烟色曲霉发酵产壳聚糖酶条件的研究

摘要

A chitosanase-producing strain was isolated from soil samples using chitosan as the sole carbon source, and preliminarily identified as Aspergillus fumigatus DNS method that measures chitosanase activity, and conditions for fermenting chitosanase from this strain were studied.The results showed that the maximum absorption wavelength of DNS method was 490nm; and the optimal cultivation for chitosanase production were as follows; using 1.00％ chitosan as carbon source and 1.00％ beef extract as nitrogen source, 250mL flask containing 75 mL medium, initial pH value 5.8,culture temperature at 38℃, inoculum amount 1.5％ (V/V) and shaking cultivation at 210 r/min for 77 hours.Under the optimal cultivition conditions, the chitosanase activity could reach 7.25U/mL.%以壳聚糖为惟一碳源从采集的土样中分离得到一株产壳聚糖酶的菌株,经初步鉴定为烟色曲霉.对测定壳聚糖酶活力的DNS法以及该菌株发酵产酶条件进行了初步研究.结果表明,DNS法的最大吸收波长在490 nm左右,试验菌株的最适产酶发酵条件为分别以1.00%壳聚糖和1.00%牛肉膏为碳源和氯源,250 mL三角瓶装液量为75 mL,起始pH值是5.8,接种量1.5%(V/V),38℃,210 r/min培养77 h.在最适产酶条件下,该菌株发酵液中壳聚糖酶活力可达到7.25 U/mL.