A soup stock made from katsuobushi is an important element of, and the basic seasoning responsible for the taste of, traditional Japanese cuisine. Fermented and ripened katsuobushi, called karebushi, is manufactured via a repeated molding process on the katsuobushi surface. Our aim was to characterize the surface Aspergillus community and their enzymes involved in the fermentation and ripening. Five dominant Aspergillus species isolated from the karebushi surface were identified-A. amstelodami, A. chevalieri, A. pseudoglaucus, A. ruber, and A. sydowii. Analyses were performed on final molding stage-samples from different manufacturers, and 1st to 4th molding stage-samples from the same manufacturer. The composition ratios of the five Aspergillus spp. varied according to the manufacturer of the karebushi. A. amstelodami and A. chevalieri tended to be detected as dominant species when the water content of the karebushi fillet was >15% and the fat content was >3.5%, respectively. In samples from a given manufacturer, the dominant species in the final molding stage tended to be A. chevalieri and A. pseudoglaucus. Mixed molds were cultured by solid-state fermentation using katsuobushi powder medium at two different water activity (aw) levels. Crude extracts from each culture showed lipase, aminopeptidase, carboxypeptidase, and protease activities. Notably, the crude extracts cultivated at 0.85 aw showed higher protease activity toward hemoglobin and lipase activity toward p-nitrophenyl palmitate than those at 0.95 aw. These hydrolytic enzymes are probably involved in decolorization of katsuobushi and lipid degradation during the long fermentative and ripening period. In addition, mixed cultures could transform 2,6-dimethoxyphenol into 1,2,3-trimethoxybenzene, previously reported as an attractive and mild flavor component. Our results may help promote the use of desirable Aspergillus spp. as starter cultures for manufacturers to stabilize and improve the quality of fermented and ripened karebushi.

中文翻译：

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胜卜氏传统发酵和成熟过程中表面曲霉群落的特征。

用胜负汤制成的汤料是传统日本料理的重要组成部分，也是调味的基本调味剂。经过发酵和成熟的胜负汤，被称为karebushi，是通过在胜负汤表面上进行重复成型工艺制成的。我们的目的是表征表面曲霉菌群落及其参与发酵和成熟的酶。从karebushi表面分离的5种优势曲霉菌被鉴定为-A。amstelodami，A。chevalieri，A。pseudoglaucus，A。ruber和A. sydowii。对来自不同制造商的最终成型阶段样品以及来自同一制造商的第一至第四成型阶段样品进行了分析。五个曲霉属的组成比。根据karebushi的制造商而有所不同。A. amstelodami和A. 当karebushi圆角的水含量分别> 15％和脂肪含量> 3.5％时，倾向于将骑士肉作为优势种。在给定制造商的样品中，最终成型阶段的优势种倾向于是奇异曲霉和拟青曲霉。混合霉菌通过使用胜布ob粉末培养基在两种不同水活度（aw）水平下进行固态发酵进行培养。每种培养物的粗提物均显示出脂肪酶，氨肽酶，羧肽酶和蛋白酶活性。值得注意的是，在0.85 aw下培养的粗提物对血红蛋白的蛋白酶活性和对对硝基苯基棕榈酸酯的脂酶活性比在0.95 aw下的更高。在长时间的发酵和成熟期间，这些水解酶可能参与了胜布ushi的脱色和脂质的降解。另外，混合培养物可以将2，6-二甲氧基苯酚转化为1,2,3-三甲氧基苯，以前据报道是一种有吸引力且温和的风味成分。我们的结果可能有助于促进使用理想的曲霉属。作为制造商的入门文化，用于稳定和提高发酵熟成的喀勒比希的质量。