Microbial compositions and methods for denitrification at high dissolved oxygen levels
The present invention provides compositions and methods for denitrification.
1. A method of decreasing the nitrate level in an aqueous system having a dissolved oxygen level above 3 ppm, the method comprising contacting the aqueous system with a composition comprising:
a. a mixture of Bacillus bacterial species comprising Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens , and Bacillus pumilus ; and
b. a mixture of lactic acid bacteria comprising Pediococcus acidilactici, Pediococcus pentosaceus , and Lactobacillus plantarum , wherein the weight ratio of the Bacilli to the lactic acid bacteria ranges from 1:10 to 10:1, thereby decreasing the nitrate level in the aqueous system.
2. The method of claim 1 , wherein the composition is embedded in a solid support.
3. The method of claim 1 , wherein the Bacillus subtilis comprises Bacillus subtilis 34KLB.
4. The method of claim 1 , wherein the Bacillus subtilis comprises Mojavensis.
5. The method of claim 1 , wherein each of the lactic acid bacteria is present in equal amounts by weight.
6. The method of claim 1 , wherein the composition further comprises an inert carrier.
7. The method of claim 6 , wherein the inert carrier is anhydrous dextrose, dextrose monohydrate, dendritic salt, maltodextrin, rice bran, wheat bran, oat bran, soybean meal, rice hulls, or a mixture thereof.
8. The method of claim 1 , wherein each of the Bacillus species is individually fermented aerobically to produce a culture, which is filtered, centrifuged, dried, and ground to an average particle size of about 200 microns.
9. The method of claim 1 , wherein each of the lactic acid bacteria is fermented anaerobically to produce a culture, which is filtered, centrifuged, dried, and ground to an average particle size of about 200 microns.
10. The method of claim 1 , wherein the composition has a moisture content of less than 5% and a final bacterial concentration of about 10 5 to 10 11 colony forming units (CFU) per gram of the composition.
11. The method of claim 6 , wherein the inert carrier comprises about 75% to 95% (wt/wt) of the composition.
12. The method of claim 1 , wherein the aqueous system is selected from the group consisting of municipal sewage, residential or commercial septic, industrial wastewater, a livestock waste water lagoon, an aquaculture pond, waste water from fruit and vegetable processing, waste water from brewery and distilling, a swimming pool, and a spa.