CAJ | 학술논문

从淀粉加工厂附近土壤中筛选得到一株普鲁兰酶高产菌株，编号为Z-13，其初始酶活达到5．7 U/mL．通过对此菌株的16S rDNA比对，以及生理生化鉴定，鉴定此菌株为克雷伯氏菌（Klebsiella variicola），通过发酵条件优化，确定最佳发酵产酶条件为：玉米淀粉1．5％，蛋白胨2．0％，KH2 PO40．05％，MgSO4·7H2 O 0．01％．装液量为70 L/250 L，培养基最初pH为6．0，发酵温度30℃，摇床转速200 r/min，发酵时间48 h，优化后菌株产普鲁兰酶的酶活高达67．8 U/mL，是优化前菌株产普鲁兰酶活性的11．89倍．
종정분가공엄부근토양중사선득도일주보로란매고산균주，편호위Z-13，기초시매활체도5．7 U/mL．통과대차균주적16S rDNA비대，이급생리생화감정，감정차균주위극뢰백씨균（Klebsiella variicola），통과발효조건우화，학정최가발효산매조건위：옥미정분1．5％，단백동2．0％，KH2 PO40．05％，MgSO4·7H2 O 0．01％．장액량위70 L/250 L，배양기최초pH위6．0，발효온도30℃，요상전속200 r/min，발효시간48 h，우화후균주산보로란매적매활고체67．8 U/mL，시우화전균주산보로란매활성적11．89배．
A high-producing strain of pullulanase Z-13 was isolated from the soil near a starch-processing factory. The initial activity was 5. 7 U/mL. Based on 16S rDNA sequence homology analysis, Z-13 was identified as klebsiella variicola,with its physiological and biochemistry characters. The optimum fermentation condition for Z-13 was deter-mined as follows:corn starch 1. 5%, peptone 2. 0%, KH2 PO4 0. 05%, MgSO4 ·7H2 O 0. 01%. When cultured at op-timum fermenting conditions ( studied as follows:the content of flask is 70 L/250 L, the inoculation quantity was 8%, cultured at pH 6. 0, 30℃, 200 r/min for 48 hours), the activity of pullulanase produced by Z-13 reached the peak at 67. 8 U/mL, which was 11. 89 times as the initial activity.