Enhanced Z-Isomerization of Astaxanthin in Paracoccus carotinifaciens via Microwave Drying.

The effects of microwave drying conditions of a Paracoccus carotinifaciens culture solution on astaxanthin Z-isomerization and degradation were investigated. The microwave drying significantly increase the ratio of astaxanthin Z-isomers, and the higher the microwave power and the longer the drying time, the higher the total Z-isomer ratio of astaxanthin, but such conditions also accelerated astaxanthin degradation. We found that the addition of powdered oils enhanced the Z-isomerization reaction. For example, when the P. carotinifaciens culture solution was dried at 1000 W power for 5 min without and with powdered rapeseed oil, total Z-isomer ratios of astaxanthin in resulting dried powder were 14.9 and 47.4%, respectively. Furthermore, the storage test of the dried P. carotinifaciens powder showed that astaxanthin Z- isomers were stable at 4℃ in a low-oxygen atmosphere. As astaxanthin Z-isomers have greater bioavailability and potentially exhibit superior biological activities than the all-E-isomer, the dried P. carotinifaciens powder obtained by the method of this study is expected to be used as a value-added astaxanthin source.

Effects of Cyclic High Ambient Temperature on Muscle Imidazole Dipeptide Content in Broiler Chickens.

Imidazole dipeptides possess important bioregulatory properties in animals. This study aimed to evaluate the effect of high ambient temperature on muscle imidazole dipeptides (carnosine, anserine, and balenine) in broiler chickens. Sixteen 14-day-old male broiler chickens were divided into two groups, which were reared under thermoneutral (25 ± 1 °C) or cyclic high ambient temperature (35 ± 1 °C for 8 h/day) for 4 weeks. Chickens exposed to cyclic high ambient temperatures displayed lower skeletal muscle anserine and carnosine content than control chickens. Balenine could not be detected in the pectoral muscle of either group. The pectoral muscles of broiler chickens kept under cyclic high-temperature exhibited significantly lower mRNA expression of carnosine synthase 1, which synthesizes carnosine and anserine; but a significantly higher mRNA expression of carnosinase 2, which degrades carnosine and anserine. Our results suggest that heat exposure decreases pectoral imidazole dipeptide content in broiler chickens. This may be attributed to a lower expression of imidazole dipeptide-synthesizing genes, but higher levels of genes involved in their degradation.

Effects of Astaxanthin Preparation Form on the Efficiency of Egg Yolk Pigmentation in Laying Hens.

This study investigated the effects of the preparation form of astaxanthin on egg yolk pigmentation and egg quality in laying hens. The following four astaxanthin sources were prepared in this study: (1) dried cell powder of Paracoccus carotinifaciens (Panaferd-AX), (2) fine cell powder of P. carotinifaciens (Panaferd-P), (3) astaxanthin oil suspension, and (4) water-soluble astaxanthin powder. These astaxanthin preparations were added to the basal diet at a final concentration of 2 mg/kg and fed to White Leghorn laying hens for 14 days. Although the administration of these astaxanthin preparations did not largely affect egg quality (i.e., egg weight, yolk weight, albumen height, and Haugh unit), feeding significantly improved astaxanthin concentration and yolk color fan score. When water-soluble astaxanthin powder was fed, the yolk astaxanthin concentration and color fan score were most improved, followed by Panaferd-P. These results indicated that astaxanthin pulverization and water solubilization significantly improved its bioavailability in laying hens. Furthermore, although diets rich in (all-E)-astaxanthin were fed to the hens, approximately 30% of astaxanthin was present as the Z-isomers in the egg yolk. These findings may contribute to improving not only the egg quality but the nutritional value of hen eggs.

Improved Flesh Pigmentation of Rainbow Trout (Oncorhynchus mykiss) by Feeding Z-Isomer-Rich Astaxanthin Derived from Natural Origin.

The use of Paracoccus carotinifaciens-derived natural astaxanthin as an alternative to synthetic astaxanthin has attracted considerable attention from the aquaculture industry. Furthermore, to enhance the bioavailability of astaxanthin, its "Z-isomerization" has been actively studied in recent years. This study investigated the effects of feeding a diet containing astaxanthin rich in the all-E- or Z-isomers derived from P. carotinifaciens on the pigmentation and astaxanthin concentration in rainbow trout (Oncorhynchus mykiss) flesh. Z-Isomer-rich astaxanthin was prepared from the P. carotinifaciens-derived all-E-isomer by thermal treatment in fish oil, and the prepared all-E-isomer-rich astaxanthin diet (E-AST-D; total Z-isomerratio = 9.1%) and Z-isomer-rich astaxanthin diet (Z-AST-D; total Z-isomer ratio of astaxanthin = 56.6%) were fed to rainbow trout for 8 weeks. The feeding of Z-AST-D resulted in greater pigmentation and astaxanthin accumulation efficiency in the flesh than those fed E-AST-D. Specifically, when E-AST-D was fed to rainbow trout, the SalmoFan score and astaxanthin concentration of the flesh were 22.1±1.4 and 1.36±0.71 µg/g wet weight, respectively, whereas when Z-AST-D was fed, their values were 26.0±2.5 and 5.33±1.82 µg/g wet weight, respectively. These results suggest that P. carotinifaciens-derived astaxanthin Z- isomers prepared by thermal isomerization are more bioavailable to rainbow trout than the all-E-isomer.

Characteristics of LED light-induced geometrical isomerization and degradation of astaxanthin and improvement of the color value and crystallinity of astaxanthin utilizing the photoisomerization.

The effects of light-emitting diode (LED) irradiation characterized by different emission wavelengths on the E/Z-isomerization and degradation of astaxanthin were investigated. LED irradiation slightly promoted Z-isomerization of astaxanthin, whereas the all-E-isomerization was highly efficiently promoted at specific wavelengths, especially at 365 nm. Astaxanthin isomers did not degrade significantly when dissolved in ethanol and subjected to LED irradiation conditions for 300 min. However, significant degradation was achieved when ethyl acetate was used for dissolution, and the samples were irradiated at the wavelength of 405 nm. The addition of α-tocopherol suppressed the photodegradation of astaxanthin. LED irradiation significantly affected the physical properties of astaxanthin Z-isomers. Irradiation with 365, 405, and 470 nm LEDs enhanced the color value (redness) and crystallinity of the Z-isomers via an all-E-isomerization reaction. These findings can contribute to the development of technologies that can arbitrarily control the E/Z-isomer ratio and physical properties of astaxanthin.

Pneumocystis pneumonia diagnosed by repeated measurements of ß-D-glucan levels.

ß-D-glucan is extensively employed as a supplementary diagnostic tool for Pneumocystis pneumonia (PCP) and typically yields positive results in most cases. We present a case of a 73-year-old woman with a history of rheumatoid arthritis, who was receiving biological agents and was admitted due to pneumonia. Initially, the ß-D-glucan test was negative. However, as the disease progressed, it eventually turned positive, leading to the diagnosis of PCP. The patient was treated with corticosteroids and trimethoprim-sulfamethoxazole, resulting in pneumonia resolution. Our findings suggest that repeated assessment of ß-D-glucan levels holds diagnostic value in patients without human immunodeficiency virus infection.

"Burgundy wine" pleural effusion: An unusual manifestation of acute bacterial empyema.

Although empyema diagnosis by thoracentesis is relatively straightforward, the pleural effusion can sometimes be bloody rather than purulent. We report a case of acute empyema with a dark-red bloody effusion, wherein multiple anaerobic bacteria were detected. Chest imaging findings improved with pleural drainage, intrapleural fibrinolytic therapy, and intravenous antibiotic treatment.

Commercial Production of Astaxanthin with Paracoccus carotinifaciens.

Paracoccus carotinifaciens is an aerobic Gram-negative bacterium that exhibits motility by a peritrichous flagellum. It produces a carotenoid mixture containing astaxanthin as the main component. Selective breeding of P. carotinifaciens has been performed using classical techniques for mutation induction, such as chemical treatment and ultraviolet irradiation, and not using genetic engineering technology. The commercial production of astaxanthin with P. carotinifaciens has been established by optimizing fermentation medium and conditions in the process. Dehydrated P. carotinifaciens is used as a coloring agent for farmed fish and egg yolks. Compared with the administration of chemically synthesized astaxanthin, dehydrated P. carotinifaciens imparts more natural coloration, which is favored by consumers. In addition, astaxanthin-rich carotenoid extracts (ARE) derived from P. carotinifaciens are developed for human nutrition. Animal and clinical studies with ARE for evaluating its efficacy have been conducted and suggested that ARE would be useful for preventing anxiety, stomach ulcer, and retinal damage, as well as improving cognitive function. The efficacy is anticipated to result from not only astaxanthin but also other carotenoids in ARE, such as adonirubin and adonixanthin, in some studies. Hence, astaxanthin commercially produced with P. carotinifaciens has been applied widely in animals and humans.

Lowering effect of viable Pediococcus pentosaceus QU 19 on the rise in postprandial glucose.

In the present study, we investigated the glucose-decreasing action of lactic acid bacteria (LAB). The finding of this study could be helpful for people in controlling their blood sugar levels. The LAB candidate was isolated from a Japanese fermented food and identified as Pediococcus pentosaceus by an analysis of its genome sequence. Postprandial blood glucose elevation was investigated using oral starch tolerance tests in mice. Normal mice were fed starch and lyophilized cells of P. pentosaceus QU 19 at the same time. Even without pre-administration of P. pentosaceus QU 19, elevation of the blood glucose level was significantly suppressed by the intake of P. pentosaceus QU 19 at the same time as oral administration of starch. According to the results for its survival in simulated digestive juice and the reduction of blood glucose level in mice, P. pentosaceus QU 19 has potential hypoglycemic activity. In vitro measurements revealed that the glucose-decreasing action of P. pentosaceus QU 19 is probably caused by the glucose assimilation of the strain, not the inhibition of carbohydrate-splitting enzymes which has been reported for other LABs previously. These findings indicate that specific strains of LAB, especially P. pentosaceus QU 19, and foods fermented by LAB may be beneficial for people who must manage glucose ingestion.

A solid-phase affinity labeling method for target-selective isolation and modification of proteins.

Solid-phase affinity labeling of a target protein, peanut agglutinin (PNA), with the specifically designed chemical tool 1 selectively and effectively furnished the labeled PNA. Furthermore, this method was applicable to native human carbonic anhydrase II in red blood cell lysate using the chemical tool 2 without the need for tedious manipulations.