摘要
【目的】筛选一株具有高效降解褐藻胶能力的海洋微生物,鉴定其降解产物,并确定菌株发酵产酶最优条件,为铜藻(Sargassum horneri)的高值化开发利用提供理论支撑。【方法】利用海藻酸钠作为唯一碳源,从海水中筛选褐藻胶降解菌株。采用透明圈法和3,5-二硝基水杨酸(DNS)比色法复筛出褐藻胶裂解酶活力性较高的菌株。运用薄层层析法(TLC)对菌株发酵液中褐藻寡糖进行鉴定。通过16S rDNA序列分析进行菌株鉴定。利用单因素优化菌株的产酶条件,并测试其在海水环境下对铜藻的降解情况。【结果】筛选获得一株高效降解褐藻胶的菌株MBP_DH9,经鉴定为弧菌属(Vibrio sp.)。该菌株降解褐藻胶产生的寡糖主要为二糖,其最优发酵条件为培养温度30℃,初始pH值6.5,海藻酸钠质量浓度6 g/L。在此优化产酶条件下,菌株MBP_DH9的褐藻胶裂解酶活力可达66.6 U/mL,较优化前(46.1 U/mL)提高44.5%。此外,菌株MBP_DH9可在海水环境下实现对铜藻有效降解,藻渣质量损失率为55.21%,还原糖增量为0.204 mg/mL。【结论】筛选得到一株高效降解褐藻胶的弧菌MBP_DH9,该菌株能够降解褐藻胶为褐藻二糖,且能在海水环境下有效降解铜藻,因此具有进一步开发用于大规模制备褐藻胶裂解酶和褐藻寡糖生物制品的潜力。
【Objective】This study aims to isolate and screen a marine microorganism with high alginate-degrading efficiency,characterize its degradation products,and optimize the fermentation conditions for maximal enzyme production,thereby providing theoretical support for the high-value development and utilization of Sargassum horneri.【Method】Alginate-degrading strains were isolated from seawater using alginate as the sole carbon source.Strains with high alginate lyase activity were rescreened using the halo formation method and 3,5-dinitrosalicylic acid(DNS)colorimetric assay.Thin-layer chromatography(TLC)was employed to identify alginate oligosaccharides in the strain's fermentation broth.The strain was identified through 16S rDNA sequence analysis.Single-factor experiments were conducted to optimize the enzyme production conditions of the strain,and its degradation effect on S.horneri in the seawater environment was investigated.【Result】A highly efficient alginate-degrading strain,MBP_DH9,was isolated and identified as Vibrio sp..During alginate degradation,this strain predominantly produced disaccharide oligosaccharides.Optimal fermentation conditions were determined to be an incubation temperature of 30℃,an initial pH of 6.5,and an alginate mass concentration of 6 g/L.Under these conditions,MBP_DH9 exhibited an alginate lyase activity of 66.6 U/mL,representing a 44.5%increase compared to the pre-optimization level of 46.1 U/mL.Additionally,MBP_DH9 effectively degraded S.horneri in a seawater environment,achieving a 55.21%mass loss of algal residue and an increase in reducing sugar concentration of 0.204 mg/mL.【Conclusion】A high-efficiency alginate-degrading strain,MBP_DH9,belonging to the genus Vibrio,has been successfully isolated.The strain is capable of degrading alginate to produce alginate disaccharide and effectively degrades S.horneri in seawater.These properties highlight its promising potential for large-scale production of alginate lyase and alginate oligosaccharide-based bioproducts.
作者
陈志超
陈逍翔
孙夏好
何佳瑶
陈艳
CHEN Zhichao;CHEN Xiaoxiang;SUN Xiahao;HE Jiayao;CHEN Yan(School of Food and Pharmacy,Zhejiang Ocean University,Zhoushan 316022,China)
出处
《广东海洋大学学报》
北大核心
2025年第6期73-80,共8页
Journal of Guangdong Ocean University
基金
浙江省自然科学基金(LTGD24H030004)
舟山市科技计划项目(2023C41009)
浙江省大学生科技创新活动计划(2024R411A012)。
关键词
褐藻胶裂解酶
褐藻寡糖
弧菌属
产酶条件优化
铜藻降解
alginate lyase
alginate oligosaccharides
Vibrio sp.
optimization of enzyme-producing conditions
Sargassum horneri degradation
