Isolation And Screening Of A Tannic Acid And Phytic Acid Degrading Microorganisms And The Reduction Of Tannic Acid And Phytic Acid In Rapeseed Meal During Solid-state Fermentation Procedure

1 Studies were conducted to isolate and screen tannic acid and phytic acid degrading microorganisms. One hundred and twenty-two isolates of microorganisms were isolated from soil and rotten fruits using enrichment-culture technique. After screening, among these,10 isolates (including bacteria and fungi,2 and 8 isolates of, respectively) exhibited tannic acid degradation potential,57 isolates (including bacteria, yeasts and fungi,19,34 and 4 isolates of, respectively) exhibited phytic acid degradation potential. Among these enzymatic potential isolates,6 isolates (including bacteria and fungi,2 and 4isolates of, respectively) exhibited joint capacity of degradation of tannic acid and phytic acid. Among the 6 isolates, Cl-6, CJ-3 and C1-1exhibiting best potential were chosen to investigate the capacity of degradation of tannic acid and phytic acid in rapeseed meal under solid-state fermentation procedure.2 The capacity of degrading tannic acid and phytic acid in rapeseed meal Isolates C1-6,CJ-3 and C1-1 was investigated during the solid-state fermentation procedure (30℃, moisture 100%). Samples were collected on the 1,2,4 and 7 d. Tannic acid and phytic acid content in both unfermented and fermented samples were analyzed. The results showed C1-6 significantly decreased the tannic acid content in rapeseed meal on 1d, however, both CJ-3 and C1-1 increased its content during the entire procedure. All three isolates exhibited no capacity of degrading tannic acid and phytic acid in rapeseed meal but to increase their content during the entire procedure significantly (P<0.05).3 Studies were conducted to investigate the effects of moisture, pH and temperature on the degradation of tannic acid and phytic acid in rapeseed meal by C1-6. C1-6 exhibited a rapid degradation of tannic acid by 18% and phytic acid by 16% in 18 h with the moisture of 100%,30℃and optimum pH 4.0 and 8.0 respectively in rapeseed meal. However, in longer time procedures, Cl-6 exhibited the capacity of increasing both tannic acid and phytic acid content in rapeseed meal.4 Isolate C1-6 was characterized as Penicillium sp. by the characteristics of its colony. The activity of tannase of C1-6 was 1.85 U/min. And its optimal pH was 4.0.