Microbiota analysis of Caspian Sea yogurt, a ropy fermented milk circulated in Japan

We analyzed the microbiota of domestic ropy fermented milk, Caspian Sea yogurt (or 'kasupikai yohguruto' in Japanese), circulated in Japan. We collected six varieties from five localities. Lactococcus ( L) lactis ssp. cremoris was isolated from all samples as the dominant strain at levels of 10⁸−10⁹ CFU/g. We show this strain produces an extracellular polysaccharide (EPS) that causes the unique characteristic viscosity of the product. From analysis of the RAPD pattern of 60 bacterial isolates from the six samples, we found that 59 strains from a total of 60 isolates were identical and produced this viscosity. Furthermore, PFGE analysis of representative strains from each sample indicated that the isolates could be classified into four subgroups. This suggests these L. lactis ssp. cremoris strains found in Caspian Sea yogurt may have been slightly mutated during subculture in Japan. In addition, Lactobacillus (L.) sakei ssp. sakei were isolated from three samples; L. plantarum , Gluconoacetobacter sacchari and Acetobacter aceti were isolated from two samples; and L. paracasei , L. kefiri , Leuconostoc ( Leu. ) mesenteroides were isolated from one sample.     

Characteristic upregulation of glucose-regulated protein 78 in an early lesion negative for hitherto established cytochemical markers in rat hepatocarcinogenesis

Previously, we reported α(2)-macroglobulin (α(2)M) to be a novel marker characteristic of rat hepatocellular preneoplastic and neoplastic lesions negative for hitherto well-established markers. In the present study, we further examined other candidate markers with specificity for the same type of lesions. Glutathione S-transferase-placental form (GST-P)-negative hepatocellular altered foci (HAF) were generated using a two-stage (initiation and promotion) carcinogenesis protocol with N,N-diethylnitrosamine (DEN) and either Wy-14,643 or clofibrate, two peroxisome proliferators. Microarray analysis using total RNAs isolated from laser-microdissected GST-P-negative HAF (amphophilic cell foci) and adjacent normal tissues was conducted along with immunohistochemistry and real-time RT-PCR. Staining for glucose-regulated protein 78 (GRP78) was detected in GST-P-negative HAF and hepatocellular adenomas, and slightly increased GRP78 mRNA expression was observed in the lesions by real-time RT-PCR analysis. Thus, an early increase of GRP78 expression in hepatocarcinogenesis is likely a feature of the amphophilic subset of HAF.     

Cylindrocladium brown leaf spot on Howea belmoreana caused by Calonectria ilicicola (anamorph: Cylindrocladium parasiticum) in Japan

Brown leaf spot disease caused by Cylindrocladium was found on Howea belmoreana on Hachijojima Island, Tokyo, Japan, in December 2001. Typical symptoms were incited after artificial inoculation. A culture of white mycelia, isolated from leaf spot symptoms, produced reddish perithecia of a nectriaceous fungus. Based on morphological and molecular analyses, this fungus was identified as Calonectria ilicicola (anamorph: Cylindrocladium parasiticum). Pathogenicity of this fungus on five plants cultivated on Hachijojima Island was confirmed by artificial inoculation. This report is the first on Cylindrocladium brown leaf spot of H. belmoreana caused by C. ilicicola (anamorph: Cy. parasiticum).     

Multiplex PCR assay for simultaneous detection of MBI-D and Q<Subscript>o</Subscript>I resistance in rice blast fungus

For sustainable control of rice blast with fungicides, efficient monitoring of the emergence and spread of fungicide-resistant isolates is needed. We developed simple and reliable PCR-based DNA markers to detect isolates resistant to melanin biosynthesis inhibitor targeting scytalone dehydratase (MBI-D) and quinone outside inhibitor (Q_oI) fungicides. Through the use of DNA templates prepared from mycelia on filter paper or from infected leaves, these markers enable rapid (a few hours) genotyping of point mutations that confer resistance. The developed multiplex marker detected resistance to both MBI-D and Q_oI in a single PCR and further reduced the time needed for diagnosis.     

Identification of bitterness-masking compounds from cheese

Bitterness-masking compounds were identified in a natural white mold cheese. The oily fraction of the cheese was extracted and further fractionated by using silica gel column chromatography. The four fractions obtained were characterized by thin-layer chromatography and nuclear magnetic resonance spectroscopy. The fatty acid-containing fraction was found to have the highest bitterness-masking activity against quinine hydrochloride. Bitterness-masking activity was quantitated using a method based on subjective equivalents. At 0.5 mM, the fatty acid mixture, which had a composition similar to that of cheese, suppressed the bitterness of 0.008% quinine hydrochloride to be equivalent to that of 0.0049-0.0060% and 0.5 mM oleic acid to that of 0.0032-0.0038% solution. The binding potential between oleic acid and the bitter compounds was estimated by isothermal titration calorimetry. These results suggest that oleic acid masked bitterness by forming a complex with the bitter compounds.     

Influence of zinc deficiency to the mice infected with Babesia microti

Zinc (Zn) is an essential trace element for DNA synthesis and for cell growth and differentiation. The deficiency induces a wide range of disorders including immunodeficiency. In this study, the influence of Zn deficiency to the mice infected with Babesia microti was examined, and was compared with the influence in the rats infected with B. rodhaini previously reported. Experiments of B. microti infection were conducted using Zn-deficient (ZD; allowed to eat ad libitum on the ZD diet), Zn-adequate (ZA; allowed to eat ad libitum on the ZA diet), and diet-restricted (DR; supplied 2 g/day on the ZA diet) mice. It was suggested that the Zn deficiency exacerbated the infection dynamics of the mice with B. microti by the growth retardation, the reduction of immunity and the decrease in PCV. The results in the mice supported the consequences in the rats previously reported.     

Effect of boiled barley-rice-feeding in hypercholesterolemic and normolipemic subjects

Barley contains approximately 10% dietary fiber and is easily cooked with rice, the dominant cereal in Japan, to increase the intake of dietary fiber. This research involved three experiments to examine the influence of barley on blood lipids in human subjects. All subjects received a boiled barley-rice (50/50 w/w mix) supplement two times per day in place of rice for 2 or 4 weeks. In the normolipemic subjects, serum lipids were unaffected by the ingestion of barley for 4 weeks. In twenty hypercholesterolemic men aged 41 ± 5 years, the ingestion of barley was associated with a significant fall in serum total cholesterol, LDL-cholesterol, phospholipids and LDL and VLDL-lipoproteins. In seven mildly hypercholesterolemic women aged 56±7 years, a significant improvement of serum lipid profiles was observed. The present study suggests the possibility that the ingestion of barley-rice could lower serum lipids in hypercholesterolemic subjects.     

Morphological and molecular characterization of <Emphasis Type="Italic">Oidium</Emphasis> subgenus <Emphasis Type="Italic">Reticuloidium</Emphasis> (powdery mildew) newly occurred on cucumber in Japan

In 2002, a powdery mildew with catenate conidia lacking fibrosin bodies was found on cucumber in a greenhouse in Kanagawa Prefecture, Japan. Morphological observation revealed that the fungus belongs to Oidium subgenus Reticuloidium, anamorph of the genus Golovinomyces. Molecular phylogenetic analyses of the nucleotide sequences of the rDNA ITS regions and D1/D2 domains of the 28S rDNA indicated that the fungus belongs to the clade of G. orontii with other Golovinomyces fungi from a wide range of host plants, suggesting that the fungus was newly transported from abroad. Because there has been no prior report of cucumber powdery mildew caused by Reticuloidium, further research on the physiology, epidemiology, control and resistant cucumber varieties is required.