Recipient Organization
KAMPACHI FARMS, LLC
1 KEAHOLE POINT RD
KAILUA KONA,HI 967402637
Performing Department
(N/A)
Non Technical Summary
Farmed marine macroalgae present a carbon negative opportunity for feedstuff production, as theydo not require land conversion, fertilizers, or freshwater. Macroalgae are already used in smallquantities in some animal diets, but the complex polysaccharides are largely indigestible. Trials atOcean Era have shown that the microbes from herbivorous reef fish can be used as the inoculum fordeconstruction of macroalgae for aquaculture feeds. The project objective is to identify microbesthat are key to fermentation of tropical macroalgal species as Partially Digested Macroalgae(PDMA) - a partial dietary replacement for aquaculture feeds. We will test a range of microbialisolates to optimize a reproducible fermentation process for deconstructing macroalgae intonutritionally beneficial feedstuffs. Reducing PDMA to a consistent, efficient process could providean economic engine for expanded seaweed farming, reduce aquaculture feed costs, and carbonfootprint.The focus of the proposedwork is microbial biomass conversion, for development of new aquafeeds from tropical macroalgae.We will ferment cultured macroalgae, with varying combinations of previously-isolated microbes,and then conduct feed trials with tilapia. Growth of tilapia will be used to evaluate effectiveness ofeach PDMA additive. With appropriate demonstration and scaling, PDMA could make a significantcontribution towards the decarbonization of aquaculture and global greenhouse gas reductiontargets. By establishing a controlled, repeatable process, we will be able to license these processesto agribusiness.
Animal Health Component
80%
Research Effort Categories
Basic
0%
Applied
80%
Developmental
20%
Goals / Objectives
The project objective is to identify microbesthat are key to fermentation of tropical macroalgal species as Partially Digested Macroalgae(PDMA) - a partial dietary replacement for aquaculture feeds. We will test a range of microbialisolates to optimize a reproducible fermentation process for deconstructing macroalgae intonutritionally beneficial feedstuffs. Reducing PDMA to a consistent, efficient process could providean economic engine for expanded seaweed farming, reduce aquaculture feed costs, and carbonfootprint.Our proposed work is in line with SBIR Phase I Topic Area 8.8, Biofuels and BiobasedProducts; New Non-food Biobased Products from New Industrial Crops. The focus of the proposedwork is microbial biomass conversion, for development of new aquafeed from tropical macroalgae.We will ferment cultured macroalgae, with varying combinations of previously-isolated microbes,and then conduct feed trials with tilapia. Growth of tilapia will be used to evaluate effectiveness ofeach PDMA additive.Technical Objective 1. Identify the microbes from the nenue microbiome that are mostimportant in the seaweed deconstruction process. During earlier work, microbial isolates ofinterest (from the nenue gut) were identified by our research partners at the NREL and theLBNL. These microbes are known to have deconstruction activity, making them the leadingcandidates for PDMA production. We will make several varieties of PDMA using these isolates as inoculum with two different macroalgal species cultivated by Ocean Era - Agardhiellasubulata and Halymenia hawaiiana.Technical Objective 2. PDMA production and nutritional analysis. The different types ofPDMA produced will be analyzed to learn how the species of seaweed and inoculum affect thenutritional qualities of the final product. Those that have desirable qualities (e.g., increasedprotein levels) will be tested as a feed ingredient for juvenile tilapia (Oreochromis niloticus X O.mossambicus).Technical Objective 3. Feed trials with juvenile fish to assess product safety andpreliminary performance. We intend to be testing at least nine different PDMA products,over the course of three feeding trials. The trials will assess the fish's growth rate and foodconversion ratio (FCR). Additionally, we will submit tissue samples from the fish forhistological evaluation. Histology of the gut, liver, brain, eyes, etc. may indicate if anyphysiological changes have occurred due to the feed.
Project Methods
Task 1 PDMA productionPDMA production to date has been at bench-top scale (up to 2 L wet weight). Theprocess involves pasteurization of dewatered macroalgal biomass (500 g, at 80°C for 30min),and then inoculation with PDMA 'starter' (from a known consortium). After inoculation, thePDMA ferments (at 28°C) for 3 or 4 days, with a further 500 g of additional pasteurizedbiomass provided each day. Harvesting the PDMA entails straining the moist product (~90%water), then immediately freezing it. Once frozen, it will be processed using a freeze drier. Thefreeze-dried PDMA is now more shelf-stable, and it can be ground into a powder for easyintegration into the experimental diets.The experimental design for PDMA production involves using previously isolated microbes to fermentmacroalgae that will go into making tilapia diets. A total of 10-20 microbial isolates will be usedto ferment on two different red macroalgal species. This will be done with previously establishedprotocols. A control using the readily available microbe Lactobacillus acidophilus will be usedfor fermentation. Over 20 PDMA treatments will be made with replication (n=3) at 100g each.These will be frozen and sent to an outside laboratory for compositional analysis.Task 2 PDMA composition as predictor of feed performance at scaleEach of the produced PDMA materials will be subjected to standard compositionalanalysis (levels of protein, fat, carbohydrate). Additionally, analysis will include, ammino acidprofile, fatty acid composition, and elemental composition (C, H, N, S, O and inorganics).Samples will be sent to University of Hawai'i Agricultural Diagnostics Labs for compositionalanalysis. A comparison between treatments will be made and preference will be given to PDMAwith high protein, high carbohydrate, and low ash composition. Based on these results, 9PDMA's will be selected to be used in the feed trials.Task 3: Feed trials - animal growth performance on diets including PDMAFeed manufacturing. Tilapia feed trials will be used to initially vet the PDMA varietiesproduced in Task 2. Using the results of the nutritional analysis described above, we willdetermine which PDMA varieties have the highest likelihood for success as a feed ingredient.The experimental diets will be produced by Dr. García-Ortega at the University of Hawai'i Hilo.All diets will be based off a commercially available tilapia feed. The tilapia feed will bepulverized, and then the freeze-dried PDMA of choice will be added to it. The powder will be reconstituted, dried, and cut into pellets of the appropriate size for the fish (~2mm). All experimental diets willinclude PDMA as 10% of the total diet (10% DW). These trials will be run as rapid bioassays, toprovide iteration to support process optimization (Task 1). Each diet will have three replicate tanks, with diets assigned randomly to specific tanks. Proximate analysiswill be performed on the test diets to ensure they are similar in protein, fat, and energy levels.Fish culture system. The feed trials will be performed in a 2500 L freshwaterrecirculating aquaculture system at Ocean Era's facility in Kailua-Kona. These tanks are in astand-alone, climate-controlled building. The 12 fish tanks are 100 L each. The water is filtered using physical and mechanical filtration. Aeration is provided to all tanks. Animals will be fed 3times daily and their tanks will be cleaned daily. Ammonia levels, temperature and dissolvedoxygen will be monitored daily. Nitrite, nitrate, and alkalinity will be checked three times per week.The tilapia juveniles will be purchased from a hatchery on Hawai'i Island one to two weeksbefore the start of each trial. We will initiate the feed trial when fish are roughly 15 grams each.Individual fish will be identified via fin clip so we can track the performance of individualanimals. There will be 10 fish per tank. The standard performance indicators, growth rate andfeed conversion ratio, will be calculated for each tank of fish. An Analysis of Variance(ANOVA) procedure will be used to determine if there are differences between treatments. Ifsignificant differences are seen, then we will perform post hoc analysis using Tukey's test toindicate where the differences occur. At the end of the feed trials, six fish from each treatment will beeuthanized, and sent to a fish pathology laboratory for histological analysis. The organs ofinterest including foregut, hind gut, eye, brain, liver, kidney and spleen will be analyzed for anychanges to tissues occurring due to the diet.