|本期目录/Table of Contents|

[1]胡有贞 关 波** 王丽军 李 梦 顾燕玲 倪永清.天山一号冰川产低温β-半乳糖苷酶菌株的筛选及其酶学特性*[J].应用与环境生物学报,2019,25(04):1-13.[doi:10.19675/j.cnki.1006-687x.2018.12017]
 HU Youzhen,GUAN Bo**,WANG Lijun,et al.Screening of psychrophile producing cold-active -galactosidase from China No. 1 glacier and its enzymatic properties*[J].Chinese Journal of Applied & Environmental Biology,2019,25(04):1-13.[doi:10.19675/j.cnki.1006-687x.2018.12017]
点击复制

天山一号冰川产低温β-半乳糖苷酶菌株的筛选及其酶学特性*()
分享到:

《应用与环境生物学报》[ISSN:1006-687X/CN:51-1482/Q]

卷:
25卷
期数:
2019年04期
页码:
1-13
栏目:
研究论文
出版日期:
2019-08-31

文章信息/Info

Title:
Screening of psychrophile producing cold-active -galactosidase from China No. 1 glacier and its enzymatic properties*
文章编号:
201812017
作者:
胡有贞 关 波** 王丽军 李 梦 顾燕玲 倪永清
石河子大学食品学院 石河子 832002
Author(s):
HU Youzhen GUAN Bo** WANG Lijun Li Meng GU Yanling NI Yongqing
?Faculty of School of Food Sciences, Shihezi University, Shihezi 832002, China
关键词:
β-半乳糖苷酶低温活性嗜冷杆菌一号冰川酶学特性
Keywords:
β-galactosidase cold-active Cryobacterium China Noo.1 glacier enzymatic properties
DOI:
10.19675/j.cnki.1006-687x.2018.12017
摘要:
从天山中国一号冰川沉积层样品中,以蓝白斑法初筛、测低温下的相对酶活复筛,获得产低温β-半乳糖苷酶的菌株。通过两级筛选,获得产低温乳糖酶的菌株24株,其中菌株LW097所产β-半乳糖苷酶在低温下的相对酶活最高。进一步通过形态、生理生化试验及16S rDNA测序分析,将该菌株鉴定为嗜冷杆菌(Cryobacterium sp. )。该菌株在以4%(w/v)的乳糖为碳源,以胰蛋白胨+酵母浸粉为组合氮源的发酵培养基中,16 ℃培养84 h产酶酶活最高达2.12±0.09 U/mL。对该菌株所产β-半乳糖苷酶的酶学性质进行分析发现,其最适反应pH为6.0,最适反应温度为30 ℃,20 ℃相对酶活为72.4%,4 ℃时酶活性仍能保持62.7%;该β-半乳糖苷酶的低温稳定性较好,对热处理敏感,60 °C处理4 h酶活几乎消失;1 mmol/L Na +和Ca2+对该酶活性基本无抑制作用。上述结果表明,菌株Cryobacterium sp. LW097 所产β-半乳糖苷酶是典型的低温β-半乳糖苷酶,其酶学特性具备在乳品低温加工领域应用的潜力。(图11 表3 参39)
Abstract:
Objectives: Cold-active β-galactosidases showed unique advantage and are of great interests for the removal of lactose in milk and dairy products at low temperatures. This paper aimed to screen cold-active β-galactosidase producing strains from glacier sediments at China No. 1 glacier in Tianshan Mountains. Methods: Strains producing β-galactosidase were isolated and screened by culture on synthetic medium supplemented with 5-bromo-4-chloro-3-indolyl- β-D-galactopyranoside (X-gal). Strains producing cold-active β-galactosidase were further screened by assaying the relative β-galactosidase activity at low temperature. The isolate confirmed with the ability of producing cold -active β-galactosidase was identified by 16S rRNA gene sequencing and phylogenetic analysis. The optimum growth and enzyme production condition of the isolate were determined. Enzymatic properties including optimal temperature, optimal pH, thermal stability and pH stability of the β-galactosidase produced by the isolate were also analyzed. Results: A cold-active β-galactosidase-producing strain LW097 was isolated and identified preliminarily as a Cryobacterium sp., and the isolate could utilize sucrose, lactose, glucose, maltose and soluble starch as carbon source producing β-galactosidase, and the β-galactosidase level was the highest using 4% lactose(w/v) as carbon source. Yeast extract and tryptone mix is the preferred nitrogen source for the maximum growth and β-galactosidase production. The yield of β-galactosidase production of LW097 could reach 2.12±0.09 U/mL after 84 h culture at 16 ℃. The β-galactosidases produced by LW097 showed maximum activity at temperatures 30 ℃ and over the pH of 6.0. The enzyme retained 72.4% relative activity at 20 ℃, and 62.7% relative activity at 4℃. The enzyme showed good stability at low temperature. It retained more than 90% activity at 10 ℃ for 4 h but lost almost all the activity after incubation at 60°C for 4 h. The activity of β-galactosidase produced by LW097 was not affected by K +, only partially inhibited by Ca2+, Mg2+, Mn2+, Na+ and Fe 3+, and strongly inhibited by Zn2+, Cu2+ and Fe2+.Conclusions: The enzymatic properties exhibited by the β-galactosidase produced by the isolate LW097 proved it a typical cold-active enzyme, which shows good application potential in food industry in future.? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

备注/Memo

备注/Memo:
收稿日期: 2018-12-09 接受日期 Accepted:2019-02-01*国家自然科学基金项目(31560432)、兵团国际科技合作项目(2017BC012)、石河子大学青年创新人才培育计划(CXRC201702)和石河子大学高层次人才科研启动项目 (RCZX201547)资助 **通讯作者(E-mail:boguan3519@163.com)点击摘要页题目后的“PDF”可下载阅读全文;本文为已录用的作者修定稿,尚未经编辑全面修改。引用本文请注明出处本刊;发表刊期和页码将以正式出版时的安排为准,但DOI确定不变。
更新日期/Last Update: 2019-02-01