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| 2. |
- Olstorpe, Matilda, et al.
(författare)
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Microbial changes during storage of moist crimped cereal barley grain under Swedish farm conditions
- 2010
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Ingår i: Animal Feed Science and Technology. - Amsterdam, Netherlands : Elsevier. - 0377-8401 .- 1873-2216. ; 156:1-2, s. 37-46
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Tidskriftsartikel (refereegranskat)abstract
- This Study investigated feed hygiene during airtight storage of non-dried barley grain under farm conditions. Microorganisms on the grain were sampled and quantified in seven Swedish firms throughout the storage period using culture dependent methods. The dominant lactic acid bacteria (LAB) and yeasts were identified by rRNA gene sequencing and moulds by morphological characterisation. Moisture content (MC) and pH of the grain were also monitored. It was difficult to obtain the optimal MC(0.30-0.45 g/g) that is necessary to initiate fermentation in the grain. Feed hygiene was maintained during storage of cereals when MC below 0.17 g/g. Intermediate MC (0.17-0.23 g/g) of the grains was conducive to mould growth, including growth of potential producers of mycotoxins, which can diminish feed safety and nutritional value. Enterobacteriaceae were found in all barleys, even at low MC, but their numbers were substantially decreased when the number of LAB was high. True fermentation of moist crimped cereal grains was only obtained on one farm with all initial barley MC of 0.3 g/g. Here, LAB reached high numbers during storage, whereas numbers of spoilage microorganisms that may reduce feed hygiene decreased considerably. However, the pH of the barley did not differ among farms. Storage stability in airtight stored barley may thus be the result of low oxygen tension, viz. airtight storage, and competition for nutrients by the microorganisms, rather than formation of lactic acid. At harvest, Enterococcus caccae dominated the LAB Population in five barleys and Lactobacillus fermentum at the remaining two. The dominant yeast species were Aureobasidium pullulans, Cryptococcus wieringae, Kazachstania aerobia and Rhodotorula glutinis. After storage, L fermentum was dominant among the LAB. The yeast species composition was highly diverse and differed among barleys. Among others, C. wieringae, Debaryomyces hansenii, K. aerobia, R. glutinis and Sporobolomyces ruberrimus were detected. This Study shows that the microbial population in airtight stored moist barley is highly diverse and not predictable. Thus, it may be necessary to influence the microbial population in the storage system by adding a starter culture.
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| 3. |
- Olstorpe, Matilda, et al.
(författare)
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Pichia anomala yeast improves feed hygiene during storage of moist crimped barley grain under Swedish farm conditions
- 2010
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Ingår i: Animal Feed Science and Technology. - Amsterdam, Netherlands : Elsevier BV. - 0377-8401 .- 1873-2216. ; 156, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- Preservation of moist crimped cereal grain is made feasible through fermentation by lactic acid bacteria. Climatic variations make it difficult to harvest at moisture contents (0.30-0.45g/g) to support optimal fermentation under practical conditions. Therefore, the yeast, Pichia anomala J121, previously found to prevent mould spoilage and improve preservation of moist grain in malfunctioning airtight silos, was added to moist crimped cereal grain stored in large plastic tubes. Freshly harvested barley grain was crimped and inoculated with P. anomala (105 colony-forming units/g grain). Due to the local weather conditions, harvest was delayed and moisture content in the cereal grain had decreased to 0.16-0.18g/g. P. anomala was inoculated into three batches of barley, each comprising 16tonnes packed into large plastic tubes. Three additional sets of plastic tubes were packed with cereal grain without addition of P. anomala. The grain tubes were left closed for 5 months, after which feeding to cattle commenced. In both the P. anomala inoculated and the control barley, the population diversity of lactic acid bacteria (LAB) was very high over the duration of storage. However, the dominant LAB shifted over the course of storage to Pediococcus pentosaceus and Lactobacillus paracasei, in inoculated and control barley, respectively. The yeast population in the inoculated barley was totally dominated by P. anomala during the entire storage period. In the control grain, the yeast population was more diverse, displaying shifts in the dominant species during storage. Pichia burtonii was the dominant species at the last sampling occasion. In P. anomala inoculated barley, numbers of naturally occurring moulds were reduced by about two log units, and the number of Enterobacteriaceae was reduced to below detection.
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| 4. |
- Melin, Petter, et al.
(författare)
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Formulation and stabilisation of the biocontrol yeast Pichia anomala
- 2011
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Ingår i: Antonie van Leeuwenhoek. International Journal of General and Molecular Microbiology. - Dordrecht, Netherlands : Springer Netherlands. - 0003-6072 .- 1572-9699. ; 99:1, s. 107-112
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Tidskriftsartikel (refereegranskat)abstract
- The yeast Pichia anomala has antifungal activities and its potential in biocontrol and biopreservation has previously been demonstrated. To practically use an organism in such applications on a larger scale the microbe has to be formulated and stabilised. In this review we give an overview of our experience of formulating and stabilising P. anomala strain J121 in a wider perspective. The stabilisation techniques we have evaluated were liquid formulations, fluidised bed drying, lyophilisation (freeze-drying) and vacuum drying. With all methods tested it was possible to obtain yeast cells with shelf lives of at least a few months and in all cases the biocontrol activity was retained. Fluidised bed drying was dependent on the addition of cottonseed flour as a carrier during the drying process. In liquid formulations a sugar, preferentially trehalose, was a required additive. These two kinds of microbial stabilisation are easily performed and relatively inexpensive but in order to keep the cells viable the biomaterial has to be stored at cool temperatures. However, there is room for optimization, such as improving the growth conditions, or include preconditioning steps to enable the cells to produce more compatible solutes necessary to survive formulation, desiccation and storage. In contrast, lyophilisation and vacuum drying require a lot of energy and are thus expensive. On the other hand, the dried cells were mostly intact after one year of storage at 30A degrees C. Inevitably, the choice of formulation and stabilisation techniques will be dependent also on the intended use.
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| 5. |
- Passoth, Volkmar, et al.
(författare)
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Past, present and future research directions with Pichia anomala
- 2011
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Ingår i: Antonie van Leeuwenhoek. International Journal of General and Molecular Microbiology. - Dordrecht, Netherlands : Springer. - 0003-6072 .- 1572-9699. ; 99:1, s. 121-125
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Tidskriftsartikel (refereegranskat)abstract
- The first International Pichia anomala Symposium provided a survey of past, recent and ongoing research on this yeast. The research community working with this yeast has focussed on several areas. Based on molecular data, a revision of the taxonomy is required: the name P. anomala is no longer applicable, as the genus Pichia is polyphyletic. The current debate centres on whether the yeast should be designated as Wickerhamomyces anomalus or if the previous name, Hansenula anomala, should be re-instated. The anti-microbial activities of this yeast received considerable attention during the symposium. H. anomala has been extensively studied as a biopreservation agent in many different post-harvest systems. Several mechanisms account for its anti-microbial activities, including the production of killer proteins and toxic volatile metabolites. Anti-idiotypic antibodies generating an "internal image" of a killer protein have been found to possess therapeutic activity against a broad range of microorganisms. A great diversity of H. anomala strains was reported at the symposium. Strains have been isolated from several food and feed systems and even from the intestine and reproductive organs of a malaria vector (Anopheles stephensi). Feed and food supplemented with certain H. anomala strains show an improved quality due, for example, to the addition of advantageous proteins and phytase activity. However, a number of apparent opportunistic pathogenic strains have also been isolated. Strain differentiation, especially the recognition of potentially pathogenic isolates, is an important challenge for the future commercialisation of this yeast. Future industrial and agricultural application of this yeast also raises questions of the economics of large-scale production, its survival during storage (formulation) and of safety regulations, all of which require further investigation.
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| 6. |
- Schnürer, Johan, 1957-, et al.
(författare)
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Pichia anomala J121 : a 30-year overnight near success biopreservation story
- 2011
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Ingår i: Antonie van Leeuwenhoek. International Journal of General and Molecular Microbiology. - Dordrecht, Netherlands : Springer Netherlands. - 0003-6072 .- 1572-9699. ; 99:1, s. 5-12
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Tidskriftsartikel (refereegranskat)abstract
- Thirty years ago, the ascomycetous yeast Pichia anomala strain J121 was isolated from moist wheat grain stored under conditions of restricted air access. Early observations indicated that an inverse relationship existed between mould and P. anomala colony forming units in grain. This yeast strain was later found to have strong antifungal properties in laboratory, pilot and farm studies with high-moisture wheat under malfunctioning airtight storage. P. anomala had the highest inhibitory activity of 60 yeast species evaluated against the mould Penicillium roqueforti. It also demonstrated strong inhibitory effects against certain Gram-negative bacteria. P. anomala J121 possesses a number of physiological characteristics, i.e. capacity to grow under low pH, low water activity and low oxygen tension and ability to use a wide range of carbon and nitrogen sources, enabling it to act as an efficient biopreservative agent. The biocontrol effect in grain was enhanced by addition of glucose, mainly through formation of the volatile antimicrobial ethyl acetate. Animal feeding trials with P. anomala J121 inoculated grains, fed to chickens and beef cattle, demonstrated that mould control observed in vitro in small scale laboratory experiments could be extended to large scale farm trials. In addition, no adverse effects on animal weight gain, feed conversion, health or behaviour were observed. We have now studied P. anomala J121 biology, ecology and grain preservation ability for 30 years. Over this period, more than 40 scientific publications and five PhD theses have been written on different aspects of this yeast strain, extending from fundamental research on metabolism, genetics and molecular biology, all the way to practical farm-scale level. In spite of the well documented biopreservative ability of the yeast, it has to date been very difficult to create the right constellation of technical, agricultural and biotechnical industries necessary to reach a commercial launch of a P. anomala J121 based biopreservation system. Additionally, the complications caused by a complex EU regulatory system remain a significant barrier to practical applications.
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| 7. |
- Björklund, Johanna, 1961-, et al.
(författare)
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Assessing ecosystem services in perennial intercropping systems : participatory action research in Swedish modern agrofores
- 2014
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Ingår i: Farming systems facing global challenges. - : IFSA Europe, Leibniz-Centre for Agricultural Landscape Research (ZALF), Humboldt-Universität zu Berlin. ; , s. 112-113, s. 1950-1959
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The focus of this paper is on how to assess ecosystem services in complex agroforestry systems using a case of edible forest gardens. Benefits of doing these assessments in a participatory learning and action research (PLAR) context are elaborated, as well as difficulties and questions that this has raised. The PLAR group comprised farmers on 13 smallholdings, researchers and a facilitator, which through collaboration and participatory methods have developed a general design of a forest garden, 60 m2 in size and established it on all 13 participating farms. Important values of the work are that ecosystem services are related to specific local contexts and that methodology for multi-criteria assessments of the generation of ecosystem services on a farm scale are being developed. Farmers engaged in formulating research questions, development of field trial designs, sampling and analysis of results improves the relevance and quality of the research as well as advance the adoption of new knowledge.
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| 8. |
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| 9. |
- Olstorpe, Matilda, et al.
(författare)
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Effect of starter culture inoculation on feed hygiene and microbial population development in fermented pig feed composed of a cereal grain mix with wet wheat distillers' grain
- 2010
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Ingår i: Journal of Applied Microbiology. - Malden, USA : Wiley-Blackwell Publishing Inc.. - 1364-5072 .- 1365-2672. ; 108:1, s. 129-138
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Investigating the influence of an added starter culture on the properties of fermented liquid pig feed.Methods and Results: Diets of cereal grain blended with wet wheat distillers' grain that were either not inoculated (WWDG), inoculated with a silage starter culture at start (WWDGsc1) or at start and at each backslopping (replacement of 80% the content with fresh mixture, simulating feed outtake, WWDGsc5) were fermented for 5 days, followed by 5 days of daily backslopping. Numbers of undesirable micro-organisms (enterobacteria, moulds) were reduced in all fermentations; particularly enterobacteria in the starter culture inoculated diets. Lactobacillus plantarum present in the starter culture became dominant in diets WWDGsc1 and WWDGsc5. However, Lactobacillus panis that was dominating WWDG was also abundant in WWDGsc1 and WWDGsc5. Yeast populations were not influenced by the starter culture, with Pichia fermentans dominating all fermentations. All diets had similar chemical characteristics with the exception of a significant increase of all tested organic acids in WWDGsc5.Conclusions: The addition of a starter culture influences the bacterial population in fermented liquid feed, but there is also a strong impact of the flora already present in the feed ingredients. The yeast population is not influenced by adding a lactic acid bacteria (LAB) starter culture. A consortium of LAB and yeast strains adapted to the fermentation should be used as starter culture.Significance and Impact of the Study: The results suggest that it is possible to influence the current unpredictable and spontaneous process of feed fermentation when appropriate starter cultures are used. For this purpose, LAB and yeasts with desirable characteristics should be isolated.
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| 10. |
- Sampels, Sabine, et al.
(författare)
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Effects of -linolenic acid and eicosapentaenoic acid from linseed and algae, respectively, on reindeer (Rangifer tarandus tarandus L.) muscle fatty acid composition
- 2010
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Ingår i: Acta agriculturae Scandinavica. Section A, Animal science. - : Informa UK Limited. - 0906-4702 .- 1651-1972. ; 60:3, s. 175-186
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Tidskriftsartikel (refereegranskat)abstract
- In an earlier study, we concluded that pellet-fed reindeer could not elongate 18:3n - 3 (-linolenic acid - ALA) sufficiently towards long-chain polyunsaturated fatty acids (LC PUFA) and need supplementation of LC PUFA. The present work investigated that the addition of n - 3 LC PUFA to feed in combination with ALA would increase the LC PUFA in the meat. Two groups of reindeer were fed pellets containing either linseed cake or linseed cake combined with algae (Nannochloropsis oculata) for 6 weeks before slaughter. Dietary n - 6/n - 3 ratio had a distinct influence on meat fatty acid (FA) composition when comparing linseed and linseed algae-fed animals with animals fed a conventional diet. Increased dietary proportions of ALA and eicosapentaenoic acid (EPA) increased these FA in muscle and docosapentaenoic acid (DPA) and docosahexaenoic acid in the polar lipid fraction compared to the conventional-fed animals. We concluded that an increased proportion of dietary EPA might lead to an increased elongation towards DPA in muscle. Algae and linseed are possible additives to reindeer feed in order to assure a similar valuable FA composition as in pasturing animals.
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