Ammonia-lowering capacity was expressed in terms of the
mean and standard error of the mean (SEM) (n ¼ 3). In the case of
the ammonia-lowering experiment with nuka-AES, one-way
ANOVA was used to assess differences among groups, and individual
means were compared by Tukey's range test with a statistical
analysis software (EXCEL Statistic 5.0, Esumi, Tokyo, Japan). A
significance level of 0.05 was used.