Large-scale aerobic submerged production of fungi
Methods are provided for cultivating fungi for scaled-up production of microbe-based products. Specifically, cultures of fungi, such as, e.g., Pisolithus tinctorius , are grown by aerobic submerged fermentation in liquid medium containing a particulate anchoring carrier to increase mycelial biomass.
1. A method of mass-producing a fungal strain and/or a fungal growth by-product, the method comprising:
inoculating a liquid growth medium with the fungal strain;
suspending a particulate anchoring carrier in the liquid growth medium as a site for nucleating fungal growth;
adding one or more antibacterial substances to the liquid growth medium; and
cultivating the strain by aerobic submerged fermentation in a reactor,
wherein the fungal strain attaches to the anchoring carrier and accumulates thereon to form a fungal-carrier mass with diameter of at least 1 mm; wherein the components of the liquid growth medium are sterilized prior to inoculation; and wherein said sterilization comprises mixing the components with 3% hydrogen peroxide in a ratio of 1:3 (w/v).
2. The method of claim 1 , wherein the anchoring carrier comprises whole, or pieces of, seeds, nuts, beans, or fruits.
3. The method of claim 1 , wherein the anchoring carrier comprises alginate beads.
4. The method of claim 3 , wherein the alginate beads are prepared by dropping a solution comprising 3% sodium alginate solution, and, optionally, nutrients and/or fungal inoculant, into a sterile 5% calcium chloride solution.
5. The method of claim 1 , wherein the fungal-carrier mass is harvested from the reactor and, dried to produce a dry fungi-based product.
6. The method of claim 5 , wherein the dry fungi-based product is milled.
7. The method of claim 5 , wherein the fungal strain is separated from the carrier prior to drying.
8. The method of claim 1 , wherein the fungal strain is a strain of ectomycorrhizal fungi.
9. The method of claim 8 , wherein the fungal strain is a strain of Pisolithus tinctorius.
10. The method of claim 1 , wherein the one or more antibacterial substances include streptomycin and/or oxytetracycline.
11. The method of claim 1 , wherein the one or more antibacterial substances include a sophorolipid, a rhamnolipid, a lipopeptide, and/or hops.
12. The method of claim 1 , carried out at a pH of about 2.0 to about 7.0.
13. The method of claim 1 , wherein the fungal growth by-product is a biosurfactant.