Probiotics are considered microorganisms that, when ingested in sufficient and adequate
amounts, can result in several benefits to the health of the host. Among the microorganisms
that have this potential, yeasts have gained prominence in terms of their probiotic application,
and among the genera, the yeast Saccharomyces boulardii is the best known and commercially
available as a probiotic. Bacupari (Garcinia gardneriana), tucumã (Astrocaryum aculeatum)
and pupunha (Bactris gasipaes Kunth), are fruits native to the Amazon region, rich in fiber,
lipids and carotenoids; appreciated mainly by the population of the North of the country and
have great biotechnological potential. Thus, the present research identified and evaluated the
probiotic potential of yeasts isolated from native fruits of the Amazon region for later
application in the food industry. 418 yeasts previously isolated from the aforementioned fruits
were reactivated, of which 321 were viable, followed for morphological analysis and growth
tests at 37°C, ability to survive an acidic environment (pH 1-2, pepsin 3 g/L and NaCl 5 g/L),
resistance to fluconazole and amphotericin B antifungals, and antagonistic activity against the
following pathogens: Salmonella enterica subsp. enterica serovar Typhimurium (ATCC
14028), Escherichia coli (CDC EDL 1284-ATCC 43893), Shigella sonnei (ATCC 11060) and
Staphylococcus aureus (ATCC 25923). Bile salt tolerance tests (0.3%), self-aggregation and
coaggregation capacity, virulence factors (lipase, gelatinase, DNAse and hemolytic activity)
and preservation in the form of lyophilization were performed. The results obtained show that
of the 321 yeasts submitted to the growth test at mammalian body temperature (37°C) 288
showed growth, of which 213 were able to grow in simulated conditions of stomach acidity.
Of the 57 yeasts that were sensitive to amphotericin B, 12 showed antagonistic activity against
the tested pathogens. In addition, all 12 yeasts tested in the presence of 0.3% oxgall showed
viability, however, in the self-aggregation and coaggregation tests, only three yeasts were
selected, which were submitted to virulence factor tests and demonstrated to be able to follow
for lyophilization using three cryoprotectants. The results obtained during the lyophilization
process indicate that the yeast LTC 13 presented the best results, and, among the
cryoprotectants used, glucose 10% presented the best performance during the process. As for
molecular identification, the three yeasts belong to the following species: Meyerozyma
carpophila, Meyerozyma guilliermondii and Rhodotorula mucilaginosa.
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