【作者】 崔艳红；

【导师】 王士长；

【作者基本信息】 广西大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 本研究以酶活力为唯一评价指标，从实验室保藏的十个菌种中分别筛选出了β-葡聚糖酶、羧甲基纤维素酶和木聚糖酶高活力菌株三株：菌株3.316，菌株3.4265，菌株5.132。通过优化产酶条件，选择出各菌株的最适培养条件和培养方法，并对其酶作用特性进行了研究，通过发酵前后饲料原料中戊聚糖含量和浸提液粘度的变化来评价非淀粉多糖的微生物降解效果。另外，通过体外消化试验评价了三个菌株所产酶制剂的作用效果。试验结果表明： (1) 菌株3.316最适碳源为a-乳糖、浓度4％，最适氮源为牛肉膏、浓度0.1％，在25℃恒温培养72h后，β-葡聚糖酶活力高达736IU／ml，该酶的最佳缓冲液是柠檬酸缓冲液，最适pH是3.0，最适反应温度为60℃，该菌株纤维素酶活力达830IU／ml，发酵后饲料粘度降低了56.59％(P＜0.01)，戊聚糖含量下降了3.28％(P＞0.05)，添加该菌株NSP复合酶后，小麦千物质、粗蛋白、粗脂肪、粗纤维的体外消化率分别提高了8.08％(P＜0.05)、6.72(P＜0.05)、10.66％(P＜0.01)、17.01％(P＜0.05)。体外消化滤液粘度下降了2.49％(P＞0.05)。 (2) 菌株3.4265最适碳源为麸皮、浓度4％，最适氮源为柠檬酸氢二铵、浓度0.1％，28℃恒温培养84h后；木聚糖酶活力达445.73IU／ml，该酶的最佳缓冲液是磷酸氢二钠-柠檬酸缓冲液，最适pH为5.4，最广西人学了吹_卜学位论文饲料中非淀粉多糖的微生物降解研究适反应温度为50℃，该菌株p一葡聚糖酶和纤维素酶酶活也达到较高水平。发酵后饲料原料粘度下降了67.91%(p<0 .01)，戊聚糖含量下降7 2.72%(p)0.05)。添加该菌株的Nsp复合酶后，小麦干物质、粗蛋白、粗脂肪、粗纤维的体外消化率分别提高了11.1%(p<0 .01)，15.47%(P(0.01)，14.70%(P(0.01)，21.70%(P<0.05)。体外消化滤液粘度降低7 3.95%(P>.05)。(3)菌株5.132菌株最适碳源为数皮、浓度4%，最适氮源为酵母膏、浓度0.1%，在25一28℃恒温培养216h后，木聚糖酶活力达470.45!U/ml，该酶的最佳缓冲液是柠檬酸缓冲液，最适pHS.O，最适反应温度为50℃，该菌株p一葡聚糖酶和纤维素酶活力较低。发酵后饲料原料粘度降低了65.31%(P<0 .01)，戊聚糖含量下降4.72%(p> .05)。添加该菌株的NsP复合酶后，小麦干物质、粗蛋白、粗脂肪、粗纤维的体外消化率分别提高了6.1%(p<0 .01)，15.96%(p(0.01)，11.67%(P(0.05)，19.29%(P(0.05)。体外消化滤液粘度降低7 4.90%(P>0.05)。更多还原

【Abstract】 In this paper, three strains (coded 3.316, 3.4265, 5.132, the same to the following) with high-producing B-glucanase , carboxymethyl cellulase and xylanasc were screened from our lab conserving ten strains ,which regarded the enzyme activity as the only index. The optimal culture conditions and methods of every strain were selected after optimazating enzyme-producing conditions, and their enzyme’s action character were studied. Evaluated the microoganism degradation result of non-starch polysaccharide as the variation of pentosan and fluid extract viscosity in the feed material for the index. In addition , the action results of their enzyme preparation were assessed with the digestion test in vitro. The results were as follows:(1)Thc optimal carbon source of strain 3.316 was a -lactose with concentration of 4%, the optimal nitrogen source was beef extract with concentration of 0.1%. Cultured 72h at temperature 25C, the B -glucanase activity of strain 3.316 was 736IU/ml .The optimal buffer for B -glucanase was citric acid buffer, the optimal pH was 3.0 , the optimal reaction temperature was 60C, the cellulase activity of strain 3.316 was 830IU/ml .The viscosity of feed material reduced 56.59%(P<0.01), the content of pentosan reduced 3.28%(P>.05) after fermentating. Added the strain’s NSP compound enzyme to wheat ,the digestion ratio in vitro of dry material ,coarse fat ,coarse protein, coarse fiber raised 8.08%(P<0.05), 6.72%(P<0.05), 10.66%(P<0.01) and 17.01 %(P<0.05) respectively. The filtrate viscosity of digestion in vitro reduced 2.49%(P>0.05). (2)The optimal carbon source of strain 3.4265 was wheat bran with concentration of 4%, the optimal nitrogen source was ammonium citrate dibasic withconcentration of 0.1%. Cultured 84h at temperature 28C,the xylanase activity of strain 3.4265 was 445.73IU/ml .The optimal buffer for xylanase was sodium phosphate dibasic-citric acid buffer, the optimal pH was 5.4 , the optimal reaction temperature was 50C, the 3 -glucanase and cellulase activity of strain 3.4265 were also high .The viscosity of feed material reduced 67.91 %(P<0.01), the content of pentosan reduced 2.72%(P>.05) after fermentating. Added the strain’s NSP compound enzyme to the wheat, the digestion ratio in vitro of dry material ,coarse fat ,coarsc protein, coarse fiber raised ll.l%(P<0.01), 15.47%(P<0.01), 14.70%(P<0.01) and 21.70%(P<0.05) respectively. The filtrate viscosity of digestion in vitro reduced 3.95%(P>0.05).(3)Thc optimal carbon source of strain 5.132 was wheat bran with concentration of 4%, the optimal nitrogen source was yeast extract with concentration of 0.1%. Cultured 216h at temperature 25-28C, the xylanase activity of strain 5.132 was 470.45IU/ml .The optimal buffer for xylanase was citric acid buffer, the optimal pH was 5.0 , the optimal reaction temperature was 50C, the B-glucanase and cellulose activity of strain 5.132were low .The viscosity of feed material reduced 65.31%(P<0.01), the content of pentosan reduced 4.72%(P>.05) after fermentating. Added the strain’s NSP compound enzyme to the wheat, the digestion ratio in vitro of dry material ,coarse fat ,coarse protein, coarse fiber raised 6.1%(P<0.01), 15.96%(P<0.01), 11.67%(P<0.01) and 19.29%(P<0.05) respectively. The filtrate viscosity of digestion in vitro reduced 4.90%(P>0.05).更多还原