Engineered Fungus Thermothelomyces thermophilus Producing Plant Storage Proteins

Abstract

An efficient Agrobacterium-mediated genetic transformation based on the plant binary vector pPZP-RCS2 was carried out for the multiple heterologous protein production in filamentous fungus Thermothelomyces thermophilus F-859 (formerly Myceliophthora thermophila F-859). The engineered fungus Th. thermophilus was able to produce plant storage proteins of Zea mays (α-zein Z19) and Amaranthus hypochondriacus (albumin A1) to enrich fungal biomass by valuable nutritional proteins and improved amino acid content. The mRNA levels of z19 and a1 genes were significantly dependent on their driving promoters: the promoter of tryptophan synthase (PtrpC) was more efficient to express a1, while the promoter of translation elongation factor (Ptef) provided much higher levels of z19 transcript abundance. In general, the total recombinant proteins and amino acid contents were higher in the Ptef-containing clones. This work describes a new strategy to improve mycoprotein nutritive value by overexpression of plant storage proteins.

The microbial food revolution

“…The new generation of SCP-based animal feed uses engineered microorganisms nutritionally tailored to the target animal 28 , 78 , 100 . Moreover, it can be also employed as a nutraceutical and therapeutic platform such as in the previously commercial omega-3 enriched Yarrowia biomass employed in Verlasso® salmon 101 , and the efforts in the start-ups such as Cyanofeed (see Table 1 ).…”

“…Because of the costs incurred for prototype development, one of the initial SCP projects by Imperial Chemical Industries (ICI) was abandoned when it failed to compete with cheap agriculture, especially with modified soybeans 10 . However, more recent technologies seem to suggest that building a plant for growing microbes could now be economically feasible 121 , which is facilitated by the optimisation of the growing conditions 122 , advanced fermentation technologies 123 , and higher yields achieved by engineered microbes 100 . Another economic barrier for commercialisation is the lengthy and expensive process associated with obtaining the necessary regulatory and safety approvals.…”

Identification of Thermostable Xylose Reductase fromThermothelomyces thermophilus: A Biochemical Characterization Approach to Meet Biofuel Challenges

“…Tt fungi have been considered safe and cheap for large-scale manufacturing methods and have been utilized effectively in metabolic engineering. 12 T h i s c o n t e n t i s Recently, xylose reductase (XR) has attracted considerable scientific attention from various researchers across the globe because of its ability to catalyze pentose sugars, mainly xylose to xylitol. 13 Effective utilization of xylose is important as Dxylose accounts for about 35% of the whole sugar present in lignocellulosic hemicellulose biomass.…”

“…These fungi possess heat-loving characteristics and cannot thrive below 20 °C. Tt fungi have been considered safe and cheap for large-scale manufacturing methods and have been utilized effectively in metabolic engineering …”

“…Tt fungi have been considered safe and cheap for large-scale manufacturing methods and have been utilized effectively in metabolic engineering. 12 …”