Fatty acids of fungi and nematodes -: possible biomarkers in the soil food chain?
Fatty acids of fungi and nematodes -: possible biomarkers in the soil food chain?
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DOI：
10.1016/s0038-0717(01)00231-0
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发表时间：
2002-06-01
影响因子：
9.7
通讯作者：
Dighton, J
中科院分区：
文献类型：
--
作者：
Ruess, L;Häggblom, MM;Dighton, J
研究了16种不同土壤真菌（子囊菌、担子菌、有丝孢子真菌）和以7种真菌为食的线虫的脂肪酸组成。此外，还比较了生长在同一真菌食物源赤霉素上的Aphelenchoides sp.和a.s aprophilus的脂肪酸谱。在真菌中检测到13种优势脂肪酸。其中大多数发生在16个物种中，但单个脂肪酸的相对数量不同，特别是不饱和脂肪酸。在此基础上，大多数真菌种类可以相互区分。我们的研究揭示了系统相关真菌的脂肪酸组成的趋同，但也有差异，即分类或系统发育关系并不一定伴随着脂肪酸谱的相似性。线虫的脂肪酸谱比真菌更宽，有17种主要脂肪酸，并且比真菌的食物含有更多的长链多不饱和酸。真菌宿主组织可能提供棕榈酸、油酸和亚油酸存在，而大部分长链不饱和脂肪酸是由线虫合成的。不饱和脂肪酸主要属于omega - 6和9家族，表明羧基导向的去饱和是一种主要的代谢途径。真菌宿主对线虫的脂肪酸谱有显著影响。然而，我们不能指定单个脂肪酸作为反映膳食来源的生物标志物，可能是由于在测试的真菌物种中有相当大的趋同性。在所分析的担子菌中，拉卡菌与其他担子菌有明显的分离，这种差异也可以在线虫中检测到，显示出食物类型的影响。我们得出结论，线虫的脂质组成是由线虫及其饮食控制的，因此监测土壤动物的脂肪酸模式可能提供一种检测地下食物网营养相互作用的方法。(C) 2002 Elsevier Science Ltd.版权所有。
The fatty acid composition of 16 different soil fungi (ascomycetes, basidiomycetes, mitosporic fungi) and a fungal-feeding nematode Aphelenchoides sp. reared on seven fungal species was investigated. Additionally, fatty acid profiles of Aphelenchoides sp. and A. saprophilus grown on the same fungal food source, Agrocybe gibberosa, were compared. Thirteen predominant fatty acids were detected in the fungi. Most of them occurred in each of the 16 species, but relative quantities of individual fatty acids differed, in particular those of unsaturated ones. Most fungal species could be differentiated from each other on this basis. Our study revealed convergence, but also, differences, in the fatty acid composition of systematically related fungi, i.e. a taxonomic or phylogenetic relationship was not necessarily accompanied by similarity in fatty acid profiles. Nematodes comprised a wider fatty acid spectrum than fungi, with 17 predominant fatty acids, and a higher amount of long-chain, polyunsaturated acids than their fungal diet. Fungal host tissue may have supplied palmitic, oleic and linoleic acid present, whereas most of the long-chain unsaturated fatty acids were synthesized by the nematodes. Unsaturated fatty acids mainly belonged to the omega6 and 9 family, indicating a carboxyl-directed desaturation as a major metabolic pathway. The fungal host significantly affected the fatty acid profile of the nematodes. However, we could not assign individual fatty acids as biomarkers reflecting the dietary source, likely due to the considerable convergence within tested fungal species. Of the basidiomycetes analyzed Laccaria laccata was distinctly separated from the others and this difference could also be detected in the nematodes showing the influence of food type. We conclude that the lipid composition of nematodes is controlled by both the nematode and its diet and that monitoring fatty acid patterns of soil animals may therefore provide a way to detect trophic interactions in belowground food webs. (C) 2002 Elsevier Science Ltd. All rights reserved.