Irradiation of Yarrowia lipolytica NRRL YB-567 creating novel strains with enhanced ammonia and oil production on protein and carbohydrate substrates

Authors: Lindquist, Mitchell; LOPEZ-NUNEZ, JUAN - National Federation Of Columbia Coffee Growers; JONES, MARJORIE - Illinois State University; COX, ELBY - Former ARS Employee; PINKLEMAN, REBECCA - South Dakota School Of Mines And Technology; BANG, SOOKIE - South Dakota School Of Mines And Technology; Moser, Bryan; Jackson, Michael - Mike; Iten, Loren; Kurtzman, Cletus; Bischoff, Kenneth; Liu, Siqing; Qureshi, Nasib; TASAKI, KENNETH - Mitsubishi Chemical Usa, Inc; Rich, Joseph; Cotta, Michael; Saha, Badal; Hughes, Stephen

Submitted to: Applied Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2015
Publication Date: 8/15/2015
Citation: Lindquist, M.R., Lopez-Nunez, J.C., Jones, M.A., Cox, E.J., Pinkleman, R.J., Bang, S.S., Moser, B.R., Jackson, M.A., Iten, L.B., Kurtzman, C.P., Bischoff, K.M., Liu, S., Qureshi, N., Tasaki, K., Rich, J.O., Cotta, M.A., Saha, B.C., Hughes, S.R. 2015. Irradiation of Yarrowia lipolytica NRRL YB-567 creating novel strains with enhanced ammonia and oil production on protein and carbohydrate substrates. Applied Microbiology and Biotechnology. 99(22):9723–9743.

Interpretive Summary: In this research, ammonia (fertilizer) and lipid (oil) production from low-cost protein and carbohydrate substrates was enhanced in the oil-producing yeast Yarrowia lipolytica. Strains capable of yielding increased oil levels and valuable bio-products are needed to improve economic feasibility of using microbial-based oil for sustainable production of biodiesel. Using ultraviolet irradiation to produce mutations in the genome, strains were developed that produced more oil and ammonia than the wild-type strain, and grew faster than the wild type. On coffee waste as the carbon source, one of the irradiated strains produced ammonia and 2 phenylethanol, a valuable fragrance and flavoring ingredient, in addition to acylglycerols (oil) containing predominantly C16 and C18 residues suitable for biodiesel. These novel strains have potential application for commercially viable biodiesel production.

Technical Abstract: Increased interest in sustainable production of renewable diesel and other valuable bioproducts is redoubling efforts to improve economic feasibility of microbial-based oil production. The yeast Yarrowia lipolytica is capable of employing a wide variety of substrates to produce oil and valuable co-products. We irradiated Y. lipolytica NRRL YB-567 with UV C to enhance ammonia (fertilizer) and lipid (oil) production on low-cost protein and carbohydrate substrates and screened the resulting mutant strains first for ammonia then for oil production using color intensity of indicator compounds on plate assays. Seven mutant strains were selected (ammonia assay) and further evaluated for growth rate, ammonia and oil production, and soluble protein content on liver infusion medium (without sugars) and for growth on various substrates. One mutant strain produced substantially more oil (Sudan Black assay) and a second mutant strain had a much faster doubling time than wild type or other mutant strains. These two mutant strains had higher soluble protein content compared to wild type and, along with two other mutant strains, produced ammonia levels (enzyme assay) slightly higher than wild type. The mutant strain with the highest oil production, with doubling time slightly faster than wild type, and with high ammonia levels and soluble protein content was selected for study on coffee waste medium. On this medium the strain produced 0.13 g/L ammonia and 0.20 g/L 2-phenylethanol, a valuable fragrance, in addition to acylglycerols (oil) containing predominantly C16 and C18 residues. The mutant strains have potential application for commercial biodiesel production.