2% (w/v) sodium hypochlorite for 5 min and then washed
with abundant sterile water. Immediately afterwards, segments
were inoculated with 20 mg dry weight G. diazotrophicus, or 20
mg dry weight X. albilineans deposited over the cut zones. These
segments were maintained for 5 d in sterile conditions at room
temperature. Then, those segments previously inoculated with
Gluconacetobacter were newly inoculated with Xanthomonas, and
those previously inoculated with Xanthomonas with Gluconacetobacter.
After a second period of 5 d at room temperature, segments
were mechanically crushed and juices were centrifuged at
10,000g for 15 min at 2C. Pellets were discarded and supernatants
were stored at 26C to be processed. Alternatively, stalk
segments were simultaneously inoculated with both microorganisms,
maintained for 10 d at room temperature and then the juice
was obtained as described. A control consisting of stalk segments
without any experimental infection was developed under the same
conditions.