Occurrence and Significance of Chitinoclastic Bacteria 



597 



Chitin Media 



Before embarking on the pelagic investigations, some pre- 

 liminary attention was given to evaluating culturing conditions 

 for marine chitinoclasts on agar pour plate media. 



Chitin was obtained from the spiny rock lobster Panulirus in- 

 terruptus, and purified according to the method of Benton (3), 

 which, briefly, involves decalcification in 1% HCl, extraction in 

 hot 2% KOH, and in boiling ethanol. The criterion for chitin de- 

 gradation by microbial action was the visible clearing of dispersed 

 chitin from chitin agar plates. Fine particles of chitin were ob- 

 tained by "dissolving" purified chitin in 50 per cent sulfuric acid, 

 precipitating by dilution with distilled water, then washing and 

 neutralizing ( 6 ) . The resultant particles were readily dispersable 

 in agar media, imparting a whitish cloudiness. 



This "precipitated" chitin was compared with ground puri- 

 fied chitin, sieved through 60 mesh, in agar media. Growth and 

 chitin degradation on agar media containing both types of chitin 

 were comparable. 



Media Constituents 



Various modifications of chitin-sea water agar media were 



TABLE 1 

 Growth and Chitinase Production by Marine Bacteria on Various Media 



