Cadaverine production by Azospirillum brasilense and its possible role in plant growth promotion and osmotic stress mitigation     

Fabricio Cassán  Santiago Maiale  Oscar Masciarelli  Alfonso Vidal  Virginia Luna  Oscar Ruiz 《European Journal of Soil Biology》2009,45(1):12-19

Polyamines are considered as plant growth regulating compounds; among them, cadaverine has been correlated with root growth promotion or osmotic stress mitigation in some plant species. The purpose of this study was to evaluate the capacity of bacterial Azospirillum brasilense Az39 strain to produce cadaverine in chemically defined medium and inoculated plants, and to correlate this capacity with root growth promotion or osmotic stress mitigation in hydroponics conditions. To evaluate cadaverine production in chemically defined medium A. brasilense Az39 was cultivated aerobically at 30 °C and 80 rpm in NFb medium or NFb-l supplemented with the precursor l-lysine. To evaluate the bacterial cadaverine production and growth promotion in plants, rice (Oryza sativa L.) cv. El Paso 144 seedlings were inoculated and hydroponically cultured under optimal conditions in growth chamber. In both, cadaverine was identified and quantified by dansyl-derivative method using a fluorescence-HPLC system, and lysine decarboxylase (LDC) activity was determined by ¹⁴CO₂ production in a closed tube system fed with [¹⁴C]-lysine. To evaluate the possible role of bacterial cadaverine in osmotic stress conditions, abscisic acid (ABA) production was analyzed in rice seedlings hydroponically cultured under 0 (no stress), ?0.47 (stress) or ?0.82 (severe stress) MPa osmotic potential generated by mannitol, with the addition of 1 nM or 1 μM cadaverine or A. brasilense Az39 inoculation. Our results indicate that A. brasilense Az39 promoted root growth and helped mitigate osmotic stress in rice seedlings, due in part to cadaverine production.  相似文献   

The enhancement of bioactive potential in Vitis vinifera leaves by application of microspheres loaded with biological and chemical agents     

Marko Vinceković  Luna Maslov Bandić  Slaven Jurić  Nenad Jalšenjak  Ana Čaić  Irena Živičnjak 《Journal of plant nutrition》2019,42(6):543-558

An overview of a research on Vitis vinifera plants treated with a chemical (calcium and magnesium ions) and biological (Trichoderma viride) agents simultaneously loaded in alginate microspheres was presented. Microspheres were applied at two growth stages: before flowering and berries pea-size. Physicochemical characteristics of leaves after the two growth stages and grapes were measured in terms of bioactive components content and antioxidant activity. After the treatments, vine leaves reached a significant increase in almost all measured parameters (polyphenols, antioxidant capacity, β-carotene, and chlorophyll) compared to the control. The highest total chlorophyll content was found after the treatment with microspheres containing Mg²⁺/Ca²⁺ cations, and T. viride. The treatments enhanced Vitis vinifera leaves in terms of bioactive potential and can be further used as a functional food. As compared to the control, somewhat elevated values of total polyphenols and antioxidant activity were found on the grape samples.  相似文献   

Modeling the Requirements of Agricultural Limestone in Acid Sulfate Soils of Brazil and Colombia     

Enrique Combatt Caballero  Alfredo Jarma Orozco  Manuel Palencia Luna 《Communications in Soil Science and Plant Analysis》2019,50(8):935-947

The aim of this study was to model the determination of the amount of agricultural limestone necessary to correct acidification in acid sulfate soils (ASS). This study used 14 equations and the chemical variables of the soils including pH, soil organic matter (SOM), potential acidity (H+ Al), sum of bases (BS), potential acidity (T), base saturation (V) and exchangeable Al with KCl. The results indicated that in the studied, the lowest requirements for doses of limestone (DL) were described by the equations DL = 2.906((H+ Al) (45-V)/100)°⁸⁰, DL = 0.08 + 1.22Al_KCl, DL = 0.6T – BS, and DL = 1.5Al_KCl, with mean values of 29.5, 30.5, 31.5 and 37.4 t ha^?1. In addition, the models with the best correlation for determining the limestone requirements to obtain 80% of the maximum production of sorghum (dry matter) were DL = ?1.43 + 0.9237 (SOM (6-pH)) and DL = ?0.022 + 2.7425 ((H+ Al) (45-V)/100).  相似文献   

Effect of light limitation on the water quality,bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity          下载免费PDF全文

Héctor M Esparza‐Leal  Ely S López‐Álvarez  Jesús T Ponce‐Palafox  Josué A Melendrez‐Soto  Marco A Medina‐Astorga  Antonio Luna‐González  Wenceslao Valenzuela‐Quiñónez  Píndaro Álvarez‐Ruiz  Gerardo Rodríguez‐Quiroz 《Aquaculture Research》2017,48(8):4371-4379

The aim of this study was to evaluate the effect of light limitation on the water quality, bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity (≈9 g L^?1). Two treatments were designed: T₁ = culture with natural sunlight and T₂ = culture in darkness. After 28 days, in both treatments, the final weight of shrimp was over 0.6 g with a specific growth rate over 7.4% d^?1, and a survival rate over 70%. In both treatments, Vibrio sp. concentration presented low values (culture with natural sunlight = 0.1 to 9.9 × 10² CFU mL^?1, culture in darkness = 0.4 to 11.7 × 10² CFU mL^?1) and Bacillus sp. had high values (culture with natural sunlight = 0.7 to 66.0 × 10⁴ CFU mL^?1, culture in darkness = 0.7 to 65.8 × 10⁴ CFU mL^?1). All water quality parameters remained within the ranges suitable for shrimp culture, except for alkalinity during the first stage of the study. Although in some sampling periods some significant differences were found in bacterial counts and water quality parameters, shrimp productive performance under culture with biofloc at low salinity was not affected significantly by light limitation.  相似文献   

Epidural anaesthesia using lignocaine, bupivacaine or a mixture of lignocaine and bupivacaine in dogs     

M. L. Cruz  S. P. L. Luna  R. M. O. Clark  F. Massone  G. B. Castro 《Veterinary anaesthesia and analgesia》1997,24(1):30-32

The time to loss of interdigital reflex, duration of action, duration of muscle relaxation and cardiorespiratory effects were compared after epidural block using lignocaine, bupivacaine or a combination of lignocaine and bupivacaine in dogs. Dogs were pre-medicated with methotrimeprazine, anaesthesia was induced with thiopentone, in order to facilitate epidural puncture, and a lumbosacral epidural block was performed. Body temperature fell after pre-medication, thiopentone and epidural anaesthesia. Minimal changes were observed in arterial O₂ saturation, end tidal CO₂, respiratory rate, heart rate and mean arterial blood pressure. The combination of bupivacaine with lignocaine produced a shorter time to loss of interdigital reflex than bupivacaine alone, longer analgesia than lignocaine alone and longer muscle relaxation than either lignocaine or bupivacaine. The combination appeared to be the best choice when surgical time is prolonged.  相似文献   

The impact of natural helminth infections and supplementary protein on growth performance of free-range chickens on smallholder farms in El Sauce, Nicaragua     

Skallerup P  Luna LA  Johansen MV  Kyvsgaard NC 《Preventive veterinary medicine》2005,69(3-4):229-244

Three on-farm studies were conducted in Nicaragua during three consecutive years (1999–2001) to assess the impact of natural helminth infections on growth performance of free-range chickens aged 3–4 months. On all participating farms, half of the chickens were treated regularly with anthelmintics (Trifén avícola – a combined formulation of piperazine, phenothiazine and dichlorophen – or albendazole) to express the growth potential of non-infected birds, whereas the other half served as non-treated controls. In 1999, treated chickens had a 39% higher weight gain compared to the control group 6 weeks after the first treatment on 15 farms. In 2000 and 2001, treated chickens had similar weight gain as the control group 10 weeks after the first treatment on 7 farms and 12 farms, respectively. The main reason for the very-different weight gain figures seems to be the weather conditions. In 1999, the study site experienced a rainy season with precipitation far above average, whereas in 2000 and 2001 the rainy seasons had precipitations far below average. Based on these findings, routine use of anthelmintics in the study area would only be recommended in wet years when production losses due to helminth infections seem to be pronounced.

In 2001, the study set-up included an assessment of the effect of protein supplementation (soybean) on growth on six farms. Supplemented chickens (treated and non-treated with anthelmintics) had 17% higher weight gain than non-supplemented. Protein supplementation affected neither worm burdens nor faecal egg counts for any of the studied helminths.

The post-mortem examinations showed that Trifén reduced burdens of Ascaridia galli, Heterakis gallinarum, and cestodes (efficacies of 100, 100 and 67%, respectively). Albendazole reduced burdens of H. gallinarum (efficacy of 100%). Efficacies against other helminths were difficult to assess due to low worm burdens. Chickens treated with albendazole had lower Ascaridia and Heterakis faecal egg counts than non-treated chickens.  相似文献   

Immune effects of four Fusarium-toxins (FB1, ZEA, NIV, DON) on the proliferation of Jurkat cells and porcine lymphocytes: in vitro study     

Severino L  Russo R  Luongo D  De Luna R  Ciarcia R  Rossi M 《Veterinary research communications》2008,32(Z1):S311-S313

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Mechanical nociceptive thresholds using four probe configurations in horses          下载免费PDF全文

Polly M Taylor  Nadia Crosignani  Carlize Lopes  Ademir C Rosa  Stelio PL Luna  José NP Puoli Filho 《Veterinary anaesthesia and analgesia》2016,43(1):99-108

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Is there a place for dexmedetomidine in equine anaesthesia and analgesia? A systematic review (2005–2017)          下载免费PDF全文

M. Gozalo‐Marcilla  F. Gasthuys  S. P. L. Luna  S. Schauvliege 《Journal of veterinary pharmacology and therapeutics》2018,41(2):205-217

The objective of this review was to perform a literature compilation of all the equine publications that used dexmedetomidine as the first article on this topic was published, in 2005. We also aimed to answer the question whether the use of dexmedetomidine can currently be justified. For that, we compiled information from databases, such as PubMed, Google Scholar and Web of Science and the proceedings of the last veterinary anaesthesiology meetings. Dexmedetomidine is an attractive drug to be used in horses, mainly due to its pharmacokinetic profile and pharmacodynamics that favour its use as intravenous constant rate infusion (CRI). Nowadays, its clinical use is popular for sedation in prolonged standing procedures and during partial intravenous anaesthesia (PIVA) and total intravenous anaesthesia (TIVA). However, legal requirements for its use should be taken into account.  相似文献   

Evaluation of a Biofloc System for Intensive Culture of Fathead Minnows,Pimephales promelas          下载免费PDF全文

Jeonghwan Park  Luke A. Roy  Nilima Renukdas  Trevor Luna 《Journal of the World Aquaculture Society》2017,48(4):592-601

This study was carried out to test the suitability of biofloc technology to improve the productivity of the fathead minnow, Pimephales promelas, a commercially important baitfish in North America. Biofloc growth was induced in treatment tanks by periodic additions of a carbon source (glucose) to maintain a C : N ratio of 12:1. Control tanks (no aeration and no carbon addition) accommodated densities equivalent to 1 million fish/ha, while treatment tanks (biofloc) had densities of 1, 2, 4, and 8 million fish/ha. Fish were fed 4% body weight using a 32% protein commercial diet. There were no significant differences in condition of fish harvested from control and treatment densities (P < 0.05). However, fish growth indicators such as final individual weight, feed conversion efficiency, and specific growth rate were significantly impaired at higher stocking densities. Survival rate was significantly lower in the 8 million/ha treatment (P < 0.05). Results were indicative of possible production efficiencies of twofold higher in biofloc systems stocked at or below 4 million/ha compared with traditional ponds. Although biofloc systems maintained the desired water‐quality parameters, biofloc microbial biomass did not seem to significantly enhance feed conversion and specific growth rates of fathead minnows.  相似文献