Effects of oral administration of heat‐killed Enterococcus faecium strain NHRD IHARA in post‐weaning piglets

Probiotic bacteria such as lactic acid bacteria (LAB) have recently received attention as candidates for alternative anti‐microbial feed additives. We previously isolated Enterococcus faecium strain NHRD IHARA (FERM BP‐11090, NHRD IHARA strain) and reported its probiotic efficacy. However, we have not determined the effect of oral administration of heat‐killed cells of this strain. Here, we performed two experiments to investigate the effect of oral administration of the heat‐killed NHRD IHARA strain on post‐weaning piglets. In Experiment 1, there was a significant improvement in growth performance (P = 0.04) and increase in serum immunoglobulin A (IgA) production (P = 0.03) in the group fed heat‐killed cells. These results were similar to previous results we obtained with live cells. We also found changes in serum and fecal IgA production that were unrelated to the patterns of microbiotal change. In Experiment 2, we detected a significant improvement in villus growth in the jejunum (P = 0.0002). In conclusion, oral administration of the heat‐killed NHRD IHARA strain in post‐weaning piglets had the same efficacy as administration of the live strain. The heat‐killed NHRD IHARA strain can be used as feed additives to improve pig growth and health on commercial farms.     

Characterization and distribution of Staphylococcus sp. implicated for improvement of fish sauce odor

ABSTRACT:   The two Staphylococcus strains that had been isolated from fish sauce mush (moromi) made from frigate mackerel in Japan and proved to improve fish sauce odor, were examined for their taxonomic positions. The sequence analysis based on 16S rRNA and rpoB showed that the two strains, R4Nu and R5G, had an identical sequence with sequence identities of 99.5% and 99.0% to the above two genes from the closest species of S. nepalensis , respectively. A DNA hybridization test of the two strains showed more than 80% DNA similarity with S. nepalensis , thus confirming the above-mentioned species identification. Polymerase chain reaction primers specific to the strain isolated from fish sauce mush were designed from rpoB and examined for the distribution of this species to various fish sauces made in Asian countries as well as to fish sauce starter (malt) made from soy beans and barley in Toyama Prefecture, Japan. The amplified DNA fragment bearing the S. nepalensis gene was detected in the enriched culture of the malt, although no positive reaction was shown with fish sauce samples. These results suggest that S. nepalensis indebted to improve fish sauce odor was originated from the fish sauce starter malt.     

Ectomycorrhizal‐fungal colonization induces physio‐morphological changes in Quercus serrata leaves and roots

To determine how colonization by different ectomycorrhizal (ECM)‐fungal species affects the physiology and morphology of Quercus serrata seedlings, we assessed the net photosynthetic rate, the respiration rate of the lateral roots, leaf and root nitrogen (N) concentrations, specific leaf area, and specific root length in 9‐month‐old Q. serrata seedlings inoculated with Pisolithus tinctorius, Scleroderma citrinum, Laccaria amethystea, and Astraeus hygrometricus. While uninoculated control plants showed no colonization, the percentage of ECM colonization of root tips attained 35% with P. tinctorius and about 86% with the other three ECM species. Similar to ECM root colonization, the photosynthetic as well as the root‐respiration rates were higher in seedlings with S. citrinum, L. amethystea, and A. hygrometricus than that in the control and those with P. tinctorius. Both the photosynthetic and root‐respiration rates were positively correlated with ECM‐fungal colonization. Similar trends were observed for the N concentration, specific leaf area, and specific root length, which differed significantly among ECM‐fungal species and were related with ECM‐fungal colonization. The results suggest that both physiological and morphological traits are specific to ECM‐fungal species. As Q. serrata seedlings with high colonization can exhibit better resource‐acquisition ability, the identification of strongly colonizing ECM‐fungal species is essential. Comparisons with high‐ and low‐colonizing ECM‐fungal species improve our understanding of source–sink relationships in carbon allocation of forest tree species.     

Nocapyrones: α- and γ-Pyrones from a Marine-Derived Nocardiopsis sp.

One new α-pyrone (nocapyrone R (1)), and three known γ-pyrones (nocapyrones B, H and L (2–4)) were isolated from the culture extract of a Nocardiopsis strain collected from marine sediment. Structures of these compounds were determined on the basis of spectroscopic data including NMR and MS. γ-Pyrones 2–4 were found to induce adiponectin production in murine ST-13 preadipocyte cells but the α-pyrone 1 had no activity. The absolute configuration of the anteiso-methyl branching in 4 was determined by HPLC comparison of a degraded product of 4 with standard samples as a 2:3 enantiomeric mixture of (R)- and (S)-isomers.     

Lime-nitrogen application affects nitrification, denitrification, and N2O emission in an acidic tea soil

Lime-N (calcium cyanamide, CaCN₂) acts as both fertilizer and pesticide. Lime-N may reduce nitrous oxide (N₂O) emission from soil, although its effectiveness and the relative mechanisms are not well understood. The aim of the study was to quantify the effect of lime-N on N₂O emission from the acidic soil of tea fields. The study design consisted of two treatments: conventional fertilizer (CF) (application of conventional organo-chemical fertilizer) and lime-N (LN) (application of approximately 53 % of the applied N as lime-N and the remaining as conventional organo-chemical fertilizer). Both treatments had the same amount of N, P₂O₅, and K₂O applied to soil between plant canopies; fertilizer was incorporated into soil. We measured N₂O emissions and environmental and microbial parameters of soil between plant canopies and under the canopy of tea plants, including the concentrations of dicyandiamide and cyanamide derived from lime-N. Nitrous oxide emission from soil between plant canopies was lower in the LN treatment than in the CF treatment, and soil ammonium oxidation activity and soil denitrification rate decreased after lime-N application. We applied the acetylene inhibition technique and analyzed isotopomer ratios of N₂O; the results of both techniques suggested that denitrification was the major process of N₂O production in the soil between plant canopies, despite relatively low water-filled pore space. Cumulative N₂O emission over the 366 days of the experiment was 36.0 % lower in the LN treatment than in the CF treatment (P?<?0.05). Our results suggest that lime-N application decreases N₂O emission by inhibiting both nitrification and denitrification processes in the acidic soil.     

Lack of exposed ice inside lunar south pole Shackleton Crater

The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all.     

Occurrence and distribution of cis-7-icosenoic acid in the lipids of Japanese marine fish,shellfish, and crustaceans

This article reports the concentration and composition of the isomers of cis-icosenoic acid (20:1) in the fatty acids of various species of Japanese marine animals. The main purpose of this study is to reveal the distribution of a positional isomer, cis-7-20:1 (c7-20:1), in marine animals. Because this isomer overlaps with the c9-20:1 isomer in gas chromatography (GC) on the commonly used polar capillary columns, less information is available on its occurrence and distribution. In this study, the monounsaturated fatty acids isolated by argentation thin-layer chromatography were analyzed by GC using a highly polar capillary column, SLB-IL111 (100 m long), with the highest polarity among the commercially available GC columns. A clear separation between the c7-20:1 and c9-20:1 isomers enabled the analysis of all the isomers of 20:1 present in marine animals. The results confirmed that the c7 isomer was a minor component in the 20:1 in the pelagic fish, which is rich in the c9 and/or c11 isomers as reported previously. In contrast, the c7 isomer was one of the major isomers in flatfish, shellfish, crabs, and brittle stars. In these samples, the c13 isomer also occurred at higher concentrations rather than the c9 isomer. Because such a specific pattern of the 20:1 positional isomers was generally observed in both benthic fish and its dietary animals, the c7 isomer in the benthic fish probably originated from its diet. These marine animals are used as food in Japan, and therefore the c7-20:1 isomer is consumed by humans.