A PINK YEAST CAUSING SPOILAGE IN OYSTERS. 21 



then subcultures were made on dextrose apir slants. These agar 

 cultures were examined daily for the growth of the yeast. 



After it was found that formaldehyde, 1 to 2,500, would kill the 

 yeast in broth cultures, this disinfectant was applied to the oyster 

 house. Early in the morning the bins and benches of the opening 

 house were swabbed, and the pink yeasts Avere recovered from the 

 swabs. The bins and benches were then scrubbed thoroughly by 

 means of brooms and running water from a hose. Following the 

 scrubbing the woodwork was washed down w^ith formaldehyde solu- 

 tion, and the bins left unused during the day. Later in the after- 

 noon the bins and benches were swabbed again, and no pink yeasts 

 were obtained. 



It is apparent that if this procedure is followed the principal 

 source of contamination can be removed. It is well to leave the 

 formaldehyde solution on the woodwork overnight or during the 

 entire day. The same procedure may be followed in washing the 

 tubs, wheelbarrows, and other contaminated objects in and about 

 the oyster house. 



DISCUSSION OF RESULTS. 



In discussing the relation of the pink yeast to the oyster industry 

 it will be well to consider the method of handling the oysters in pre- 

 l^aring them for shipment, as practiced in most of the establishments 

 in Rhode Island where this study was conducted, to note the possibili- 

 ties of contamination with the pink yeast in the process, and draw 

 some conclusions from the data already collected as to the source of 

 the contamination. 



The oysters are caught in large dredges and dumped on the deck 

 of the boat, after which they are shoveled back along the deck to a 

 large pile amidship. The day's catch of oysters is taken to the oyster 

 house, and unloaded by shoveling the oysters into wooden tubs in 

 which they are carried back into the house and dumped into bins. 

 The oysters are opened into metal dippers and taken to the wash- 

 room to be cleansed and iced for shipment. They are first washed on 

 a skimmer with fresh water from a hose, then put into tubs of salt 

 water for 15 minutes, at the end of which time the salt water is re- 

 placed with fresh water, and a piece of ice added. ^Vlien the oysters 

 are thoroughly chilled they are washed on a second skimmer with 

 salt water. The oysters, thus washed, are measured into 1-, 2-, or 5- 

 gallon cans, and covered with a tight-fitting tin cover which is not, 

 however, air-tight. These cans, which are cylindrical, are packed in 

 square wooden boxes of the proper size to hold the can, leaving a 

 space in each corner which is filled with cracked ice. The cover of 

 the box is nailed on, and the oysters thus packed are shipped. 



As stated elsewhere (page 1), oysters packed in this way and sent 

 for long distances are often pink when they reach their destination. 



