Continuing Project Proposal: Production of DHA Rich Algae Biomass as Cattle Feed Supplement to Enhance Milk Quality
PrincipAL Investigator(s) and Cooperator(s):
PI Dr. Shulin Chen, Professor, Department of Biological Systems Engineering, Washington State University 99164-6120; Phone: (509)335-3743; Fax: (509) 335-2272
Co-PI Dr. Zhanyou Chi, Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120; Phone: (509)335-6239 Fax: (509) 335-2272;
FUNDING REQUEST: $20,000; Matching fund: $30,000, by Washington State Potato Commission
TOTAL PROJECT DURATION: January 1, 2008 through December 31, 2008
CURRENT YEAR: 2007
Abstract: The goal of this project is to develop a cost-effective algal cultivation process to convert under-valued cull potatoes to high-value docosahexaenoic acid (DHA) that has significant beneficial health effects. The DHA enriched algal biomass will then be used as a feed additive for dairy cows to enhance the nutritional value of the milk. In the first year of the project, we discovered (1) a two-stage growth process of the microalgae Schizochytrium that required separate culture conditions, and (2) a “shifting” strategy to significantly increase the cell culture to more than 100 g/L algae dry biomass within 96 hours at lab-scale The results from the first year demonstrated great commercial potential of this technology. The overall objective for the second year’s research is to scale-up and optimize this process for commercialization. The specific objectives are to: (1) scale-up of this DHA production process; (2) assess the economic viability and overall feasibility of the process. If successful, this production process will decrease the cost of algae culture for DHA production, since cull potato is used as an inexpensive raw material. This process also benefits dairy industry in that the DHA enriched algal biomass, upon being used as a feed additive for dairy cows, will enhance the nutritional value of the milk. Ultimately, human health will be improved by consuming the omega-3 enhanced products.
Introduction / justification:
The goal of this study is to develop a cost-effective algal cultivation process to convert under-valued cull potatoes to high-value docosahexaenoic acid (DHA) that has significant beneficial effects in the treatment of neurological and cardiovascular diseases as well as in infant brain and ocular development. The DHA enriched algal biomass will then be used as a feed additive for dairy cows to enhance the nutritional value of the milk, thus the price of the milk.
DHA is an important w-3 polyunsaturatted fatty acids (PUFA). It is the component of the photoreceptor cells of infant retinas and is also involved in the development of infant brain tissue. The inclusion of supplementary DHA in infant formulas is strongly recommended by the World Health Organization (WHO). Also, research continues to demonstrate the need for DHA beyond infancy. Furthermore, studies suggested a positive correlation between DHA consumption and the reduced risk of age related neurological disorders, such as Alzheimer’s and dementia. As a result, DHA is not only used as additives in infant formulas, but also in adult dietary supplement in food and beverage. Example foods are cheeses, yogurts, spreads and dressings, and breakfast cereals. Other markets include foods for pregnant and nursing women and applications in cardiovascular health. These markets may have much greater growth potential than infant formulae. The proposed project offers an attractive alternative for omega-3 PUFA production and supplementation in food. It addresses three of BIOAg’s targeted areas as below:
(1) This process will convert the under-value cull potatoes to high-value omega-3 fatty acid, which addresses the priority area of bioproducts. Development of new markets for the cull potato is essential to the profit margins of the potato producers because the cost to grow the culls is $70-120/ton while presently they can be sold as an animal feed for only about $10-20/ton. Converting the culls to a value added bioproduct is an excellent way to develop new markets and overcome the cost to produce the culls, since they can provide starch, protein, vitamins, and salt nutrients for the fermentation process.
(2) The omega-3 enriched algae biomass will be fed to dairy cows. This addresses the priority area of organic dairy development. The cow will benefit from higher intakes of algal biomass because these algae contain a high level of protein, amino acids, lipids and vitamins, which are crucial for cows’ growth. Studies have shown that DHA enriched algae biomass enhanced the disease immunity of farmed fish. Some beneficial roles of DHA to fish probably work for cows also.
(3) The cow milk quality will be enhanced by the supplementation of omega-3. This addresses the priority area of food quality. Dietary supplements containing DHA for dairy cow could help promote marketing of milk based upon its DHA content. Study showed that the inclusion of fish oil in the diet of grazing dairy cows notably affects the fatty acids profile of milk fat. Concentrations of CLA, TVA and omega-3 PUFA were significantly increased, which represents a positive impact upon dietetic quality of milk. Thus, the omega-3 enriched milk can provide a favorite dietary source of omega-3 for Americans. Also, the omega-3 enriched milk, as the raw material, can be further developed to more favorite food, such as cheeses and yogurts.
Objectives:
During the first project year (2007), a “two step” strategy fed batch culture was developed, with which more than 100 g/L algae biomass was produced within 96 hr and more than 20% of the algae biomass was DHA. Such high productivity of this process makes it very promising for commercialization. Thus, the objectives in 2008 are:
(1) Scale up of this algae culture process: The dissolved oxygen (DO) concentration probably become a limiting nutrient in processes of high oxygen demand (fast growing microorganisms, high biomass) or when the rheological properties of the broth offer a high resistance to the mass transfer. The cell density in the later stage of this algae culture process is more than 100 g/L and although less oxygen is consumed for the fatty acid accumulating step, such high cell density, on the whole, will require a large amount of oxygen. Also, this high cell density probably will change the rheological properties of the broth, which may offer a high resistance to mass transfer and decrease the oxygen transfer rate. We will study the optimal mixing strategy and the relationship between oxygen supply rate, mixing level and reactor size so that adequate oxygen supply will be provided with the minimum energy consumption.
(2) Assess the economic viability and overall feasibility of the process: To meet the market requirement, the quality of produced algae biomass needs to be analyzed in term of nutrient ingredients, fatty acids profile, vitamin profile, etc, and the value of the product need to be assessed. Based on the calculation and comparison of production cost and produced algae biomass value, an economical viability of this process will be evaluated for different production scales with raw material supply scenarios
Expected Outputs:
Work to be completed:
(1) Scaling-up the laboratory scale DHA production process to pilot scale: Scale-up using the new optimized media obtained in objective 1 will be accomplished using 1 L, 25L, and 125L fermentors within the Bioprocessing Service Center Laboratory at WSU. For the oxygen transfer issue, the OUR, OTR, and KLa values in both the seed cell producing stage and fatty acid accumulating stage will be investigated at various aeration and agitation rates in a 1 liter lab scale fermentor (0.1–1.0 vvm and 200–500 rpm, respectively) as well as in a 25 L fermentor (0.1 –1.0 vvm and 200–500 rpm, respectively). The KLa values of both scales will be compared to find out a control condition that gives the same KLa for scale-up study. The effect of KLa to the algae’s growth and fatty acid accumulation in the 1L, 25 L, and 125L fermentors will be recorded and compared. Problems such as oxygen concentration gradients in the fermentor in this scaling up process will be recorded and investigated if it is encountered.
(2) Economic viability assessment: The cost of raw materials, energy, labors, as well as the process productivities etc. in the pilot study will be recorded and studied. A techno-economic assessment of the feasibility of DHA enriched algae biomass production will be conducted using Matlab Simulink software using the laboratory and scale-up results and standard chemical engineering plant design and costing concepts as summarized by Peters and Timmerhaus (1991).
Publications, Handouts, Other text & web products to be made available:
1~2 journal paper will be published with this work;
1~2 conference presentation will be made on this work.
Outreach & Education activities:
1 master or Ph.D student will take part in this work as a research assistant. Once the process is scaled-up and data is made available in regard to nutritive content of algal biomass and effect on cow and milk production, the entire process will be hopefully patented and several outreach activities will be planned for outreach through existing BIOAG programs. More specifically, poster and oral presentations will be made at sponsored BIOAG and Potato Commission activities.
Expected Impacts
Short-Term (knowledge gained and shared):
If successful, this production process will decrease the cost of algae culture for DHA production, since cull potato is used as an inexpensive t raw material. This process also benefits dairy industry in that the DHA enriched algal biomass will enhance the nutritional value of the milk.
Intermediate-Term (current & expected change in behaviors):
Better understanding the relationship between cell growth and lipids accumulation in lipid-producing microorganisms, especially microalgae as this project did, not only improve the production of omega-3 fatty acids, but probably more widely, improve all single cell oil (SCO) producing processes, including biodiesel production from algae, which is the largest potential SCO application, and currently, an important issue in the bioenergy field.
Long-Term (potential change in economic/environmental/social situations):
Besides using as the feed additive to cattle, the produced omega-3 enriched algae biomass could provide an inexpensive source of omega-3 that does not originate from fish meal. Currently, farm-raised fish obtain omega-3 only from fish meal. Fish oil production amounts to about 1 million tons annually, of which 70~80 % is utilized for the production of fish feed for farmed fish. As the aquaculture feed demand increases and ocean fishery resources decline, using fish meal to support aquaculture growth becomes non-sustainable. In addition, the development of an organic fish movement requires an omega-3 source that does not originated from fish meal. Therefore, feeding an organic diet supplemented with enriched omega-3 algae becomes almost the only future option for the aquaculture industry. Therefore, this technology has the potential to enhance the organic nature and sustainability of animal production.
Budget:
Salary/Wages / $14,000Materials and Supplies / $5,000
Travel / $1,000
Total / $20,000