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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Quality and Safety Assessment Research Unit » Research » Publications at this Location » Publication #423720
Research Project: Smart Optical Sensing of Food Hazards and Elimination of Non-Nitrofurazone Semicarbazide in Poultry

Location: Quality and Safety Assessment Research Unit

Title: Upcycling nutrients from poultry slaughterhouse wastewater through cultivation of the nutritional yeast, Yarrowia lipolytica

Author
item SHANMUGAM, SARAVANAN - Auburn University
item SCHORER, RACHEL - Auburn University
item ARTHUR, WELLINGTON - Auburn University
item DRABOLD, EDWARD - Auburn University
item RUDAR, MARKO - Auburn University
item HIGGINS, BRENDAN - Auburn University

Submitted to: Journal of Environmental Chemical Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Poultry processing generates large volumes of solids that are separated from the plant’s wastewater stream. These solids are mostly fat along with bits of meat, blood, and feathers that made it past upstream screens. Such solids are separated from the wastewater using a process called dissolved air flotation and typically, such material is screened to reduce its water content before the solids are land applied. The water that is extracted from these solids, which we call “blood water,” is very rich in protein and amino acids and is currently disposed of in the sewer. As this is quite wasteful, we tested the use of this blood water for the growth of a nutritional yeast. The yeast could grow well on blood water, sustaining growth over six continuous batches of production. This suggests that blood water can be repurposed to create a food product rather than disposing of it as a waste.

Technical Abstract: Poultry processing is a major global industry and a large generator of nutrient-rich waste streams. One such stream is the liquid that is separated from the fatty material in dissolved air flotation units. Currently, this stream (referred to as “blood water” in this study) is discharged to the sewer for treatment in municipal wastewater treatment facilities. High levels of free amino acids (~3.5 g/L) and proteins (~0.9 g/L) in blood water make it a potentially attractive material for the cultivation of single cell protein. Here, we investigated the feasibility of utilizing blood water as a fermentation medium for the nutritional yeast, Yarrowia lipolytica. One of the key bottlenecks to using blood water as a growth medium is its short lifespan and propensity to generate malodors. Hence, we investigated the impact of storage temperature (-20 ', 4 ' and 22 ') and duration on media quality for Y. lipolytica cultivation. The results from this study indicate that blood water could support the growth of Y. lipolytica at all storage temperatures with little loss in performance after 1 week of storage. Thereafter, growth declined by ~0.5 log for blood water stored at -20 ' and 4 ' (p < 0.05) and by >0.8 log for blood water stored at 22 ' (p = 0.05). Moreover, frozen storage prevented loss of amino acids and development of malodors caused by formation of sulfur containing volatiles derived from amino acid biodegradation. The yeast simultaneously generated and removed sulfur-containing malodourous compounds when grown in blood water. Cool storage at 4 ' also prolonged the lifespan of amino acids and had significantly higher yeast growth than the material stored at 22 ' (p < 0.05). The results suggest the need for adjacent yeast production facilities to minimize the need for blood water chilling and transport.