Four kinds of carotenoid pigments were found in Rhodococcus rhodochrous RNMS1. Spectroscopic and chemical evidence showed two of them to be monocyclic carotenoids each containing a tertiary hydroxyl group at Cr, and their structures were determined as r,2'-dihydro-/J,^-caroten-rol and r-hydroxy-r,2'-dihydro-/?,^r-caroten-4-one. The other two were novel carotenoid derivatives, one being a monoglycoside of the latter carotenoid and the other monoesters of this carotenoid glycoside, which were esterified with nine major fatty acids at the C6 hydroxyl group of the glucose moiety. The fatty acids consisted of four saturated (C16 : 0-C19 : 0), four mono-unsaturated (C18 : 1-C21 : l) and one branched-chain (10-methyl C19: 0) acid, including the odd-numbered ones. The structures were determined to be r-[(^-D-glucopyranosyl)oxy]-r,2'-dihydro-^,^r-caroten-4-one and r-[(6-0-acyl-0-D-glucopyranosyl)oxy]-1^2 ' Klihydro-/^-caroten-4-one. Rhodococcus rhodochrous RNMS1 , formerly called "Bacillus megaterium roseus" B3-9,1'2) forms light orange colored colonies. Wehave already found that pigments causing this color belonged to several carotenoids.3) Colonies of other species of the Rhodococcus genus are known to be red, orange or pink colored.4) Recently, Ichiyama et al. have reported the presence of carotenoids in several species of the Rhodococcus genus.5) However, conclusive identification of these carotenoids has not be undertaken.

A ribonucleoside 2',3'-cyclic phosphodiesterase (cyclic phosphodiesterase) having 3'-nucleotidase activity was purified from the cell-free extract of Bacillus subtilis var. amyloliquefacus, and its enzymatic properties were examined. The molecular weight was approximately 74,000. The enzyme was highly specific for ribonucleoside 2',3'-cyclic monophosphate (2',3'-cyclic mononucleotide), and ribonucleoside 3'-monophosphate (3'-mononucleotide), and also hydrolyzed bis p-nitrophenyl phosphate (bis p-NPP) but at a rate much slower than that of 3'-mononucleotide. Both cyclic phosphodiesterase and 3'-nucleotidase activities had an optimum pH of about 6.7, and phosphodiesterase activity against bis p-NPP indicated a relatively sharp pH optimum at 5.0. Only phosphodiesterase activity against bis p-NPP was greatly activated by Co2~, but both cyclic phosphodiesterase and 3'-nucleotidase activities were inhibited. However, Co2+ had an effect of protecting the enzyme against heat inactivation. 3'-Nucleotidase activity was not affected by EDTA, while phosphodiesterase activities against both 2',3'-cyclic mononucleotide and bis p-NPP were greatly inhibited. The enzyme hydrolyzed 3'-AMP with Km 0.046 mM and Vmax 1,585 µmol per hr per mg protein, bisp-NPP with Km 0.16 mM and Vn,a. 233 ,umol per hr per mg protein.In the course of studies on the physiological changes occurring after infection of Bacillus subtilis var. amyloliquefacus with phage, we became aware that a phosphodiesterase activity hydrolyzing bis p-nitrophenyl phosphate (bis p-NPP) under the acidic pH region (an optimal pH of about 5.0) exists in the phage uninfected cell-free extract, and that this activity did not change after infection of host cell with phage.In a preliminary experiment, attempts were made to characterize the substrate specificity using the enzyme partially purified by DEAF-cellulose chromatography. 487