在全球变暖的背景下,海水温度升高引起的珊瑚白化是珊瑚礁退化的主要原因。利用珊瑚有益微生物(BMC)进行珊瑚微生物组工程已成为珊瑚礁保护和恢复领域的热点。研究群体淬火(QQ)细菌减轻热应力的潜力可能为珊瑚微生物工程修复提供更多工具。在这项研究中,在75株珊瑚源细菌中筛选出QQ菌株假单胞菌SCSIO43740,并将其群体感应抑制剂(QSI)化合物分离并鉴定为2,4-二叔丁基苯酚(2,4-DTBP)。然后,通过三个不同处理的30天对照实验测试了QQ细菌对珊瑚的热应激缓解潜力:对照组(Con:29°C),高温组(HT:31°C),和一组高温用QQ菌接种(HTQQ:31℃+QQ菌)。结果表明,接种QQ菌SCSIO43740可以显著减轻热胁迫下的珊瑚大豆鸟共生藻类的损失和光合作用效率的损害。HT和HTQQ之间的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性没有显着差异。此外,接种QQ菌抑制了珊瑚微生物群落β-分散,提高了热胁迫下微生物共生网络的稳定性。提示接种QQ菌可通过重塑微生物相互作用缓解珊瑚热应激,维持珊瑚微生物群落稳定性。本研究为QQ菌在珊瑚中的益生功能提供了新的证据,阐明了用于珊瑚礁保护的新型微生物工具的开发。
In the background of global warming, coral bleaching induced by elevated seawater temperature is the primary cause of coral reef degradation. Coral microbiome engineering using the beneficial microorganisms for corals (BMCs) has become a hot spot in the field of coral reef conservation and restoration. Investigating the potential of alleviating thermal stress by quorum quenching (QQ) bacteria may provide more tools for coral microbial engineering remediation. In this study, QQ bacteria strain Pseudoalteromonas piscicida SCSIO 43740 was screened among 75 coral-derived bacterial strains, and its quorum sensing inhibitor (QSI) compound was isolated and identified as 2,4-di-tert-butylphenol (2,4-DTBP). Then, the thermal stress alleviating potential of QQ bacteria on coral Pocillopora damicornis was tested by a 30-day controlled experiment with three different treatments: control group (Con: 29 °C), high temperature group (HT: 31 °C), and the group of high temperature with QQ bacteria inoculation (HTQQ: 31 °C + QQ bacteria). The results showed that QQ bacteria SCSIO 43740 inoculation can significantly mitigate the loss of symbiotic algae and impairment of photosynthesis efficiency of coral P. damicornis under thermal stress. Significant difference in superoxide dismutase (SOD) and catalase (CAT) enzyme activities between HT and HTQQ was not observed. In addition, QQ bacteria inoculation suppressed the coral microbial community beta-dispersion and improved the stability of microbial co-occurrence network under thermal stress. It was suggested that QQ bacteria inoculation can alleviate coral thermal stress via reshaping microbial interaction and maintain community stability of coral microbiome. This study provided new evidence for the probiotic function of QQ bacteria in corals, which shedding light on the development of new microbiological tools for coral reef conservation.