TKoDi ciioN oi' |•.^/,^ .\ii:s 



189 



Krassiliiikov as Proarlinonit/ns ci/tapkiujiis, 

 all of whicli, (>sp(>('ially the first, appear to 

 Ix'lonu; to the nocardia tiroup. 



'riicrc is no (lucstioii that ('('llulolytic en- 

 zymes ai'e in\-ol\-e(l in tliese |)i()eesses, al- 

 tliouiili lliey ha\(' not \'et heeii denionst I'ated 

 with any decree of e(>rtainty. 



Li|)ast' ami Kslorase 



Aetinoniyei^tes are found ahundantly on 

 fats, especially on butter. Jensen diMnon- 

 strated in 1!K)2 that certain chi'oinojiXMiic 

 actinoniycetes are al)le to <>;r()\v in sterile 

 butter and produce consideral)le amounts 

 of acid. I.ieske r(>poi'ted that act inoniycetes, 

 espcH'ially the aerol)ic forms jjroduciu'j; long 

 mycelium, are capal)le of attacking a ^•ariety 

 of fats. The fatty acids produced nrv neutra- 

 lized by the salts in the medium, gi\'ing rise 

 to characteristic, mostly needle-shaped, cr^'s- 

 tals. To what extent hydrolytic mechanisms 

 of the lipase and esterase t,ype are involved 

 is still uncertain. Some of these systems ap- 

 jjeartoplay an important part in the spoilage 

 of N'arious fats and cacao and in odor produc- 

 tion. 



Oxidative Enzymes 



Actinomycetes possess a number of oxida- 

 tive mechanisms, only a few of which are 

 recognized at the present time (Sano, 1902). 

 The production of phenol oxidases by certain 

 actinomyc(*tes has recently attracted con- 

 siderable attention. Hockenhull ef al. (1954) 

 studied a-phenyl mamiosidase production 

 by .S. griseus. After a suitable manometric 

 method for the determination of this en- 

 zyme had been worked out, a phenol oxidase 

 of the laccase type was found by 8e\cik in 

 *S'. antibiolicus. This laccase was an endo- 

 enzyme with a maximiun acti^'ity at pH 

 4.0 to 4.5. Hydnxjuinone was oxidized most 

 lapidly, catechol more slowly, and p-phen- 

 ylenediamine very slowly. When growing S. 

 antibioticus in submerged cultures on diffei- 

 ent media using a rotating shaker, Sevcik 



found a dii-ect rc'lation between the produc- 

 tion of the antibiotic actinomycin and that 

 of phenol oxidases. ( )n the basis (>( these 

 results, he concluded that phenol oxidase of 

 the lacca.se type pai't icipates most probably 

 in the bio.synthesis of actinomycin by .S. 

 (UttihiolicKs. 



Kiister demonstrated the presence of 

 phenol oxidases in the autolyzate of various 

 cultures of st i-ejitomyees such as S. virido- 

 rhn»H(>(i(N(s. These enzymes are capable of 

 producing humic acid-like substances; this 

 finding was believed to be evidence of the 

 role of actinomycetes in humus formation. 



Hirsch and Wallace (1951) studied tlie 

 octanoxida.se system of *S. anrenfaciens, and 

 Kempf and Hayles (1946) the oxidation- 

 reduction potentials of S. griseus. Cochrane 

 made a comprehensive examination of the 

 enzymes in\-olved in the utilization of car- 

 bohydrate by S. coelicolor. The organism 

 forms the enzymes phosphofructokinase, al- 

 dolase, triose phosphate isomerase, triose 

 phosphate dehydrogenase, phosphoglyceryl 

 kinase, enolase, and ethanol dehydrogenase, 

 (xrowth of *S. coelicolor resembles yeast fer- 

 mentation in its re(iuirements for phosphate, 



50 



40 

 ^ 20 



,-^ -^ i A i I 



10 15 20 



r//^E IN MINUTES 



30 



35 



Figure 78. Oxidation processes by cell-free ex- 

 tracts of .V. (oraUina: 1. endogenous; 2, thymuie; 

 3. uracil; 4. l)arl)iturate. (Reproduced from: Lara, 

 F. J. S. J. Bacteriol. 64, 2S1, 1952). 



