The IDEA consortium is honored to share some latest project updates. IDEA position papers on different topics related to the algae value chain are becoming publically available. The added value of algae-based bioactive ingredients in chicken feed was evaluated in a chicken trial. Further, short updates are given on IDEA scientific papers and the progress made in the IDEA capitalization part where the integration of waste-streams for the supply of water, nutrients (N,P), CO2 and/or heat are considered.
First two IDEA position papers available on the IDEA website
IDEA is a multidisciplinary project that covers activities along the whole algae value chain with major attention to the interlinkage of the different aspects and stakeholders. The Interreg NWE IDEA project did foresee to disseminate some general findings via position papers targeting the key players in the algae value chain, like algae growers, processors, formulating industry, authorities, policymakers, investors, etc.
Four position papers have been elaborated by the IDEA consortium as compact and easy-to-read 4-pagers, that cover the following topics:
Algae value chain as a whole
Algae cultivation
Applications with algae biomass
Logistic aspects
The first two positions papers on algae value chains and algae cultivation have been made publically available via the IDEA-website. The other position papers will follow soon.
Exploring the potential of algae fractions as broiler feed ingredient
One avenue for algae valorization is the inclusion of algae (fractions) in animal feed. As algae are often claimed to be rich in bio-active compounds, they can potentially improve animal health even when consumed in low amounts. Researchers from the Interreg NWe IDEA and Interreg 2seas Valgorize research projects joined forces to investigate this potential. A broiler trial was set up to explore the health impact of the incorporation of defatted algae in broiler feed. Three types of defatted algae biomass were included in broiler feed and their impact on broiler growth, gut health and morphology were evaluated. Algae biomass was provided by IDEA algae cultivation partners (Forschungszentrum Jülich (D), Thomas More (B) and VITO (B)) and subsequently desalted, defatted, and dried by VITO. Preliminary in vitro tests performed by VITO provided a first idea of the behavior of algae during digestion. Following this preliminary trial, a broiler trial was performed by ILVO (B). Three algae fractions were tested: defatted Chlorella, defatted Chloromonas, and defatted Nannochloropsis.
Preliminary in vitro tests were performed to simulate gastric and small intestinal digestion. Significant amounts of soluble carbohydrates were present in the biomass after the digestion steps. These indigestible carbohydrates are a potential substrate for the avian gut microbiota. The growth potential of Lactobacillus amylovorus, one of the Lactobacillus species considered probiotic, on de predigested algae was studied. Two of the three algae fractions stimulated the growth of L. amylovorus in vitro when compared with the digestion blank. These promising results supported the setup of an animal trial to study the health impact in vivo.
For the broiler trial, all animals received the same standard starter diet to which one of the three algae species was added on top at a 1% or 2% level or not (control treatment). Animals were weighed individually every 4 days to monitor growth while feed intake was measured at pen level at the end of the starter and grower periods (day 11 and 29). On day 29, all animals were euthanized. The gut length was measured and scored for inflammation and the presence of coccidiosis. Also, other organs were weighed and scored for overall aspects related to health status. Gut wall was sampled for histology analysis and for determination of ovotransferrin, an indicator of gut leakage and damage.
Image by ILVO
Animal weight and daily growth tended to be higher for animals receiving Chlorella and Chloromonas algae supplemented diets. Feed intake was similar among treatment groups over the entire experimental period, except for the control animals, which had a somewhat lower feed intake. Feed conversion ratio tended to be lower for several treatment groups than for control animals.
Gut morphology analysis indicated significant differences in liver weight, pancreas weight, and ileum length. Villi height and crypt depth were significantly higher for one treatment group compared to the control. Data processing is still ongoing for liver and gut scoring, together with the analysis of histology coupes and ovotransferrin analysis. After final data processing and statistical analysis, all findings will be compiled and used to prepare a scientific publication.
Short updates
Re-use of nitrogen from digestates for algae growth. Excess nitrogen in the environment is a concern that puts pressure on the agro-sector and that encourages the re-use of nitrogen. Within IDEA, the potential to re-use nitrogen present in digestate (after digestion of plants and/or manure) for algae cultivation is being evaluated. To this end, Swansea University (SU, UK) is pretreating several digestate samples based on knowledge from the Interreg NWE AlgAD project, to produce a concentrated product that is suitable as N-source for the algae. Algae growth trials at lab scale were initiated to determine suitable dosings. Pilot-scale growth trials in collaboration with several IDEA partners will follow later this year.
DIGESTAE PRE-TREATMENT & LABSCALE ALGAE GROWTH TRIALS ON DIGESTATE. Images by Swansea Univ.
Harvesting of mixed algae cultures grown on N-containing process water. Open ponds can be used to grow algae on processwater for reducing the nitrogen content before discharge. To maintain the culture and removed excess algae biomass, harvesting of large amounts of low-density algae culture is required. As centrifugation is suboptimal for these conditions, the MAF submerged membrane-based technology was evaluated for realizing a first dewatering of such a mixed low-density algae culture. So far, three rounds of MAF algae filtrations were performed off-site by VITO (B) using algae culture volumes up to 5.4 m³ originating from an algae pond linked to a demineralization plant. As good dewatering results were obtained (up to > 200 times volume reduction), a continuous on-site harvesting trial is being prepared.
Off-site MAF trials (VITO) will be followed soon with on-site trials. Image by VITO.
Agro-applications. Algae biomass cultivated within IDEA is being evaluated for its potential as biostimulation and/or pest and disease control in the agro-sector. To this end, algae species considered within IDEA so far (like Scenedesmus, Nannochloropsis, Pophyridium, Chloromonas and Chlorella) as well as algae biomass grown on side-streams (including mixed cultures) are envisioned. Up to now, two sets of algae extracts were prepared by VITO (B) and were provided to PCFruit (B) for in vitro trials, comprising pest control trials. First results are encouraging and plans for in vivo trials are being made.
Thoré, E.S.J, F. Schoeters, J. Spit & S. Van Miert (2021). Real-time monitoring of microalgal biomass in pilot-scale photobioreactors using nephelometry. https://www.mdpi.com/2227-9717/9/9/1530