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- Borling, Jenny Maria, et al.
(författare)
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Combined moist airtight storage and feed fermentation of barley by the yeast Wickerhamomyces anomalus and a lactic acid bacteria consortium
- 2015
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- This study combined moist airtight storage of moist grain with pig feed fermentation. Starter cultures with the potential to facilitate both technologies were added to airtight stored moist crimped cereal grain, and the impact on storage microflora and the quality of feed fermentations generated from the grain was investigated. Four treatments were compared: three based on moist barley, either un-inoculated (M), inoculated with Wickerhamomyces anomalus (W), or inoculated with W anomalus and LAB starter culture, containing Pediococcus acidilactici DSM 16243, Pediococcus pentosaceus DSM 12834 and Lactobacillus plantarum DSM 12837 (WLAB); and one treatment based on dried barley (D). After 6 weeks of storage, four feed fermentations FM, FW, FWLAB, and FD, were initiated from M, W, WLAB, and D, respectively, by mixing the grain with water to a dry matter content of 30%. Each treatment was fermented in batch initially for 7 days and then kept in a continuous mode by adding new feed daily with 50% back-slop. During the 6 week storage period, the average water activity decreased in M, W and WLAB from 0.96 to 0.85, and cereal pH decreased from approximately 6.0 at harvest to 4.5. Feed fermentation conferred a further pH decrease to 3.8-4.1. In M, W and WLAB, molds and Enterobacteriaceae were mostly below detection limit, whereas both organism groups were detected in D. In fermented feed, Enterobacteriaceae were below detection limit in almost all conditions. Molds were detected in FD, for most of the fermentation time in FM and at some sampling points in FW and FWLAB. Starter organisms, especially W anomalus and L. plantarum comprised a considerable proportion of the yeast and LAB populations, respectively, in both stored grain and fermented feed. However, autochthonous Pichia kudriavzevii and Kazachstania exigua partially dominated the yeast populations in stored grain and fermented feed, respectively.
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| 2. |
- Fredlund, Elisabeth, et al.
(författare)
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Influence of ethyl acetate production and ploidy on the anti-mould activity of Pichia anomala
- 2004
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Ingår i: FEMS Microbiology Letters. - : Elsevier. - 0378-1097 .- 1574-6968. ; 238:1, s. 133-137
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Tidskriftsartikel (refereegranskat)abstract
- A diploid and a haploid strain of Pichia anomala were tested for their biocontrol ability against the spoilage mould Penicillium roqueforti in glass tubes filled with grain at two water activities (a(w)). At a(w) 0.98, the two yeast strains grew and inhibited mould growth equally well and showed similar patterns of ethyl acetate production, reaching maximum values of 10-14 mug ml(-1) headspace. At a(w) 0.95, both growth and biocontrol performance of the haploid strain were reduced. Ethyl acetate formation was also substantially reduced, with maximum headspace concentrations of 4 mug ml(-1). We conclude that ethyl acetate is a major component of the anti-mould activity. The inhibitory effect of ethyl acetate was confirmed in a bioassay where the pure compound reduced biomass production of P. roqueforti.
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| 3. |
- Hedén, Su-Lin, et al.
(författare)
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Biocontrol efficacy of Wickerhamomyces anomalus in moist maize storage
- 2014
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Ingår i: African journal of biotechnology. - 1684-5315. ; 13, s. 4208-4214
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Tidskriftsartikel (refereegranskat)abstract
- White maize cultivar ‘Kasai’ was harvested and stored moist, sealed in airtight plastic barrels, with and without inoculation of the biocontrol yeast, Wickerhamomyces anomalus. Microbes were enumerated at harvest and after 2, 5 and 8 months of storage. Moist storage of maize yielded a type of fermentation, in which high levels of lactic acid bacteria (LAB) naturally present on maize (108 cfu/g), were maintained throughout storage. Activity of LAB in both control and inoculated maize likely contributed to the decline in Enterobacteriaceae to < 10 cfu/g after 2 months storage, a good outcome for food and feed hygiene. The biocontrol yeast, W. anomalus, appeared to have died out in the inoculated treatment after 2 months; nevertheless, a positive effect was seen in significantly reduced mould counts to < 100 cfu/g compared with the uninoculated maize. Reducing moulds during storage minimises the risk for mycotoxin production. Storage for 8 months with the biocontrol yeast did not appear to affect nutritional parameters of the maize, such as dry matter, crude protein and total amino acids. Compared with the uninoculated control, inoculated maize had significantly better contents of three amino acids (alanine, aspartic acid and glycine), but poorer contents of six amino acids (arginine, lysine, ornithine, proline, serine and tyrosine). The absence of nutritional improvement in inoculated maize could be due to the poor survival of the biocontrol yeast, and altered formulation practices may address this.
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| 7. |
- Olstorpe, Matilda, et al.
(författare)
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Controlling fungal growth and mycotoxins in animal feed
- 2011
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Ingår i: Protective cultures, antimicrobial metabolites and bacteriophages for food and beverage biopreservation. - : Elsevier. - 9781845696696 ; :201, s. 225-239
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- 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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