Biociii'.Mic \i, AciiN I rii:s 



153 



Acconlinii to W'cltlcy d al. ( 1'.),"),")), the 

 MU'chaiiisin of breakdown of co-pliciiyl-siit)- 

 stitulcd latty acids 1)\- .V. opitai was as 

 follow s: Acids with an odd ininitici' of cail)on 

 atoms in the side chain (phenylpropionic, 

 phenyl\-aleric, and phen\lhept>lic acids) 

 wei'e conx'ei'ted to IxMizoic acid, and cinnaniic 

 acid was an intei-niechate; o-hych-oxyphenyl- 

 acetic acid was identified as a coinnion prod- 

 uct when acids witli an e\-en inmihei- of car- 

 hon atoms (plienylacetic, phenyihutyiix, 

 plienylcaproic,and phenylcapi-yHc) weixuised, 

 thus support iiii;- tlie theory of /:J-oxidat ion 

 as a mechanism of l)reakd()wn of short -chain 

 fatty acids by A\ opaca. \\'el)ley ct al. (1957) 

 later demonstrated that a strain of A^. opaca 

 will con\-ert o- and 4-monochlor()phenoxy- 

 l)Utyric acids to the corresponding sul)sti- 

 tuted acetic acids. During these conversions 

 an intermeditite is formed which proved to 

 lie fi-hydroxy-7-(4-chlor()pheiio.\y) butyric 

 acid. 



Adelson et al. found in soil a strain of S. 

 (piseus that had the capacity to bring about 

 demyelination of boA'ine spinal cord in vitro. 

 Just what mechanisms this process involves 

 are still difficult to tell. 



Proteolytic Activities of Actiiioniycetes 



Actinomycetes are capable of attacking a 

 large number of plant and animal proteins, 

 as pointed out elsewhere. Mace was among 

 the first to demonstrate their marked pro- 

 teolytic properties. The proteins are hydro- 

 lyzed to amino acids, polypeptides, and 

 ammonia. Waksman and Starkey compared 

 the utilization of proteins of animal and 

 plant origin by bacteria, fungi, and actino- 

 mycetes. The actinomycetes were found to 

 occupy an intermediate position between the 

 other two groups of organisms in the ratio 

 of protein decompo.sed to protein synthe- 

 sized. The presence of a carbohydrate was 

 found to be of great importance in influenc- 

 ing both the amount of protein decomposed 

 and that of cell material svnthesized. When 



proteins were used as a somce of bol h carbon 

 and nitrogen, the reaction of the medium 

 changed rapidly to alkaline. ( 'onsidei'able 

 annnoni.M, liber.ated in the decomposition of 

 the proteins, was lost by \-olal ilizal ion. 



A iuimb(>r of amino acids can be utilized 

 by actinomycetes in synthetic media. This 

 is true of i)roline, glutamic acid, arginine, 

 aspartic acid, and histidine. The fact tliat 

 actinomycetes can utilize anunonia and ni- 

 trate as sourcesof nitrogen, and that amino 

 acids are degraded to annnonia, suggests 

 that the carl)()n residue of the amino acids 

 may be more important in the actinomycete 

 economy than iwv the nitrogen-containing 

 groups. Problems of deamination and amino 

 acid degradation l)y streptomycetes have 

 been discu.ssed by Gottlieb and Ciferri. 



Actinomycetes are characterized by in- 

 tense activity in breaking down proteins to 

 ammonia. This is true especially when a long 

 period of incubation is employed. These or- 

 gani.sms are capable of allowing a large accu- 

 mulation of ammonia e\'en in the presence of 

 available carbohydrates. 



When washed cell material of S. lavendulae 

 was shaken with different amino acids at 

 pH 6.8, deamination could be measured by 

 ammonia formation. Arginine and histichne 

 were acted upon most readily; /8-alanine was 

 deaminated only about one-third as readily 

 as D-alanine; leucine, isoleucine, and certain 

 other amino acids were deaminated not at 

 all or only in mere traces. 



The formation of proteolytic enzymes are 

 discussed in detail in Chapter \ 1 . 



Decomposition of Keratins 



Actinomycetes possess the uni(iue capacity 

 to decompose keratins. This was show-n first 

 in connection with the ability of certain 

 pathogenic forms to attack the skin and 

 horny portions of feet (Acton and AIcGuire) . 

 When a soil is enriched with keratinized tis- 

 sues, such as hinnan hair and feathers, or- 

 ganisms belonging to the genus Actinoplanes 



