Protocols for dry DNA storage and shipment at room temperature

The globalization of DNA barcoding will require core analytical facilities to develop cost‐effective, efficient protocols for the shipment and archival storage of DNA extracts and PCR products. We evaluated three dry‐state DNA stabilization systems: commercial Biomatrica^® DNAstable^® plates, home‐made trehalose and polyvinyl alcohol (PVA) plates on 96‐well panels of insect DNA stored at 56 °C and at room temperature. Controls included unprotected samples that were stored dry at room temperature and at 56 °C, and diluted samples held at 4 °C and at ?20 °C. PCR and selective sequencing were performed over a 4‐year interval to test the condition of DNA extracts. Biomatrica^® provided better protection of DNA at 56 °C and at room temperature than trehalose and PVA, especially for diluted samples. PVA was the second best protectant after Biomatrica^® at room temperature, whereas trehalose was the second best protectant at 56 °C. In spite of lower PCR success, the DNA stored at ?20 °C yielded longer sequence reads and stronger signal, indicating that temperature is a crucial factor for DNA quality which has to be considered especially for long‐term storage. Although it is premature to advocate a transition to DNA storage at room temperature, dry storage provides an additional layer of security for frozen samples, protecting them from degradation in the event of freezer failure. All three forms of DNA preservation enable shipment of dry DNA and PCR products between barcoding facilities.     

NMR-based metabonomics of bovine blood: an investigation into the effects of long term storage on plasma samples

Freezers in research institutions often contain a plethora of samples left over from studies performed years or even decades ago. Along with samples stored in biobanks, these could prove to be treasure troves for metabonomic research. Although the influence of sample handling and short to medium term storage on conventionally determined blood parameters has been reported, little is known about the effects of long term storage (years to decades) on plasma samples. The aim of this study was to investigate the influence of long term storage on the metabolite profile and to assess the value of archived samples for metabonomic studies. Heparinised plasma of 22 heifers that had been stored at ?20 °C for between 2 and 15 years was analysed using NMR spectroscopy and statistical analysis techniques. Lactate (principal component 1) explained 79.6 % of variance between all spectra, but was not correlated with storage time. The highest correlation with storage time (R ² = 0.474) was found for betaine, with other metabolites (acetoacetate, histidines, glycerol, lipids and glucose) also showing moderate correlation (R ² values between 0.217 and 0.437). Our results indicate that samples stored for extended periods of time can potentially be used in metabonomics studies, if precautions are taken during data analysis.     

Cold storage of <Emphasis Type="Italic">Trichogramma nerudai</Emphasis> using an acclimation period

The availability of suitable storage methods for parasitoids is a valuable tool in biological control programs. Studies were conducted to investigate the effects of cold storage with acclimation period on the quality of Trichogramma nerudai Pintureau and Gerding. Prepupae were stored 50, 75 and 100 days at 5 °C with a previous acclimation period of 10 or 20 days at 12 °C. It was possible to arrest the development of T. nerudai. All the treatments with acclimation period of ten days had emergence values under 10% that were not useful to establish a cold storage protocol. Twenty days of acclimation had a positive impact on cold storage tolerance at 50 and 75 days. The adult emergence, the emergence time, the sex ratio, the parasitism and the progeny quality have not been affected by the storage of T. nerudai using an acclimation period of 20 days and until 50 days under cold temperature.     

Stability of targeted metabolite profiles of urine samples under different storage conditions

Introduction

Few studies have investigated the influence of storage conditions on urine samples and none of them used targeted mass spectrometry (MS).

Objectives

We investigated the stability of metabolite profiles in urine samples under different storage conditions using targeted metabolomics.

Methods

Pooled, fasting urine samples were collected and stored at ?80 °C (biobank standard), ?20 °C (freezer), 4 °C (fridge), ~9 °C (cool pack), and ~20 °C (room temperature) for 0, 2, 8 and 24 h. Metabolite concentrations were quantified with MS using the AbsoluteIDQ? p150 assay. We used the Welch-Satterthwaite-test to compare the concentrations of each metabolite. Mixed effects linear regression was used to assess the influence of the interaction of storage time and temperature.

Results

The concentrations of 63 investigated metabolites were stable at ?20 and 4 °C for up to 24 h when compared to samples immediately stored at ?80 °C. When stored at ~9 °C for 24 h, few amino acids (Arg, Val and Leu/Ile) significantly decreased by 40% in concentration (P < 7.9E?04); for an additional three metabolites (Ser, Met, Hexose H1) when stored at ~20 °C reduced up to 60% in concentrations. The concentrations of four more metabolites (Glu, Phe, Pro, and Thr) were found to be significantly influenced when considering the interaction between exposure time and temperature.

Conclusion

Our findings indicate that 78% of quantified metabolites were stable for all examined storage conditions. Particularly, some amino acid concentrations were sensitive to changes after prolonged storage at room temperature. Shipping or storing urine samples on cool packs or at room temperature for more than 8 h and multiple numbers of freeze and thaw cycles should be avoided.

     

Comparison of agarophytes (Gelidium, Gracilaria, and Gracilariopsis) as potential resources for bioethanol production

This study explores the possibility of producing ethanol using the acid hydrolysate of three abundant agar-containing red seaweeds (agarophytes): Gelidium amansii, Gracilaria tenuistipitata, and Gracilariopsis chorda. The main component in the seaweed samples was agar, which ranged from 20 to 51 % (g g^?1 dry weight). After optimizing acid hydrolysis, 100 g of seaweed was hydrolyzed at 130 °C for 15 min with 0.2 M H₂SO₄. Then, 120 mL of a 1:2 mixture of the hydrolysate broth and basal medium was fermented in a 200-mL bottle at 30 °C for 96 h. Of the three seaweeds, G. amansii had the best ethanol yield, producing 0.23 g g^?1 of galactose or 45 % of the theoretical yield. This yield increased to 60 % after detoxification of the hydrolysate with activated carbon.     

Variations in myocardial CPK and Na+-K+ ATPase following long-term freezing.

The activity of the soluble enzyme CPK and the membrane bound enzyme Na⁺-K⁺ ATPase as a function of storage temperature, time of storage and cryoprotectant type and concentration in canine myocardial tissue was invesigated. Activity of CPK is well preserved at ?196 °C and ?79 °C and falls off during one month storage at ?40 °, ?20 °, and 0 °C. Na⁺-K⁺ ATPase demonstrates a greater liability. After an initial cryoprotectant “activation,” activity drops. In all cases, however, addition of the cryoprotectant preserved activity better than in samples stored only in buffer.     

Investigation into the Potential of Bacteriocinogenic Lactobacillus plantarum BFE 5092 for Biopreservation of Raw Turkey Meat

The bacteriocin-producing Lactobacillus plantarum BFE 5092 was assessed for its potential as a protective culture in the biopreservation of aerobically stored turkey meat. This strain produces three bacteriocins, i.e. plantaricins EF, JK and N. The absolute expression of Lactobacillus plantarum BFE 5092 16S rRNA housekeeping gene, as well as l-ldh, plnEF and plnG genes as determined by quantitative, real-time-PCR, revealed that these genes were expressed to similar levels when the strain was grown at 8 and 30 °C in MRS broth. On turkey meat, Lactobacillus plantarum BFE 5092 did not grow but survived, as indicated by similar viable cell numbers during a 9-day storage period at 8 °C. When inoculated at 1 × 10⁷ CFU/g on the turkey meat and subsequently stored at 10 °C, the culture did again not show good growth. Lactobacillus plantarum BFE 5092 could not inhibit the growth of naturally occurring listeriae or Gram-negative bacteria on the turkey meat at 10 °C, or that of Listeria monocytogenes when it was co-inoculated at a level of 1 × 10⁵ CFU/g. Gene expression analyses showed that the bacteriocin genes were expressed on turkey meat stored at 10 °C. Moreover, the investigation into the absolute expression of the three plantaricin genes of Lactobacillus plantarum BFE 5092 in co-culture with Listeria monocytogenes on turkey meat by qRT-PCR showed that the plantaricin genes were indeed expressed during the low-temperature storage condition. The Lactobacillus plantarum BFE 5092 strain overall could not effectively inhibit L. monocytogenes and therefore it would not make a suitable protective culture for biopreservation of turkey meat stored aerobically at low temperature.     

Storability, post-storage conversion and genetic stability assessment of alginate-encapsulated shoot tips of monopodial orchid hybrid Aranda Wan Chark Kuan ‘Blue’ × Vanda coerulea Grifft. ex. Lindl.

An efficient short-term storage system of synthetic seeds, produced using in vitro shoot tips of the monopodial orchid hybrid Aranda Wan Chark Kuan ‘Blue’ × Vanda coerulea Grifft. ex. Lindl. (AV), was developed. In vitro shoot tips (3–4 mm) were successfully encapsulated, resulting in uniform spherical beads (capsules), using 3 % sodium alginate with 75 mM CaCl₂·2H₂O. Maximum (~100 %) conversion (into plantlets with shoot and root) of capsules (or synthetic seeds) was achieved on quarter-strength Murashige and Skoog regrowth medium, while full-strength MS medium was required for effective conversion of non-encapsulated shoot tips. The capsules showed distinct difference in their response to temperature during storage. The conversion efficiency declined upon storage duration at both 4 and 25 °C, with those stored at 25 °C being more tolerant to storage. Capsules stored at 4 °C had rapid deterioration and faced complete death within 160 days while those stored for 200 days at 25 °C showed relatively high conversion (71.6 %). An inter-simple sequence repeats fingerprinting approach, employed on indiscriminately chosen plantlets from converted capsules (following 4 and 25 °C of storage), ensured the post-storage genetic stability.     

Effect of Low-Temperature Storage on Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae)

We evaluated the effects of constant low-temperature storage on Diaeretiella rapae (McIntosh) (Braconidae, Aphidiinae). Diaeretiella rapae mummies were stored at 5?±?1°C for 0–36 days. The percentage of D. rapae emergence varied (100-83%) after 0–32 days of storage. After 32 days, emergence reduced to 55%. According to our Probit analysis, 50% mortality (LT50) of the population of D. rapae was reached after 40 days of storage at 5°C. Storage for up to 32 days did not negatively affect emergence and survival. Cold exposure of D. rapae for 36 days did not influence morphological malformations, sex ratio, and emergence of the F1 generation. After 4–36 days of storage, D. rapae showed a gradual decrease in emergence, longevity, reproductive capacity, and F1 sex ratio. Diaeretiella rapae can be stored for up to 24 days at 5°C, at which time the percentage of parasitism and the F1 sex ratio remain above 38% and at 0.50, respectively.     

Low Temperature Storage of <Emphasis Type="Italic">Telenomus remus</Emphasis> (Nixon) (Hymenoptera: Platygastridae) and its Factitious Host <Emphasis Type="Italic">Corcyra cephalonica</Emphasis> (Stainton) (Lepidoptera: Pyralidae)

We conducted three bioassays to evaluate the effect of low-temperature storage of eggs (host) and pupae and adults (parasitoid) on the biology and parasitism capacity of the egg parasitoid Telenomus remus (Nixon) (Hymenoptera: Platygastridae). Viable stored Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) eggs were parasitized to the same degree or even higher than fresh eggs when stored until 14 days at 5°C or until 21 days at 10°C. In contrast, the percentage of parasitized sterilized eggs was equal to the control only when stored for 7 and 14 days. Survival of T. remus pupae declined with storage time at both studied temperatures (5 and 10°C). However, after 7 days of storage, survival of pupae was still 86.3 and 64.9% at 10 and 5°C, respectively. The number of adult male survivors remained similar until the fourth storage day at both 5 and 10°C. In contrast, female survival did not differ until day 8 at 10°C or day 6 at 5°C. Parasitism capacity of stored adults was not altered by storage compared with the control. Therefore, we conclude that the maximal storage time at 10°C is 21 days for viable C. cephalonica eggs and 7 days for T. remus pupae, while parasitoid adults should not be stored for more than 4 days at either 5 or 10°C.     

Production of microsclerotia by Brazilian strains of Metarhizium spp. using submerged liquid culture fermentation

We investigated the potential production and desiccation tolerance of microsclerotia (MS) by Brazilian strains of Metarhizium anisopliae (Ma), M. acridum (Mc) and M. robertsii (Mr). These fungi were grown in a liquid medium containing 16 g carbon l^?1 with a carbon:nitrogen ratio of 50:1. One hundred milliliters cultures were grown in 250 ml Erlenmeyer flasks in a rotary incubator shaker at 28 °C and 200 rpm for 5 days. Five-day-old MS were harvested, mixed with diatomaceous earth (DE) and air-dried for 2 days at 30 °C. The air-dried MS–DE granular preparations were milled by mortar + pestle and stored in centrifuged tubes at either 26 or ?20 °C. Desiccation tolerance and conidia production were assessed for dried MS granules by measuring hyphal germination after incubation for 2 days on water agar plates at 26 °C and for conidia production following 7 days incubation. Yields of MS by all strains of Metarhizium were 6.1–7.3 × 10⁶ l^?1 after 3 days growth with maximum MS yields (0.7–1.1 × 10⁷ l^?1) after 5 days growth. No differences in biomass accumulation were observed after 3 days growth, whereas Ma-CG168 showed the highest biomass accumulation after 5 days growth. Dried MS–DE preparations of all fungal strains were equally tolerant to desiccation (≥93 % germination) and the highest conidia production was obtained by MS granules of Mc-CG423 (4 × 10⁹ conidia g^?1). All MS granules showed similar stability after storage at either 26 or ?20 °C for 3.5 months.     

Proteomic Studies of Saliva: A Proposal for a Standardized Handling of Clinical Samples

Background

In recent years, differential analysis of proteins from human saliva, i.e., proteomic analysis, has received much attention mainly due to its unstressful sampling and its great potential for biomarker research. It is widely considered that saliva is a highly stable medium for proteins thanks to a large amount of antiprotease agents, even at ambient and physiological temperatures.

Objective

To find the best protocol for the handling of samples, we have investigated the stability of saliva proteins stored at different temperatures (from ?80 to 20°C) by one- and two-dimensional electrophoresis.

Results

At 20°C, no major changes were observed on protein one-dimensional profiles following 1 day of storage; however, between 7 days and 30 days, the native alpha-amylase band decreased slightly to give several bands with molecular weight between 35 and 25 kDa. The same phenomenon appeared after 30 days of storage at 4°C. Two-dimensional analysis of salivary maps revealed degradation from day 7 of several protein groups for samples stored at 20°C.

Conclusion

All these findings have to be carefully considered when saliva is collected for clinical proteomic analysis. We can conclude that, to maintain the optimum stability of saliva proteins, saliva samples should be collected on ice followed by the addition of protease inhibitor cocktail, centrifuged to remove insoluble material, and stored at ?20 or ?80°C.     

Changes in carotenoid and chlorophyll content of black tomatoes (Lycopersicone sculentum L.) during storage at various temperatures

Black tomatoes have a unique color and higher lycopene content than typical red tomatoes. Here, black tomatoes were investigated how maturation stage and storage temperature affected carotenoid and chlorophyll accumulation. Immature fruits were firmer than mature fruits, but failed to develop their distinctive color and contained less lycopene when stored at 8 °C. Hunter a^* values of black tomatoes increased with storage temperature and duration; storage of immature fruits at high temperature favored lycopene accumulation. Chlorophyll levels of black tomatoes declined during storage, but differences between mature and immature tomatoes stored at 12 °C were minimal. β-Carotene levels of black tomatoes increased during early storage, but rapidly declined beginning 13 d post-harvest. The highest lycopene and chlorophyll levels were observed in mature black tomatoes stored at 12 °C for 13 d; these conditions also yielded the best quality fruit. Thus, the unique pigmentation properties of black tomatoes can be precisely controlled by standardizing storage conditions.     

Encapsulation, cold storage, and growth of Hibiscus moscheutos nodal segments

Nodal segments of Hibiscus moscheutos (hardy hibiscus) were excised from proliferating axillary shoot cultures and encapsulated in high density sodium alginate hardened by 50 mM CaCl₂. Nodal segments 4 mm long grew as well as and were easier to encapsulate than 8 mm long nodal segments. Although nodal segments grew regardless of the concentration of sodium alginate, 2.75% was determined to produce the highest quality encapsulated nodal segments beads (sufficient alginate coating and ease of use) because of the viscosity produced by the 2.75% sodium alginate solution. When encapsulated segments were stored at 5°C they did not grow in light or darkness. During the first month on fresh proliferation medium under normal incubation conditions following 5°C storage in the dark for up to 24 weeks, root number and root and shoot elongation were inhibited linearly as storage time increased. All encapsulated nodal segments survived 24 weeks of 5°C storage in two separate experiments. In fact, 80% of encapsulated hardy hibiscus nodal segments survived refrigerated storage for 1½ years (78 weeks) and after 3 months on proliferation medium, the nodal segments produced nearly the same length axillary shoots with the same number of axillary nodes per shoot as compared to encapsulated segments either not stored at 5°C or stored for 24 weeks at 5°C. Growth from encapsulated and cold-stored ‘Lord Baltimore’ nodal segments was more vigorous than from ‘Southern Belle’ nodal segments.     

Organic acid extraction from rhizosphere soil: effect of field-moist, dried and frozen samples

This study investigates the effect of soil treatment and storage on organic acid extraction. For this study one clayey-loamy (Typic Udochrept) and one sandy-loamy (Aquic Ustifluvent) soil were selected and used to grow Lupinus albus L. plants in a climate chamber. After 4 weeks the rhizosphere soil was sampled and divided into five portions: (a) field moist, no storage; (b) air-dried; (c) oven-dried, (d) field-moist at +4°C for 8 weeks; (e) field-moist at ?20°C for 8 weeks. Organic acid extraction (1:4 w/v) was carried out for each soil portion both in water and in 10 mM NaH₂PO4. Organic acid concentration was subsequently determined by reversed-phase high performance liquid chromatography (HPLC). Oxalic, fumaric, malonic and α-ketoglutaric acid were identified in the rhizosphere of both soils but the extractable concentration was significantly higher in the sandy-loamy soil. For both soils NaH₂PO₄ extracted significantly higher organic acid concentrations than water. Oven drying increased the extractability of organic acids in both soils. Field moist samples (i.e. where no storage occurred) of the sandy-loamy soil showed a similar behaviour than ?20° stored samples whereas the one of the sandy-loamy soil were more close to the air-dried samples. These results indicate that organic acid extraction strongly depends on soil storage as well as on the soil type. Sample storage seems thus to be a crucial issue for the determination of organic acids in rhizosphere soil and needs to be considered prior analysis.     

Effect of temperature and ripening stages on membrane integrity of fresh-cut tomatoes

The shelf-life of fresh-cut tomatoes mainly depends on loss of tissue integrity and firmness that occurs also in intact fruits after long-term cold storage due to chilling injury. Round-fruit tomatoes (Solanum lycopersicum L.) cv. Jama were stored in 1.1-L plastic (polyethylene) fresh-cut produce containers as 10.0-mm-thick tomato slices and as intact tomatoes at 4 ± 0.5 °C. The aim of this work was to study the loss of membrane integrity and biochemical processes involved in membrane disruption. Electrolyte leakage and lipid peroxidation were studied at different stages of maturity: mature green, pink (PK), fully ripe and two different storage temperatures: 4 and 15 °C. The tomato slices of PK stage stored at 4 °C did not show changes for both parameters, while significant increase in membrane leakage and lipid peroxidation was observed at 15 °C, especially after 24 h of storage. The enzymes showed a simultaneous increase in their activities with a rise in electrolyte leakage and lipid peroxidation after 7 days of storage. Finally, phospholipase C (PLC) and phospholipase D (PLD) were investigated for intact fruit and tomato slices stored at 4 °C. The PLC had higher activity compared with PLD. In conclusion, the loss of membrane integrity in fresh-cut tomatoes is mainly affected by ripening stages, storage temperature and duration. The wounds enhance the PLC and PLD activities and they play a role late during storage.     

Influence of an Acrylic Polymer Blend on the Physical Stability of Film-Coated Theophylline Pellets

The purpose of this study was to investigate the physical stability of a coating system consisting of a blend of two sustained release acrylic polymers and its influence on the drug release rate of theophylline from coated pellets. The properties of both free films and theophylline pellets coated with the polymer blend were investigated, and the miscibility was determined via differential scanning calorimetry. Eudragit^® RS 30 D was plasticized by the addition of Eudragit^® NE 30 D, and the predicted glass transition temperature (T _g) of the blend was similar to the experimental values. Sprayed films composed of a blend of Eudragit^® NE 30 D/Eudragit^® RS 30 D (1:1) showed a water vapor permeability six times greater than films containing only Eudragit^® NE 30 D. The presence of quaternary ammonium functional groups from the RS 30 D polymer increased the swellability of the films. The films prepared from the blend exhibited stable permeability values when stored for 1 month at both 25°C and 40°C, while the films which were composed of only Eudragit^® NE 30 D showed a statistically significant decrease in this parameter when stored under the same conditions. Eudragit^® NE 30 D/Eudragit^® RS 30 D (1:1)-sprayed films decreased in elongation from 180% to 40% after storage at 40°C for 1 month, while those stored at 25°C showed no change in elongation. In coated pellets, the addition of Eudragit^® RS 30 D to the Eudragit^® NE 30 D increased the theophylline release rate, and the pellets were stable when stored at 25°C for a period of up to 3 months due to maintenance of the physico-mechanical properties of the film. Pellets stored at 40°C exhibited a decrease in drug release rate over time as a result of changes in film physico-mechanical properties which were attributed to further coalescence and densification of the polymer. When the storage temperature was above the T _g of the composite, instabilities in both drug release rate and physical properties were evident. Stabilization in drug release rate from coated pellets could be correlated with the physico-mechanical stability of the film formulation when stored at temperatures below the T _g of the polymer.     

Systematic overestimation of Salicaceae seed survival using radicle emergence in response to drying and storage: implications for ex situ seed banking

Biodiversity conservation programmes are underpinned by seed banking following drying to low water contents (WC), and supported by both the assessment and prediction of seed viability over time. The means of judging viability is thus crucial to the comprehension of seed vigour. We selected seeds of three species and one hybrid in the Salicaceae likely to have variation in tolerance to drying, processing and storage, including in relation to cryobanking, and compared survival growth as radicle emergence (germination) and normal seedling production. With three seed lots of Salix gracilistyla, air-drying to 8–10 % WC enhanced seed survival after 40 days’ storage at 5 °C as compared with non-treated seeds at 14–20 % WC. Four seed lots of Populus alba × P. glandulosa showed equally high germination (88–100 %) and proportions of normal seedlings (81–99 %) when stored at 5 °C for 7–10 weeks. Among seven seed lots of S. gracilistyla, two groups with different storage behaviour could be statistically distinguished with normal seedling production ranging from 0 to 45 % after storage at 5 °C for 13 weeks. Seed tolerance to WC manipulation and cryopreservation was very variable among species and seed lots. Seed lots of S. hallaisanensis and S. gracilistyla with ~80 % germination survived cryopreservation at 10 % WC, but were sensitive to lower WCs. In contrast, Populus seeds had greater desiccation tolerance combined with cryopreservation capability. With seed lots of all species and hybrids, cryopreservation had little effect on viability unless the high moisture freezing limit had been exceeded (~10–20 % WC, depending on seed lot). However, under all conditions of handling (drying, rehydration, storage at 5 °C or cryopreservation) using germination as the only indicator of viability over-estimated survival compared with normal seedling production.     

Effect of 1-MCP and low-temperature storage on postharvest conservation of camu–camu

Camu–camu, a native fruit from the Amazon region, is a rich source of bioactive compounds. However, its intense metabolic activity and high-water content limit the fruit’s postharvest storage and marketing. The aim of this study, conducted in two parts, was to evaluate the effects of 1-MCP and storage temperature on the physiology and postharvest preservation of camu–camu fruit. In part 1 of the study, fruit harvested at maturity stage 3 were divided into groups: control, 1-methylcyclopropene (1-MCP; 900 nL L^?1; 12 h) and ethylene (1000 µL L^?1; 24 h) and were stored at 22?±?1 °C and 85?±?5% RH for 9 days. In part 2, fruit harvested at maturity stage 3 were stored at 5, 10, 15, 20, or 25?±?1 °C and 85?±?5% RH for 9 days. During storage, fruit were evaluated daily for decay, mass loss, respiratory activity, and ethylene production, and every 3 days they were evaluated for peel color, pulp firmness, soluble solids content, total titratable acidity, ascorbic acid, total chlorophyll, and total anthocyanins. Fruit treated with 1-MCP exhibited delayed ripening due to lower metabolic activity, as evidenced by delay to softening, reduced mass loss and no decay. Storage at 5 °C prevented ethylene production, mass loss, color changes, and maintained pulp firmness, while did not affect soluble solids content. The results indicated that storage of camu–camu fruit at 5 °C or at 25 °C following application of 900 nL L^?1 1-MCP were effective strategies to delay ripening and maintain fruit quality up to 9 days.     

Highly selective hydrolysis for the outer glucose at the C-20 position in ginsenosides by β-glucosidase from Thermus thermophilus and its application to the production of ginsenoside F2 from gypenoside XVII

β-Glucosidase from Thermus thermophilus has specific hydrolytic activity for the outer glucose at the C-20 position in protopanaxadiol-type ginsenosides without hydrolysis of the inner glucose. The hydrolytic activity of the enzyme for gypenoside XVII was optimal at pH 6.5 and 90 °C, with a half-life of 1 h with 3 g enzyme l^?1 and 4 g gypenoside XVII l^?1. Under the optimized conditions, the enzyme converted the substrate gypenoside XVII to ginsenoside F₂ with a molar yield of 100 % and a productivity of 4 g l^?1 h^?1. The conversion yield and productivity of ginsenoside F₂ are the highest reported thus far among enzymatic transformations.