Taxonomic Studies on Japanese Industrial Strains of the Aspergillus (Part 32)

Abstract

For discrimination of clusters, arrangement of sterigmata, culture temperature and large conidia were found to be most available, and the stalks length, diameter of conidia and conidial heads, conidial walls and occasionally color of conidial heads were also seemed to be significant from the figures in Part 31 and some experimental results. Thus, all of the strains of the Black Aspergilli were classified into 2 groups, i. e. the A. niger group and the Black Koji-mold group, and they were divided into 4 series and 3 series, respectively, as shown in Table 98, which was obtained by transplacing the cluster e in the cluster f in Part 31, in order to simplify the classification system.
Some common characters of the principal series were described below.
A. niger group
A. niger series: conidial heads mostly black and large, conidiophores long and thick, nitrites mostly not assimilating, amylase activity low but acid production usually much, including many authentic strains from abroad.
A. pulverulentus series: similar to A. niger series except for the small conidial heads.
Black Koji-mold group
A. aureus series: conidial heads showing mostly dark brown and large, nitrites not assimilating, amylase activity and acid production varying with strain, including many black koji-molds as well as those emphasized by R. NAKAZAWA in 1916 as' golden yellow koji-mold'.
A. awamori series: conidial heads showing mostly brown and small, nitrites usually assimilating, amylase activity high but acid production variable, including many Black Koji-molds ; strains showing umber to cinnamon with some green shades were named A. luchuensis Inui and discriminated from those of A. awamori Nakazawa not showing such a color.
The nitrites assimilation was too drastic to be generally taken as a key as seen in Fig. 46 in Part 31. The activity to produce acid or amylase is difficult to be taken into a key character, however, it is of great interest in view of their industrial uses that strains in some clusters showed peculiar activity of acid production and amylase as seen in Figs. 47 and 48 in Part 31, respectively.