Browsing by Subject "in vitro"
Now showing items 1-5 of 5
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(2020)The usual dietary sources of vitamin B12 are animal-based foods such as meat, milk, fish and shellfish. Vitamin B12 is an essential water-soluble vitamin for humans, which have many necessary tasks in human body. People who lack animal foods like vegetarians and vegans might be at risk of vitamin B12 deficiency. Microorganisms are the only original sources of vitamin B12 in nature. Especially Propionibacterium freudenreichii synthesizes active form of vitamin B12 for humans. P. freudenreichii is GRAS -graded bacteria and it is safe to use in food matrices. Recently, it has been used for natural fortification of vitamin B12 in plant-based products by fermentation. However, the bioaccessibility of vitamin B12 of those products in human body is not very well known. In the beginning of the study, stability of different B12 vitamers were studied in different light and pH conditions. Vitamin B12 forms are very light-sensitive, especially its physiological forms methyl- and adenosylcobalamin. The aim of this research was to study bioaccessibility of vitamin B12 from P. freudenreichii cells and selected food products using a static in vitro assay. After the in vitro model, vitamin B12 content was analysed with UHPLC system. In addition of bacterial cell samples, bioaccessibility was studied also in some food samples, like bread, pasta and spray-dried powder, fortified with P. freudenreichii cells. In vitamin B12 stability studies, red light seemed to improve the stability of B12 forms. In yellow light methyl- and adenosylcobalamin degraded after 15 minutes. In red light they were detectable after hours of exposure. Methylcobalamin seems to be the most sensitive form of vitamin B12 vitamers. The study revealed that the bioaccessibility of B12 was very small (1,5 %) in P. freudenreichii cells but over 50% in whole bacterial broth. Heat treatment for the samples improved the bioaccessibility to some extent. In B12 fortified food samples, the bioaccessibility of B12 was very good (>70 %). The number of heat treatments and food structure could be one reason why bioaccessibilities in food samples are better than in cell samples. According to this research, in situ fortified food products could be a promising source of vitamin B12 in future.
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Camelinalipidien vaikutus pötsin metaanintuotantoon in vitro ja kaasunmittausmenetelmän kehittäminen (2024)Märehtijät tuottavat huomattavan osan maatalouden kasvihuonekaasupäästöistä, joista yksi merkittävimmistä on metaani. Kasvien lipidit ruokinnassa ovat vähentäneet pötsin metaanintuotantoa keskimäärin 12 %. Viljelyn vaativuus ja sadon onnistumisen epävarmuus rajoittavat rypsin (Brassica rapa ssp. oleifera) ja rapsin (Brassica napus) viljelyä. Suomen valkuaistäydennysrehujen omavaraisuusaste onkin vain 23 %. Camelina (Camelina sativa) on ikivanha kotimainen ristikukkainen öljykasvi, joka on vaatimattomampi viljelyolosuhteiden suhteen ja kestää paremmin tauti- ja rikkapainetta kuin rypsi. Camelina vastaa valkuaiskoostumukseltaan hyvin rypsiä ja sen lipidit sisältävät enemmän monityydyttymättömiä rasvahappoja. Tämän työn tavoitteena oli tutkia camelinan lipidien vaikutusta pötsin metaanipäästöihin rypsiin verrattuna in vitro. Työssä myös pystytettiin ja testattiin uuden sukupolven in vitro -kaasunmittauslaite (Gas Endeavour, Bioprocess Control, Ruotsi) menetelmineen. Inkubaatioajoissa käytettiin kahdelta ayrshirelehmältä kerättyä pötsinestettä ja McDougallin puskuria (1:2, vol:vol). Ajot kestivät 24 tuntia ja ne toistettiin neljä kertaa. Yksi inkubaatiopullo sisälsi pelkän puskuri-pötsinesteen, yksi sisälsi inkubaatiorehuna pelkän säilörehun (6 g) ja muissa oli säilörehun lisäksi joko camelinaöljyä, rypsiöljyä, rypsipuristetta, punasiemenistä camelinapuristetta tai ruskeasiemenistä camelinapuristetta. Lisätyn lipidin määrä oli 5 g/kg ka. Inkubaatiopulloista mitattiin kokonaiskaasun- ja metaanintuotanto sekä kuiva-aineen sulavuus. Puhtailla öljyillä ei ollut vaikutusta pötsin metaanintuotantoon (ml/g sulanut ka), mutta ne heikensivät kuiva-aineen sulavuutta. Öljykasvipuristeet vähensivät metaanintuotantoa, mutta rypsin ja camelinan välillä ei ollut suurta eroa (ml/g sulanut ka). Puristeiden välillä oli kuitenkin eroa metaanintuotannolla inkuboidun neutraalidetergenttikuidun määrään suhteutettuna. Punasiemenisen camelinapuristeen metaanituotos oli 10 % rypsipuristetta ja 7 % ruskeasiemenistä camelinapuristetta pienempi. Tämän tutkimuksen perusteella ero camelinan ja rypsin lipidikoostumuksessa ei vaikuta pötsin metaanintuotantoon. Puristeilla näyttäisi olevan suurempi metaanintuotannon vähentämispotentiaali kuin öljyillä ja ne toimisivat samalla valkuaistäydennysrehuina. Jatkotutkimuksissa (in vitro) tulisi olla ajokohtaiset rinnakkaisnäytteet tulosten luotettavuuden parantamiseksi.
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(2017)The aim of this master’s thesis was to investigate the potential of reducing enteric methane production from dairy cows by replacing barley grain with oat grain on a grass silage-based diet. The effects of grain species on in vitro methane production, digestibility, pH and volatile fatty acid (VFA) production pattern were investigated and a regression analysis was performed to entangle possible methane mitigating mechanisms of oats. The study was conducted in the laboratory at the Department of Agricultural Research for Northern Sweden in the autumn of 2016. An in vitro gas production system was applied, consisting of 16 diets with two replicates, four blanks and three runs, each with a three-day incubation time. The feed material consisted of eight varieties of barley, eight varieties of oats and timothy silage incubated at a grain/silage ratio of 1:1 on a dry matter basis. Rumen fluid was collected from two cannulated Nordic Red dairy cows after morning feeding. Gas sampling was performed at 2, 4, 8, 12, 24, 32 and 48 hours of incubation, meanwhile VFA-sampling, pH-measurements and sampling of incubation residues were performed at 48 hours. Methane production was estimated as predicted in vivo methane production and stoichiometrically predicted methane production. The in vitro digestibility was determined as true dry matter digestibility (TDMD). Content of indigestible neutral detergent fiber (iNDF) was determined by applying a 12-day in situ incubation in two Ayrshire dairy cows. Oats had a higher content of crude protein, neutral detergent fiber (NDF), iNDF and fat compared to barley, whereas barley had a higher content of starch. Replacing barley with oats decreased predicted in vivo methane production by 9% and stoichiometrically predicted methane production by 11%. Variety within grain was not found to have any significant effect on methane production. True DM digestibility and total VFA production were lower in oat-based diets compared to barley-based diets. No significant differences were observed between the diets considering VFA molar proportions. The pH was lower in barley-based diets compared to oat-based diets. True DM digestibility was the best predictor of methane production. Among grain composition parameters, iNDF content was the best predictor of methane production, followed by NDF. Crude fat content also predicted methane production relatively well. Based on the results of this experiment, it can be concluded that replacing barley grain with oat grain in the diet of dairy cows has a potential to lower methane production predicted in vitro. Furthermore, the methane mitigating effect observed in this experiment is at least partly due to the higher fat content and lower digestibility of oats compared to barley.
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(2024)Biochar, produced by heating biomass in oxygen-limited environments, is known for its potential to reduce methane emissions, by altering rumen fermentation. However, the literature lacks exploration on how biochar affects nutrient digestibility and ruminal methane production across various diets. Therefore, we examined the effects of spruce (Picea abies) biochar on several forage plant species options and forage-to-concentrate (F:C) ratios. Two in vitro trials of 24 hours were conducted with Gas Endeavour® equipment at Animal Science laboratory of the University of Helsinki. There were three rumen fluid donor animals and the ratio of rumen fluid and McDougall’s buffer was 1:2 (vol:vol). The first trial tested biochar levels (0%, 0.25%, and 0.5% of diet dry matter (DM)) with four silage options that were pure grass (Phleum pratense – Festuca pratensis), grass mixed 1:1 in DM with red clover (Trifolium pratense), faba bean (Vicia faba), or maize (Zea mays L) at a fixed F:C ratio of 65:35. The concentrate consisted of oats and rapeseed meal. The second trial explored the effects of the biochar (0.5% of diet DM) and an alternative methane inhibitor (product X) alone or combined across 65:35 and 45:55 F:C ratios. Key parameters such as total gas and methane production, DM digestibility, rumen fluid pH, and volatile fatty acid (VFA) concentrations were analyzed. Grass silage (D-value 669, neutral detergent fiber (NDF) 523 g/kg DM) and red clover silage (D-value 626, NDF 362 g/kg DM) were harvested from the first cut. Maize silage was more digestible than faba bean silage (D-value 679 vs. 593 g/kg DM) and contained more starch (278 vs. 48 g/kg DM). High forage diet (65:35) had higher NDF content (453 vs 407 g/kg DM) and lower starch content (114 vs 179 g/kg DM) than low forage diet (45:55). Biochar's effect on DM digestibility and the production of rumen methane or carbon dioxide was not significant across different silage plant species and F:C ratios. Grass silage led to lower total methane production compared to silage mixtures (p<0.05), and the combination of biochar and product X in a low forage diet numerically reduced gas production. However, when methane production was calculated per digested DM, no differences were observed. Feeding maize silage increased the total production of methane and carbon dioxide in the rumen compared to faba bean silage (p<0.001), but gas productions per digested DM remained unaffected. Biochar did not significantly affect final rumen pH across silage species. Biochar with grass silage linearly reduced the total VFA content of the rumen fluid (p=0.003) and had tendency for smaller molar proportion of acetic acid in VFA (p= 0.075). In the second trial biochar or product X didn´t have significant effect on rumen fermentation pattern across forage levels. The effects of biochar, silage plant species and F:C ratios on in vitro rumen fermentation and methane production were minimal, despite differences in diet composition.
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(2024)The legalization and evolving laws around the world regarding to cultivation of Cannabis sativa L. have led to a growing demand for optimized methods of mass propagation of cannabis plants. A micropropagation is a vital tool in this context, as it offers advantages such as rapid multiplication of elite clones, reduced space requirements, and produces clean plant material minimizing risks with diseases and pests. With micropropagation, the cannabis industry can ensure consistent quality and higher yields. Micropropagation methods for cannabis have been developed in numerous research, but the effect of light on the success of micropropagation has been studied fairly little. Using specially tailored LED lighting in cannabis production has proven to increase yield, cannabinoid content and affect the plant morphology. Thus, there is reason to believe that the effect of light intensity and spectra could have the same effect also in vitro. This research aimed to compare the effects of three different spectra and intensity levels on the multiplication rate and rooting of Cannabis sativa L. in vitro. Using hemp type cultivar Carmagnola, three different spectra: sunlike NS12, red and blue dominant AP67, and their combination AP67NS12 (C65, Valoya Oy, Helsinki, Finland) and three different intensity levels 30, 70, and 170 μmol m-2 s-1. Results of this study show that intensity has a significant effect on the formation of shoots, shoot height, number of leaves, and number of rooted plants. The lower intensity of 30 μmol m-2 s-1 results to more desirable morphological characteristics in all cases than the high intensity of 170 μmol m-2 s-1. Spectrum had significant effects on the number of shoots, number of leaves, and number of rooted plants. Treatment with spectrum NS12 resulted into the highest number of shoots, leaves, and tallest shoots. Treatment with spectrum AP67 can increase the number of rooting plants. This study gives encouraging results that optimizing light quality and quantity can have a positive effect on the desired morphological traits in the micropropagation of cannabis.
Now showing items 1-5 of 5