产褐藻胶裂解酶阿氏芽孢杆菌的筛选及其对马尾藻降解效果  

Screening of Bacillus aryabhattai Producing Alginate Lyase and Its Degradation Efficiency on Sargassum denticarpum

作　　者：冯娟 罗霜 苏雅健 房耀维 杨光 侯晓月 陈梦 刘姝 FENG Juan;LUO Shuang;SU Yajian;FANG Yaowei;YANG Guang;HOU Xiaoyue;CHEN Meng;LIU Shu(College of Marine Food and Bioengineering,Jiangsu Ocean University,Lianyungang 222005,China;Lianyungang City Food and Drug Testing Center,Lianyungang 222069,China)

机构地区：[1]江苏海洋大学海洋食品与生物工程学院,江苏连云港222005 [2]连云港市食品药品检验检测中心,江苏连云港222069

出　　处：《广东海洋大学学报》2025年第1期68-76,共9页Journal of Guangdong Ocean University

基　　金：江苏海洋大学2023年研究生科研与实践创新计划项目(KYCX2023-39)。

摘　　要：【目的】筛选褐藻胶降解菌,评价其对马尾藻(Sargassum denticarpum)的降解效果,为提高马尾藻的利用率提供理论支持。【方法】运用透明圈法和酶活力测定法获得产褐藻胶裂解酶水平较高的菌株,通过16S rDNA序列分析进行菌株鉴定。利用单因素和响应面优化菌株产酶条件,通过扫描电镜观察马尾藻的降解情况,测定藻渣质量和还原糖质量浓度变化。【结果】获得1株符合条件的菌株MAL001,鉴定为阿氏芽孢杆菌Bacillus aryabhattai。优化后产酶条件为NaCl质量分数1%,pH 7.0,温度23℃,转速180 r/min,接种体积分数2%,培养时间24 h,此条件下褐藻胶裂解酶活力达65.8 U/mL,为优化前(44.7 U/mL)的1.5倍。MAL001的褐藻胶裂解酶最适温度为35℃,最适pH为7.0,在最适温度下保持12 h其酶活力仍能在最初酶活力的70%以上;在pH 6.6~8.6时,其酶活力仍保留初始酶活力的60%以上,金属离子Al^(3+)、Fe^(3+)及Co^(2+)抑制褐藻胶裂解酶活力,Mg^(2+)则具有促进作用;该酶降解海藻酸钠的终产物为二糖、三糖和四糖。扫描电镜结果表明,菌株MAL001通过破坏细胞结构裂解马尾藻,藻渣失重率为42.13%,还原糖增量为0.121 mg/mL。【结论】筛选并鉴定得到褐藻胶降解菌阿氏芽孢杆菌Bacillus aryabhattai MAL001,其对马尾藻有良好的降解效果。【Objective】To screen for alginate-degrading bacteria and evaluate their degradation effect on Sargassum denticarpum and to provide theoretical support for improving the utilization rate of S.denticarpum.【Method】The transparent circle method and enzyme activity assay were used to obtain strains with high levels of alginate lyase production.Strain identification was performed through 16S rDNA sequence analysis,and enzyme production conditions were optimized using single factor and response surface methodology.The degradation of sargassum was observed by scanning electron microscopy.The changes in the quality of algae residue and mass concentration of reducing sugar were determined.【Result】A strain MAL001 that meets criteria was obtained identified as Bacillus aryahattai.The optimized conditions for enzyme production were mass fraction of NaCl 1%,pH 7.0,temperature 23℃,rotation speed 180 r/min,inoculation amount 2%,incubation time 24 h.The alginate lyase activity reached 65.8 U/mL,which was 1.5 times that of the preoptimization(44.7 U/mL);The optimum temperature of alginate lyase from strain MAL001 was 35℃.The optimum pH was 7.0.At the optimal temperature for 12 h,the enzyme activity was still more than 70%of the initial enzyme activity,and between pH 6.6‒8.6,the enzyme activity was retained more than 60%of the initial enzyme activity.Metal ions Al^(3+),Fe^(3+)and Co^(2+)inhibited the activity of alginate lyase,while Mg^(2+)promoted it.The final products of alginate lyase degradation were disaccharide,trisaccharide and tetrasaccharide.Scanning electron microscopy showed that the strain MAL001 lysed S.denticarpum by disrupting the cell structure.The weight loss rate of alga residue was 42.13%,and the increase of reducing sugar was 0.121 mg/mL.【Conclusion】The alginate degrading bacterium Bacillus aryabhattai MAL001 has good degradation effect on S.denticarpum.

关 键 词：阿氏芽孢杆菌 褐藻胶裂解酶 发酵优化 酶学性质 马尾藻降解 

分 类 号：TS201.3[轻工技术与工程—食品科学]