1110 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1957 



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6 8 10 12 



INCUBATION TIME IN WEEKS 



14 



16 



18 



Fig. 4 — Examples of H2S production by marine bacteria in anaerobic sea 

 water test with Poly (Vinyl Chloride) plastics as carbon source. 



ticizer, fatty acid lubricant probably serves as a source of nutrient. For 

 comparative purposes, the examples of hydrogen sulfide production 

 plotted in Fig. 4 are for the same plastics included in Fig. 3 which relates 

 to the data from the aerobic procedure. 



Jute is attacked by the anaerobic bacteria just as it is utilized by the 

 aerobic organisms. However, neither the epoxide casting resin (Table 

 X) or the polyester casting resin (Table XI) seem to serve as a source 

 of carbon. 



The results of the anaerobic test with the elastomers are presented in 

 Table XII. It is interesting to note that early attack occurs on the 

 natural and butyl rubber jackets, but that none of the other elastomers 

 is utilized by the organism. It is somewhat surprising that attack on 

 GR-S did not progress at about the same rate as on natural and butyl 

 rubber. 



The data which have been obtained in the aerobic and anaerobic parts 

 of the BOD-type test are summarized in Table XIII. There is one out- 

 standing fact about the data — no material was utilized by the anaerobic 

 bacteria which was not utilized also by the aerobic organisms. Under 

 the conditions of the test, however, materials did serve as a carbon 

 source for aerobic bacteria and not for the anaerobes. 



3.. 2 Conductor Test 



It is apparent that the BOD test provides considerable fundamental 

 information on the ability of halophilic bacteria to utilize organic ma- 



