Softening and Salts Movement in the Ripening Process of Camembert Cheese

Experimental Camembert cheese softened from the surface to the center portion after 3-4 weeks of ripening.As ripening progressed,pH value rose from 4.5 to 7.8,lactic acid content decreased from 1.0% to 0.1%,ammonia content increased from 0.04g to 0.063g/100g,calcium content decreased from 0.3g to 0.048g/100g and phosphorus content decreased from 0.25g to 0.12g/100g in the center portion of cheese. The changes in these values were considered as criteria leading to softening of mold surface-ripened cheeses.Mold starter Penicillium candidum AM used the cheese manufacture possesses the abilities lactic acid,producing ammonia and lowering pH when supplemented with lactic acid and peptone Czapek Dox solution.However,normal softening was not observed by incubation of green cheese under ammonia atomsphere conditions.Also,lactic acid free cheese did not soften in spite of mold growth.It is proposed that the primary factor of softening in mold surface-ripened cheese is a rise of casein solubility caused by lowering of calcium crosslinking due to a decrease of calcium level in the cheese texture.The results suggested that the lactic acid metabolism and pH rise play a main part in inducement,and that insolble calcium phosphate accumulates in the cheese surface.本研究は、カマンベールチーズの熟成における軟化の主因と考えられているチーズ内でのpHや塩類の動態を追跡したものである。熟成開始前のグリーンチーズに比べて熟成が完了した4週目のチーズ中心部では、pHは4.5から7.8に上昇、乳酸は1.0% から0.1% で約1/10に低下、アンモニアは100g当たり0.04gから0.063gで約1.5倍に上昇、カルシウムは100g当たり0.3gから0.04gで約1/10のに減少、リンは100g当たり0.25gから0.12gで約1/2に減少した。これらの変化が本チーズの熟成軟化の要件と推察される。培養試験から、本チーズに使用したかびスターター　Pen. candidumに乳酸の代謝能とアンモニアの生成能を有すること、その結果pHが上昇することが確認された。しかし、未成熟のグリーンチーズをアンモニア蒸気にさらした場合も、乳酸を含まないチーズを熟成させた場合も正常な軟化は生じなかった。最も顕著な変化は、pH、乳酸、カルシウムに認められたが、これらのチーズ内での動態が主導的な役割を果たすものと推察された

Conformational alterations in unidirectional ion transport of a light-driven chloride pump revealed using X-ray free electron lasers

光でイオンを輸送する膜タンパク質の巧妙な仕組み --XFELが捉えた光駆動型イオンポンプロドプシンの構造変化--. 京都大学プレスリリース. 2022-02-28.Light-driven chloride-pumping rhodopsins actively transport anions, including various halide ions, across cell membranes. Recent studies using time-resolved serial femtosecond crystallography (TR-SFX) have uncovered the structural changes and ion transfer mechanisms in light-driven cation-pumping rhodopsins. However, the mechanism by which the conformational changes pump an anion to achieve unidirectional ion transport, from the extracellular side to the cytoplasmic side, in anion-pumping rhodopsins remains enigmatic. We have collected TR-SFX data of Nonlabens marinus rhodopsin-3 (NM-R3), derived from a marine flavobacterium, at 10-µs and 1-ms time points after photoexcitation. Our structural analysis reveals the conformational alterations during ion transfer and after ion release. Movements of the retinal chromophore initially displace a conserved tryptophan to the cytoplasmic side of NM-R3, accompanied by a slight shift of the halide ion bound to the retinal. After ion release, the inward movements of helix C and helix G and the lateral displacements of the retinal block access to the extracellular side of NM-R3. Anomalous signal data have also been obtained from NM-R3 crystals containing iodide ions. The anomalous density maps provide insight into the halide binding site for ion transfer in NM-R3

Epidemiological Observations on Infectious Hepatitis Prevailed in Okayama Prefecture

6246 infectious hepatitis cases treated at 25 hospitals located in Okayama Prefecture during the last six years, 1952 to 1957, were studied mainly from the epidemiological point of view, and the following results were obtained. 1) Infectious hepatitis has been prevailed all over the prefecture since the initial epidemic in 1951. As the mode of epidemic became protracted, chronic and abortive forms were prone to increase in number. The ratio of total patients to infectious hepatitis cases was 1.27 per cent. 2) Extensive infections among villagers were noted in 73 hamlets, and it was presumed that the epidemic has been prevailed over the whole prefecture taking a hamlet, village or a town as unit. Infections among family were noted in 62 families, however, fnrther detailed study in the epidemic areas might show the higher morbidity. It was not certain whether these infections were entirely family or simultaneous infections. 3) As to seasonal occurence, considerable number of cases had onset of the disease during the period of early summer to early fall. 4) As to age, it has ranged mostly from the second to third decade, rather many in children but not rare in the aged. As to sex, predominant in males in general, but considerable differences were seen among hospitals and times. No definite relationship was noted between the epidemc and sex. 5) Throughout the last six years there have been 38.7 per cent of chronic hepatitis cases. In 41.3 per cent of the whole patients presented jaundice in their clinical courses. The fact that the longer the period of the epidemic the more increase increase in anicteric cases was noted. 6) Two year's follow-up studies after the epidemic, showed 209 of relapsed cases in whom 36.4 per cent were icteric. 7) 110 cases has jaundice, which was thought to be infectious hepatitis, in the past. Some of them were presumably reinfections or superinfections but definite conclusion could not be made. 8) 20 cases of fulminant hepatitis, malignant type of infectious hepatitis, and 6 cases of protracted form were studied. 22 cases of them were fatal. Such severe hepatitis patients were seen mainly in males of the second and third decades. 9) 61 cases (0.98%) developed postnecrotic cirrhosis, and 10 cases of them were fatal. 10) Serum hepatitis was noted in 1.6 per cent of the whole patients seen in Medical Services at 18 hospitals in Okayama Prefecture during the last six years, 1952 to 1957. No definite correlation between the epidemic of infectious hepatitis and outbreak of serum hepatitis was noted