分子生态网络揭示冶金微生物对能源底物的响应

Molecular ecological network reveals the response of metallurgical microorganisms to energy substrates

摘要:

通过分析不同铁硫比的能源底物驯化下冶金微生物群落的演替过程，基于分子生态网络揭示冶金微生物对能源底物的响应特征。对富铁少硫、富硫少铁条件下不同驯化批次的微生物样本进行高通量测序，分析物种组成，比较冶金微生物群落的α多样性和β多样性，并构建分子生态网络，探究驯化过程微生物之间的相互作用关系。鉴定关键物种，分析冶金微生物群落对能源底物的响应。研究发现在基于不同能源底物驯化过程中，富铁少硫群落的优势物种为嗜酸氧化亚铁硫杆菌Acidithiobacillus ferrooxidans和铁氧化嗜酸硫杆菌A. ferriphilus；而富硫少铁群落经过3个批次的驯化，氧化硫硫杆菌A. thiooxidans占比高达90%。α、β多样性分析结果表明，富硫少铁能源底物驯化过程使冶金微生物群落多样性降低，且随着驯化批次的增加群落组成发生显著变化。分子生态网络分析显示关键物种均为低丰度稀有物种，富硫少铁条件下菌种间具有更紧密的互作共生关系，群落更加稳定。通过该驯化实验，明确了不同能源底物对冶金微生物群落的影响。采用富硫少铁能源底物驯化冶金微生物，使冶金微生物群落更加稳定，有助于优势物种高效发挥铁、硫氧化功能，促进硫化矿物的氧化溶解，为生物冶金工业育种微生物群落的定向驯化提供理论基础。

Abstract:

By analyzing the shift of microbial communities under different iron/sulfur ratios, the response of metallurgical microorganisms to energy substrates was investigated based on molecular ecological networks. High-throughput sequencing of microbial samples from different domesticated batches was conducted to analyze the changes in community composition, alpha and beta diversity. Based on the molecular ecological network, the interactions between microorganisms under different iron/sulfur ratios were explored. Keystones were identified to analyze the community response to energy substrates. In the process of domestication based on different energy substrates, the dominant species in the in iron-rich and sulfur-less community were Acidithiobacillus ferrooxidans and A. ferriphilus. A. thiooxidans accounted for up to 90% in the sulfur-rich and iron-less community after 3 domesticating batches. The results of alpha and beta diversity analysis show that the domestication process of sulfur-rich and iron-less substrates reduced the diversity of microbial communities. Molecular ecological network analysis shows that the keystones were all rare species with low abundance. During the domestication by sulfur-rich and iron-less energy substrates, the bacterial species had a closer symbiotic relationship and the community was more stable. Through this domestication experiment, the impact of different energy substrates on microbial aggregation was clarified. Domesticating metallurgical microorganisms by using sulfur-rich and iron-less energy substrates made the microbial colonies to be more stable, which was conducive to the oxidation of iron and sulfur, promoting the dissolution of sulfide minerals. Our findings provide a reference for the directional domestication of metallurgical microorganisms.