by/4.0/).J. Gao et al.Synthetic and Systems Biotechnology 6 (2021) 110engineered to make many chemicals and value-added compounds, which include D-lactic acid [13], 2,3-butanediol (BDO) [14], 2-phenylethanol [15], isobutanol and isobutyl acetate [16], carotenoids [17], lovastatin [18], and nootkatone [19] (Fig. 1). Within this overview, the synthetic biology tools necessary for the construction and optimization of all-natural item biosynthetic pathways in P. pastoris are firstly summarized, in parti.