Effects of Inulin Chain Length on Fermentation by Equine Fecal Bacteria and Streptococcus bovis

Grass fructans can be fermented by Gram-positive bacteria (e.g., Streptococcus bovis) in the equine hindgut, increasing production of lactic acid and decreasing pH. The degree of polymerization (DP) of fructans has been suggested to influence fermentation rates. The objective of the present study was to determine how DP impacts fermentation by equine fecal bacteria and a model S. bovis. Fecal microbes from three mares were harvested by differential centrifugation, washed, and resuspended in anaerobic media containing short-chain (SC; DP ≤ 10) or long-chain (LC) inulin (DP ≥ 23) from 0% to 2% wt/vol. After 24 hours of incubation (37°C), samples were collected for pH determination. Data were analyzed using the general linear models (GLM) procedure testing for the effect of treatment, concentration, and treatment × concentration (SAS v. 9.3). At all concentrations, the pH was lower in SC fermentations than in LC (P < .0001, in all cases). To determine the effect of DP on S. bovis, cultures were grown (39°C, 9 hours) with 0.1%, 0.5%, or 1.3% SC or LC inulin. Optical density (600 nm) was determined by spectrophotometry. Maximum specific growth rates (μ) were determined by linear regression (2–5 hours). Data were analyzed using the one-way analysis of variance procedure (SAS v. 9.3). The final optical density (600 nm), μ, and yield were higher with SC than with LC fermentation (P < .05). These results indicate that SC inulin may be more available for fermentation than LC inulin by equine fecal bacteria and S. bovis, specifically.     

刈割处理和收获时间对菊苣根中菊粉产量的影响

采用裂区设计进行试验,研究刈割处理和收获时间对菊苣根中菊粉产量的影响。结果表明:适度的刈割使菊苣根中菊粉产量显著增加,刈割2次的最大产量为144.4±11.8 g/m2,比不刈割的91.5±9.81g/m2提高了57.8%。过度刈割又使其下降,刈割3次的最大产量为104.4±7.86 g/m2,比刈割2次的144.4±11.8 g/m2降低了38.3%。刈割作用下菊苣根中菊粉产量与收获时间呈显著二次曲线关系。     

半干旱地区海涂海水灌溉对不同品系菊芋产量构成及离子分布的影响

在半干旱海涂以不同品系菊芋（Helianthus tuberosusL．）为材料进行田间试验，研究了海水灌溉对不同品系菊芋产量构成及离子分布的影响。结果表明：（1）南芋2号根和地上部生物量较其他品系大，南芋5号和南芋3号株高在各浓度海水灌溉下均显著高于其他菊芋品系，而茎粗在各处理下变化不一致，在30％海水灌溉下，南芋1号根和地上部物质积累未受到抑制作用，其他各品系菊芋的根和地上部物质积累受到了一定抑制。（2）各菊芋品系块茎产量差异较显著，在30％海水灌溉下，南芋2号产量显著高于其他品系，各菊芋品系块茎单重在各处理下差异也较显著，南芋1号和2号块茎单重最大，各菊芋品系块茎总糖和菊糖含量差异较显著。（3）随海水浓度的增加，各品系菊芋根、茎和叶的C1-和Na^＋含量均增加，但品系间差异较显著，叶片的Na’含量显著低于根和茎的Na’含量。从生物积累量和块茎产量、总糖和菊糖含量及离子分布看，南芋1号和南芋2号较其他品系更适合在半干旱海涂利用适当浓度海水进行灌溉种植。     

菊苣菊粉水解工艺的研究

[目的]为菊苣菊粉水解的生产实践提供理论依据。[方法]以普那菊苣为材料,单因素试验研究水解时间、水解温度、硫酸浓度(体积分数)对菊粉果糖转化率的影响,正交试验结合方差分析确定菊粉水解的最优工艺参数,并进行验证。[结果]单因素试验结果表明,随着水解时间的延长、水解温度的升高和硫酸浓度的增大,果糖转化率均呈先增加后降低的趋势,分别在水解时间60min、水解温度70℃和硫酸浓度3%时达到峰值。各因素对果糖转化率的影响程度由大到小依次为:水解时间>硫酸浓度>水解温度。[结论]菊苣菊粉水解的最优工艺为:菊苣菊粉浓度15%,水解时间65min,水解温度65℃,硫酸浓度3.5%,该工艺条件下,果糖的平均转化率为91.62%。     

不同盐浓度对菊苣中菊粉含量的影响

[目的]探讨盐浓度对菊苣中菊粉含量的影响。[方法]以荷兰菊苣为材料,用Hoagland营养液配制的盐浓度为0.5%、1.0%、1.5%、2.0%、2.5%、3.0%的固体海水分别处理菊苣7 d,采用紫外分光光度法测定各盐浓度处理菊苣根和茎叶中菊粉含量,确定菊粉含量最高的盐浓度。[结果]随着盐浓度的提高,菊苣中菊粉含量呈先上升后下降的趋势,1.5%的盐浓度处理下菊粉含量最高,茎叶中菊粉含量为15.02 mg/g,根中菊粉含量为29.01 mg/g。[结论]研究结果为实施江苏沿海开发国家战略中有效开发利用盐碱滩涂奠定了基础。     

The effect of dietary crude protein concentration and inulin supplementation on nitrogen excretion and intestinal microflora from finisher pigs

A 2 × 2 factorial experiment was used to investigate the interaction between dietary crude protein (CP) concentration (200 vs 140 g/kg) and inulin supplementation (0 vs 12.5 g/kg) on nitrogen (N) excretion and intestinal microflora from 16 boars (n = 4, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high CP diets had a higher excretion of urinary N (P < 0.01), faecal N (P < 0.01) and total N (P < 0.001) than the pigs offered the low CP diets. Inulin supplementation increased faecal N excretion (P < 0.05) and decreased urine: faeces N ratio (P < 0.05) compared to the inulin free diets. There was no significant effect (P > 0.05) of dietary treatment on N retention. There was an interaction (P < 0.05) between dietary CP concentration and inulin supplementation on caecal E.coli. Pigs offered the diet containing 200 g/kg CP plus inulin decreased the population of E.coli compared to the inulin supplemented 140 g/kg protein diet. However, CP concentration had no significant effect on the population of E.coli in the unsupplemented diets. Inulin supplementation increased caecal bifidobacteria (P < 0.01) compared to the inulin free diets. In conclusion, inulin supplementation favourably altered N excretion and lowered the population of E.coli at high CP concentrations.     

In Vitro Gas Production from Batch Cultures of Stomach and Hindgut Digesta of Horses Adapted to a Prebiotic Dose of Fructooligosaccharides and Inulin

Fructooligosaccharides (FOS) and inulin may modulate hindgut fermentation. It was tested if digesta batch cultures taken from horses adapted to FOS and inulin show different fermentation compared with such taken from nonsupplemented horses. Six horses received 0.15 g FOS and inulin/kg body weight/d via Jerusalem artichoke meal (JAM) upon a hay-based diet; six horses received corncob meal without grains (CMG) as placebo. The horses were euthanized after 20 days. Digesta samples were taken from stomach, cecum, ventral colon ascendens (VCA), and colon transversum (CT). Digesta batch cultures were incubated 48 hours to measure in vitro gas production as well as pre- and post-incubation pH and oxidation-reduction potential (ORP). A distinct fermentation of the surplus of fructans present in the inoculum was found with JAM-adapted batch cultures. Gas production was accelerated in inoculated gastric contents of horses adapted to JAM compared with CMG adapted ones (7.8 vs. 16.4 hours to achieve half of the 48 hours gas quantity, respectively; P > .05). Although buffered, pH decreased during fermentation. Postincubation pH was lower with JAM than CMG-adapted batch cultures (P > .05). Preinoculation ORP was lower with stomach batch cultures adapted to CMG than with such adapted to JAM. The ORP increased twofold from pre- to post-incubation with the latter. Asymptotic maximal gas production decreased gradually using cecum, VCA, or CT digesta. Parts of FOS and inulin of digesta are fermented in the stomach, which reduce possible effects on hindgut fermentation. Elevated fermentation may considerably impact stomach health.     

A Single‐Blood‐Sample Method Using Inulin for Estimating Feline Glomerular Filtration Rate

Background

Application of a multisample method using inulin to estimate glomerular filtration rate (GFR) in cats is cumbersome.

Objectives

To establish a simplified procedure to estimate GFR in cats, a single‐blood‐sample method using inulin was compared with a conventional 3‐sample method.

Animals

Nine cats including 6 clinically healthy cats and 3 cats with spontaneous chronic kidney disease.

Methods

Retrospective study. Inulin was administered as an intravenous bolus at 50 mg/kg to cats, and blood was collected at 60, 90, and 120 minutes later for the 3‐sample method. Serum inulin concentrations were colorimetrically determined by an autoanalyzer method. The GFR in the single‐blood‐sample method was calculated from the dose injected, serum concentration, sampling time, and estimated volume of distribution on the basis of the data of the 3‐sample method.

Results

An excellent correlation was observed (r = 0.99, P = .0001) between GFR values estimated by the single‐blood‐sample and 3‐sample methods.

Conclusions and Clinical Importance

The single‐blood‐sample method using inulin provides a practicable and ethical alternative for estimating glomerular filtration rate in cats.     

微波法提取菊芋中菊糖的工艺研究

[目的]优选菊芋中菊糖的微波提取工艺。[方法]以新鲜的菊芋块茎为原料,在单因素试验的基础上,以微波功率、提取时间、料液比、提取次数和提取温度为因素,设计5因素4水平的正交试验L16(45),研究菊糖的提取及其分离纯化的最佳工艺条件。[结果]确定微波法提取菊糖的最佳工艺条件为:微波时间8 min,提取温度95℃,微波功率500 W,料液比为1∶20(W/V,g/ml,下同),提取3次;在此条件下,菊芋菊糖的提取率为68.11%。[结论]该方法优选出了菊芋中菊糖的微波提取工艺,结果准确可行。     

DSC法测定菊粉对油脂抗氧化性的研究

[目的]研究菊粉对油脂的抗氧化效果,为替代市场上人工合成抗氧化剂提供参考。[方法]通过差示扫描量热法(DSC)试验确定了添加不同抗氧化剂(0.1%菊粉+猪油、0.1%TBHQ+猪油、0.05%菊粉+0.05%VC+猪油)对猪油的抗氧化效果。[结果]特丁基对苯二酚(TBHQ)的抗氧化效果小于菊粉,而菊粉的抗氧化效果比VC和菊粉协同作用稍差。[结论]菊粉对油脂有一定抗氧化效果,是一种较好的食用油抗氧化剂。