scholarly journals Design of a new lyoprotectant increasing freeze-dried Lactobacillus strain survival to long-term storage

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aurore Bodzen ◽  
Audrey Jossier ◽  
Sébastien Dupont ◽  
Pierre-Yves Mousset ◽  
Laurent Beney ◽  
...  
Keyword(s):  
Water Content ◽  
Water Activity ◽  
Freeze Drying ◽  
Sucrose Solution ◽  
Bound Water ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Micellar Casein ◽  
Term Storage

Abstract Background Stabilization of freeze-dried lactic acid bacteria during long-term storage is challenging for the food industry. Water activity of the lyophilizates is clearly related to the water availability and maintaining a low aw during storage allows to increase bacteria viability. The aim of this study was to achieve a low water activity after freeze-drying and subsequently during long-term storage through the design of a lyoprotectant. Indeed, for the same water content as sucrose (commonly used lyoprotectant), water activity is lower for some components such as whey, micellar casein or inulin. We hypothesized that the addition of these components in a lyoprotectant, with a higher bound water content than sucrose would improve lactobacilli strains survival to long-term storage. Therefore, in this study, 5% whey (w/v), 5% micellar casein (w/v) or 5% inulin (w/v) were added to a 5% sucrose solution (w/v) and compared with a lyoprotectant only composed of 5% sucrose (w/v). Protective effect of the four lyoprotectants was assessed measuring Lactiplantibacillus plantarum CNCM I-4459 survival and water activity after freeze-drying and during 9 months storage at 25 °C. Results The addition whey and inulin were not effective in increasing Lactiplantibacillus plantarum CNCM I-4459 survival to long-term-storage (4 log reduction at 9 months storage). However, the addition of micellar casein to sucrose increased drastically the protective effect of the lyoprotectant (3.6 log i.e. 0.4 log reduction at 9 months storage). Comparing to a lyoprotectant containing whey or inulin, a lyoprotectant containing micellar casein resulted in a lower water activity after freeze-drying and its maintenance during storage (0.13 ± 0.05). Conclusions The addition of micellar casein to a sucrose solution, contrary to the addition of whey and inulin, resulted in a higher bacterial viability to long-term storage. Indeed, for the same water content as the others lyoprotectants, a significant lower water activity was obtained with micellar casein during storage. Probably due to high bound water content of micellar casein, less water could be available for chemical degradation reactions, responsible for bacterial damages during long-term storage. Therefore, the addition of this component to a sucrose solution could be an effective strategy for dried bacteria stabilization during long-term storage.

scholarly journals Moulds occurrence in woodchips

2014 ◽  
Vol 60 (No. 4) ◽  
pp. 155-158
Author(s):  
J. Souček
Keyword(s):  
Water Content ◽  
Wood Chips ◽  
Effect Of Water ◽  
Long Term Storage ◽  
Term Storage ◽  
Storage Temperatures

The research, whose results are presented, is aimed at determination of development of moulds number in wood chips under different storage temperatures. The experiments were carried out with the moisture of samples 65%, 22% and 1%. During the long-term storage the effect of water content in material on development of moulds can be recorded. The risks linked to mould occurrence can be considerably eliminated by reduction of water content.  

40 Comparison of slow and rapid freezing in freeze-dried ram spermatozoa

2020 ◽  
Vol 32 (2) ◽  
pp. 146
Author(s):  
L. Palazzese ◽  
D. A. Anzalone ◽  
P. Toschi ◽  
P. Loi
Keyword(s):  
Liquid Nitrogen ◽  
Rapid Freezing ◽  
Cell Stage ◽  
Food Industries ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Cheap Alternative ◽  
Group 2 ◽  
Term Storage

Semen lyophilisation is an interesting technique that might be a cheap alternative to long-term storage in liquid nitrogen. The first significant result of this method was achieved by Wakayama and Yanagimachi in the 1998 and demonstrated, for the first time, the birth of healthy mouse pups from epididymal freeze-dried (mouse) spermatozoa. The authors follow the lyophilisation technique, commonly used in the pharmaceutical and food industries, namely, deep freezing, which requires direct immersion of the semen sample into liquid nitrogen before vacuum drying. In this work, we focused on the freezing phase to improve and make the technique more reliable. We compared two protocols: 1) rapid freezing, where the semen is plunged directly into liquid nitrogen (LN group), and 2) slow freezing, where the sample is frozen with a freezing rate of 1°C min−1 until −50°C (SL group). Then, both frozen samples were lyophilized. Subsequently, after an interval ranging between 1 and 3 months, dry spermatozoa from LN and SL groups were used for intracytoplasmic sperm injection (ICSI), and the embryo development was evaluated at 24h (2-cell stage) and 7 days (expanded blastocyst) post-ICSI. Moreover, acrosome integrity was evaluated with Pisum sativum agglutinin (PSA) staining on part of the semen, immediately after freezing. The LN-group semen showed the acrosome completely melted, whereas the SL group showed better integrity of the acrosome, which was comparable to that of the normal frozen (vital) spermatozoa. At 24h post-ICSI the number of cleaved embryos in the SL group was higher than in the LN group (42/100 (42%) vs. 19/75 (25.3%), SL and LN, respectively; P=0.0253). The blastocyst rate 7 days after ICSI in the SL group was higher (7/100 (7%) than that in the LN group (2/75 (2.7%); P=0.0238). Our data show that lyophilisation can be conveniently achieved in ram spermatozoa without liquid nitrogen, thus simplifying the procedure. These data support the idea that lyophilisation might be a valuable and cheaper alternative to liquid nitrogen for long-term storage of ram semen.

Survival Rate of Microbes after Freeze-Drying and Long-Term Storage

Cryobiology ◽  
2000 ◽  
Vol 41 (3) ◽  
pp. 251-255 ◽  
Author(s):  
Yukie Miyamoto-Shinohara ◽  
Takashi Imaizumi ◽  
Junji Sukenobe ◽  
Yukie Murakami ◽  
Sugio Kawamura ◽  
...  
Keyword(s):  
Survival Rate ◽  
Freeze Drying ◽  
Long Term Storage ◽  
Term Storage

Development of a freeze-drying protocol for the long-term storage of S9-fraction at ambient temperatures

Cryobiology ◽  
2009 ◽  
Vol 58 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Sebastian Buchinger ◽  
Elisabeth Campen ◽  
Eckard Helmers ◽  
Valeri Morosow ◽  
Marianne Krefft ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Ambient Temperatures ◽  
Long Term Storage ◽  
Term Storage ◽  
S9 Fraction

scholarly journals Lyophilization Preserves the Intrinsic Cardioprotective Activity of Bioinspired Cell-Derived Nanovesicles

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1052
Author(s):  
Yub Neupane ◽  
Chenyuan Huang ◽  
Xiaoyuan Wang ◽  
Wei Heng Chng ◽  
Gopalakrishnan Venkatesan ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Ischemia Reperfusion Injury ◽  
Biological Activities ◽  
Ischemia Reperfusion ◽  
Target Cells ◽  
Residual Moisture ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Term Storage

Recently, bioinspired cell-derived nanovesicles (CDNs) have gained much interest in the field of nanomedicine due to the preservation of biomolecular structure characteristics derived from their parent cells, which impart CDNs with unique properties in terms of binding and uptake by target cells and intrinsic biological activities. Although the production of CDNs can be easily and reproducibly achieved with any kind of cell culture, application of CDNs for therapeutic purposes has been greatly hampered by their physical and chemical instability during long-term storage in aqueous dispersion. In the present study, we conceived a lyophilization approach that would preserve critical characteristics regarding stability (vesicles’ size and protein content), structural integrity, and biological activity of CDNs for enabling long-term storage in freeze-dried form. Compared to the lyoprotectant sucrose, trehalose-lyoprotected CDNs showed significantly higher glass transition temperature and lower residual moisture content. As assessed by ATR-FTIR and far-UV circular dichroism, lyophilization in the presence of the lyoprotectant effectively maintained the secondary structure of cellular proteins. After reconstitution, lyoprotected CDNs were efficiently associated with HeLa cells, CT26 cells, and bone marrow-derived macrophages at a rate comparable to the freshly prepared CDNs. In vivo, both lyoprotected and freshly prepared CDNs, for the first time ever reported, targeted the injured heart, and exerted intrinsic cardioprotective effects within 24 h, attributable to the antioxidant capacity of CDNs in a myocardial ischemia/reperfusion injury animal model. Taken together, these results pave the way for further development of CDNs as cell-based therapeutics stabilized by lyophilization that enabled long-term storage while preserving their activity.

scholarly journals Assessing the tolerance to room temperature and viability of freeze-dried mice spermatozoa over long-term storage at room temperature under vacuum

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuko Kamada ◽  
Sayaka Wakayama ◽  
Ikue Shibasaki ◽  
Daiyu Ito ◽  
Satoshi Kamimura ◽  
...  
Keyword(s):  
Room Temperature ◽  
Long Term Storage ◽  
Freeze Dried ◽  
Term Storage

Survival and Thermal Resistance of Salmonella Enteritidis PT 30 on Almonds after Long-Term Storage

2019 ◽  
Vol 82 (2) ◽  
pp. 194-199 ◽  
Author(s):  
PICHAMON LIMCHAROENCHAT ◽  
MICHAEL K. JAMES ◽  
BRADLEY P. MARKS
Keyword(s):  
Thermal Resistance ◽  
Water Activity ◽  
Salmonella Enteritidis ◽  
Thermal Treatments ◽  
Long Term Storage ◽  
Group I ◽  
Log Linear ◽  
Term Storage ◽  
Salmonella Survival

ABSTRACT Salmonella survival and thermal resistance on the surface of almond kernels were evaluated after periods of storage. Almond kernels were inoculated with Salmonella Enteritidis PT 30 and equilibrated to 0.45 water activity. Samples were separated into two groups (I and II) and stored in sealed metal cans at room temperature. Group I samples (stored 7, 15, 27, and 68 weeks) were re-equilibrated in controlled humidity chambers to 0.45 water activity before performing the thermal treatments after each storage period, but group II samples (stored 70 and 103 weeks) were thermally treated immediately after the cans were opened. For thermal treatments, individual almond kernels were vacuum sealed in thin plastic bags, heated isothermally in a water bath (80°C) for nine intervals, immediately cooled in an ice bath, and assayed for surviving Salmonella. Log-linear and Weibull models were fit to the inactivation data. Salmonella population decreased (P < 0.05) more than 2 log CFU/g during the long-term storage. Salmonella survival in group II at 70 weeks (7.3 log CFU/g) was higher (P < 0.05) than in group I (which had been re-equilibrated multiple times) at 68 weeks (6.2 log CFU/g). However, the thermal resistance of Salmonella Enteritidis PT 30 did not decrease (P > 0.05) for up to 68 weeks of storage, and the log-linear model best described the thermal inactivation data. Overall, the results suggest that re-equilibrating almonds (group I) multiple times may have increased the rate of reduction of Salmonella populations during long-term storage. However, Salmonella thermal resistance on almonds appears to be essentially unaffected by long-term storage, which is important information for designing and conducting validation studies for pathogen control processes.

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