Application of Grass Juice for Microalgae Cultivation
Translated title
Anvendelse af græs saft til dyrkning af microalgaer
Authors
Rafique, Iqra ; Joseph-Ifeji, Queenie Adaora
Term
4. term
Education
Publication year
2021
Submitted on
2021-06-04
Pages
50
Abstract
The growing demand for organic protein feed, coupled with the challenges of long-distance transport, CO2 emissions, and GMO concerns associated with soy, motivates alternative, local solutions. This thesis explores whether alfalfa (Medicago sativa) brown juice—a byproduct of green biorefinery leaf protein extraction—can serve as a nutrient medium for cultivating microalgae as a sustainable protein source. Two brown juice types were evaluated: fermented and heat-coagulated. The study included characterization of the juices (pH, total nitrogen, ammonium, and orthophosphate), centrifugation/filtration, inoculum preparation, high-throughput multiwell screening, and cultivation in 250 mL shake flasks under light and dark conditions. Additional nitrogen and phosphorus supplementation was tested, and growth and biomass were assessed by cell counting, dry matter, and protein analyses. Based on the reported results, fermented brown juice supported microalgal growth under light when supplemented with nitrogen and phosphorus. These findings indicate that fermented alfalfa brown juice, with targeted nutrient adjustment, can function as a low-cost medium for microalgal cultivation; details on optimal concentrations, dark cultivation, and full comparisons with heat-coagulated juice are not available in the provided excerpt.
Efterspørgslen efter økologiske proteinkilder til foder stiger, og importeret soja er udfordret af transportafstande, CO2-udledning og GMO-problematikker. Denne afhandling undersøger, om brunsaft fra lucerne (Alfalfa) – en reststrøm fra grøn bioraffinering – kan anvendes som næringsrigt væskemedie til dyrkning af mikroalger som et lokalt, bæredygtigt proteinalternativ. To typer brunsaft blev evalueret: fermenteret og varmekoaguleret. Arbejdet omfattede karakterisering af brunsafterne (pH, total kvælstof, ammonium og ortofosfat), forbehandling ved centrifugering/filtrering, opformering af inokulum, high-throughput screening i mikrotiterplader samt dyrkning i 250 mL rysteflasker under lys og mørke. Der blev desuden testet tilsætning af ekstra kvælstof og fosfor, og vækst og biomasse blev vurderet via celletælling, tørstof og proteinbestemmelse. I de rapporterede resultater understøttede fermenteret brunsaft mikroalgevækst under lys, når mediet blev suppleret med kvælstof og fosfor. Undersøgelsen peger dermed på, at fermenteret lucernebrunsaft, med målrettet næringsstofjustering, kan fungere som et lavomkostningsmedie for mikroalgedyrkning; detaljer om optimale koncentrationer, mørkedyrkning og fulde sammenligninger med varmekoaguleret brunsaft ligger uden for det tilgængelige uddrag.
[This apstract has been generated with the help of AI directly from the project full text]