42 



THE ACTINOMYCETES, Vol. I 



Among the many organisms that he found 

 in the atmosphere, some, frequently desig- 

 nated as branching bacilli and cladothrix, 

 no doubt belonged to the actinomycetes. 



Rossi-Doria, in 1891, made a detailed in- 

 \'estigation of the actinomycetes in the air. 

 He was the first to use the specific name alba 

 for actinomycete species. Since the genus to 

 which this species belongs is now know^n as 

 Stirptomyces, the Streptothrix alba of Rossi- 

 Doria is now recognized as the type species 

 Strcptomyccs or S. albus. Among the other 

 species listed by him as occurring widely in 

 the atmosphere, were S. violacea, S. albido- 

 flava, S. nigra, S. carnea, S. aurantiaca, and 

 S. chromogena. 



In 1903, Beijerinck and van Delden iso- 

 lated a culture of an organism which was 

 believed capable of purifying laboratory air 

 rich in carbon monoxide. They suggested 

 that the culture used CO gas as a source of 

 energy, the CO being oxidized thereby to 

 COl' . The organism was described as a Ba- 

 cillus, under the name of B. oligocarbophilus. 

 Lantzsch repeated these studies later and 

 found that the organism was actually a true 

 actinomycete; it could assimilate not only 

 CO) but also higher aliphatic hydrocarbons, 

 except benzol and xylol. He, therefore, 

 changed its name to .4 . oligocarbophilus. 



Numerous other investigators observed 

 the occurrence of actinomycetes in the air. 

 Caminiti found the organisms in hospital 

 air, Barthel observed them in the dust of 

 stables, Bellisari reported their occurrence 

 on the dust covering cereals. 



Occurrence of Actinomycetes on Food 

 Products 



Actinomycetes are found extensively on 

 and in various food products. In some cases 

 they are able to produce extensive growth 

 and have, therefore, been recognized as the 

 cause of c()nsid(M-able spoilage. The damage 

 was believed to be duo not so much to the 

 actual destruction of the foodstuffs as to the 



undesiral)le musty odors the organisms im- 

 part to the food. The characteristic odors 

 produced by actinomycetes have attracted a 

 great deal of attention. Rullmann first be- 

 lie\-ed that the odor was characteristic only 

 of a certain species that he designated as A. 

 odorifer. The odor itself was referred to fre- 

 quently as "earthy," since it is similar to 

 that of well-aerated soil. 



Actinomycetes usually develop upon food- 

 stuffs under conditions not very favorable 

 to either fungi or bacteria, corresponding to 

 fairly high temperatures and low moisture 

 contents. At a moisture suboptimum for de- 

 velopment of other spoilage-producing mi- 

 croorganisms and at too high temperatures, 

 food materials may be subject to attack by 

 actinomycetes, especially under aerated con- 

 ditions. 



Actinomycetes are responsible for unde- 

 sirable odors and flavors produced in milk. 

 Barthel was primarily concerned with the 

 occurrence of microorganisms in fresh milk 

 and in the cow's udder. He isolated two cul- 

 tures designated as A. albus and .1. chro- 

 mogcncs, both typical Strcptomyccs species, 

 and came to the conclusion that these come 

 from the air. Fellers directed attention to 

 the possible damage to milk due to the un- 

 desirable odors and flavors. Hla\'ackova 

 (1951) reported that as many as 16.3 per 

 cent of samples of raw milk may contain 

 actinomycetes. Their presence was consid- 

 ered as an indicator of the degree of contam- 

 ination of the milk with dust and excreta. 

 These organisms may be pigmented and 

 may thus cause additional damage to milk 

 and butter. If the milk is insufficiently or 

 improperly pasteurized, the actinomycetes 

 will survive. Gratz and Vas isolated two 

 streptomyces cultures from Littauer cheese. 

 Jensen recorded their occurrence in butter. 

 Chatterjee found an actinomyces in fer- 

 mented milk in India. 



The earthy oi' "nuiddy taint" occasionally 

 t'ouud ill fish was studied in detail by Thay- 



