基于宏基因组学的海带降解菌群微生物多样性及其褐藻多糖降解酶系分析

Microbe Diversity of Microbes Digesting Laminaria japonica and Brown Alga Polysaccharide Digesting Enzymes Revealed by Metagenomic Sequencing

为系统探讨一组高效海带降解菌群的微生物多样性及其褐藻多糖降解酶系,本实验利用高通量测序技术对该菌群进行组学分析。结果表明,共获得36552330条reads,预测得到105145条基因序列,比对显示此高效海带降解菌群中有75.41%的厚壁菌门(Firmicutes)细菌,优势菌属包括Lachnoclostridium、芽孢杆菌属(Bacillus)、类芽孢杆菌属(Paenibacillus)、解硫胺素芽孢杆菌属(Aneurinibacillus)、短芽孢杆菌属(Brevibacillus)。数据显示有4526个基因编码蛋白质具有海带多糖降解相关酶活性,其中糖苷水解酶(GH)基因数量最多(1520),碳水化合物结合模块(CBM)(764)、碳水化合物酯酶(CE)基因(706)和糖基转移酶(GT)(693)数量次之,多糖裂合酶(PL)基因(107)和辅助氧化还原酶(AA)基因(126)数量较少。在不同的GH基因家族,归属于GH109、GH13、GH18、GH43家族的基因较多。此外还发现了少量的纤维小体组分蛋白基因。本研究发现海带降解菌群中有丰富的褐藻胶裂解酶,纤维素酶,果胶酶,淀粉酶酶系产酶菌,为进一步开发人工高效褐藻降解菌群及褐藻多糖降解酶提供参考。

In order to investigate systematically the diversity and brown algal polysaccharide degrading enzymes of Laminaria japonica degrading microbes,the metagenome of these microbes was sequenced with massively parallel sequencing technology in this study.A total of 36,552,330 reads were obtained and 105,145 genes were modeled.The results showed that the microbes in phylum Firmicutes accounted for 75.41%among the microbes digesting L.japonica.The dominant bacteria were from genera Lachnoclostridium,Bacillus,Paenibacillus,Aneurinibacillus and Brevibacillus.In total,4,526 genes were found to encode enzymes degrading L.japonica.The number of glycoside hydrolase(GH)genes was the largest(1,520),which was followed by that of carbohydrate binding module(CBM)genes(764),carbohydrate esterase(CE)genes(706)and glycosyl transferase(GT)genes(693).The polysaccharide lyase(PL)genes(107)and their auxiliary protein(AP)genes(126)were the two least.A large portion of GH genes belonged to GH109,GH13,GH18 and GH43 families.In addition,a small number of cellulosome component protein genes were found.We found also abundant alginate lyase,cellulase,pectinase and amylase producing bacteria,which provided basic data for further technological developments of highly efficient artificial degradation of L.japonicaand brown algal polysaccharide exploitation.