NOTES ON COCONUT, COPRA, AND COCONUT OIL. 123 



jDlant or is split up, being trausforraed by progressive syntliesis into sugar 

 and finally to cellulose. 



Sugar is lost by meat and milk, but a corresponding quantity is 

 gained by the foot, the total amount in the nut remaining approximately 

 the same. 



A small amount of crude fiber is lost by the meat, but a much larger 

 quantity is produced in the sprout and roots. 



III. THE ACTION ON COPHA 01? MICROORGANISMS IN PUKE CULTURE. 



It has been shown previously ^ that moist copra is readily attacked by 

 microorganisms with consequent splitting up and destruction of the 

 oil and it has also been proved that the action of such organisms is most, 

 pronounced when the copra has a water content of from 10 to 15 per 

 cent. With this content of moisture the mold growth largely predomi- 

 nates over that of the bacteria. Wlien much more water is present, and 

 the bacteria are in excess of the molds, destruction of fat is greatly 

 diminished. These observations led logically to the belief that hydrolysis 

 of oil in copra was due to the action of molds alone, although the data 

 available at the time the previous work was done did not exclude the 

 possibility of symbiosis and interdependence in this fat-splitting process 

 between molds and bacteria. Dr. Edwards, of the Biological Laboratory 

 of this Bureau, undertook further work to settle this question definitely 

 and in j)nrsuing it separated as many different organisms as possible, 

 some fifteen in all, from several samples of moldy copra and coconut 

 meat, finally succeeding in isolating in pure cultures the majority of the 

 gro^^ths present. As a culture medium he used sterilized coconut meat 

 in most instances. The subsequent procedure was as follows : 



Ten-gram samples of anhydrous copra were placed in large test tubes stop- 

 pered with cotton, and after the addition of 1.50 grams of water these were 

 sterilized in an autoclave for half an hour. It was found by e.>;periment that 

 about 0.10 gram of water was taken up by the copra during sterilization, so 

 that the samples thus prepared contained approximately 13.8 per cent of moisture, 

 an amount which had been found previously to favor the growth of both molds 

 and bacteria. The tubes ^ere inoculated after sterilization with pure cultures of 

 the organisms previously isolated, and allowed to stand at laboratory tempera- 

 ture (26° to 30°) for forty-one daj's. Cultures were then made from each tube. 

 All tubes were dried to constant weight at 100° in order to determine the 

 change in weight of the drj' copra. The latter was next extracted with chloro- 

 form to determine oil and finally with hot water to take out the ^ugar, which 

 was inverted and determined with Fehling's solution. The changes taking place 

 in forty-one days are shown in the following table. Only those tubes which 

 showed a good growth in this time and were proved by cultures to contain 

 only one organism are noted. 



"This Journal (I'JOO), 1, 123. 



