Effects of storage on characteristics and hygienic quality of digestates from four co-digestion concepts of manure and biowaste

This study evaluated the effects of storage in northern winter conditions (5 degrees C) on the characteristics and nutrients separation of digestates from co-digestion of manure and biowaste as well as the hygienic quality of the digestates after digestion and storage. During 3-11 months' storage average nitrogen losses and reductions of total solids (TS) and volatile solids (VS) were 0-15%. With some exceptions, soluble chemical oxygen demand (SCOD) had increased slightly (from approximately 6.5 to approximately 7.5g/l) after 3 months' storage, while after 9-11 months' it had decreased from 8.3-11 to 5.6-8.4g/l. The concentrations of P(tot) and PO4-P in the separated liquid fractions decreased 40-57% after 3 months' storage and 71-91% after 9 months' storage compared to the initial concentrations. The methane potential losses during 9-11 months' storage corresponded 0-10% of the total methane potential without storage. The hygienic quality of the digestates from the 55 degrees C reactor and during storage fulfilled the Animal By-Products Regulation (ABPR) demands while the 35 degrees C digestate contained 0-105cfu/g of indicator bacteria (faecal coliforms, enterobacteria, enterococcus) and >10cfu/g of spiked salmonella, which amounts decreased slowly during storage. Sulphite reducing clostridia was not affected by either digestion or storage.     

Short-term storage of ova of common carp and tench in extenders

In a study of the effect of short-term storage on the hatching rate of common carp Cyprinus carpio and tench Tinca tinca ova in vitro in various extenders at 21° C under aerobic conditions, the best extender for 30 min storage for common carp appeared to be Dettlaff 1. This gave the same hatching rate as controls without extender (55% v. 56%). For 60 min storage of ova, the best extenders were Dettlaff 2 (24% hatching rate) and Dettlaff 3 (30%), but hatching was significantly lower than in the control (58%). In carp ovarian artificial fluid (CAF) extender, the hatching rate of common carp ova was also high after 10 min, but decreased to 12% after 30 min. In tench, the hatching rate of ova increased after 10 min storage in Dettlaff 5 extender (44%) compared to the control (41%) without extender. However, it was significantly lower after storage in Dettlaff 1, 2, 3, 4, 5 and CAF extenders for 20, 30 and 60 min, compared to controls. Malformations (10–50%) were observed in the tench second control groups without extender after 10, 20 and 30 min storage of ova.     

Viability of basidiomycete strains after cryopreservation: comparison of two different freezing protocols

The viability of 250 basidiomycete strains was determined after a 2-d and then after a 2-year storage under liquid nitrogen using two different freezing protocols. Using an original agar plug protocol (OP), 162 strains (65%) of the 250 strains survived a 2-d storage and 158 strains (63%) survived a 2-year storage in liquid nitrogen. Using a straw protocol (CP), 246 strains (98%) of the 250 strains survived a 2-d storage and 243 strains (97%) a 2-year storage in liquid nitrogen. In addition, other 106 strains were newly estimated using the CP protocol; 104 (98%) of them survived successfully a 2-d storage and 101 (95%) of them survived a 2-year storage in liquid nitrogen. The results indicate that the protocol used for cryopreservation can significantly influence strain survival. Markedly better results were obtained using the CP protocol.     

黄肉红心猕猴桃‘东红’果实在不同贮藏方式下的生理和品质变化研究

以中华猕猴桃（Actinidia chinensis Planch.）黄肉红心新品种‘东红’为材料,对其果实在常温和低温贮藏方式下的生理及品质变化进行了研究。结果表明,果实硬度在2种贮藏方式下均呈先快速下降后缓慢下降的趋势。可溶性固形物含量、总糖含量、固酸比和糖酸比等4个品质指标均表现为先快速上升后维持在较高水平（低温贮藏下）或继续小幅上升（常温贮藏下）的趋势。总酸含量整体上均呈现逐渐下降之势,至果实软熟时稳定在0.9%的水平。维生素C含量却在常温贮藏下基本呈逐渐上升之势,而在低温贮藏下大致表现为先上升后轻微下降。果实失重率和腐烂率均随贮藏时间的延长而逐渐增加,在常温贮藏时上升较快,而在低温贮藏时上升非常缓慢。总体而言,‘东红’果实主要的生理和品质指标在常温贮藏2~3周后或低温贮藏9周后发生明显转变,果实进入可食用阶段;并且继续低温贮藏15周内还能较好地保持果实品质,耐贮性较好。     

The storage of cow eggs at room temperature and at low temperatures.

The survival and development of cow eggs in the rabbit oviduct after storage at room temperature and after cooling and storage at 0-7-5 degrees C was examined. In PBS medium at room temperature 88% of Day-5 and 85% of Day-3 eggs showed normal development, but in TCM 199, 71% of Day-5 and only 49% of Day-3 eggs showed normal development. Duration of storage (1 1/2-2 hr or 6 1/2-7 1/2 hr) and cleavage stage before storage had no appreciable effect on development. Some retardation of development occurred in Day-3 eggs after 96 hr in the rabbit oviduct when compared to Day-5 eggs after 48 hr. Cooling of Day-5 and Day-6 eggs to 0-7-5 degrees C resulted in degeneration of a large proportion of eggs. Of the factors examined, storage medium (PBS or PBS+20%FCS), storage time (2 min, 24 hr) and storage temperature (0, 2, 5 or 7-5 degrees C) had little effect, but slower cooling rates tended to improve survival of eggs although the differences were not significant. More morulae (greater than 32 cells) than 8-to 24-celled eggs developed normally.     

Effect of short-term preservation of sea lamprey gametes on fertilisation rate and embryo survival

We assessed the effect of short-term (4.7–75.3 h) storage at low temperature (approximately 1 °C) on the viability of sea lamprey ( Petromyzon marinus L.) gametes. Hatching success decreased with storage time, but more than 20% eggs hatched even after 75.3 h of preservation. However, storage time drastically reduced the survival rate to the burrowing stage (i.e. the last prelarval stage), which decreased from 76% when the gametes were stored for 4.7 h to 0% after 75.3 h of storage.     

黄肉红心猕猴桃‘东红’果实在不同贮藏方式下的生理和品质变化研究

以中华猕猴桃( Actinidia chinensis Planch.)黄肉红心新品种‘东红’为材料,对其果实在常温和低温贮藏方式下的生理及品质变化进行了研究。结果表明,果实硬度在2种贮藏方式下均呈先快速下降后缓慢下降的趋势。可溶性固形物含量、总糖含量、固酸比和糖酸比等4个品质指标均表现为先快速上升后维持在较高水平(低温贮藏下)或继续小幅上升(常温贮藏下)的趋势。总酸含量整体上均呈现逐渐下降之势,至果实软熟时稳定在0. 9%的水平。维生素C含量却在常温贮藏下基本呈逐渐上升之势,而在低温贮藏下大致表现为先上升后轻微下降。果实失重率和腐烂率均随贮藏时间的延长而逐渐增加,在常温贮藏时上升较快,而在低温贮藏时上升非常缓慢。总体而言,‘东红’果实主要的生理和品质指标在常温贮藏2 ~ 3周后或低温贮藏9周后发生明显转变,果实进入可食用阶段;并且继续低温贮藏15周内还能较好地保持果实品质,耐贮性较好。     

The influence of housefly Musca domestica embryo age on viability in water and at low temperatures

The sensitivity of housefly Musca domestica L. (Diptera: Muscidae) embryos to storage at low temperatures (5 and 10 °C on moist sponges in Petri dishes) and in water at 26 °C was investigated to develop suitable protocols for the storage and transport of housefly eggs. The youngest embryos (aged 0–3 h) were the most sensitive to storage at 5 °C, with 45% survival after storage for 24 h. Storage of embryos aged 3–12 h at 5 °C for 24 h had no negative effect; longer storage resulted in significantly decreased larval survival (30–34% after 48–72 h, compared with 61% in the control group) and reduced hatching rates (83% after 72 h storage). No negative effects were observed when embryos aged 0–9 h were stored at 10 °C for 24 h, but this temperature did not completely inhibit development and eggs began to hatch if stored for longer than 24 h. All age groups of embryos showed high mortality after storage in water at 26 °C for 24 h, with the youngest embryos being least resistant to submersion.     

Storing energy crops for methane production: effects of solids content and biological additive

The effect of storage on chemical characteristics and CH4 yield (taking into account loss of VS during storage) of a mixture of grasses and ryegrass, ensiled as such (low solids content) and after drying (medium and high solids) with and without biological additive, were studied in field and laboratory trials. Up to 87% and 98% of CH4 yield was preserved with low solids grass (initial TS 15.6%) and high solids ryegrass (initial TS 30.4%), respectively, after storage for 6months, while under suboptimal conditions at most 37% and 52% of CH4 yield were lost. Loss in CH4 yield was mainly due to VS loss, presumably caused by secondary fermentation as also suggested by increasing pH during storage. Biological additive did not assist in preserving the CH4 yield.     

广西喀斯特移民迁入区土地利用变化对土壤有机碳和全氮储量的影响

土地利用变化是影响土壤碳、氮循环的重要因素,也是研究全球气候变化的热点.本研究基于固定深度法(FD)和等效质量法(ESM),从森林开垦和退耕还林还草两个角度探讨喀斯特移民迁入区土地利用变化对土壤有机碳(SOC)和全氮(TN)储量的影响.结果表明: 原始森林被开垦为草地、桉树林和农田后,SOC和TN储量均显著减少;基于FD方法计算的SOC和TN储量分别损失了47.4%、41.6%,而通过ESM方法计算的SOC和TN的损失率分别为54.8%、49.7%.农田撂荒为草地及种植桉树后,SOC和TN储量显著增加;基于FD方法计算的SOC和TN储量提高了60.5%、49.7%,通过ESM方法计算的SOC和TN分别增加85.5%和70.8%.FD方法忽略了土地利用变化后土壤容重的差异,而森林开垦后会显著增加土壤容重,因此,FD方法高估了SOC和TN储量;农田恢复后土壤容重减小,FD方法则会低估SOC和TN储量的增加.建议相关研究选择ESM方法测算土地利用变化对SOC和TN储量的影响.     

Physiological and growth responses of Cedrus libani seedlings to cold storage

The effects of cold storage duration on the physiological characteristics and growth of two-year-old Taurus cedar (Cedrus libani A. Rich) seedlings were studied. Taurus cedar seedlings were lifted in December, January and February and stored at +4 °C (cold storage) for 0, 2, 3 and 4 months. Xylem water potential (Ψ), shoot (SMC) and root moisture (RMC) contents, root growth potential (RGP), root electrolyte leakage (REL) and total carbohydrate contents were determined before and after the cold storage. The survival and growth were also evaluated at the end of the first growing season. Ψ, SMC and RMC, RGP and total carbohydrate contents were dramatically affected by the storage duration. The decrease in total carbohydrate contents during the storage showed a parallelism with RGP and survival. It was also found that storage duration had important effects on survival and growth. While survival was above 85 % even after storage of 4 months in seedlings that were lifted in December and January, this rate was reduced to 30 % after storage of 4 months in seedlings that were lifted in February. Total carbohydrate content and RGP can be used as an indicator of survival after cold storage.     

In vitro and in vivo comparison of Ham's F-10, Emcare holding solution and ViGro holding plus for the cooled storage of equine embryos

Equine embryos have been successfully transferred after 24h cooled storage in Ham's F-10. The aim of this study was to compare the viability of equine embryos in vitro and in vivo after 6 and 24h cooled storage using three media and to examine the relationship between embryo size and viability after 24h cooled storage. In Experiment 1, the viability of embryos was evaluated using DAPI-staining after 0, 6 or 24h in Ham's F-10, 24h in Emcare embryo holding solution (EHS) or 24h in ViGro holding plus (VHP) (n=10/group). The mean number of dead cells was similar for embryos stored in Ham's F-10, EHS and VHP for 24h. Larger Day 7 embryos appear to withstand 24h cold storage better than small Day 7 embryos. The embryo quality for 24h cold storage was negatively correlated with size. In Experiment 2, 40 embryos were stored (n=20/group) either in Ham's F-10 or in EHS then transferred as pairs in recipient mares. Fifteen of the 20 recipient mares (75%) were pregnant. Out of 17 surviving embryos, 9 embryos (53%) were stored in Ham's F-10 and 8 (47%) in EHS. These results suggest that EHS and VHP offer a good alternative to Ham's F-10 for 24h cooled storage of equine embryos and that larger embryos may have a better viability after 24h of cooled storage than smaller embryos.     

Identification of sperm subpopulations in canine ejaculates: effects of cold storage and egg yolk concentration

The aim of this study was to evaluate the effects of cold storage and egg yolk concentration on the distribution of spermatozoa within the different subpopulations. Twenty ejaculates from 4 dogs were collected, diluted in either TRIS buffer containing 20% (TEY20) or 10% centrifuged egg yolk (TEY10) and cooled following a conventional protocol. The kinematic parameters of individual spermatozoa were evaluated in fresh ejaculates and after 24 and 72 h of preservation at 5°C. A multivariate clustering procedure separated 54,261 motile spermatozoa into four subpopulations: Subpopulation 1 consisting of poorly active and non-progressive spermatozoa (19.80%), Subpopulation 2 consisting of slow and low-linear spermatozoa (25.21%), Subpopulation 3 consisting of high speed and progressive spermatozoa (23.88%), and Subpopulation 4 consisting of highly active but non-progressive spermatozoa (31.11%). Although, cold storage had a significant (P<0.05) effect on both the frequency distribution of spermatozoa within subpopulations and the motion characteristics of each subpopulation, the sperm subpopulation structure was perfectly maintained after cold storage. Subpopulations 1 and 2 significantly (P<0.001) decreased during cold storage (Subpopulation 1: 26.6, 16.9 and 18.4%; and Subpopulation 2: 33.6, 21.3 and 24.0%, respectively, for fresh, 24 and 72 h post-cooled), whereas Subpopulations 3 and 4 significantly (P<0.05) increased (Subpopulation 3: 16.7, 27.6 and 24.3%, and Subpopulation 4: 23.1, 34.1 and 33.4%, respectively, for fresh, 24 and 72 h post-cooled). Regarding the relative percentage of spermatozoa within each extender, Subpopulation 3 was more frequently observed in TEY20 after both 24 and 72 h of cold storage. Significant correlations (P<0.05) were found between the proportions of spermatozoa assigned to Subpopulation 3 in the fresh ejaculates and those in stored samples after 24 h (r=0.48498). In conclusion, cold storage significantly modified both the specific parameters and the distribution of spermatozoa within subpopulations. These changes did not affect the general motile sperm structure present in dog, which is conserved during cold storage. The analysis of the changes observed in structures of subpopulations also suggests that the TEY20 provide more effective preservation of dog semen during cold storage.     

Low temperature storage of larvae and synchronization of adult emergence in the predatory midge Aphidoletes aphidimyza.

Diapause larvae of Aphidoletes aphidimyza were stored at a temperature of 3 degrees C under continuous darkness for up to 7 months with survival rates above 50%; after storage for 1 year the survival rate dropped to 12%. Diapause was terminated in the majority of individuals within 120 days of chilling under storage conditions. Brief exposure (10-60 s) to the vapor of n-hexane appeared to be a useful alternative to chilling for the termination of diapause. The larvae with terminated diapause required, on average, an additional 31 days at 22 degrees C and long-day conditions in order to reach the adult stage. The 10-90% adult emergence spanned a period of 21.1 days. When the larvae with terminated diapause were exposed to 30 degrees C for 1 week after the end of low temperature storage, the survival rate was not affected, the average "time-to-adult" shortened moderately to 28 days, and the synchrony of adult emergence improved considerably to 10 days. Low temperature storage of nondiapause larvae resulted in a decrease in survival from 98 to 31% during the first 60 days of storage. Nondiapause larvae did not enter diapause during low temperature storage and, as a consequence, the adults emerged relatively rapidly (after 14-15 days) and synchronously (within 2-3 days) after the end of storage. Directions for future research, which might bring further improvement in low temperature storability and synchrony of adult emergence in A. aphidimyza, are proposed.     

Control of microbiological quality and shelf-life of catfish (Clarias gariepinus) by chemical preservatives and smoking

Fresh catfish ( Clarias gariepinus ) were subjected to different concentrations of sodium benzoate or potassium sorbate and smoked traditionally before evaluation for microbiological, chemical and organoleptic characteristics during ambient tropical storage. Unsmoked fish samples showed diverse microflora ( Enterobacter, Escherichia, Serratia, Bacillus, Staphylococcus, Streptococcus, Penicillium, Aspergillus and Achlya genera) while smoked samples were dominated by Gram-positive bacterial flora ( Bacillus, Staphylococcus and Streptococcus ) and spoilage moulds ( Penicillium verrucosum, Aspergillus flavus and Achlya spp.). Significant reduction in microbial population occurred in most samples following smoking with samples subjected to 0.4% (w/v) potassium sorbate showing the lowest microbial load and maximum shelf-stability. However, marked microbial increase occurred after day 4 of storage in control and benzoate-treated samples. Changes in pH were marginal but decreased after day 12 of storage. Moisture content decreased sharply after smoking and remained low after day 4 of storage. Overall, potassium sorbate treatment (0.4% w/v) was most effective in controlling microbial quality and extended the shelf-life of the samples by 8 d.     

Long-term preservation of mouse spermatozoa after freeze-drying and freezing without cryoprotection

The widespread production of mice with transgenes, disrupted genes and mutant genes, has strained the resources available for maintaining these mouse lines as live populations, and dependable methods for gamete and embryo preservation in these lines are needed. Here we report the results of intracytoplasmic sperm injection (ICSI) with spermatozoa freeze-dried or frozen without a cryoprotectant after storage for periods up to 1.5 years. Freeze-dried samples were stored at 4 degrees C. Samples frozen without cryoprotection were maintained at -196 degrees C. After storage, spermatozoa were injected into the oocytes by ICSI. Zygotic chromosomes and fetal development at Day 15 of gestation were examined after 0, 1, 3, 6, 9, and 12 mo of sperm storage. When fresh spermatozoa were used for ICSI, 96% of resultant zygotes contained normal chromosomes, and 58% of two-cell embryos transferred developed to normal viable fetuses. Similar results were obtained when spermatozoa were frozen without cryoprotection and then used for ICSI (87% and 45%, respectively; P > 0.05) and after 12 mo of sperm storage (mean of six endpoints examined: 87% and 52%, respectively; P > 0.05). Freeze-drying decreased the proportion of zygotes with normal karyoplates (75% vs. 96%; P < 0.001) and the proportion of embryos that developed into fetuses (35% vs. 58%; P < 0.001), but similar to freezing, there was no further deterioration during 12 mo of storage (mean of six endpoints examined: 68% and 34%, respectively; P > 0.05). Live offspring were obtained from both freeze-dried and frozen spermatozoa after storage for 1.5 yr. The results indicate that 1) the freeze-drying procedure itself causes some abnormalities in spermatozoa but freezing without cryoprotection does not and 2) long-term storage of both frozen and freeze-dried spermatozoa is not deleterious to their genetic integrity. Freezing without cryoprotection is highly successful, simple, and efficient but, like all routine sperm storage methods, requires liquid nitrogen. Liquid nitrogen is also required for freeze-drying, but sperm can then be stored at 4 degrees C and shipped at ambient temperatures. Both preservation methods are successful, but rapid freezing without cryoprotection is the preferred method for preservation of spermatozoa from mouse strains carrying unique genes and mutations.     

Basidiomycete cryopreservation on perlite: evaluation of a new method

A new cryopreservation method using perlite as a carrier was evaluated on a large set of mycelial cultures of basidiomycetes. The viability and some other characteristics--growth, macro- and micromorphology, and laccase production--of 442 strains were tested after 48-h and then after 3-year storage in liquid nitrogen using a perlite protocol (PP). All (100%) of them survived successfully both 48-h storage and 3-year storage in liquid nitrogen without noticeable growth and morphological changes. Also laccase production was unchanged. The viability and laccase production of a part (250) of these strains were compared with those of the strains subjected to an original agar plug protocol (OP). Using OP, 144 strains (57.6%) out of 250 survived a 3-year storage in liquid nitrogen. The results indicate that the cryopreservation protocol used significantly influences survival of the strains. Markedly better results were achieved using the PP.     

Rates of Drying and Survival of Rhizobium meliloti Strains During Storage at Different Relative Humidities

An investigation was made of the survival of six strains of Rhizobium meliloti filtered on membrane filters and held in atmospheres of controlled relative humidities (RH) of from 0 to 100% at 30°C in the presence of air. The rate of water loss in the desiccator was determined by the humidity-controlling solution used. Drying was accelerated by a mild evacuation of the desiccator during the drying step. Survival rates of R. meliloti strains were much higher after slow drying to 0% RH than immediately after rapid drying. Fast drying (drying period less than 3.4 h) was shown to adversely affect the tolerance to storage at all RH values tested (no survival after 2 to 5 days of storage). When survival during storage was measurable (after slow drying), the optimum RH values for storage were 43% for strains A145 and Wu498, 22 to 43% for strains RCR2011, Wu499, and Ar16, and 83% for strain RCR2004. The most favorable drying periods were 8, 9.2, 14.2, and 50.1 h for the subsequent storage of strain RCR2011 at RH values of 0, 22, 43, and 83%, respectively. The damaging effects of rapid drying on the tolerance of strain RCR2011 to storage at different RH values could be prevented either by rehydration and subsequent slow redrying or incomplete rapid drying followed by slow drying. It is suggested that R. meliloti strains are susceptible to desiccation stresses. However, the quantitative differences among strains appear to be large enough to permit selection with regard to tolerance to desiccation and storage in dried states.     

米蛾卵繁育的螟黄赤眼蜂的适宜冷贮温度和虫龄

为了全面评价冷贮对米蛾Corcyra cephalonica Stainton卵繁育螟黄赤眼蜂Trichogramma chilonis Ishii的影响, 本试验采用米蛾卵为寄主, 以冷贮温度（3和10℃）、 冷贮虫龄（以接蜂开始时间为起点, 接蜂后1, 2, 3, 4, 5, 6, 7, 8和9日龄）和冷贮时间（1, 2, 3和4周）为试验因子, 研究了冷贮对螟黄赤眼蜂活蛹率、 羽化率和畸形率的影响。结果表明： 3个因素均能单独或互作显著影响活蛹率、 羽化率和畸形率（P＜0.05）。综合各冷贮虫龄对低温的反应, 螟黄赤眼蜂对3℃较敏感, 此温度下1-3日龄的活蛹率和各虫龄的羽化率均显著下降（P＜0.05）, 不适宜长期冷贮; 10℃下各虫龄的活蛹率受冷贮时间的影响不显著, 1-3日龄的羽化率受冷贮时间的影响也不显著, 冷贮4周后仍有74%以上的羽化率, 10℃适宜冷贮。不同冷贮温度下冷贮适宜虫龄不同。在10℃下, 最适冷贮虫龄是3日龄的赤眼蜂, 此虫龄不同冷贮时间的活蛹率（74.09%～77.59%）和羽化率（74.26%～90.37%）均与对照无显著差异（P>0.05）, 但显著高于其他虫龄（P＜0.05）。此虫龄在10℃下冷贮1~3周, 畸形率在27%以内。结果表明米蛾卵内螟黄赤眼蜂不同冷贮温度下适宜冷贮虫龄不同。     

The effect of organ preservation on polysomal messenger RNA

Organ preservation decreases polysomal RNA⁺-poly(A) in mouse kidneys. Warm storage at 37 °C markedly decreased the total polysomal RNA. Moreover, the percentage of ³H-polysomal RNA⁺-poly(A) is decreased 24.1% after 1 hr. Cold storage does not decrease the amount of polysomal RNA, but the decrease in the ³H-polysomal RNA which is poly(A)⁺ was diminished 83.7% after 48 hr of cold storage.