Co-Culture of Myxobacteria and Pseudomonas for Enhanced Production of Biosurfactants and Other Metabolites
Methods are provided for enhanced production of microbial biosurfactants, the methods comprising co-cultivating Myxococcus xanthus and Pseudomonas chlororaphis. In certain embodiments, the biosurfactants are rhamnolipids or rhamnolipids-like glycolipids. In certain embodiments, other microbial growth by-products are produced, such as organic hydrocarbons including terpenes and/or terpenoids. Microbe-based products produced according to the subject methods are also provided, as well as their uses in, for example, agriculture, oil and gas recovery, and health care.
1 . A method for enhanced production of one or more microbial growth by-products, the method comprising co-cultivating a first microorganism and a second microorganism in a fermentation reactor,
wherein the first microorganism is a myxobacterium and the second microorganism is a non-pathogenic strain of Pseudomonas, 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 myxobacterium is a Myxococcus spp. bacterium
3 . The method of claim 2 , wherein the Myxococcus spp. bacterium is M. xanthus.
4 . The method of claim 1 , wherein the non-pathogenic strain of Pseudomonas is a strain of P. chlororaphis.
5 . The method of claim 4 , wherein the strain is P. chlororaphis subsp. aureofaciens strain 306 or P. chlororaphis subsp. aureofaciens strain 111.
6 . The method of claim 1 , wherein the myxobacterium is M. xanthus and the strain of Pseudomonas is either strain 306 or strain 111.
7 . The method of claim 1 , wherein the Pseudomonas strain produces the one or more growth by-products.
8 . The method of claim 1 , wherein the one or more growth by-products are biosurfactants.
9 . The method of claim 8 , wherein the biosurfactants are rhamnolipids (RLP).
10 . The method of claim 8 , wherein the biosurfactants are flavolipids.
11 . The method of claim 1 , wherein the one or more growth by-products are terpenes and/or terpenoids.
12 . The method of claim 11 , wherein the terpenoids are carotenoids.
13 . The method of claim 1 , wherein co-cultivating the first and the second microorganisms comprises:
inoculating the fermentation reactor with the first microorganism and inoculating the fermentation reactor with the second microorganism, wherein the fermentation reactor comprises a liquid nutrient medium;
incubating the first and second microorganisms in the reactor under conditions favorable for growth and production of the one or more microbial growth by-products;
extracting the one or more growth by-products from the reactor; and, optionally,
purifying the one or more growth by-products.
14 . The method of claim 13 , wherein the liquid nutrient medium comprises glucose, casein peptone, glycerol, yeast extract, monopotassium phosphate, disodium phosphate, ammonium nitrate, magnesium sulfate heptahydrate, ferrous sulfate, and trace metals.
15 . The method of claim 13 , further comprising suspending a particulate anchoring carrier in the liquid nutrient medium.
16 . (canceled)
17 . The method of claim 15 , 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.
18 . The method of claim 13 , further comprising adding an aqueous base solution comprising 15 to 25% NaOH to the reactor.
19 . The method of claim 13 , further comprising feeding 500 g/L of glycerol into the reactor after 48 hours of incubation.
20 . The method of claim 13 , further comprising feeding 3% canola oil into the reactor every 24 hours.
21 - 23 . (canceled)
24 . A composition comprising one or more microorganisms and/or one or more microbial growth by-products, said one or more microorganisms comprising Myxococcus xanthus and Pseudomonas chlororaphis, and said one or more microbial growth by-products comprising biosurfactants, terpenes, and/or terpenoids.
25 . The composition of claim 24 , wherein the biosurfactants are rhamnolipids and/or flavolipids.
26 . (canceled)
27 . The composition of claim 24 , wherein the P. chlororaphis is strain 111 or strain 306.