Denaturing gradient gel electrophoresis analysis of gut bacterial community for the Japanese earthworms

The gut bacterial community structure for Pheretima hilgendorfi and P. heteropoda (Family Megascolecidae), and Allolobophora japonica (Family Lumbricidae) collected from agricultural grasslands in Japan was analyzed by denaturing gradient gel electrophoresis of polymerase chain reaction-amplified 16S rRNA gene fragments (PCR-DGGE) and compared with those in the surrounding soils. Denaturing gradient gel electrophoresis (DGGE) profiles indicated that each earthworm species had their own specific bacterial communities, and multidimentional scaling analysis grouped the DGGE profiles into three groups: gut samples from P. hilgendorfi and P. heteropoda, gut samples from A. japonica and samples from the surrounding soils. Nine dominant bands were identified by their direct sequencing and cloning. Major three bands from P. hilgendorfi and P. heteropoda were closely related to Bacillus species belonging to the phylum Firmicutes. Major four and two bands from A. japonica were closely related to the phyla Proteobacteria and Bacteroidetes, respectively.     

Increase in soil carbon sequestration using rice husk charcoal without stimulating CH4 and N2O emissions in an Andosol paddy field in Japan

Abstract

Biochar application has been recognized as an effective option for promoting carbon (C) sequestration, but it may also affect the production and consumption of methane (CH₄) and nitrous oxide (N₂O) in soil. A 1-year field experiment was conducted to investigate the effects of rice husk charcoal application on rice (Oryza sativa L.) productivity and the balance of greenhouse gas exchanges in an Andosol paddy field. The experiment compared the treatments of rice husk charcoal applied at 10, 20 and 40 Mg ha^?1 (RC10, RC20 and RC40, respectively), rice husk applied at 20 Mg ha^?1 (RH20), and the control (CONT). Rice straw and grain yields did not significantly differ among the treatments. The seasonal cumulative CH₄ emissions were 38–47% higher from RC10, RC20 and RC40 than from the CONT. However, the increases were not in proportion to the application rates of rice husk charcoal, and their values did not significantly differ from the CONT. On the contrary, the RH20 treatment significantly increased the cumulative CH₄ emission by 227% compared to the CONT. The N₂O emissions during the measurement were not affected by the treatments. As a result, the combined global warming potential (GWP) of CH₄ and N₂O emissions was significantly higher in RH20 than in the other treatments. There was a positive linear correlation between C storage in the top 10 cm of soil and the application rate of rice husk charcoal. The increases in soil C contents compared to the CONT corresponded to 98–149% of the C amounts added as rice husk charcoal and 41% of the C added as rice husk. Carbon dioxide (CO₂) fluxes in the off season were not significantly different among RC10, RC20, RC40 and CONT, indicating that C added as rice husk charcoal remained in the soil during the fallow period. The CO₂ equivalent balance between soil C sequestration and the combined GWP indicates that the rice husk charcoal treatments stored more C in soil than the CONT, whereas the RH20 emitted more C than the CONT. These results suggest that rice husk charcoal application will contribute to mitigating global warming without sacrificing rice yields.     

Durability analysis of bio-cemented slope soil under the exposure of acid rain

Journal of Soils and Sediments - Instability of slope surface is a critical concern in Geotechnical and Environmental Engineering. MICP (Microbial-Induced Carbonate Precipitation), an innovative...     

A possible connection between psychosomatic symptoms and daily rhythmicity in growth hormone secretion in healthy Japanese students

Background  

Students suffering from psychosomatic symptoms, including drowsiness and feelings of melancholy, often have basic lifestyle problems. The aim of this study was to investigate whether psychosomatic complaints may be related to circadian dysfunction.     

Use of a beta 2-adrenergic stimulant (clenbuterol) for eliminating night-time calving.

To determine whether beta 2-adrenergic stimulant (clenbuterol) would exhibit beneficial effects upon the elimination of night-time calving, 42 Holstein Friesian cows and heifers at the first stage of labour were injected intramuscularly twice with clenbuterol; 300 micrograms at 18:00 and 210 micrograms at 22:00. Other 26 cows and heifers of the same breed at the first stage of labour at 18:00 were not treated and served as controls. All of the treated animals, but one, calved after 5:00 in the next morning, showing a peak of parturition between 5:00 and 10:00. In contrast to this, 42% of the control animals calved at night between 22:00 and 5:00. Thus, the double administrations of clenbuterol were shown to be effective for eliminating night-time calving. The cows treated with clenbuterol tended to show lower incidences of dystocia and retained placenta and a higher first insemination conception rate than the control animals. No adverse effects of the treatment on the viability of newborn calves and milk yields were observed.     

Effects of rumen‐protected methionine on milk production in early lactation dairy cattle fed with a diet containing 14.5% crude protein

We evaluated the influence on milk production of feeding early lactation cows a diet that included 14.5% crude protein (CP) and that did not meet methionine (Met) requirements or that met them by supplying rumen‐protected Met (RPMet). Thirty‐nine multiparous Holstein cows were allocated into two groups. For 15 weeks after calving, each group was fed one of the two total mixed rations, Control (n = 20) or Treatment (n = 19). The Treatment group received added RPMet at 0.034% (8 g/day) of the Control diet on dry matter basis. The adequacies of Met for the Control and Treatment groups were 96% and 106%, respectively, and for other amino acids, >110%. The CP level (14.5%) was 1 percentage point lower than that recommended by the Japanese Feeding Standard (2006). No between‐group differences were found in milk yield (40 kg/day), milk composition, plasma profile, rumen fermentation, nitrogen balance, or cow health. Met intake and the amount of rumen‐undegradable feed Met were higher in the Treatment group (p < 0.05). Microbial Met and total metabolizable Met did not differ between groups. Supplying RPMet in a 14.5% CP diet during early lactation did not dramatically affect milk production, because the amount of total metabolizable Met was unchanged.     

Change in river water chemistry as affected by the confluence of forest drainage water in dairy farming area on Hokkaido Island, Northern Japan

We evaluated i) the difference in river water chemistry between a watershed mainly consisting of pasture and a watershed mainly consisting of forest, and ii) how the chemistry of river draining the pasture is influenced by that of the river draining the forest. We selected one river (designated as the T-river) draining the pasture (3,587 ha), and two rivers draining a forest (738 and 879 ha) in eastern Hokkaido, northern Japan. During higher river flow due to precipitation and thawing, the concentrations of NO ₃ ⁻ , SO ₄ ²⁻ , K⁺, Fe, and Al increased, suggesting the relative importance of the shallow soil layer as their source. On the other hand, Na⁺, Mg²⁺, Ca²⁺, and Si decreased, suggesting the relative importance of the source in a deep soil layer. The concentrations of NO ₃ ⁻ , Cl⁻, SO ₄ ²⁻ , K⁺, Na⁺, Mg²⁺, Ca²⁺, and Fe were higher in the T-river than in the forest drainage waters, suggesting the contribution of the excretion components from the milk cows. The Si concentration exhibited the opposite pattern. The concentrations of NO ₃ ⁻ , Cl⁻, SO ₄ ²⁻ , K⁺, Na⁺, Mg²⁺, Ca²⁺ (p<0.001), and Fe (p<0.05) in the T-river decreased after the confluence of the forest drainage waters, while Si concentration increased (p<0.001). The reason for the change in river chemistry was the confluence of the forest drainage waters. These findings suggested the environmental role of the forest in the dilution of the polluted river. Prof. S. Ohata, and Prof. H. Takeda, Graduate School of Agriculture, Kyoto University, facilitated this study. Prof. T. Sakai, Graduate School of Informatics, Kyoto University, offered this study some convenience. Dr. M. Sakimoto, and Dr. M. Katsuyama, Graduate School of Agriculture, Kyoto University, offered useful advise.     

Transition state leading to β-O′ quinonemethide intermediate of p-coumaryl alcohol analyzed by semi-empirical molecular orbital calculation

The radical coupling reaction leading to the β-0′ quinonemethide intermediate of p-coumaryl alcohol was analyzed by semi-empirical molecular orbital calculation with MOPAC2002. By analyzing the radical monomer in a one-electron oxidation, the spin density of the unpaired electron at the 4-oxygen was less than half of the values at the C₁, C₃, C₅, and C_β positions. By analyzing the transition state during the radical coupling reaction, the activation enthalpy was evaluated as 9.76 kcal/mol, which corresponds to the activation energies for the propagation of common vinyl polymers. From the analysis of atomic interactions in the transition state, it was found that the activation enthalpy was largely composed of a high coulombic repulsion between C_β of the first monomer and the phenolic oxygen of the second monomer. After passing the transition state, the two radical monomers formed a metastable quinone-methide intermediate. The optimum conformation of the quinonemethide intermediate was formed from the meta-stable conformation through a second transition state with a small energy barrier. Part of this article was presented at the 46th Lignin Symposium, held in Fukuoka, October 31-November 1, 2002     

Comparison of the odor-active compounds in unhopped beer and beers hopped with different hop varieties

Odorants comprising the hop aromas of beers were examined. Strongly hopped beers with Saazer, Hersbrucker, and Cascade hops were compared with unhopped beer by gas chromatography-olfactometry (CharmAnalysis) and sensory evaluation. Twenty-seven odorants were revealed as hop-derived, which derived either directly from hops or via metabolization, and 19 components were identified. Of the components, linalool, geraniol, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, and ethyl 2-methylpropanoate were determined as odor-active components from their Charm values and aroma values. The muscat-like aroma of Cascade beer and the spicy aroma of Hersbrucker beer were predominant in sensory evaluation, and the contributors to these characteristics were investigated.     

Relationship between pH and Temperature in the Ruminal Fluid of Cows, Based on a Radio-Transmission pH-Measurement System

To assess the relationship between pH and temperature in the ruminal bottom fluid, circadian changes were monitored using cows fed a control diet (C diet) or a rumen acidosis-inducing diet (RAI diet) by using a wireless radio-transmission pH- measurement system. These two parameters were measured simultaneously at 10-min intervals on day 14 after commencement of feeding. Compared to the mean ruminal pH for 60 min immediately after the morning feeding (0 hr), significantly lower pH was noted 3-13 hr later (P<0.05) and 4-19 hr later (P<0.01) in cows fed the C and RAI diets, respectively, although the reduction in the latter was much higher than that in the former. In contrast, significantly higher ruminal temperature was found at 8 and 12-14 hr later (P<0.05) and 6, 8, and 10-19 hr later (P<0.01) in cows fed the C and RAI diets, respectively. A significant negative correlation was observed between the lowest ruminal pH and its corresponding ruminal temperature in cows fed the C and RAI diets (r=-0.722 and -0.650, P<0.01, respectively), suggesting active fermentation and volatile fatty acid production in the rumen. However, ruminal pH profiles may not be predictable by measuring only ruminal temperature because decreases in ruminal pH were preceded by increases in ruminal temperature, and circadian changes in pH and temperature were associated with ruminal fermentation.