Investigation of lactic acid bacterial strains for meat fermentation and the product's antioxidant and angiotensin‐I‐converting‐enzyme inhibitory activities

In the lactic acid bacteria (LAB) strains screened from our LAB collection, Lactobacillus (L.) sakei strain no. 23 and L. curvatus strain no. 28 degraded meat protein and tolerated salt and nitrite in vitro. Fermented sausages inoculated strains no. 23 and no. 28 showed not only favorable increases in viable LAB counts and reduced pH, but also the degradation of meat protein. The sausages fermented with these strains showed significantly higher antioxidant activity than those without LAB or fermented by each LAB type strain. Angiotensin‐I‐converting‐enzyme (ACE) inhibitory activity was also significantly higher in the sausages fermented with strain no. 23 than in those fermented with the type strain. Higher ACE inhibitory activity was also observed in the sausages fermented with strain no. 28, but did not differ significantly from those with the type strain. An analysis of the proteolysis and degradation products formed by each LAB in sausages suggested that those bioactivities yielded fermentation products such as peptides. Therefore, LAB starters that can adequately ferment meat, such as strains no. 23 and no. 28, should contribute to the production of bioactive compounds in meat products.     

MCPB-ethyl疏花对富士苹果授粉受精及胚珠发育的影响

通过在花期用MCPB-ethyl处理,对富士苹果花粉的发芽、花粉管的伸长以及胚珠的发育等进行了形态方面的观察和探讨,以阐明MCPB-ethyl的疏花机制。结果表明,MCPB-ethyl对花粉的发芽及花粉管的伸长没有影响,整个受精过程与对照相同,没有发现异常。但受精后胚乳核只进行了数次分裂便停止生长,此后珠皮、珠心细胞迅速解体。根据以上结果,认为MCPB-ethyl的疏花效果不是通过影响花粉的发芽或花粉管的伸长阻碍受精所致,而是使胚和胚珠的发育停止,形成离层导致了落花。     

Response of gas exchange rates in <Emphasis Type="Italic">Abies firma</Emphasis> seedlings to various additional stresses under chronic acid fog stress

In order to clarify the chronic influence of acid fog on the gas exchange rates of momi fir (Abies firma Sieb. et Zucc.) trees, we exposed them to simulated acid fog (pH 3) for 3 years. The composition of the acid fog was similar to that observed in a region where momi fir trees have been declining, and it contained organic acids. We then treated the firs with various additional stresses, such as drought, low temperature, fine root cutting, ozone exposure, soil acidification, nitrogen load, and rhizosphere aluminum stress. Under chronic exposure to acid fog, the momi fir seedlings exhibited a pattern of stomatal behavior whereby they excessively opened in summer and closed in winter. Furthermore, the stomata of these seedlings tended to open during drought stress, and their needles were visibly injured after ozone exposure. The net photosynthesis rates of the seedlings exposed to acid fog were regulated by their stomatal aperture, rather than directly by acid fog. These results suggest that acid fog exposure disturbs the control of stomatal function in the momi fir seedlings. In addition, we found that chronic acid fog exposure suppressed the decrease in net photosynthesis rate, due to its nitrogen load.     

Pathological analysis of batch safety testing of veterinary vaccines using small laboratory animals

Batch safety tests (BSTs) of veterinary vaccines are conducted using small laboratory animals to assure the safety of vaccines according to several criteria, including clinical signs and change in body weight. Although the latter is used as an evaluation index in BSTs, there have been no reports on the internal changes that affect body weight during the test period. Therefore, we analyzed BST via pathological examination of the tested animals. Here, BSTs were performed for 176 batches using mice and 126 batches using of guinea pigs. Most of the gross findings could be classified into four lesion types (nodules, adhesions, ascites, no apparent signs), with only one vaccine inducing lesions that could not be classified into any of these four types. Histopathological examination revealed that the reactions caused by BST were pyogenic and/or granulomatous inflammation. Nodular or adhesive lesions comprised more severe pyogenic granulomatous inflammation than ascites or cases with no apparent gross lesions. These nodular or adhesive lesions were more frequently induced by vaccines that contained an adjuvant than by vaccines that did not contain an adjuvant. The cases with “exceptional” gross findings histologically presented severe necrosis of the hematopoietic system. Additional testing showed that these “exceptional” lesions were induced when a specific type of light liquid paraffin was injected along with other vaccine additives. Our results show that body weight loss and/or lesions during BST were induced by proinflammatory properties of the tested vaccines and that BST is a sensitive method for detecting unexpected effects of vaccine components.     

Mitigation of pyrexia by a Th-1-biased IgG subclass response after infection with equine herpesvirus type 1 in horses pre-immunized with inactivated vaccine

The immunoglobulin G (IgG) subclass response was investigated in horses with or without pyrexia after natural infection with equine herpesvirus type 1 (EHV-1) in the field. All horses were kept at the training centers of the Japan Racing Association and were immunized with an inactivated EHV-1 vaccine before EHV-1 infection. An IgG subclass response dominated by IgGa and IgGb was induced in horses without pyrexia after EHV-1 infection. In contrast, horses that developed pyrexia showed increased IgGc and IgG (T) subclass production in addition to IgGa and IgGb. Although inactivated EHV-1 vaccines are considered to induce a mainly Th-2-biased response, these results indicated that the responses in horses inoculated with inactivated EHV-1 vaccine were not uniform, and that horses with a Th-1-biased response were likely to be protected from pyrexia.     

Co-transmission of <Emphasis Type="Italic">Tomato yellow leaf curl virus</Emphasis> (TYLCV)-Mld and TYLCV-IL by the whitefly <Emphasis Type="Italic">Bemisia tabaci</Emphasis>

The ability of the whitefly Bemisia tabaci to transmit two strains of Tomato yellow leaf curl virus, the Israel and Mild strains, was studied after serial transfers of individual whiteflies that were viruliferous for both strains to tomato plants. After single whiteflies had successive acquisition feedings first on a single plant infected with one strain and then on a plant infected with the other strain, the single whiteflies later transmitted intermittently one, the other, or both strains to the test plants during serial transfers at 1-day intervals. Because both strains were found in the head, abdomen, and legs dissected from whiteflies during the retention period after the two successive acquisition feedings, both strains apparently circulate from midgut cells to salivary glands through the hemolymph.     

Thermal tolerance of a thermally selected strain of rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis> and the pedigrees of its F1 and F2 generations indicated by their critical thermal maxima

A thermally selected strain of rainbow trout has been established by selective breeding since 1966 in Miyazaki, Japan. In the present study, we compared the critical thermal maxima (CTMs), the temperatures at which organisms reach a predefined sublethal endpoint and lose their equilibrium, between a thermally selected and two normal (Donaldson) strains of rainbow trout. The CTM of one normal strain from Nikko (Nikko strain) acclimated to 20 °C (29.7 °C) was significantly lower than those of the thermally selected strain (30.0 °C) and the other Donaldson strain from Aomori (29.9 °C) (P?<?0.05). The F1 generations, F1T and F1N, were produced by crossing thermally selected strain females with Nikko strain males and Nikko strain females with thermally selected strain males, respectively. No significant difference was observed in the CTM between F1T [30.1?±?0.15 °C (n?=?30)] and F1N [30.1?±?0.16 °C (n?=?30)] (P?>?0.05) for fish acclimated to 20 °C, suggesting that the F1 offspring inherited the thermal tolerance trait from one thermally selected strain parent irrespective of whether it was the male or female. F2 offspring of F1T or F1N also showed the thermal tolerance trait. The coefficients of variation for CTM were also compared among all the datasets obtained in the present study and their values for F1 hybrids were lower than those of the parental generation of the Nikko strain (P?<?0.05). In contrast, the coefficients of variation of F2s were the same as those of their parental generation. Furthermore, the thermally selected strain and Nikko strain as a reference family provide a F2 generation for segregating phenotypes, which is required for in-depth genetic analysis of the thermally selected rainbow trout strain.     

Tracking the Northern Pacific sea star <Emphasis Type="Italic">Asterias amurensis</Emphasis> with acoustic transmitters in the scallop mariculture field of Hokkaido,Japan

The Northern Pacific sea star Asterias amurensis has a major negative impact on scallop mariculture. In northern Japan, fishermen clean up sea stars before releasing young scallops in the mariculture field; however, new sea stars constantly invade the field from outside areas to feed on scallops. Thus, it is important to determine the migration speed and seasonal behavioral patterns of the Northern Pacific sea star to implement effective density control measures. Here, we set out to quantify these parameters using acoustic telemetry. In a rearing experiment, acoustic transmitters were retained on sea stars for up to 71 days using nylon fishing line. In the field experiment, we showed that the moving distance of the Northern Pacific sea star over a 1-week period was significantly further in spring (90.9 ± 49.9 m) than in summer (25.1 ± 18.9 m), and that the moving speed was significantly faster in spring (18.1 ± 15.2 m/day) than in summer (4.3 ± 9.1 m/day). Our results are the first to present the two-dimensional movement of Northern Pacific sea star individuals in spring and summer. We suggest that sea star extermination practices should be extended beyond the immediate culture area.