Matrix fermentation systems and methods for producing microbe-based products
The subject invention provides methods of producing advantageous microbes and/or by-products using a modified form of solid-state fermentation, or matrix fermentation. In particular, the methods utilize foodstuff mixed with liquid nutrient medium to produce a three-dimensional scaffold substrate having ample surface area on which the microbes can grow. The methods can be used to cultivate yeasts, fungi and bacteria at high concentrations without susceptibility to total contamination. The subject invention can be used in remote locations and can be transported with ease.
1. A method of cultivating a microorganism and/or producing a microbial growth by-product, the method comprising:
a) placing a solid substrate, mixed with nutrients for microbial growth, into a container to form a matrix;
b) applying an inoculant of the microorganism to the matrix;
c) placing the container with the inoculated matrix into an incubation space; and
d) incubating the container at a temperature between 25-40° C. for an amount of time to allow the microorganism to grow throughout the matrix, wherein the solid substrate comprises a plurality of pieces, morsels, grains or particles of rice, beans, legumes, lentils, corn, grains, pasta, oats, oatmeal, wheat bran, wheat flour, corn flour, nixtamilized corn flour, corn meal, and/or partially hydrolyzed corn meal.
2. The method of claim 1 , wherein the incubation space is a proofing oven used in commercial baking.
3. The method of claim 1 , wherein the incubation space is a thermostable enclosure comprising:
a ceiling, a floor and four vertical walls;
a ceiling vent for air flow; and
UV lights.
4. The method of claim 1 , wherein the inoculant comprises cells, spores or propagules of the microorganism, and wherein applying the inoculant comprises spraying, pouring or pipetting the inoculant onto the matrix.
5. The method of claim 1 , wherein the microorganism requires oxygenation, and wherein the incubation space comprises an aeration system to provide slow motion air supply.
6. The method of claim 5 , wherein the incubation space utilizes a passive air exchange system comprising an inlet, with an air filter, through which ambient air travels into the incubation space, and an outlet, through which air exits the incubation space.
7. The method of claim 1 , wherein after the microorganism grows, the microorganism, growth by-products and substrate are harvested and blended into a slurry.
8. The method of claim 7 , wherein the slurry is homogenized and dried to produce a dry microbe-based product.
9. The method of claim 7 , wherein the dried microbe-based product comprises from 1×10 8 to 1×10 12 cells, spores or propagules per gram.
10. The method of claim 7 , wherein dried microbe-based product is mixed with water to produce a liquid microbe-based product with a concentration of 1×10 6 to 1×10 7 CFU/ml.
11. The method of claim 7 , wherein the slurry is mixed with a solvent to form a slurry-solvent mixture, and the slurry-solvent mixture is pressed through a filter to extract a liquid product comprising a biosurfactant.
12. The method of claim 1 , wherein the microorganism is a yeast, fungus or bacteria.
13. The method of claim 12 , wherein the microorganism is a yeast selected from Wickerhamomyces anomalus, Pichia kudriavzevii, Pichia guilliermondii, Pichia occidentalis, Starmerella bombicola, Pseudozyma aphidis , and Saccharomyces boulardii , or the microorganism is a bacteria selected from Azotobacter spp., Pseudomonas spp., and Bacillus spp.
14. The method of claim 13 , wherein the Bacillus spp. are selected from Bacillus subtilis, B. licheniformis, B. firmus, B. laterosporus, B. megaterium, B. amyloliquefaciens and Bacillus coagulans GBI-30 (BC30).
15. The method of claim 12 , wherein the microorganism is a fungus selected from Lentinula edodes, Trichoderma reesei, Trichoderma harzianum, Trichoderma viride , and Trichoderma hamatum.
16. A composition, produced according to the method of claim 1 , wherein the composition comprises a microorganism and/or a growth by-product thereof, a substrate on which the microorganism was grown, and nutrients for microbial growth.
17. The composition of claim 16 , wherein the growth by-product is a biosurfactant selected from sophorolipids, rhamnolipids, trehalose lipids, iturin, surfactin, fengycin, lichenysin and mannosylerythritol lipids.
18. The composition of claim 16 , wherein the growth by-product is selected from levan, emulsan, xanthan gum, alginate, hyaluronic acid, PGAs, PHAs, cellulose, and lignin.
19. The composition of claim 16 , wherein the growth by-product is selected a phytase, a chitinase, a glucosidase and/or a glucanase (e.g., exo-β-1,3-glucanase).