Fluorescein diacetate hydrolysis as a measure of fungal biomass in soil (original) (raw)
Related papers
Fatty acids of fungi and nematodes—possible biomarkers in the soil food chain?
Soil Biology and Biochemistry, 2002
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 pro®les 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 pro®les. 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 v6 and 9 family, indicating a carboxyl-directed desaturation as a major metabolic pathway. The fungal host signi®cantly affected the fatty acid pro®le of the nematodes. However, we could not assign individual fatty acids as biomarkers re¯ecting 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 in¯uence 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. q
2014
Analyses were conducted on 30 winter wheat samples growing under controlled conditions and following inoculation with fungi Fusarium culmorum. In inoculated samples the mean concentration of 30 analysed fatty acids was significantly higher in relation to the control and amounted to 1396 mg/kg vs. 1046 mg/kg in the control kernels. Recorded concentrations for individual cultivars were significantly correlated with the concentration of fungal biomass.
Fungal Lipids: The Biochemistry of Lipid Accumulation
International Journal of Chemical Engineering and Applications, 2014
After having M.Sc. degree at Uludag University on 1994, she had her Ph.D. degree at the Department of Biological Sciences of the University of Hull, United Kingdom, on 1997. The topic of her Ph.D. project funded by Higher Education Council of Turkey was on fungal lipid metabolism and a novel fatty acid was identified from a sewage fungus. The main lectures given by Mrs. Akpinar-Bayizit are instrumental analysis, microbial process technology, food fermentations, functional foods and plant hygiene and sanitation. Her areas of her research interest include fermentation technology, particularly microbial fermentations, and lipid technology. Up till today she has supervised 5 M.Sc. studies, and supervising ongoing 4 M.Sc. and 2 Ph.D. projects. She has published several research and review articles in international journals and has two book chapters.
Soil Biology & Biochemistry, 2010
The phospholipid fatty acid biomarkers 18:1ω9, 18:2ω6,9 and 18:3ω3,6,9 are commonly used as fungal biomarkers in soils. They have, however, also been found to occur in plant tissues, such as roots. Thus, the use of these PLFAs as fungal biomarkers in sieved soil, which may still contain small remains of roots, has been questioned. We used data from a recent beech tree girdling experiment to calculate the contribution of roots to these biomarkers and were able to demonstrate that not more than 0.61% of 18:1ω9 and 18:2ω6,9 in sieved soil samples originated from roots (but 4% of 18:3ω3,6,9). Additionally, the abundance of the biomarker 18:2ω6,9 in the soil was found to be highly correlated to ectomycorrhizal root colonization, which further corroborates its fungal origin. PLFA biomarkers were substantially reduced in vital roots from girdled trees compared to roots of control trees (by up to 76%), indicating that the major part of PLFAs measured in roots may actually originate from ectomycorrhizal fungi growing inside the roots. We calculated, that even a near to 50% reduction in fine root biomass -as observed in the girdling treatment -accounted for only 0.8% of the measured decrease of 18:2ω6,9. Our results demonstrate that both 18:1ω9 and 18:2ω6,9 are suitable biomarkers for detecting fungal dynamics in soils and that especially 18:2ω6,9 is a reliable biomarker to study mycorrhizal dynamics in beech forests.
Scientific Journal of Medical Research
The present study was aimed for rapid identification of lipids accumulation of oleaginous fungi isolated from oil-rich soil in Basrah /Iraq. Methods: Soil samples were collected from oil-rich soil of Basrah-Iraq; dilution plate method was used to identification of fungi, as well as the percentage of frequency and occurrence was determined after identification of fungal isolates according of morphological features. Congo red agar was employed for evaluation of lipase production of fungal isolates, while lipid accumulation of fungal isolates was estimated by using Sudan black B technique. As well as, four fungal isolates that revealed highest lipid accumulation were underwent of DNA extraction and the result of genomic DNA was amplified with two universal primers ITS1 and ITS4, PCR products were purified and sequenced, furthermore, sequencing results of fungal species were identified in " BLAST " provided by the NCBI.
2020
Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile...
Soil Biology and Biochemistry, 2005
We evaluate the use of signature fatty acids and direct hyphal counts as tools to detect and quantify arbuscular mycorrhizal (AM) and saprotrophic fungal (SF) biomass in three Hawaiian soils along a natural soil fertility gradient. Phospholipids16:1u5c and 18:2u6,9c were used as an index of AM and saprotrophic fungal biomass, respectively. Both phospholipid analysis and hyphal length indicated that the biomass of AMF was greatest at the highest fertility site, and lowest where phosphorus limits plant growth. Saprotrophic fungal biomass did not vary. Hyphal length counts appeared to underestimate SF abundance, while the phospholipid AMF:SF ratio was in line with expectations. This study indicates that phospholipids may be a valuable and reliable tool for studying the abundance, distribution, and interactions between AM and saprotrophic fungi in soil.
2006
A method based on fatty acid (FA) analysis is used to profile microbial community structure (MCS). Various extraction protocols are available, which alter the types of FAs extracted from soils. The more time consuming but widely used protocol extracts only FAs from phospholipids (PLFA). This technique is desirable because PLFAs are largely of microbial origin and from viable cells, since they rapidly degrade upon microbial death. This stands in contrast to other more rapid methods that directly extract FAs but may extract FAs of nonmicrobial origin. In this thesis, two such methods of FA extraction (EL-FAME and MIDI) were compared to PLFA extracts for detecting shifts and interpreting profiles of MSC. Soil samples from a wide array of vegetation and climatic conditions were extracted by these methods, and their FA composition analyzed by gas chromatography. MIDI extracts contained major plantspecific FAs. Ordination multivariate analysis showed that separation of MCS among samples was driven mostly by these FAs, rather than by microbial FA markers. The degree of similarity between EL-FAME and PLFA results was affected by the environmental conditions. The major differences among methods were in the general fungal and arbuscular-mycorrhizal fungal markers that were related to the vegetation type where soils were found. Nevertheless, crosssample relative differences in the amounts of prokaryote FAs were not impacted by EL-FAME I would like to thanks the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq-Brazil) for my scholarship and for funding part of this research, and the Brazilian Agency for Agricultural Research (Embrapa) for the opportunity to pursue this degree at OSU and financial support. I am indebted to Joan Sandeno for all her crucial support in laboratory and editing activities. Thanks to my colleagues Cecilia Cespedes, Siré Diedhiou, Belen Hinojosa, and Jenn Moore Kucera, for being important laboratory partners, for the useful discussions every day and their friendship. The Department of Crop and Soil Science staff is thanked for their technical support. I would like to express my gratitude to my parents Porfirio and Vera Lucia, my parentsin-law Roberto and Maria, and all my family for their support and always believing in me. Thanks to all the friends I have met here in Corvallis. I would especially like to thank Patricia Medeiros, Renato Castelão and Guilherme Chaer; in addition to their friendships, they also have contributed with technical support in many aspects of this work. Above all I would like to express my most sincere appreciation to my wife Roberta and my son João, whose love, understanding, and joy have given me the strength to pursue this degree.
Stable isotope analysis has been used as a powerful tool in food web studies in terrestrial ecosystems. In addition the occurrence and abundance of fatty acids may serve as indicator for feeding strategies of soil animals. Here we combine both approaches and investigate the fatty acid composition, d 13 C values of bulk tissues and individual fatty acids in soil organisms. The fungi Chaetomium globosum and Cladosporium cladosporioides were isotopically labelled by fructose derived from either C 3 or C 4 plants, and the fungal-feeding nematode Aphelenchoides sp. was reared on C. globosum. Fungi and nematodes were used as diet for the Collembolan Protaphorura fimata. The sugar source was fractionated differently by fungal lipid metabolism in a species-specific manner that points to a sensitivity of physiological processing to the non-random distribution of 13 C/ 12 C isotopes in the molecule. As a general trend stearic acid (18:0) was depleted in 13 C compared to the precursor palmitic acid (16:0), whereas its desaturation to oleic acid (18:1 u9) favoured the 13 C-rich substrate.
Fatty acid composition and dynamics of selected fungal-feeding nematodes and fungi
Comparative Biochemistry and Physiology B-biochemistry & Molecular Biology, 2001
Fatty acid profiles of fungal-feeding nematodes, Aphelenchus avenae and Aphelenchoides composticola, and selected fungi were determined in microcosm cultures of agar, broth, or sand amended with organic matter. Fatty acids of A. avenae and A. composticola included 16:0 18:0, 18:1ω7, 18:1ω9, 18:2, 20:0, 20:1, 20:2, 20:3 and 20:4 phospholipid fatty acids (PLFAs) and neutral lipid fatty acids (NLFAs). The nematodes differed in relative amounts of saturated and C18 fatty acids. Similar C16 and C18 PLFAs and whole-cell fatty acids were found in Rhizoctonia solani, Fusarium oxysporum and Trichoderma sp. with 18:2ω6 as the major component. The C20 fatty acids were not found in these fungi. Although only present in the nematodes, C20 PLFAs were only detected when nematode population levels were ≥22 per gram of sand, suggesting that there is a detection threshold that might limit their use as biomarkers in the soil community. After removal of nematodes from a food source, the relative amount of C20 PLFAs (structural components of nematode cell membranes) decreased more slowly than the C16 and C18 PLFAs, which may have reflected ingested fungal cytoplasm in the nematode intestine. In the early stage of organic matter decomposition, total and fungal PLFAs were lower in the presence of A. composticola then in its absence at C:N ratios ≥30:1.