Browsing by Subject "Microalgae"

Sort by: Order: Results:

Now showing items 1-7 of 7
  • Lamminen, Marjukka Elina; Halmemies-Beauchet-Filleau, Anni Ilona Karoliina; Kokkonen, Tuomo Juhani; Simpura, Ilkka Antero; Jaakkola, Seija Liisa; Vanhatalo, Aila Orvokki (2017)
    Two experiments were conducted to evaluate microalgae as a protein supplement in the nutrition of lactating dairy cows in relation to unsupplemented and rapeseed meal supplemented diets. In both experiments multiparous Finnish Ayrshire cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (11 kg/d in Exp. 1 and 12 kg/d in Exp. 2), and grass silage ad libitum. In Exp. 1, six cows (212 days in milk; DIM) were used in a replicated 3 × 3 Latin square. Diets were supplemented isonitrogenously with rapeseed meal (pelleted rapeseed supplement, RSS), mixture of Spirulina platensis and Chlorella vulgaris microalgae (1:1 on dry matter (DM) basis; ALG) or a mixture of RSS and ALG (1:1 on crude protein (CP) basis; RSS-ALG). In Exp. 2, four intact cows and four rumen cannulated cows (190 DIM) were used in a replicated 4 × 4 Latin square. Treatments consisted of basal diet without protein supplement (NEG) or supplemented similarly as in Exp. 1 with the exception of RSS-ALG and ALG containing only S. platensis. Protein supplementation increased fibre and N digestibility but did not affect dry matter intake (DMI) or milk yield. The substitution of rapeseed by microalgae did not affect total DMI or milk yield in neither of the experiments, but changed the quality of DMI in Exp.2 by linearly decreasing concentrate:forage ratio of the diet due to poorer palatability of microalgae. The efficiency of N utilisation (NUE) in milk production varied from moderate (Exp. 1) to high (Exp. 2), and in Exp. 2 was decreased by both protein supplementation and microalgae inclusion in the diet. Protein supplementation or microalgae inclusion in the diet did not affect ruminal pH or major volatile fatty acids in Exp. 2, but both increased ruminal NH3-N concentration. There was likely a shortage of N for rumen microbes on NEG in Exp. 2 as indicated by low milk urea N and increased microbial N flow on protein supplemented diets. In both experiments, only minor differences were observed in plasma metabolites when microalgae substituted rapeseed. Even though arterial histidine concentrations were high, arterial histidine and carnosine concentrations (Exp. 1 and 2) and milk protein yields (Exp. 2) decreased by microalgae inclusion suggesting that histidine supply may become suboptimal on microalgae supplemented diets. Experiments demonstrated the suitability of microalgae as protein supplement for dairy cows, however, the protein value of microalgae is likely slightly lower than that of rapeseed meal.
  • Tossavainen, Marika; Nykänen, Anne; Valkonen, Kalle Santeri; Ojala, Anne; Silja, Kostia; Romantschuk, Martin (2017)
    Growth and fatty acid production of microalga Selenastrum sp. with associated bacteria was studied in lab-scale experiments in three composting leachate liquids. Nutrient reduction in cultures was measured at different initial substrate strengths. A small, pilot-scale photobioreactor (PBR) was used to verify labscale results. Similar growth conditions supported growth of both Selenastrum and bacteria. CO2 feed enhanced the production of biomass and lipids in PBR (2.4 g L-1 and 17% DW) compared to lab-scale (0.1-1.6 g L-1 and 4.0-6.5% DW) experiments. Also prolonged cultivation time increased lipid content in PBR. At both scales, NH4-N with an initial concentration of ca. 40 mg L-1 was completely removed from the biowaste leachate. In lab-scale, maximal COD reduction was over 2000 mg L-1, indicating mixotrophic growth of Selenastrum. Co-cultures are efficient in composting leachate liquid treatment, and conversion of waste to biomass is a promising approach to improve the bioeconomy of composting plants. (C) 2017 The Authors. Published by Elsevier Ltd.
  • Lamminen, Marjukka Elina; Halmemies-Beauchet-Filleau, Anni Ilona Karoliina; Kokkonen, Tuomo Juhani; Jaakkola, Seija Liisa; Vanhatalo, Aila Orvokki (2019)
    This experiment was conducted to evaluate different microalgae species as protein supplements in the nutrition of lactating dairy cows in comparison to soya bean meal. Four multiparous lactating Finnish Ayrshire cows (112 days in milk) were used in a balanced 4 × 4 Latin square study. Cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (12.5 kg/d) and grass silage ad libitum. Experimental treatments consisted of four isonitrogenous protein supplements: soya bean meal (SOY), Spirulina platensis (SPI), Chlorella vulgaris (CHL) and a mixture of C. vulgaris and Nannochloropsis gaditana (1:1 on dry matter (DM) basis; CHL-NAN). The substitution of soya bean meal by microalgae did not affect the quantity of total DM intake (DMI), but changed the composition of DMI by decreasing the concentrate:forage ratio of the diet (P=0.054) owing to the poorer palatability of microalgae. Intake of methionine was increased (P<0.01) and that of histidine decreased (P<0.01) with microalgae diets compared to SOY, but no significant changes in arterial concentrations were observed. The digestibility of nutrients, milk or energy corrected milk (ECM) yield were not affected by dietary treatments. Though, owing to SPI, algae diets resulted in numerically +2.2 kg/d higher ECM yield than SOY. Microalgae diets tended to result in higher milk fat (P=0.073), arterial acetic acid (P=0.055) and non-esterified fatty acid (P=0.060) concentrations than SOY. Milk fat (P<0.05) and arterial acetic acid (P=0.010) concentrations were increased and milk fat yield tended to increase (P=0.098) on SPI compared to CHL and CHL-NAN. Urinary nitrogen excretion was also lower (P<0.05) for microalgae diets than for SOY. Microalgae diets resulted in higher secretion of Δ16:2 (P<0.05), cis-9, cis-12, cis-15 18:3 (α-linoleic acid; ALA) (P<0.05), cis-6, cis-9, cis-12 18:3 (P<0.05) and polyunsaturated fatty acids (PUFA) (P<0.05) in milk than SOY. Secretion of cis-5, cis-8, cis-11, cis-14, cis-17 20:5 (eicosapentaenoic acid; EPA) in milk tended to be higher on CHL and CHL-NAN than on SPI (P=0.060), and was higher on CHL-NAN than on CHL (P<0.05). Also the omega-6:omega-3 ratio was lower (P<0.05) for CHL-NAN than for CHL. The results suggest that microalgae are likely comparable protein feed to soya bean meal in dairy cow nutrition, especially if palatability of microalgae can be improved.
  • Stamm, Matthias (Helsingin yliopisto, 2015)
    Microalgae (MA) are a novel feed ingredient for dairy cows. They are an alternative high quality protein source and rich in polyunsaturated fatty acids (PUFA). Supplementation of MA in dairy cow feeds has a potential to increase the amount of beneficial PUFA and bioactive molecules in milk. Four multiparous Finnish Ayrshire cows fed grass silage-based diets were used in a 4 × 4 Latin square with 21-d experimental periods to evaluate the effects of various protein supplements on fatty acid composition, oxidative stability, milk fat globule size and phospholipid content of milk. Dietary treatments consisted of 4 concentrate supplements containing soya (control), or one of three MA supplements: (i) Spirulina platensis, (ii) Chlorella vulgaris or (iii) Chlorella vulgaris + Nannochloropsis gaditana. Inclusion of MA in the diet decreased saturated fatty acid (SFA) content in milk compared to soya and tended to increase monounsaturated fatty acid and PUFA concentrations in milk. MA supplements increased 4:0, 5:0, 6:0, 17:0, 18:1 + trans-15 18:1, and 18:3n-3. Among algae, Chlorella vulgaris lead to highest contents of PUFA and 18:2n-6, Spirulina platensis to highest contents in 14:0, 16:0 and 18:3n-6 and Chlorella vulgaris + Nannochloropsis gaditana to highest contents of 6:0, 20:0 and 20:5n-3 in milk. Oxidation stability and phospholipid content of the milk were not affected by treatment. Diets containing Chlorella vulgaris led to a decrease in the number of milk fat globules, but mean globule diameter (d4,3) and milk fat globule size distribution in terms of volume were unaffected by treatment. Additionally, effects of individual animals on milk fat globule size distribution and phospholipid contents have been shown. In conclusion, MA supplementation moderately increased the content of PUFA at the expense of SFA compared to soya. Enrichment of specific fatty acids depended on the fatty acid composition of the supplement and stronger alterations of milk fatty acid composition will require higher contents of algal fatty acids. Premature spoilage through oxidation was not an issue. Finally, MA fed in the current study could only slightly alter the milk fat globule distribution, but phospholipid contents remained unchanged.
  • Tossavainen, Marika; Ilyass, Usman; Ollilainen, Velimatti; Valkonen, Kalle; Ojala, Anne; Romantschuk, Martin (2019)
    Nitrogen limitation is considered a good strategy for enhancement of algal lipid production while conversely N repletion has been shown to result in biomass rich in proteins. In this study, the influence of long-term N limitation on Euglena gracilis fatty acid (FA), protein, chlorophyll a, and carotenoid concentrations was studied in N limited cultures. Biomass composition was analyzed from three-time points from N starved late stationary phase cultures, exposed to three different initial N concentrations in the growth medium. Total lipid content increased under N limitation in ageing cultures, but the low N content and prolonged cultivation time resulted in the formation of a high proportion of saturated FAs. Furthermore, growth as well as the production of proteins, chlorophyll a and carotenoids were enhanced in higher N concentrations and metabolism of these cellular components stayed stable during the stationary growth phase. Our findings showed that a higher N availability and a shorter cultivation time is a good strategy for efficient E. gracilis biomass production, regardless of whether the produced biomass is intended for maximal recovery of polyunsaturated FAs, proteins, or photosynthetic pigments. Additionally, we showed an increase of neoxanthin, beta-carotene, and diadinoxanthin as a response to higher N availability.
  • Mercier, Léon (Helsingin yliopisto, 2018)
    PURPOSE AND GOALS Microalgae are unicellular eukaryotic organisms capable of photosynthesis. They harvest sunlight and efficiently take up carbon dioxide and nutrients such as nitrogen and phosphorus from their environment and use them for their growth. Due to these properties, their rapid growth and ability to survive in a variety of environments, microalgae have potential in biotechnological applications that promote nutrient recovery and recycling, water purification and the carbon neutral production of biochemicals and possibly biofuels. The purpose of this study was to investigate the suitability of a side stream water originating from the production of baker’s yeast (yeastwater) for the cultivation of a species of microalga called Euglena gracilis. The study aimed to determine the capacity of this water to support growth and protein production of E. gracilis as well as the capacity of E. gracilis to remove nutrients from the water. The effect of filtration of the water on these parameters was also studied. Yeastwater contains an organic molecule called betaine in relatively high concentrations. Betaine has previously been shown to boost the production of the important vitamin cobalamin in bacteria. The study aimed to determine the effect of betaine on the growth of E. gracilis and on the production of cobalamin in the algal-bacterial symbiosis. METHODS E. gracilis was cultured in laboratory scale photobioreactors. Its growth, protein production and nutrient uptake capacity was determined. Baker’s yeast production side stream water diluted with MQ-water was used as the growth medium either in filtered or unfiltered form. A control treatment was prepared where no microalgal inoculate was added to the photobioreactor. The same microalga was also grown in a synthetic nutrient medium with and without betaine. The uptake of betaine and biomass concentrations of cobalamin were determined. For the determination of microalgal growth, dry weight determination and flow cytometry analysis were used. Protein production was determined on the basis of total nitrogen concentration in the biomass. Spectrophotometric measuring kits were used for the determination of nutrient concentrations. Liquid chromatography techniques were used for the determination of betaine and cobalamin concentrations. RESULTS Significant microalgal growth was observed in filtered yeastwater, while growth in unfiltered yeastwater was very low. Nitrogen removal was higher in presence of E. gracilis compared to the control treatment. Protein production in yeastwater was comparable to that of microalgae grown in synthetic medium. E. gracilis grew much better in the synthetic media supplemented with betaine than without the addition. Betaine enrichment had no effect on cobalamin production. Cobalamin was produced in unfiltered yeastwater both with and without the presence of E. gracilis. CONCLUSIONS Unfiltered yeastwater does not support growth of E. gracilis possibly due to its high turbidity. Filtered yeastwater, on the other hand can support the production of E. gracilis biomass. E. gracilis can be used to reduce nitrogen concentrations in yeastwater. Yeastwater can support cobalamin production by bacteria, but this phenomenon did not benefit from the presence of the microalga. The effect of betaine on microalgal growth warrants further study to determine whether it is related to the accumulation of intracellular nutrients, storage compounds or to some other phenomenon. Yeastwater is a promising nutrient feedstock for microalgal biomass production. However, the role of filtration and possibility of using other methods for turbidity reduction needs to be further studied.
  • Enberg, Sara; Majaneva, Markus; Autio, Riitta; Blomster, Jaanika; Rintala, Janne-Markus (2018)
    The phytoplankton biomass in the Baltic Sea is low during the cold-water season (October to May) compared to the warm-water season(June to September). However, the sea ice is a habitat for diverse assemblages in polar and subpolar areas. These areas, including the Baltic Sea, are subject to changing environmental conditions due to global warming, and temporal and spatial studies are required to understand changes in the processes the organisms are involved in. We delineated microalgal succession in the northern Baltic Sea during the cold-water season using a weekly collected data set. Microscopy results together with molecular methods showed that 5 microbial groups could be distinguished: the sea-ice microalgal assemblage and 4 phytoplankton assemblages(fall, winter, under-ice water and spring). Based on cell enumeration, the microalgal biomass in the water column remained low until the end of the ice-covered season and was dominated by small flagellates and dinoflagellates. The young-ice assemblage in January resembled the water-column assemblage, but indicated a partly selective species-concentrating mechanism during ice formation due to lower species richness in ice than in the water column. Biomass of microalgae increased in the ice and water column during the March to May period, and the assemblage changed from flagellate-dominated to diatom-and dinoflagellate-dominated. The result that the spring phytoplankton, based on species and biomass, formed a separate as semblage indicates that sea-ice algae did not contribute to the spring bloom phytoplankton assemblage.