接种含ACC脱氨酶的假单胞菌能部分缓解干旱胁迫对豌豆生长、产量及成熟的影响

Two preselected plant growth promoting rhizobacteria （PGPR） containing 1-aminocyclopropane-1-carboxylate （ACC）- deaminase （EC 4.1.99.4） were used to investigate their potential to ameliorate the effects of drought stress on growth, yield, and ripening of pea （Pisum sativum L.）. Inoculated and uninoculated （control） seeds of pea cultivar 2000 were sown in pots （four seeds pot-1） and placed in a wire house. The plants were exposed to drought stress at different stages of growth （vegetative, flowering, and pod formation） by skipping the respective irrigation. Results revealed that inoculation of peas with PGPR containing ACC-deaminase significantly decreased the ＂drought stress imposed effects＂ on the growth and yield of peas. Exposure of plants to drought stress at vegetative growth stage significantly decreased shoot growth by 41% in the case of uninoculated plants, whereas, by only 18% in the case of inoculated plants compared to nonstressed uninoculated control.
Grain yield was decreased when plants were exposed to drought stress at the flowering and pod formation stage, but inoculation resulted in better grain yield （up to 62% and 40% higher, respectively） than the respective uninoculated nonstressed control. Ripening of pods was also delayed in plants inoculated with PGPR, which may imply decreased endogenous ethylene production in inoculated plants. This premise is further supported by the observation that inoculation with PGPR reduced the intensity of classical ＂triple＂ response in etiolated pea seedlings, caused by externally applied ACC. It is very probable that the drought stress induced inhibitory effects of ethylene could be partially or completely eliminated by inoculation with PGPR containing ACC-deaminase.     

Perspectives of Using L-Tryptophan for Improving Productivity of Agricultural Crops: A Review

Plant growth regulators are biologically active signaling molecules that regulate a number of plant physiological processes. Auxin (indole-3-acetic acid) is an important plant growth regulator and is synthesized within plant tissues through L-tryptophan (L-TRP)-dependent and -independent pathways. It has been found that plants respond to exogenously applied L-TRP due to insufficient endogenous auxin biosynthesis. The exogenous application of L-TRP is highly significant for normal plant growth and development. L-tryptophan is applied through foliar spray, seed priming, and soil application. Soil-applied L-TRP is either directly taken up by plants or metabolized to auxin by soil microbiota and then absorbed by plant roots. Similarly, foliar spray and seed priming with L-TRP stimulates auxin synthesis within plants and improves the growth and productivity of agricultural crops. Furthermore, L-TRP contains approximately 14% nitrogen (N) in its composition, which is released upon its metabolism within a plant or in the rhizosphere and plays a role in enhancing crop productivity. This review deals with assessing crop responses under the exogenous application of L-TRP in normal and stressed environments, mode of action of L-TRP, advantages of using L-TRP over other auxin precursors, and role of the simultaneous use of L-TRP and auxin-producing microbes in improving the productivity of agricultural crops. To the best of our knowledge, this is the first review reporting the importance of the use of L-TRP in agriculture.     

Chemical and antimicrobial studies of monoterpene: Citral

6,7-Citral-epoxy derivative (a mixture of E and Z isomers with respect to the C2 = C3 double bond) could be react with DNA base producing a major adduct. The mixture of epoxides was condensed with 2 mol of cytosine to give the adduct through condensation between aldehyde and amino groups. Antifungal and antibacterial studies were carried out on citral and citral-epoxide. Studies on the antifungal especially Penicilliumitalicum and Rhizopus stolonifer showed that citral and citral-epoxide have good antibacterial action. Antimicrobial studies of P.italicum and R. stolonifer explained also that citral and citral-epoxide have good antimicrobial activity. Citral epoxide shows high activity against the growth of bacteria methicillin resistant Staphylococcus aureus (MRSA) and fungi comparing by citral. The epoxide shows antibacterial activity more than the antibiotics nalidixic acid (NA) and ampicillin (AP) and nitrofurantoin (NI). The results revealed that these complexes are most effective against MRSA.     

Simultaneous HPLC determination of gamma amino butyric acid (GABA) and lysine in selected Pakistani rice varieties by pre-column derivatization with 2-Hydroxynaphthaldehyde

A selective and sensitive HPLC method for the simultaneous determination of gamma amino butyric acid (GABA) and lysine in Pakistani rice varieties was developed. Both analytes were detected in rice varieties as Schiff base derivatives with 2-hydroxynaphthaldehyde. The derivatives were analyzed on a reverse phase C-18 column with Diode Array Detector (DAD) at 254 nm. The calibration curves were found linear over a concentration range of 3.83–34.58 μg/mL for GABA and 5.16–48.68 μg/mL for lysine with a correlation coefficient of 0.998 for both standards. GABA and lysine contents were found higher in brown rice varieties (4.1–6.58 mg/100 g for GABA and 15.1–27.6 mg/100 g for lysine) than the polished varieties (0.32–0.47 mg/100 g GABA and 13.1–19.8 mg/100 g lysine). This method could be used for separation and quantification of GABA and lysine simultaneously in food samples, especially in cereal seeds.     

Evaluation of Pasteurella multocida isolated from rabbits by capsular typing, somatic serotyping, and restriction endonuclease analysis.

The goal of this study was to characterize Pasteurella multocida isolated from rabbits. Five hundred and fifty-three apparently healthy rabbits were sampled for this study. Nasal swabs were collected from each rabbit for P. multocida isolation and identification. Isolates were further characterized by capsular and somatic antigens and genomic DNA fingerprinting. Thirty-nine P. multocida isolates were recovered from 553 rabbits (7%). Capsular typing was done by depolymerization of P. multocida capsule by Staphylococcus aureus hyaluronidase and by disc diffusion with mucopolysaccharidase enzymes (heparinase III, chondroitinase AC, and hyaluronidase). Thirty-one (79%) of the isolates were capsular type A, and 8 isolates (21%) had untypable (UT) capsules. The gel-diffusion precipitin test was used to determine the somatic type of P. multocida isolates. Nineteen isolates were somatic serotype 3 (49%), 12 were serotype 1 (31%), 1 was serotype 2, 2 were serotype 5, 2 were serotype 12 with a weak reaction to antiserum raised against serotype 7 (5%), and 1 was serotype 4. Two of the isolates (5%) were UT. Restriction endonuclease analysis of the DNA of the isolates revealed 7 distinct profiles by digestion with HindIII, and 12 profiles were obtained with HpaII, whereas digestion with EcoRI did not differentiate between any of the P. multocida DNA isolates studied. The DNA restriction endonuclease enzyme HpaII was found more useful for differentiating between DNA fingerprints of P. multocida rabbit isolates. However, no correlation between capsular type, somatic serotypes, and DNA fingerprints was seen in this study.     

鸡新城疫病毒与大肠杆菌内毒素的相互作用

利用细胞培养、鸡胚及 8周龄幼鸡对鸡新城疫病毒 ( NDV)与大肠杆菌内毒素的相互作用进行了研究。这些相互作用通过在宿主系统中诱导产生的特异性或非特异性反应 ,以及在鸡胚和鸡体内产生的病毒滴度得到评价。1　大肠杆菌内毒素可导致活鸡法氏囊萎缩给鸡静脉注射大肠杆菌内毒素诱导产生的血液抗病毒活力成分称为干扰素 ,与在水泡性口炎病毒蚀斑减少试验中所检出的结果相同。因在鸡胚成纤维细胞 ( CEF)上 NDV蚀斑形成的数量没有发生变化 ,所以内毒素不对鸡胚成纤维细胞造成毒害 ,也不导致任何抗病毒效应。鸡群感染 NDV前 3d注射大肠杆菌…     

Haloarchaea as Cell Factories to Produce Bioplastics

Plastic pollution is a worldwide concern causing the death of animals (mainly aquatic fauna) and environmental deterioration. Plastic recycling is, in most cases, difficult or even impossible. For this reason, new research lines are emerging to identify highly biodegradable bioplastics or plastic formulations that are more environmentally friendly than current ones. In this context, microbes, capable of synthesizing bioplastics, were revealed to be good models to design strategies in which microorganisms can be used as cell factories. Recently, special interest has been paid to haloarchaea due to the capability of some species to produce significant concentrations of polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), and polyhydroxyvalerate (PHV) when growing under a specific nutritional status. The growth of those microorganisms at the pilot or industrial scale offers several advantages compared to that of other microbes that are bioplastic producers. This review summarizes the state of the art of bioplastic production and the most recent findings regarding the production of bioplastics by halophilic microorganisms with special emphasis on haloarchaea. Some protocols to produce/analyze bioplastics are highlighted here to shed light on the potential use of haloarchaea at the industrial scale to produce valuable products, thus minimizing environmental pollution by plastics made from petroleum.     

Brucella antibodies in sudanese camels

Summary Sera of 740 camels of both sexes from three regions of Sudan were tested for antibodies toBrucella abortus. The overall incidence of antibodies was 4.9%. The highest positive number of samples (7.5%) was from the Eastern Region followed by Darfur Region (3.1%) and the Central Region (2.0%).Brucella antibodies were as frequent in males (5.6%) as females (4.5%).

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Anticuerpos De Brucela En Camellos Sudadeses

Resumen Se analizaron 740 sueros de camellos de ambos sexos, provenientes de tres regiones de Sudán, para detectar anticuerpos deBrucella abortus. La incidencia general de anticuerpos fué de 4.9%. El más alto número de pruebas positivas (7.5%) correspondió a la Regió Oriental, seguida de la Región de Darfur (3.1%) y la Región Central (2.0%). Los anticuerpos fueron tan frecuentes en machos (4.5%), como en hembras (5.6%).

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Anticorps Brucelliques Chez Les Chameaux Du Soudan

Résumé Les anticorps anti-brucelliques (Brucella abortus) ont été recherchés dans les sérums de 740 chameaux des deux sexes originaires de trois régions du Soudan. L'incidence globale des anticorps étant de 4,9 p. 100. Le nombre d'échantillons positifs le plus élevé (7,5 p. 100) provenait de la région Est suivi par le Darfour (3,1 p. 100) et le Centre (2,0 p. 100). Les anticorps brucelliques étaient aussi fréquents chez les mâles (4,5 p. 100) que chez les femelles (5,6 p. 100).