scholarly journals Effect of Long-Term Storage on Mycobiota of Barley Grain and Malt

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1655
Author(s):  
Soňa Felšöciová ◽  
Przemysław Łukasz Kowalczewski ◽  
Tomáš Krajčovič ◽  
Štefan Dráb ◽  
Miroslava Kačániová

Contamination of malting barley grain and malt with micromycetes sampled at various periods post-harvest (3rd, 6th, and 9th month of storage) and types of storage (storage silo and floor warehouse) was investigated. Each of these barley grain samples was malted. This article reports on the changes in the fungal microbiome composition and their overall count in barley grain and malt. From the surface-disinfected barley grain samples collected immediately after harvest, there were eight genera isolated, with a predominance of Alternaria. A small increase of isolated microfungi was detected in barley stored in silo for 3 and 6 months (from 142 isolates to 149) and decreased below the number of isolates in barley before storage (133 isolates). Fungal count during storage gradually decreased up to 9 month in barley stored in floor warehouse (from 142 isolates to 84). The initial total count of microscopic fungi in malt before storage was the highest (112 isolates) with 7 genera detected, compared to malts prepared from barley stored for longer time (54 isolates, 7 genera, 9th month of storage). Alternaria was the most abundant and frequent genus. Quantitative representation of the filamentous microscopic fungi was lower compared to yeasts especially in barley and malt prepared from barley stored at third month of storage in both type of storage. Yeasts were identified from all grain samples and malt samples with mass spectrometry. Most attention was given to the widely distributed fungus Penicillium, 79% of strains produced at least one mycotoxin detected under in vitro assays using the TLC method (97% of them produced griseofulvin, 94% CPA, 79% patulin, 14% roquefortin C, and penitrem A was produced by two screening strains under laboratory conditions). It is therefore important to monitor the microflora throughout the production cycle of “barley to beer”.

2016 ◽  
Vol 9 (3) ◽  
pp. 379-388 ◽  
Author(s):  
N. De Clercq ◽  
G. Vlaemynck ◽  
E. Van Pamel ◽  
D. Colman ◽  
M. Heyndrickx ◽  
...  

Penicillium expansum is the principal cause of blue mould rot and associated production of patulin, a weak mycotoxin, in apples worldwide. P. expansum growth and patulin production is observed during improper or long-term storage of apples. We have investigated the extent to which each successive step during long-term storage contributes to patulin production in various P. expansum isolates. Fungal isolates collected on apples from several Belgian orchards/industries were identified to species level. Random amplification of polymorphic DNA (RAPD) analysis and β-tubulin gene sequencing identified P. expansum and Penicillium solitum as the most prevalent Penicillium species associated with Belgian apples. All 27 P. expansum isolates and eight reference strains were characterised for their patulin production capacity on apple puree agar medium for five days under classical constant temperature and atmosphere conditions. Under these conditions, a large range of patulin production levels was observed. Based on this phenotypic diversity, five P. expansum isolates and one reference strain were selected for in vitro investigation of patulin production under representative conditions in each step of long-term apple storage. Patulin accumulation seemed highly strain dependent and no significant differences between the storage steps were observed. The results also indicated that a high spore inoculum may lead to a strong patulin accumulation even at cold temperatures (1 °C) combined with controlled atmosphere (CA) (3% O2, 1% CO2), suggesting that future control strategies may benefit from considering the duration of storage under CA conditions as well as duration of deck storage.


1970 ◽  
Vol 10 ◽  
pp. 15-20
Author(s):  
Shambhu P. Dhital ◽  
Hira K. Manandhar ◽  
Hak T. Lim

Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of sucrose concentration, hardening temperature and different cryopreservation methods on the survival rate of potato shoot tips after cryopreservation. Excised shoot tips of in vitro plantlets of potato cultivars, Atlantic and Superior were cryopreserved by vitrification, encapsulationvitrification and encapsulation-dehydration. Cryopreservation by vitrification method was used to determine the optimum concentration of sucrose and cold hardening temperature during sub-culturing period to the donor plantlets. Nine-percent sucrose gave 46.7% survival in Atlantic and 40% in Superior. The most optimum hardening temperature for 50% survival in Atlantic and 43.3% in Superior was 10°C. In the case of comparative study of three different cryopreservation methods, the highest survival (52%) as well as regeneration (46%) were observed when the shoot tips were cryopreserved by encapsulation-vitrification method, and the lowest survival (36%) and regeneration (28%) from the vitrification. Plant and tuber morphology of potato regenerated after cryopreservation were similar to those of the non-cryopreserved in vitro plantlets (control). Thus, this study demonstrated that encapsulation-vitrification method was the most effective one among other methods for higher survival as well as regeneration in in vitro shoot tips of potato.Key words: Cryopreservation; Dehydration; Encapsulation; Potato; Regeneration; VitrificationDOI: 10.3126/njst.v10i0.2804Nepal Journal of Science and Technology Volume 10, 2009 December Page: 15-20


2014 ◽  
Vol 41 (No. 2) ◽  
pp. 55-63 ◽  
Author(s):  
Dj. Ružić ◽  
T. Vujović ◽  
R. Cerović

In vitro-grown shoot tips of Gisela 5 (Prunus cerasus × Prunus canescens) cherry rootstock were tested for regrowth after cryopreservation using vitrification technique. Explants were precultured in the dark at 23°C, in a liquid MS medium with a progressively increasing sucrose concentration (0.3 M for 15 h, then 0.7 M for 5 h), and subsequently loaded in a solution containing 2 M glycerol and 0.4 M sucrose for 20 minutes. Shoot tips were dehydrated at 0°C using either the original PVS2 or modified PVS2 solution (PVS A3 – 22.5% sucrose, 37.5% glycerol, 15% ethylene glycol and 15% DMSO) for 30, 40 and 50 minutes. The survival and regrowth of the cryopreserved shoot tips dehydrated with the original PVS2 solution ranged between 36–54% and 8–17%, respectively. However, the dehydration with the PVS A3 solution resulted in considerably higher survival rates (81–92%), as well as higher regrowth rates (39–56%) after cryopreservation. These results prove the feasibility of the PVS A3-based vitrification technique for a long-term storage of this genotype.  


Parasitology ◽  
2020 ◽  
Vol 147 (9) ◽  
pp. 1048-1054
Author(s):  
Teivi Laurimäe ◽  
Philipp A. Kronenberg ◽  
Cristian A. Alvarez Rojas ◽  
Theodor W. Ramp ◽  
Johannes Eckert ◽  
...  

AbstractThe metacestode of Echinococcus multilocularis is the etiological agent of alveolar echinococcosis. The metacestode stage used for research is maintained in rodents by serial passages. In order to determine whether cryopreservation of E. multilocularis metacestodes would be suitable for long-term maintenance and replace serial passages, isolates of different geographic origin were cryopreserved in 1984–1986. The aim of the current study was to test the viability of cryopreserved isolates following long-term cryopreservation (up to 35 years) and to determine the phylogenetic clades these isolates belonged to. Cryopreserved isolates were tested for viability in vitro and in vivo in gerbils. In vitro results of 5 isolates indicated protoscolex survival in 13 of 17 experiments (76%) and metacestode survival in 5 of 12 (42%) in vivo experiments. In vivo results showed ‘abortive lesions’ in 13 of the 36 animals, 15 were negative and 8 harboured proliferating metacestode tissue containing protoscoleces. Genetic analysis confirmed the isolates belonged to European, Asian and North-American clades. In conclusion, the results of the current study indicate that metacestodes of E. multilocularis are able to survive long-term cryopreservation. Therefore, cryopreservation is a suitable method for long-term storage of E. multilocularis metacestode isolates and reduces the number of experimental animals.


2016 ◽  
Vol 55 (3) ◽  
pp. 783-790 ◽  
Author(s):  
Katherine A. Lau ◽  
Torsten Theis ◽  
Joanna Gray ◽  
William D. Rawlinson

ABSTRACT The unprecedented 2015 Ebolavirus (EBOV) outbreak in West Africa was declared a public health emergency, making diagnosis and quality of testing a global issue. The accuracy of laboratory diagnostic capacity for EBOV was assessed in 2014 to 2016 using a proficiency testing (PT) strategy developed by the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) in Biosecurity. Following a literature search, EBOV-specific gene targets were ranked according to the frequency of their use in published methods. The most commonly used gene regions (nucleoprotein [NP], glycoprotein [GP], and RNA-dependent RNA polymerase [L]) were selected for the design of in vitro RNA transcripts to be included in the simulated EBOV specimens used for EBOV detection with PCR-based assays. Specimens were tested for stability and found to be stable on long-term storage (1 year) at −80°C and on shorter-term storage in lyophilized form (1 week at ambient temperature and a subsequent week at −80°C). These specimens were used in three EBOV PTs offered from April 2014 to March 2016. In the first and third PTs, all laboratories (3/3 and 9/9, respectively) correctly identified specimens containing EBOV RNA transcripts, while in the second PT, all but one laboratory (5/6) correctly confirmed the presence of EBOV. The EBOV PT panel was useful for ensuring the competency of laboratories in detecting EBOV in the absence of readily available clinical samples. The simulated EBOV specimen was safe, stable, and reliable and can be used in lyophilized form for future EBOV PT programs, allowing simplicity of transport.


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