塑料降解昆虫肠道核心真菌的多样性

Diversity of Core Fungi in Enteric Gut of Plastic-Degradable Insects

大麦虫(Zophobas atratus)、黄粉虫(Tenebrio molitor L.)、黑粉虫(Tenebrio obscurus)和大蜡螟(Galleria Mellonella L.)幼虫均能取食和降解聚苯乙烯泡沫塑料。在昆虫降解塑料的过程中,肠道菌群发挥了重要作用。现有报道大多集中在对塑料降解昆虫肠道细菌的研究上,对其肠道真菌的研究比较缺乏。本研究通过ITS rDNA扩增子测序,发现四种昆虫肠道真菌群落结构基本情况相似。门水平上子囊菌门(Ascomycota)具有绝对优势;科水平上酵母科(Saccharomycetales)和格孢菌科(Pleosporaceae)具有较高的相对丰度;属水平上双角菌属(Diutina)、念珠菌属(Candida)、链孢菌属(Alternaria)、丛赤壳属(Nectriaceae)、镰刀菌属(Fusarium)占据优势。经对比分析找到了33个共有的核心真菌OTUs,这些OTUs的序列占每种昆虫总序列的51.2%~94.6%,其中OTU 1在所有样品中的相对丰度均较高(17.7%~80.6%),表明其在昆虫肠道中的普遍性及重要性。FUNGuild预测到的核心菌群大都属于腐生菌,在物质循环降解中有一定作用,是潜在的塑料降解菌。本研究揭示了在昆虫肠道中存在的四种具有聚苯乙烯泡沫塑料降解能力的核心真菌菌群,为进一步阐明昆虫降解塑料的机制及挖掘塑料降解微生物菌株提供了新的启示。

Larvae of barley pest(Zophobas atratus),mealworms(Tenebrio molitor),dark mealworm(Tenebrio obscurus),and Galleria mellonella(Galleria mellonella)can all feed on and degrade polystyrene foam plastics.During the process of insect degradation of plastics,the enteric gut microbial community plays an important role.The existing reports focus on the research of plastic-degradable bacteria in insect enteric gut,while research on their enteric gut fungi relatively lacks.Through ITS rDNA amplicon sequencing,it was found that the fungal community structure in the enteric gut of these four insects were basically similar.At the phylum level,Ascomycota had an absolute advantage.At the family level,Saccharomycetales and Pleosporaceae had high relatively abundant.At the genus level,Diutina,Candida,Alternaria,Nectriaceae,and Fusarium predominate.33 fungal core OTUs were identified,with sequences accounting for 51.2%-94.6%of the total sequences in each insect.OTU 1 Alternaria was relatively abundant in all samples(17.7%-80.6%),indicating its prevalence and importance in the insect enteric gut.FUNGuild predicts that the majority of the core fungal communities are saprophytic fungi,playing a role in material cycling and degradation,making them potential plastic degradable fungi.This article reveals the existence of core fungal communities in the enteric gut of the insects that have the potential to degrade polystyrene foam plastics.It provides new enlightenment for further elucidating the mechanism of insect plastic degradation and exploring microbial strains for plastic degradation.