不同氮源对瘤胃真菌产纤维素酶活性的影响

Effect of Nitrogen Sources on the Cellulase Activities Fermented by Rumen Anaerobic Fungi

本试验通过体外模拟瘤胃内环境,利用取自崂山奶山羊瘤胃内的混合厌氧真菌为菌种,以花生蔓为发酵底物,通过添加等量不同氮源(菌糠、酵母膏、尿素、氯化铵、硫酸铵),并以羧甲基纤维素酶、木聚糖酶、β-葡萄糖苷酶的酶活性和发酵液p H值为监测指标,研究不同氮源对混合瘤胃厌氧真菌产纤维素酶活性的影响。结果表明,添加氮源试验组的纤维素酶活性明显高于不加氮源的对照组(P<0.05)。以氯化铵做氮源时3种纤维素酶活性均为最高,其木聚糖酶和β-葡萄糖苷酶最高酶活性显著高于其他试验组(P<0.05),羧甲基纤维素酶活性与硫酸铵组相比差异不显著(P>0.05),但显著高于另外3种氮源组(P<0.05)。各组p H值随着时间增长而逐渐下降,5种氮源组120 h的p H值下降值与对照组相比差异显著(P<0.05),其中以菌糠组下降最快。从试验结果可以看出,添加不同氮源对瘤胃厌氧真菌产纤维素酶活性及p H值有影响,以氯化铵做氮源时产酶活性最高。

An in vitro study was conducted to determine the effects of nitrogen sources on cellulase （carboxymethyl ceUulase, xylanase, 13-glucosidase）activities. Anaerobic fungi in the ruminant fluid of Laoshan dairy goats were used in this present study. Fermentation substrate was peanuts tendril, and nitrogen sources were mushroom bran, yeast extract, urea, NILCl and （NIL） 2SO4, respectively .There were three replicates for each group .The results showed that NH4Cl-N could produce the greatest cellulase ac- tivity, the activity of xylanase and [3-glueosidase were significantly higher compare to other nitrogen sources （P〈0.05）.The pH val- ue declined with the increase of the fermentation time, supplementation of nitrogen source influenced pH value at 120 h fermenta- tion point.The pH value in mushroom bran was the lowest and decreased up to 0.86 at 120 h point.In conclusion,nitrogen source could affect the activities and pH value of cellulose produced by rumen anaerobic fungi, NH4Cl-N could produce higher celluase activity.