In total, 71 samples of leaves, flowers, seeds, algae, stones, sands,
and fermented foods (Table 1) were obtained from Sanriku Satoumi
areas between 2014 and 2015, kept in cold storage, and delivered
within 2 days of collection. To isolate and screen the yeasts,
approximately 2e5 g of sample was soaked in 25 mL of glucoseyeast
extract-peptone (GYP) broth (glucose 20 g/L, yeast extract
10 g/L, and polypeptone 10 g/L) containing 5 mL/L lactic acid and
100 mg/L chloramphenicol. After incubation at 30 C for 3e7 days, a
loopful of the culture was streaked onto potato dextrose agar (PDA,
Oxoid, Basingstoke, UK) and incubated at 30 C for 3 days. Gas
formation and cell morphology of the culture in 20% (w/v) glucosecontaining
GYP broth incubated at 30 C for 3 days were observed.
Finally, the ammonia-lowering capacity of the gas-producing isolates
having Saccharomyces-like morphology was evaluated.