Co-cultivation of a myxobacterium and acinetobacter for enhanced production of emulsan
Methods are provided for enhanced production of one or more microbial biopolymers, the methods comprising co-cultivating Stigmatella aurantiaca and Acinetobacter venetianus . In certain embodiments, the one or more biopolymers are emulsan. In certain embodiments, other microbial growth by-products are produced, such as biosurfactants. Microbe-based products produced according to the subject methods are also provided, as well as their uses in, for example, oil and gas recovery, agriculture, and health care.
1. A method for enhanced production of one or more microbial growth by-products selected from the group consisting of biopolymers and biosurfactants, the method comprising co-cultivating a first microorganism and a second microorganism in a fermentation reactor comprising a liquid nutrient medium and incubating the microorganisms in the reactor under conditions favorable for growth and production of the one or more microbial growth by-products, feeding clear liquefied paraffin into the reactor after 24 hours of incubation, extracting the one or more growth by-products from the reactor, and, optionally, purifying the one or more growth by-products,
wherein the first microorganism is Stigmatella aurantiaca and the second microorganism is Acinetobacter venetianus RAG-1,
wherein the biopolymer is emulsan and the biosurfactant is a glycolipid or a lipopeptide, and
wherein a greater concentration of the one or more microbial growth by-products is achieved than would be achieved if the first and second microorganisms were cultivated individually.
2. The method of claim 1 , wherein the liquid nutrient medium comprises sucrose, casein hydrolysate, magnesium sulfate, dipotassium phosphate, monopotassium phosphate, calcium chloride, ammonium sulfate, trace metals, and water.
3. The method of claim 1 , further comprising suspending a particulate anchoring carrier in the liquid nutrient medium.
4. The method of claim 3 , wherein the first and/or second microorganism attaches to the particulate anchoring carrier and accumulates thereon in the form of a biofilm to form a plurality of bacterial-carrier masses.
5. The method of claim 1 , further comprising adding an aqueous base solution comprising 15 to 25% NaOH and/or an aqueous acid solution comprising 15 to 25% citric acid to the reactor.
6. The method of claim 1 , comprising feeding 7% of clear liquefied paraffin into the reactor after 24 hours of incubation.
7. The method of claim 1 , further comprising feeding 6% oil-based defoamer into the reactor every 24 hours.
8. The method of claim 1 , wherein the first microorganism stimulates enhanced production of the one or more growth by-products by the second microorganism.