Production of bacteriocin by Leuconostoc mesenteroides 406 isolated from Mongolian fermented mare's milk,airag

The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral‐pH cell‐free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat‐stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α‐chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24–36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut‐off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin‐producing Leuconostoc strain from airag. An application to fermented milks would be desired.     

Evaluation of sugarcane smut resistance in wild sugarcane (Saccharum spontaneum L.) accessions collected in Japan

ABSTRACT

Sugarcane smut, caused by Sporisorium scitamineum, is one of the most important sugarcane diseases in Japan. Wild sugarcane, Saccharum spontaneum, is known to be a key breeding material to obtain high-yielding clones. In this study, we sought to identify Japanese wild sugarcane accessions with high resistance to smut. Thirty wild sugarcanes and three sugarcane cultivars were tested by the pinprick method. The results of the inoculation tests aided in identifying wild sugarcanes with high resistance to smut disease, namely JW90, Iriomote8, and Iriomote15. After screening the germplasm, progeny distribution of smut resistance from the inoculation test and dry matter productivity in the smut disease-free field were compared. The highly resistant wild sugarcane accession had a much better impact on progeny distribution of smut resistance compared with the susceptible accession. No relationship was found between smut resistance and dry matter productivity in both populations.     

Regulation of root-to-leaf Na and Cl transport and its association with photosynthetic activity in salt-tolerant soybean genotypes

ABSTRACT

Soil salinity is a major constraint to sustainable crop production. Genetic improvements are needed for growing soybean in salinity-prone environments. Salt-tolerant soybean genotypes alleviate a reduction in photosynthesis and growth under saline conditions; however, the detailed mechanisms involved remain unclear. Here, we aimed to clarify how Na and Cl root-to-leaf transport is quantitatively regulated, and to identify whether photosynthetic tolerance depends on traits associated with either stomata or with mesophyll tissues. Two pairs of pot-grown soybean near-isogenic lines (NILs) consisting of tolerant and susceptible counterparts, derived from a cross between salt-tolerant FT-Abyara and salt-sensitive C01, were subjected to salinity treatment in a rainout greenhouse. Comparison of photosynthetic responses between genotypes indicated that genotypic differences in salinity tolerance depended on the ability for sustained CO₂ assimilation in mesophyll tissues, rather than stomatal conductance. The ratio of photosynthetic rate to intercellular CO₂ concentration (A/Ci) declined exponentially with increasing Na and Cl concentration regardless of genotype, but tolerant genotypes effectively kept both elements at significantly low levels. Under saline conditions, tolerant genotypes reduced Na and Cl content at the two transport pathways: from root to stem, and from stem to leaf, but the reduction of Cl at each pathway was only minor. These results suggest that integrating genetic capacity for Cl transport regulation and osmotic adjustment should be an important target in salinity-tolerance soybean breeding.     

Genetic relationship of body measurement traits at early age with carcass traits in Japanese black cattle

Estimates of genetic parameters were obtained for body measurement traits of 648 animals at 4 months of age, of 545 at 8 months and carcass traits of 14 972 animals with the use of an animal model by the restricted maximum likelihood procedure. The estimated heritabilities for carcass traits were high (0.41 to 0.54). At 4 months the estimated direct heritabilities for body measurement traits were moderate to high (0.28 to 0.64), except for chest width (0.19); at 8 months they were also moderate to high (0.23 to 0.49), except for chest depth and chest width (0.18 and 0.06, respectively). Maternal heritabilities for all body measurement traits were low at both ages. The results indicate that because of their moderate direct genetic correlations with body measurement traits, carcass weight, rib thickness and subcutaneous fat thickness can be improved; however, rib eye area and beef marbling standard show little such possibility considering their correlation with body measurement traits.     

Anti-acne activity of tannin-related compounds isolated from Terminalia laxiflora

In our investigation to find out new anti-acne agent, we focused on Terminalia laxiflora Engl & Diels (Combretaceae) methanolic wood extract, which has been selected during previous screening experiments for anti-acne agents, which included 29 species of Sudanese medicinal plants. Based on the biologically guided fractionation using an antibacterial assay against Propionibacterium acnes, a lipase inhibitory assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay; five tannin-related compounds were isolated, such as ellagic acid, flavogallonic acid dilactone, terchebulin and gallic acid. Terchebulin showed good antibacterial activity; minimum inhibitory concentration (MIC) = 125 μg/ml and minimum bactericidal concentration (MBC) = 250 μg/ml. Gallic acid exhibited lipase inhibitory activity with IC₅₀ value of 149.3 μM, which showed strong inhibition compared with terchebulin, IC₅₀ 260.7 μM. However, all compounds exhibited better or equal DPPH radical scavenging activity to (+)-catechin as positive control. Ellagic acid and terchebulin showed the best DPPH radical scavenging activities, IC₅₀ 4.86 and 4.90 μM, respectively. This study demonstrated that terchebulin has potentiality as an anti-acne agent.     

Characterization of the perylenequinone pigments in Japanese Andosols and Cambisol

The green fraction of humic acid (Pg) and the chloroform-extractable green fraction (CEGF) are characteristic soil organic matter (SOM) components. These alkaline solutions are green-colored due to the presence of 4,9-dihydroxyperylene-3,10-quinone (DHPQ) chromophore. While both of which are potential indicators for the effect of land use and paleoclimatic environment in the fields of soil science as well as geochemistry, CEGF as well as its relationship with Pg in soils are not yet fully documented. In this study, we firstly investigated the chemical properties of soil CEGF fractions by ultraviolet–visible (UV–Vis) and infrared (IR) method. Two CEGF components were separated by sequential liquid-liquid extraction using aqueous ammonium hydroxide (NH₄OH) followed by aqueous sodium hydroxide (NaOH). Results showed that the UV–Vis spectral shape of NH₄OH-extractable component is very similar to that of DHPQ, except that it is red-shifted. The solubility and UV–Vis spectrum of the NaOH-extractable fraction were completely identical with those of synthesized DHPQ. Their IR spectral shapes were also almost the same. Subsequently, the distribution of CEGF in humic acid (HA), fulvic acid (FA) and humin (HN) from Japanese Andosols and Cambisol was quantitatively evaluated by sequential extraction. Most of CEGF was detected in the HA (60–78%) and HN (22–40%), but not in the FA. While the UV–Vis spectral shape of CEGF extracted from Andosols HAs showed a relatively higher proportion of DHPQ than its derivative, the opposite was observed in Cambisol HA, whose CEGF is similar to that of sclerotium grain (one of the possible origin of CEGF). These results suggest the diversity of CEGF-producing soil fungi. Quantitative data also indicated that 35–49% of Pg consisted of a chloroform-soluble fraction (i.e., CEGF) and the remaining 51–65% of Pg was chloroform-insoluble. Based on these results, we propose that CEGF is composed of DHPQ and DHPQ-derivatives and that CEGF is one of the major fractions of Pg.     

Molecular cloning and sequence analysis of feline interferon-stimulated gene 15

The interferon-stimulated gene 15 (ISG15) is induced by type I interferon (IFN). Recent studies have revealed that like ubiquitin, ISG15 is conjugated with target proteins. In this study, the feline ISG15 (FeISG15) gene was cloned from feline IFNomega (FeIFNomega)-stimulated feline kidney epithelial (CRFK) cells. According to gene sequence results, cDNA was 474bp long and encoded a protein of 157 amino acids. The putative amino acid sequences showed 62.5-72.1% identity with those of other mammalian ISG15s. Similar to human and mouse ISG15, FeISG15 included tandem ubiquitin-like domains; its homology with feline ubiquitin was 36.3-39.5%. The LRLRGG conjugating motif was located only in the carboxyl terminal ubiquitin-like domain. FeISG15 also lacked the carboxyl terminal extension after the LRLRGG motif, which is present in mouse and human ISG15. Recombinant FeISG15 protein was expressed as a His-tagged fusion protein in Escherichia coli and purified by ion-exchange chromatography followed by affinity chromatography. Monoclonal anti-FeISG15 antibodies revealed free FeISG15 and FeISG15 conjugated with target proteins in cells after IFNomega stimulation by Western blotting analysis. Furthermore, mRNA of IFNgamma was detected from peripheral blood mononuclear cells (PBMCs) after stimulation with rFeISG15 extracellularly by RT-PCR. Taken together, these results suggested that FeISG15 had ubiquitin- and cytokine-like activity, as in other species.     

Pharmacokinetics and toxicity of zonisamide in cats

With the eventual goal of making zonisamide (ZNS), a relatively new antiepileptic drug, available for the treatment of epilepsy in cats, the pharmacokinetics after a single oral administration at 10mg/kg and the toxicity after 9-week daily administration of 20mg/kg/day of ZNS were studied in healthy cats. Pharmacokinetic parameters obtained with a single administration of ZNS at 10mg/day were as follows: Cmax=13.1microg/ml; Tmax=4.0h; T(1/2)=33.0h; areas under the curves (AUCs)=720.3microg/mlh (values represent the medians). The study with daily administrations revealed that the toxicity of ZNS was comparatively low in cats, suggesting that it may be an available drug for cats. However, half of the cats that were administered 20mg/kg/day daily showed adverse reactions such as anorexia, diarrhoea, vomiting, somnolence and locomotor ataxia.     

Adjusting for heterogeneity of variance for carcass traits affects single and multiple trait selections in genetic evaluation of Japanese Black cattle

Heterogeneity of variance among subclasses of an effect is a potential source of bias in genetic evaluation. Degrees of the heterogeneity of variance among farm‐market‐year‐sex (FMYS) subclasses for carcass weight, beef marbling standard number, rib‐eye area, rib thickness and subcutaneous fat thickness were investigated in Japanese Black cattle. Consequences of adjusting for the heterogeneity on the predicted breeding values (PBVs) or on the genetic indexes derived from the PBVs of the five carcass traits were assessed. A total of 57 461 records were collected between 1997 and 2002 from steers and heifers fattened at farms across Japan. These records were grouped into 1591 FMYS subclasses. Bartlett's test showed that the degree of the heterogeneity of variance among the FMYS subclasses was sizeable in all traits (P < 0.0001). By applying a two‐step adjustment procedure it was possible to reduce the standard deviation, the coefficient of variation and the Gini coefficient of the phenotypic variances by 67.5% to 75.0% in the different traits. The applied adjustment caused a substantial re‐ranking of elite dams in the PBV for each trait as well as in the genetic index. This study provided evidence that the applied adjustment reduces the bias in the PBVs due to heterogeneous variances and increases the accuracy of bull‐dam selection.     

Effects of a probiotic bacterial <Emphasis Type="Italic">Lactobacillus rhamnosus</Emphasis> dietary supplement on the crowding stress response of juvenile Nile tilapia <Emphasis Type="Italic">Oreochromis niloticus</Emphasis>

To test the effects of probiotic bacteria against crowding stress, juvenile Nile tilapia Oreochromis niloticus were fed commercial feed supplemented with 1 × 10¹⁰ cfu/g pellets of Lactobacillus rhamnosus for 3 weeks. The fish were confined and subjected to crowding for 7 and 14 days after which their physiological condition was investigated. The administration of probiotic prophylaxis improved growth performance even in the stressed fish. After 7 days of stress exposure, fish receiving probiotic-supplemented feed showed proactive behavior and coping responses to the stressor, as evidenced by elevated plasma glucose levels and osmolality, stabilized plasma electrolytes, and a higher RNA:DNA ratio. Fish stressed for 7 days and fed normal commercial diet showed impairment of plasma electrolytes; after 14 days, the plasma osmolality, electrolytes, glucose, and RNA:DNA ratio decreased, indicating physiological maladaptation to the stressor. The growth rate was also found to be reduced, suggesting that energy demand exceeded the energy available from metabolism and dietary uptake. This latter effect was not observed in fish fed the probiotic-supplemented diet. The results suggest that probiotic bacteria prophylaxis may increase energy availability for metabolic support of the crowding stress response and improve the stress coping capacity of fish.