Oct. 22, I92I 



Flora of Corn. Meal 



I8i 



bage juice showed, in four of the nine samples, the presence of lacto- 

 bacilH with the morphology and cultural characters of the organism of 

 pickle and sauerkraut fermentation. N>) bacterial colonies were obtained 

 in plain agar from two of the samples. A duplicate of sample 9 proved 

 equally negative. Mold colonies were obtained in all samples. These 

 represented in varying proportions Aspergillus repens De Bary, A. niger 

 Van Tieghem, A. fiavus hink, Fusarium, various mucors, and unidentified 

 colonies. 



Table I. — Results of cultural examination of commercial corn meals 



A more extensive series of studies was conducted in cooperation with 

 the Plant Chemical Laboratory of this bureau. The general results 

 of this experiment are described elsewhere (2). In brief, during the 

 spring of 1920, a series of bags of meal were prepared for this storage 

 experiment from com bought by the mill in the regular course of business. 

 This grain, while sold as No. 2, was obviously wet and barely passable 

 as a fair product. Infected and even badly decomposed ears were not 

 uncommon among the ears of corn received in bulk. Although the lots 

 of meal included were milled at water contents varying from 12.7 to 

 16.18 per cent, the conditions of storage were such that no spoilage 

 determinable by the senses took place. Cultures were made from the 

 meal as freshly ground in April, then, beginning May 5, once each week 

 until July. In all these cultures no evidence of multiplication of either 

 mold or bacteria was found. It was, therefore, possible to follow the 

 relative numbers of viable organisms in the various groups from the 

 time of grinding through the four months of storage. 



In the freshly milled samples the average count of colonies of bacteria 

 upon plain agar was about 1,000,000 per gram of meal, with variations 

 from 600,000 to 1,600,000. Upon wort agar the count of mold colonies 

 averaged about 100,000 per gram of meal, with variations in different 

 samples from 70,000 to 160,000. Of the bacterial colonies observed 

 about 60 per cent were acid producers. 



