Microbial diversity of mangrove sediment in Shenzhen Bay and gene cloning, characterization of an isolated phytase-producing strain of SPC09 B. cereus
Microbial diversity of mangrove sediment in Shenzhen Bay and gene cloning, characterization of an isolated phytase-producing strain of SPC09 B. cereus
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DOI：
10.1007/s00253-015-6405-8
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发表时间：
2015-02
影响因子：
5
通讯作者：
Sheng-peng Zhang;Shaoan Liao;Xiaoyuan Yu;H. Lu;Jian-An Xian;Hui Guo;Anli Wang;Jian Xie
中科院分区：
文献类型：
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作者：
Sheng-peng Zhang;Shaoan Liao;Xiaoyuan Yu;H. Lu;Jian-An Xian;Hui Guo;Anli Wang;Jian Xie
植酸酶能分解植酸释放无机磷，从而降低作物肥料对磷的需求，从而减少环境污染。采用高通量焦磷酸测序技术，对2012年9月采集的广东中国深圳湾根际沉积物中的微生物群落进行了分析，结果表明，根际沉积物中的优势分类门为绿藻、腐殖菌和变形杆菌，有益细菌中芽孢杆菌的比例为4.95%。共分离到29株可培养植酸酶产生菌，分析了它们的解磷能力，并对它们进行了分类鉴定。通过16S核糖体RNA(RRNA)基因序列分析确定它们的系统发育位置。结果表明，除7株肠杆菌、2株假单胞菌和1株海洋螺菌外，大部分分离株为芽孢杆菌属。从蜡样芽孢杆菌SPC09中克隆到植酸酶基因，该基因是分离菌株中解磷能力最强的菌株。该基因编码335个氨基酸的初级翻译产物。将含有1005个核苷酸的ORF片段BC-PHY转化到大肠杆菌中。重组植酸酶的最适温度为60℃，最适pH为6.5。定量聚合酶链式反应(QPCR)分析表明，细菌中含有丰富的Bc-植物基因；红树林中的细菌含量普遍高于滩涂，表层土壤中的含量高于底层土壤，最高值出现在6月份。在此，我们报道了从红树林系统中分离出来的一种新的植酸酶的克隆、性质和活性。
Phytases hydrolyze phytate to release inorganic phosphate, which decreases the requirement for phosphorus in fertilizers for crops and thus reduces environmental pollutants. This study analyzed microbial communities in rhizosphere sediment, collected in September 2012 from Shenzhen Bay, Guangdong, China, using high-throughput pyrosequencing; the results showed that the dominant taxonomic phyla wereChloroflexi,Firmicutes, andProteobacteria, and the proportion of the beneficial bacteria,Bacillus, was 4.95 %. Twenty-nine culturable, phytase-producing bacteria were isolated, their phosphorus solubilization capacity was analyzed, and they were taxonomically characterized. Their phylogenetic placement was determined using 16S ribosomal RNA (rRNA) gene sequence analysis. The result shows that most of the isolates are members of the orderBacillales, although seven strains ofEnterobacteriales, two strains ofPseudomonadales, and one strain ofOceanospirillaleswere also identified. The phytase gene was cloned from SPC09,Bacillus cereus, which showed the highest phosphorus solubilizing ability among the isolated strains. The gene encoded a primary translation product of 335 amino acids. A construct including the 1005-nt ORF fragment,Bc-phy, was transformed intoEscherichia coli. The recombinant phytase was produced and purified, which revealed the temperature optima at 60 °C and pH optima at 6.5. The assessment by quantitative PCR (qPCR) showed an abundance of bacteria containing theBc-phygene; the level was generally higher in the mangrove forest than in the tidal flats and in surface soil compared to bottom soil, and the highest value was obtained in June. Herein, we report on the cloning, characterization, and activity of a novel phytase isolated from a mangrove system.