Adoption of a novel medium for the industrial (3000 L) production of Serendipita indica employing a nutrient limitation strategy using insoluble carbon and phosphate sources

Abstract

The use of the endophytic fungus Serendipita indica has rapidly increased due to its wide range of host species, ability to foster plant-growth, and ability to confer tolerance to a number of stresses. However, its industrial-scale production is still in its infancy due to its low-biomass yield and prolonged cultivation time. Thus far, Hill-Kafer medium has traditionally been used for S. indica cultivation, resulting in lower yields and excessively long incubation times. Here, we adopted a simple insoluble carbon and phosphate input medium for rapidly generating high biomass. We developed and optimized the SIF1 medium, achieving maximum biomass production (424.5 ± 1.9 g/L), significantly outperforming Hill-Kafer medium. Statistical optimization of SIF1 identified optimal levels (15 g/L oats, 7.5 g/L tricalcium phosphate, 95-hr incubation). Validated results in the laboratory (FUS-10 L: 484.4 ± 4.7), pilot (300 L: 496.5 ± 7 g/L), and industrial (3000L: 492.4 ± 7.1 g/L) bioreactors proved the efficacy of SIF1. Compared to Hill-Kafer (54.8 ± 3.7 g/L), SIF1 showed nine-fold higher biomass productivity and reduced cultivation time by approximately 6 days. Based on our findings, it appears that SF1 will be a highly efficient medium for producing S. indica on an industrial scale and expanding its use.

One-sentence summary: This study presents a rapid industrial production strategy for the beneficial fungus Serendipita indica, providing a scalable solution for wider applications and contributing to global food security and environmental sustainability.

Keywords: Serendipita indica; Hill–Kafer medium; fungal biomass; mass production; media optimization.

Graphical Abstract

Fig. 1.

Growth evaluation of S. indica with various C and P sources using fresh biomass. (a) C sources: MC1-Maize, MC2-Soymeal, MC3-Oats, MC4-Wheat, MC-PDB (b) P sources: MP1-KP, MP2-TCP, MP3-Al-P, and MP4-Fe-P.

Fig. 2.

Growth evaluation of S. indica in different formulated media for mass production in a submerged laboratory bioreactor.

Fig. 3.

Three-dimensional response surface showing the relationship between every element taken into account during BBD analysis and predicted point validation. (a) Carbon source and phosphate source. (b) Carbon source and incubation time TCP. (c) Phosphate source and incubation time. (d) Predicted point validation of SF1.

Fig. 4.

SF1 (oats and TCP-based) medium resulted in higher biomass production of S. indica in submerged culture, circumventing the growth constraint through readily soluble sugar (sucrose) and phosphate (KH₂PO₄) sources.