MAINE SARDINE INDUSTRY. 21 



Bacteriology of the Feed of Herring and its Bearing on Swells in Canned 



Sardines. 



In other investigations that have been made on swelled canned 

 sardines the relation of the bacteria associated with the feed to the 

 swelling of canned sardines has not been considered. Thus Cath- 

 cart(o) gives the results of the bacteriological examination of swelled 

 cans of sardines. All the cans examined emitted gas when they were 

 opened. The contents had an extremely bad odor, but were normal 

 in appearance. Four different organisms were isolated,, one of which 

 was found to be Bacillus coli. Injections made intraperitoneally into 

 guinea pigs of cultures of the unidentified organisms proved two of 

 them to be pathogenic, while the third, seemingly, had no effect. 

 In a bacteriological study of swelled sardines canned in Maine and 

 New Brunswick, Sadler isolated eight strains of gas-producing 

 bacteria from the swells examined(25). Very complete detailed 

 descriptions of the cultures and organisms found, including bio- 

 chemical reactions and morphological and biological features, are 

 given in Dr. Sadler's report. 



A very brief s umm ary of the bacteriological studies made during 

 this investigation upon the feed and upon swelled cans of sardines, 

 both native and imported, is given here. 1 No aerobic bacteria were 

 found, but Bacillus- Walfisclirauschbrand, 2 a rapid spore former, was 

 isolated in pure culture. This organism was traced through the gills 

 and stomach contents of the fish to the bodies of the live schizopods, 

 usually in the thoracic region, and to the masses of copepods. It 

 produced gas in the dead fish by its decomposition of the feed within 

 the digestive tract. 



During the investigation another organism was isolated, first from 

 the stomach contents of a fish ready to be packed and later traced to 

 the massed copepods fresh from deep-sea water. This organism, 

 designated as Bacillus B., was pathogenic to mice and guinea pigs 

 and capable of producing a chemical decomposition similar to that 

 produced by B. WalfiscJirauschbrand. It did not form spores, how- 

 ever, and was therefore much less resistant to heat. The BaciUus 

 WalfiscTirausMrand lived through the processing of the sealed cans 

 whenever the temperature of the bath was slightly below the boiling 

 point and when cans floated or protruded above the surface of the 

 water. 



Samples of various portions of the bodies of many herring were 

 cultured anaerobically and aerobically. The flesh was invariably 

 free from bacteria when the fish were removed from the weirs. 



1 The bacteriological work was conducted by M. M. Obst, of the Bureau of Chemistry (21). 



2 Bacillus WalfischrauscfibTan-d is the name applied by Xielsenf20) to the organism found in whales 

 made sick by being shot with arrows previously inoculated with material from dead whales. The 

 practice of shooting with such arrows was employed in certain whale fisheries at that time. The animal 

 was easier to harpoon and land by this method. 



