【作者】 苗又青；

【导师】 艾庆辉；

【作者基本信息】 中国海洋大学 ， 水产养殖， 2010， 硕士

【摘要】 1.本研究旨在从环境中分离筛选能降解单宁和植酸的微生物。利用富集培养技术,从土壤及腐烂水果中分离得到纯菌株122株(其中细菌37株、酵母54株、霉菌31株),使用选择培养基,经筛选、纯化,最终得到单宁降解菌10株,包括细菌2株和霉菌8株；筛选出植酸降解菌57株,包括细菌19株、酵母34株和霉菌4株。水解透明圈法结果表明,菌株C1-6、CJ-3和C1-1对单宁和植酸均具有较强的降解能力。2.为研究经选择性培养基筛选出的具有单宁和植酸降解能力的株菌,将C1-6、CJ-3和C1-1分别接种到灭菌菜粕中进行固态发酵(30℃,水分含量100%),并在不同发酵时间(1、2、4和7d)进行取样,测定发酵前后菜粕中单宁和植酸含量。实验结果显示,C1-6在1d时能有效降解菜粕单宁(P<0.05),而CJ-3和C1-1不具有这种能力。C1-6、CJ-3和C1-1在此条件下均未表现出降解菜粕植酸的能力,反而显著增加了菜粕单宁和植酸含量(P<0.05)。3.开展了不同水分、pH和温度对菌株C1-6固态发酵对菜粕单宁和植酸降解特性的研究。实验结果显示,C1-6 18h内在水分含量为100%,温度为30℃,pH为4.0时可降解菜粕中18%单宁；在水分含量为100%,温度为30℃,pH为8.0时可降解菜粕中16%的植酸。当发酵时间超过1d时,C1-6显著增加菜粕中单宁和植酸含量(P<0.05)。4.通过菌落形态学初步鉴定C1-6属于青霉属。测定了C1-6产生的单宁酶活力及其最适pH,研究结果发现其最适pH为4.0,此时其活力为1.85 U/min。更多还原

【Abstract】 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.更多还原