Suppression of rice blast,cabbage black leaf spot,and tomato bacterial wilt diseases by Meyerozyma guilliermondii TA-2 and the nature of protection

This study was conducted to evaluate the efficacy of yeast strain TA-2 for controlling rice blast, cabbage black leaf spot, and tomato bacterial wilt diseases. Microscopic and phylogenetic analyses based on rDNA-internal transcribed region (ITS) and rDNA-D1/D2 sequences indicated that yeast strain TA-2 is Meyerozyma guilliermondii. Pretreatment with TA-2 by soil drenching significantly reduced the severity of black leaf spot disease caused by Alternaria brassicicola and leaf blast disease caused by Magnaporthe oryzae. Symptom development of tomato bacterial wilt caused by Ralstonia solanacearum in both soil drench and needle inoculation tests was significantly reduced in TA-2-pretreated plants under soil drenching. Disease severity and R. solanacearum growth were significantly reduced in tomato plants pretreated with yeast culture, cell suspension, or culture filtrate of TA-2 under soil drenching. TA-2 does not produce antibiotics. The present study indicates that disease suppression is systemic, as the roots were treated with TA-2 and the pathogens were inoculated onto leaves or stems, thereby separating the two spatially. M. guilliermondii TA-2 could become a promising natural antimicrobial agent against rice blast, cabbage black leaf spot, and tomato bacterial wilt diseases and might be useful as an eco-friendly control measure, contributing to sustainable agriculture.     

Distribution of radioactive cesium in edible parts of cattle

After the disastrous incident of the Fukushima Daiichi Nuclear Power Station, various agricultural, livestock and fishery products have been inspected for radioactive contamination with cesium in Japan. In this study, radioactive cesium was measured in various edible parts of cattle to verify the current inspection method for cattle, in which the neck tissues are generally used as samples. Radioactive cesium concentration in the short plate, diaphragm, liver, lung, omasum, abomasum and small intestine were lower and sirloin, tenderloin, top round meat and tongue were higher than that in the neck. There was no significant difference between the other organs (heart, kidney, lumen and reticulum) and the neck. Ninety‐five percent upper tolerance limits of the relative concentration to the neck were 1.88 for sirloin, 1.74 for tenderloin, 1.87 for top round and 1.45 for tongue. These results suggest that a safety factor of 2 is recommended for the radioactivity inspection of cattle to prevent a marketing of meat with higher cesium than the legal limit. Re‐inspection should be conducted using another part of muscle, for example, top round, when suspicious levels of 50–100 Bq/kg are detected in the neck.     

Purification and characterization of polyphenol oxidase from cauliflower (Brassica oleracea L.)

Polyphenol oxidase (PPO) of cauliflower was purified to 282-fold with a recovery rate of 8.1%, using phloroglucinol as a substrate. The enzyme appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The estimated molecular weight of the enzyme was 60 and 54 kDa by SDS-PAGE and gel filtration, respectively. The purified enzyme, called phloroglucinol oxidase (PhO), oxidized phloroglucinol (K(m) = 3.3 mM) and phloroglucinolcarboxylic acid. The enzyme also had peroxidase (POD) activity. At the final step, the activity of purified cauliflower POD was 110-fold with a recovery rate of 3.2%. The PhO and POD showed the highest activity at pH 8.0 and 4.0 and were stable in the pH range of 3.0-11.0 and 5.0-8.0 at 5 °C for 20 h, respectively. The optimum temperature was 55 °C for PhO and 20 °C for POD. The most effective inhibitor for PhO was sodium diethyldithiocarbamate at 10 mM (IC(50) = 0.64 and K(i) = 0.15 mM), and the most effective inhibitor for POD was potassium cyanide at 1.0 mM (IC(50) = 0.03 and K(i) = 29 μM).     

Evaluation of the effects of irrigation water on groundwater budget by a hydrologic model

Paddy and Water Environment - Groundwater is a valuable water resource, and it is used for domestic, industrial or agricultural use around the world. Especially, water use in paddy fields is very...     

A method for estimating radioactive cesium concentrations in cattle blood using urine samples

In the region contaminated by the Fukushima nuclear accident, radioactive contamination of live cattle should be checked before slaughter. In this study, we establish a precise method for estimating radioactive cesium concentrations in cattle blood using urine samples. Blood and urine samples were collected from a total of 71 cattle on two farms in the ‘difficult‐to‐return zone’. Urine ¹³⁷Cs, specific gravity, electrical conductivity, pH , sodium, potassium, calcium, and creatinine were measured and various estimation methods for blood ¹³⁷Cs were tested. The average error rate of the estimation was 54.2% without correction. Correcting for urine creatinine, specific gravity, electrical conductivity, or potassium improved the precision of the estimation. Correcting for specific gravity using the following formula gave the most precise estimate (average error rate = 16.9%): [blood ¹³⁷Cs] = [urinary ¹³⁷Cs]/([specific gravity] ? 1)/329. Urine samples are faster to measure than blood samples because urine can be obtained in larger quantities and has a higher ¹³⁷Cs concentration than blood. These advantages of urine and the estimation precision demonstrated in our study, indicate that estimation of blood ¹³⁷Cs using urine samples is a practical means of monitoring radioactive contamination in live cattle.     

No abomasal curd formation in pre-ruminant calves after ingestion of a clotting milk replacer

The aim of this study was to ultrasonographically evaluate curd formation in 29 pre-ruminant calves that were fed a clotting milk replacer. Abomasal curd was absent in 8/29 calves at 2 h after feeding. In these eight calves, abomasal contents were observed as an anechoic image with small echogenic spots (five calves), or as an echogenic image with an unclear outline (three calves), but there was no echogenic image with a clear outline corresponding to curd that was visualised in the other 21 calves. The curd was not observed until 7 h after feeding in the eight calves. Our analysis also indicated that the absence of curd formation in the pre-ruminant calves did not have a significant impact on the appearance, appetite and vigour of pre-ruminant calves or on their blood parameters, including serum triglyceride, blood urea nitrogen and glucose concentrations. The study provided the first evidence that the abomasum of some calves does not form curd despite ingestion of a clotting milk replacer.     

The effect of experimental inhibition of gastric acid secretion on curd formation in abomasum and weight gain of calves

Eight Holstein bull calves were divided into two groups; a non-treated control group and a famotidine treated group. Fresh milk was fed twice a day. The experiment was conducted between 7 and 14 days of age. During the experimental period the control group was injected with physiological saline, and the famotidine group was injected with famotidine, a histamine-H2-receptor blocker, into the jugular vein 30 minutes prior to each feeding. The control group showed maximum curd formation 2 h after feeding at both 7 and 14 days of age. Curd scores of 7-day-old and 14-day-old calves were significantly lower in the famotidine than in the control group at 2 and 4 h after feeding. Most fecal samples from the famotidine group exhibited an acidic smell. The famotidine group showed significantly lower values for both average weight gain and the rate of weight gain from 7 to 14 days of age. The inhibition of gastric acid secretion decreased curd formation in the abomasum as well as daily weight gain compared to non-treated control calves. This suggested that curd formation in the abomasum is important for the weight gain of newborn calves.     

Comparative insecticidal activities and metabolic rates of lindane and its hexadeuterio-analog

Hexadeuterio-lindane(γ-BHC-d₆) was several times as toxic as lindane against the mosquito (Culex pipiens pallens), house fly (Musca domestica), German cockroach (Blattella germanica) and American cockroach (Periplaneta americana). The neuroexcitatory activity of these two compounds did not differ. Lindane was considerably synergized by piperonyl butoxide, but lindane-d₆ was not. A large isotope effect was observed in the in vivo breakdown of lindane-d₆. Thus, the intrinsic toxicities of both compounds are equivalent. The difference in insecticidal activity seems to be due to the different rates of detoxifying biodegradation caused by the kinetic deuterium isotope effect.     

Oxidative metabolism of lindane and its isomers with microsomes from rat liver and house fly abdomen

Lindane and other hexachlorocyclohexane isomers produced 2,4,6-trichlorophenol as the major oxidative metabolite when incubated in the presence of NADPH under aerobic condition. A mechanism for the formation of 2,4,6-trichlorophenol is proposed, which includes direct oxygenation of the cyclohexane ring. The proposed mechanism is supported by data from studies of model chemical reactions of the pentachlorocyclohexanol isomers. Pathways leading to 1,2,4-trichlorobenzene, tetrachlorobenzene isomers, 2,4,5-trichlorophenol, and tetrachlorophenol isomers are discussed, and are considered to include the route through pentachlorocyclohexene and hexachlorocyclohexene. Reductive dechlorination of lindane under anaerobic condition was observed using microsomes and NADPH.