Cyanide-initiated oxygen consumption in autoclaved culture medium containing sugars

The consumption of oxygen initiated by KCN in an autoclaved sugar-containing rinse medium with protoplasts is described. The effect of autoclaving on several sugars was examined. Fructose solutions, followed in decreasing order by glucose, sucrose and sorbitol, were found to contain the largest amount of degraded products that could react with oxygen in the presence of KCN. Mannitol was found to be stable under the autoclaving conditions used in this investigation. KCN generally has an inhibitory effect on respiration, but in some plant tissues, respiration is stimulated by it. Under certain circumstances the degradation artefact described here may confuse interpretation of the results of respiration measurements. The use of autoclaved media containing sugars should be avoided in respiration studies that involve the application of KCN.Abbreviations SHAM salicylhydroxamic acid     

Sugar production from agricultural woody wastes by saccharification with Trichoderma viride cellulase.

The saccharification of agricultural woody wastes was studied using a commercial enzyme preparation, Cellulase onozuka, derived from Trichoderma viride or the solid culture extracts of the fungus. With the intention of producing sugar at low cost, a simple procedure of enzymatic saccharification of rice straw, bagasse, and sawdust was studied. Delignifying methods of these wastes were investigated using dilute sodium hydroxide solution and dilute peracetic acid. Rice straw and bagasse were effectively delignified by boiling in a 1% sodium hydroxide solution for 3 hr or by autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr. The sawdust from a broad leaved tree (Machilus thunbergii) was delignified by autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr and by subsequent boiling in diluted 1/5 peracetic acid for 1 hr. This type of sawdust was also delignified by boiling in 1/5 peracetic acid for 1 hr and by subsequent autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr. The sawdust from a coniferous tree (Cryptomeria japonica) was delignified by boiling in 1/5 peracetic acid for 1 hr and by subsequent autoclaving at 120 degrees C in a 1% sodium hydroxide solution for 1 hr; however, the successive treatment by autoclaving with alkali solution and subsequent boiling with diluted peracetic acid failed to bring about the desired effect. The saccharification of delignified rice straw, bagasse, and sawdust was examined using Cellulase onozuka, wheat bran or rice straw solid culture at various substrate concentrations, resulting in the formation of 5 to 10% sugar solutions after incubation at pH 5.0, 45 degrees C for 48 hr. The optimum substrate concentration existed at around 10%. Reuse of cellulase solution and resaccharification of residual sawdust were considered to be inadequate.     

弗里熊蜂蜜罐中糖液成分分析

【目的】熊蜂是众多植物的重要传粉昆虫,以采集并贮藏花蜜和花粉为主要食物。本研究旨在探究熊蜂的营养需求及明确其对采集的食物是否存在酿制过程。【方法】利用白砂糖溶液(糖浓度50%)饲喂弗里熊蜂Bombus friseanus蜂群,收集并检测其贮藏在蜜罐中1~7 d的糖液,作为处理组样品;同时将上述白砂糖溶液置于灭菌离心管中,排除熊蜂取食,作为对照组样品,测定贮藏期间处理组和对照组糖液的pH值、糖浓度、糖组分及α-淀粉酶和转化酶活性。【结果】弗里熊蜂B. friseanus贮藏在蜜中1~7d的糖液pH值平均为3.74±0.13,显著低于对照组(6.55±0.15);糖浓度与贮藏时间显著正相关,贮藏6d后糖浓度显著高于贮藏1~3 d时的;糖液组分更加丰富,除蔗糖外利用HPLC还检出果糖、葡萄糖、麦芽糖和海藻糖,贮藏4~5 d的糖液中己糖含量极显著高于贮藏1~3 d和6~7 d时的,己糖和麦芽糖含量分别与蔗糖含量极显著负相关,总糖中果糖和麦芽糖含量与贮藏时间极显著负相关,葡萄糖、蔗糖和海藻糖的含量分别与贮藏时间极显著正相关。贮藏6 d的糖液中α-淀粉酶活性显著高于其他时间,其他贮藏时间样品间α-淀粉酶活性差异不显著,而所有样本的转化酶活性在21.17~38.05 U/g FW之间,随贮藏时间的延长差异不显著。【结论】弗里熊蜂B. friseanus采集人工饲喂的糖溶液贮藏在蜜罐中,经其加工后发生了物理和生物化学变化,揭示熊蜂存在酿蜜能力。本研究的结果为熊蜂生物学及繁育研究提供了参考。     

Agarose soy casein digest medium for replacement of blood agar for potency determinations of live Pasteurella vaccines

Blood agar, prepared with Trypticase (BBL Microbiology Systems, Cockeysville, Md.) soy agar and 5% defibrinated bovine blood, is used for testing the potency of live Pasteurella multocida and Pasteurella haemolytica vaccines, but its potential for variation makes it undesirable to use in a standard assay method. Tests done with RPMI 1640 and Trypticase soy medium indicated that the benefits obtained by adding defibrinated blood to the Trypticase soy agar medium were more likely due to neutralization of toxic components than to the presence of transferrin or iron as growth factors. Reduction of toxic components in the Trypticase soy agar medium was accomplished by replacing agar with agarose and by autoclaving glucose as a separate solution to produce the replacement medium. The replacement medium was prepared by autoclaving three separate solutions--Trypticase soy broth without glucose; glucose; and agarose--cooling to 55 degrees C, and mixing and then pouring the mixtures into petri dishes. The growth obtained with this medium as judged by determination of the number of CFU and the colony sizes of P. multocida or P. haemolytica was equal to or better than those obtained with blood agar.     

Agarose soy casein digest medium for replacement of blood agar for potency determinations of live Pasteurella vaccines.

Blood agar, prepared with Trypticase (BBL Microbiology Systems, Cockeysville, Md.) soy agar and 5% defibrinated bovine blood, is used for testing the potency of live Pasteurella multocida and Pasteurella haemolytica vaccines, but its potential for variation makes it undesirable to use in a standard assay method. Tests done with RPMI 1640 and Trypticase soy medium indicated that the benefits obtained by adding defibrinated blood to the Trypticase soy agar medium were more likely due to neutralization of toxic components than to the presence of transferrin or iron as growth factors. Reduction of toxic components in the Trypticase soy agar medium was accomplished by replacing agar with agarose and by autoclaving glucose as a separate solution to produce the replacement medium. The replacement medium was prepared by autoclaving three separate solutions--Trypticase soy broth without glucose; glucose; and agarose--cooling to 55 degrees C, and mixing and then pouring the mixtures into petri dishes. The growth obtained with this medium as judged by determination of the number of CFU and the colony sizes of P. multocida or P. haemolytica was equal to or better than those obtained with blood agar.     

Quantitative Analysis of Sugars in Plant Extracts by Ion-exchange Chromatography,with Special Reference to the Examination of Conditions for Preparing the Sample Sugar Solutions

Critical examinations were made on the conditions for preparing the sugar solutions to be analyzed by ion-exchange chromatography of sugar-borate complexes by the method of Khym and Zill. A procedure was proposed which gave the best recovery of sugars with minimum hydrolysis of sucrose. By means of this procedure, sugar solutions were prepared from potato tubers which had been stored at a high (30°C) or low temperature (6°C). Results of the chromatographic separation and determination of component sugars showed that main sugars present in potato tubers were sucrose, glucose, and fructose. Maltose and pentoses could not be detected. The contents of sucrose, glucose, and especially, fructose were far greater in potatoes stored at a low temperature than in those stored at a high temperature.     

Calorimetric and molecular simulation study on unfrozen water characteristics in aqueous sugar solutions: implications for biopreservation

Intensive studies have been conducted to determine the protective mechanisms of sugars that have proven beneficial to the biopreservation application. However, little has been known about the unfrozen water content that aqueous sugar solutions can possess when frozen at cryogenic temperatures. This study conducted calorimetric measurements to determine the unfrozen water content in frozen aqueous solutions of glucose, fructose, sucrose and trehalose of multiple concentrations. The hydrogen-bonding network in these solutions was characterised by molecular simulations. The experimental results showed that more water could be prevented from ice crystallisation in a more concentrated solution. Disaccharides, especially trehalose, are more effective than other protectants (e.g., glucose, glycerol and dimethyl sulfoxide) for detaining water in the unfrozen state. Moreover, it was found that, at molecular levels, there were more hydrogen bonds between sugar and water molecules in a more concentrated solution. From both macro- and microscopic perspectives, trehalose was demonstrated to be a much more effective cryoprotectant than others. This comparative study proved that the unfrozen water should be mainly attributed to hydrogen bonds between sugar and water in the mixture. Our findings will provide valuable information for determining the physical state of cryopreserved biomatrix and guiding the preparation of protective formulations.     

Further improvement of the ACD-AG protective solution for blood. III. Improvement of the oxygen transport function of erythrocytes in sorbitol xylitol pyruvate solutions with elevated Ph]

If the pH value in the ACD or in the ACD-AG storage solution is enhanced, the glucose in the autoclaving with undergo a caramelizing process. For this reason glucose was replaced by sorbite in the storage solutions with a pH value of 6.0 and additions of xylitol and pyruvate. The initial pH value in the blood amounted to 7.3. The content of 2.3 DPG of the erythrocytes remained fully preserved in the blood with sorbitol and additions of xylitol and pyruvate during the first 2 weeks of storage and decreased to 30% only in the third week. There were only slight amounts of 2.3 DPG in the ACD-AG blood at that time of storage. Up to the third week of storage the ATP content of erythrocytes as well as the haemoglobin level in the plasma revealed no essential differences between stored blood with sorbitol and xylitol as a substrate or glucose + xylitol respectively. The quick decrease of the ATP level to zero and the simultaneous strong increase of haemolysis in the sorbitol blood within the fourth week of storage is discussed in connection with a lowering of the NAD/NADH2 quotient. For the purpose of keeping the 2.3 DPG level of erythrocytes a storage solution with sorbite and xylitol (ASCX-AG-Pyr 10mM) seems to be well suited for a storing time of 2---3 weeks at first.     

Effects of autoclave-induced carbohydrate hydrolysis on the growth ofBeta vulgaris cells in suspension

Media of de Greef & Jacobs (1979) were autoclaved either with all the nutrient components in a single vessel (medium 1) or with the following components in separate vessels: FeNa–EDTA+CaCl₂ (medium 2), FeNa–EDTA+NaH₂PO₄ (medium 3) or sucrose (medium 4). Medium 5 was prepared by autoclaving FeNa–EDTA+NaH₂PO₄ and sucrose in two separate vessels. It was found that the dry mass yield of cell suspensions ofBeta vulgaris was lowest in medium 1, followed by media 2 and 3. There was no significant difference among media 3, 4, and 5.The plot of dry mass yield of the cell suspensions against the rates of cyanide-initiated oxygen consumption which indicate the extent of carbohydrate hydrolysis of the media during autoclaving, indicated the presence of a threshold rate of about 17–20 nmol ml^–1 min^–1. Dry mass yield of the suspensions decreased rapidly when the rate exceeded this value.For media with glucose as the source of carbohydrate, the rate of cyanide-initiated oxygen consumption exceeded the threshold value by a factor of 1.5 to 2, depending on the volume of the media autoclaved.Abbreviations FeNa-EDTA ferric monosodium ethylenediamine-tetraacetic acid     

Sugar Absorption and Surface Carbohydrase Activity of Peltigera polydactyla (Neck.) Hoffm.

A method suitable for the study of the physiology of absorptionof substances from solution and of respiration of Peltigerapolydactyla was elaborated making use of discs of tissue whichcould be floated on solutions. The rate of absorption of hexosesugars by the discs was sensitive to temperature, the presenceof inhibitors, such as sodium fluoride and silver nitrate, butrelatively insensitive to hydrogen ion concentration. Glucosewas absorbed preferentially to fructose from equimolar solutions.Absorption of sugar from sucrose solutions involved inversionby an enzyme system held on the cell surface. This system wasrelatively unaffected by exposure to moderate temperature, tosodium fluoride or silver nitrate but sensitive to hydrogenion concentration. Sucrose did not seem to be absorbed as suchand the glucose was absorbed preferentially from the productsof inversion. All parts of the thallus were equally effectivein inversion but absorption was mainly into the algal layer.The entry into the tissues was associated with a respiratoryrise.     

De-icers derived from corn steep water

Corn steep water (CSW) and other byproducts derived from fermentations and sugar productions are presently forming the base of compositions for de-icing and anti-icing materials. Since the de-icing and anti-icing values are in part a colligative property, increase in the molar concentration of ionic species has been frequently necessary to decrease further the freezing point of this byproducts stream. In the present study this has been achieved by the generation of biodegradable organic acid salts in situ, without the use of chloride or other inorganic salts, by the alkaline degradation of reducing sugars added to corn steep water, which alone is not an efficient de-icer. Reducing sugars, such as glucose, react with alkali metal hydroxides to produce principally hydroxy carboxylic acids that react with the alkali metal hydroxide to form a mixture of organic acid salts. The ionic strength of the resulting solution is increased since each sugar molecule produces nearly two acid molecules upon degradation. The ionic strength necessary to achieve the desired freezing point depression is determined by the amount and concentration of the alkali metal hydroxide used, with the necessary counter anions being derived from the degradation of the reducing sugar. The amount of the sugar used is that required to result in a near to neutral final solution. The well-known anti-corrosive property of CSW is used in the de-icer preparations, either by conducting the alkaline degradation of the sugar in this medium, or by using water for the degradation of the sugar followed by dilution of the resulting solution with CSW to adjust the viscosity of the final solution to meet the requirements for spraying. The monovalent metal hydroxides are more efficient in producing de-icer solutions than the divalent metal hydroxides.     

Calorimetric study of the thermal denaturation of beta-lactoglobulin in the presence of urea and phosphate ions]

The denaturation of beta-lactoglobulin in solution with different content of urea and phosphates has been studied calorimetrically. It has been shown that the increase of phosphate ion concentration in solution leads to an increase of beta-lactoglobulin stability, while increase of urea concentration leads to an opposite effect. The variation of these components in solution practically does not influence the value of the heat capacity increment of beta-lactoglobulin in the considered temperature region. Accordingly the denaturation enthalpy is a linear function of temperature whose slope does not differ for solution with urea concentration less than 4.4 M. However, the absolute value of denaturation enthalpy in these solutions at corresponding temperatures differs significantly due to the heat effect of additional urea solvation during transition to the denatured state. The latter leads to a decrease of the overall denaturation enthalpy and, as a result, a shift of the enthalpy plot to higher temperatures providing conditions for studying the thermodynamic and structural characteristics of the molecule in the cold denatured-state.     

Osmotic stress on dilution of acid injured Escherichia coli O157:H7

To determine surviving numbers of Escherichia coli from cultures or food systems, dilution with 0.1% peptone is regularly used. Higher numbers of survivors could be obtained from an acid-treated culture if 0.5 mol l-1 sucrose was added to the 0.1% peptone. Sorbitol, glucose or sodium chloride, but not glycerol, could be used in place of sucrose. Using electron microscopy distinct differences could be seen between acid-treated and untreated cells. The osmolarity of the diluents ranged from 5 to 500 mosmol kg-1 H2O for the 0.5 mol l-1 sugar or glycerol solutions, to about 1000 mosmol kg-1 H2O for the salt solution. Maximum recovery diluent has an osmolarity of about 300 mosmol kg-1 H2O and resulted in recovery of similar numbers of injured cells as a 0.5 mol l-1 solution of sugar in 0.1% peptone. Taking into account the observed damage to acid-treated cells and the differences in osmolarity of the diluents, it is likely that dilution in 0.1% peptone imposed additional stress on the acid-injured cells which caused further cell damage. Dilution in a more osmotically stable solution alleviated this osmotic stress.     

再水合溶液能有效改善急性脱水女举重运动员的运动表现

本研究旨在探讨女子举重运动员急性脱水后口服4种不同组成的溶液,对液体存留率、胃肠道舒适度、血液值和无氧动力的影响。本研究以12位大学生女子举重运动员为对象,采交叉、平衡次序设计;研究参与者于脱水2%体重后分别补充相当于1.5倍脱水量的低渗透压电解质液(HES)、等渗透压电解质液(IES)、运动饮料(SB)或纯水(W),补充时间为脱水后立即、再水合期的30 min、60 min及90 min。再水合期间记录胃肠舒适分数、测量体重(计算液体存留率),并采集静脉血以测量血液渗透压、葡萄糖及钠、钾与氯离子,于脱水前与再水合期120 min时进行Wingate无氧动力测验。研究结果显示:补充HES、IES及运动饮料(SB)于再水合期90 min时的胃肠道舒适分数显著低于补充纯水(W)、而补充3种溶液于再水合期60 min时的血糖值则显著高于补充纯水(W),补充HES于再水合期120 min时的血钾值显著高于补充运动饮料(SB)及纯水(W);但补充4种溶液后的无氧动力与液体存留率并无显著差异。本研究证实举重运动员急性脱水后补充4种不同口服再水合溶液并不会影响再水合后的无氧动力,但补充含有糖类及电解质的溶液能有较佳的胃肠道舒适度,并血糖与血液电解质有维持的效果。     

Filter Mud as a Carrier for Rhizobium Inoculants

Laboratory tests indicated that filter mud, a waste product from sugar cane mills, proved to be a suitable carrier for Rhizobium inoculants, provided it was not dried by heating. Autoclaving air dried material was not detrimental and ensured high survival when held at room temperature. The adverse effect of oven drying, which was increased by subsequent autoclaving or gamma irradiation, lessened with time.     

Factors contributing to inactivation of isolated thylakoid membranes during freezing in the presence of variable amounts of glucose and NaCl.

During freezing of isolated spinach thylakoids in sugar/salt solutions, the two solutes affected membrane survival in opposite ways: membrane damage due to increased electrolyte concentration can be prevented by sugar. Calculation of the final concentrations of NaCl or glucose reached in the residual unfrozen portion of the system revealed that the effects of the solutes on membrane activity can be explained in part by colligative action. In addition, the fraction of the residual liquid in the frozen system contributes to membrane injury. During severe freezing in the presence of very low initial solute concentrations, membrane damage drastically increased with a decrease in the volume of the unfrozen solution. Freezing injury under these conditions is likely to be due to mechanical damage by the ice crystals that occupy a very high fraction of the frozen system. At higher starting concentrations of sugar plus salt, membrane damage increased with an increase in the amount of the residual unfrozen liquid. Thylakoid inactivation at these higher initial solute concentrations can be largely attributed to dilution of the membrane fraction, as freezing damage at a given sugar/salt ratio decreased with increasing the thylakoid concentration in the sample. Moreover, membrane survival in the absence of freezing decreased with lowering the temperature, indicating that the temperature affected membrane damage not only via alterations related to the ice formation. From the data it was evident that damage of thylakoid membranes was determined by various individual factors, such as the amount of ice formed, the final concentrations of solutes and membranes in the residual unfrozen solution, the final volume of this fraction, the temperature and the freezing time. The relative contribution of these factors depended on the experimental conditions, mainly the sugar/salt ratio, the initial solute concentrations, and the freezing temperature.     

Formation of Psicose from Glucose in Autoclaved and Uninoculated Fermentation Media

When a fermentation medium consisting of the high concentration of K₂HPO₄ and KH₂PO₄ and glucose as a sole carbon source is autoclaved in the alkaline side, an unknown sugar is formed. This sugar is identified as psicose by paper chromatography and high-voltage paper electrophoresis. The notion that weak alkali causes the isomerization of reducing sugar could account for the formation of psicose in the medium. It is thus concluded that psicose is chemically formed from glucose in the alkaline side and in the high concentration of K₂HPO₄ and KH₂PO₄ during autoclaving.     

Effect of luminal Na+ on the kinetics of intestinal absorption of sugars in vivo

The effect of sodium concentration on the absorption kinetics of glucose, galactose and 3-o-methyl-glucose in rat and hamster jejunum in vivo has been studied. In consecutive 1 min periods the total absorption and absorption in presence of 0.5 mM phlorizin were measured. The difference between them was taken as the active transport rate. The perfusion rate value was 5.6 ml X min-1 and sugar concentrations in the perfusion solution ranged from 1 to 10 mM. The results for the different sodium concentrations show a nearly common Vmax for the same sugar and animal species, while the apparent KT values increase when the sodium concentration in the lumen decreases, mimicking a pure affinity-type activation system. The absorption of sugar when solutions without Na+ are perfused, is greater than that entering passively in the presence of phlorizin. An explanation may be that appreciable amounts of endogenous Na+ find their way to the intestinal lumen in favour of the gradient, making Na+-sugar cotransport possible.     

小地老虎食诱剂糖醋酒液配方筛选及发酵增效作用

【目的】为筛选和规范诱集小地老虎Agrotis ipsilon成虫的最佳糖醋酒液配方及最佳发酵时间,确定发酵液中的挥发物成分。【方法】优选以单一纯物质糖、醋、酒和水进行混配的配方A, B, C和D, 其配比分别为蔗糖(g)∶乙酸(mL)∶无水乙醇(mL)∶纯水(mL)(m/v/v/v)=3∶1∶3∶80, 3∶1∶3∶160, 3∶1∶6∶80和1∶1∶3∶80及常见配方E［白糖(g)∶白醋(mL)∶白酒(mL)∶自来水(mL)= 6∶3∶1∶10(m/v/v/v)］,分别并采用Y型嗅觉仪及GC-MS测试和分析小地老虎成虫对发酵1~15 d后的糖醋酒液的趋性及发酵液中的挥发物成分。【结果】趋性试验结果表明,糖醋酒液B配方对小地老虎诱集效果显著优于A, C, D和E配方,C配方次之。小地老虎成虫对B和C这两种配方发酵8 d发酵液的选择反应率均显著高于对未发酵及发酵5 d和7 d外的其他发酵时间发酵液的选择反应率。挥发物成分组成分析结果显示,糖醋酒液B配方发酵8 d发酵液的挥发物共有41种化合物,主要包括17种烃类化合物、8种醛类化合物、2种酮类化合物、4种醇类化合物、5种酯类化合物和5种醚类化合物。而且发酵8 d的糖醋酒液B配方与其未发酵以及发酵4 d和发酵12 d的糖醋酒液B配方之间的挥发物成分差异较大。【结论】优选并明确单一物质糖、醋、酒和水进行混配的小地老虎食诱剂配方(3∶1∶3∶160, m/v/v/v),其糖醋酒液通过发酵可以产生增效作用,最佳发酵时间为8 d。     

Exploration of biodegradation traits in dairy cows and protein spectroscopic features in microwaved and moist heated tannin and non-tannin Faba bean

The objective of this study was to explore if microwave irradiation and moist autoclaving treatments could change nutritive values, nutrients availability and protein inherent spectral structural characteristics in tannin (var. Fatima) and non-tannin (var. Snowbird) faba beans. An in situ approach with four cannulated dry Holstein dairy cows was applied in this study. The results showed that beans heated with microwave and autoclaving had increased contents of ether extract and neutral detergent insoluble CP and reduced soluble CP, sugar and tannin concentrations when compared with the raw seeds. Heating reduced degradable nutrients in the rumen and increased intestinally absorbable nutrients, but it failed to improve digestibility in total tract. All the results showed heating with moisture and pressure would be stronger and severer than microwave irradiation. The variety of faba bean interacted with thermal treatment on total truly intestinally absorbed protein value which showed to be highest in the microwaved brown faba bean and lowest in the unheated Snowbird bean. The degraded protein balance (OEB) value was significantly decreased after both kinds of heating process, suggesting that heating treatments could mitigate loss of nitrogen from the rumen to a large extent. We further collected spectral data using mid-IR spectroscopy and found heat processed beans had varied peak height and area ratios compared with raw beans. However, multivariate results implied that heating process failed to completely change the whole molecular conformation in the protein amide region. Correlations were found between ADF/ADL and spectral features, and the OEB value was negatively related to protein secondary structural α-helix. In conclusion, both faba beans were more sensitive to autoclaving treatment than microwave irradiation in terms of nutrient availability in ruminants.