42 Bacterial Disease of the Mango 



An experiment was also conducted to test the ability of the bacillus 

 to withstand desiccation on glass cover slips. 



A 48-hours old culture on nutrient agar was suspended in a normal 

 saline solution and a number of sterile cover slips smeared with the 

 suspension were put in a sterile petri dish to dry. 



A Hempel desiccator containing sulphuric acid was prepared, the 

 dry cover slips transferred to a sterile ventilated capsule, and placed 

 in the desiccator. The latter was then sealed up and partially exhausted. 

 At intervals cover slips were removed from this apparatus with sterile 

 forceps and dropped into tubes of nutrient broth. After 40 days 

 drying a culture of the organism could be still obtained from the cover 

 slips ; at the end of that time the experiment was discontinued. 



Resume of Salient Characters. 



Bacillus mangiferae n. sp. An organism causing a disease of the 

 leaves and fruit of the mango (Mangifera indica) ; it attacks the paren- 

 chyma, causing black angular spots on the leaves; and on the fruit 

 discoloured roughened areas often accompanied by deep longitudinal 

 cracks. 



A short motile rod with rounded ends averaging 1*5 x 'Qfi; usually 

 single, chains formed in pellicle on liquid media ; motile, with 2 — 8 long, 

 peritrichiate flagella; no spores observed; capsules in ring above 

 liquid media ; involution forms (?) in broth containing high percentages 

 of NaCl; stains readily with usual stains and by Gram's method. 



Forms shining yellowish colonies on nutrient agar, undulate at 

 25° C. ; liquefies gelatine ; clouds nutrient broth forming ring pellicle 

 and sediment; grows readily on blood serum, but does not cause 

 liquefaction ; grows slowly in milk finally causing coagulation, at 37° C. 

 the casein is slowly dissolved. Grows on potato making a shining 

 yellowish spreading growth over moist part of medium ; the latter is 

 not discoloured ; heavy growth on beet and in beet juice, also in cabbage 

 broth; slightly clouds Cohn's solution; no growth in Uschinsky's 

 solution or on starch jelly made with Fermi's solution. 



No gas formation in carbohydrate media, but medium becomes 

 slightly more acid. No formation of diastatic or invertin enzymes, 

 small percentage of alcohol in dextrose broth; nitrates reduced, 

 tolerates up to 8-75 % NaCl ; reduces litmus and several other colouring 

 matters; indol in media containing peptone but no phenol. 



Aerobic, facultative anaerobe; very sensitive to action of mercuric 



