An inexpensive high-throughput method to extract high yields of good quality DNA from fungi

We developed an efficient method for high-throughput extraction of high-quality DNA from various fungi. In this method, fungal mycelia were cultured and harvested on the surfaces of membranes on media plates. We degraded cell walls using a lytic enzyme (Yatalase). Purification was performed on 96-well glass fibre filter plates. DNA was successfully extracted from various fungi provided (102 genus 132 species) at high yields and quality, and proved suitable for storage, polymerase chain reaction amplification and restriction enzyme digestion. The method described is rapid, inexpensive and automation friendly. This enables the simultaneous extraction of large numbers of samples, significantly improving the potential throughput in genomics, particularly in diagnostic and population studies.     

一种改良的植物基因组DNA通用提取方法

高质量的基因组DNA是分子生物学研究的基础,而从富含糖类和次生代谢物且异质性强的植物材料中分离DNA相对困难。本方法在CTAB法和商业DNA提取试剂盒的基础上,在裂解细胞之前,对植物材料进行预处理．去除干扰DNA提取的代谢物,并在后续步骤中进行了一些优化。该方法适于多种不同的植物种类,所提取的基因组DNA质量较好,能满足下一步基因操作的要求,是一种通用的植物基因组DNA提取方法。     

A method for obtaining DNA from compost

An effective cell lysis method for extraction of bacterial genomic DNA from compost was developed in this study. Enzymatic disruption method, physical–chemical combination method, and commercial kit method were used to extract DNA from compost samples and were compared by analyzing DNA yield and efficient cell lysis. The results showed that all the three methods can be used to extract high-quality DNA from compost, but the enzymatic method had better cell lysis efficiency and DNA yields than others without the use of special equipment and expensive spending. Comparison of different methods for lysing gram-positive bacteria Bacillus subtilis indicated that the enzymatic cell lysis is superior for destroying the gram-positive cell wall. Spin-bind DNA column was used for DNA purification, and the purity of the purified sample was checked by polymerase chain reaction to amplify a region of the 16S rRNA. Results indicated that the part of 16S rRNA were amplified from all the purified DNA samples, and all the amplification products could be digested by the restriction enzyme HhaI.     

Rapid and simple methodology for isolation of high quality genomic DNA from coniferous tissues (<Emphasis Type="Italic">Taxus baccata</Emphasis>)

Various investigations have been so far performed for extraction of genomic DNA from plant tissues, in which the extracted intact DNA can be exploited for a diverse range of biological studies. Extraction of high quality DNA from leathery plant tissues (e.g., coniferous organs) appears to be a critical stage. Moreover, for some species such as Taxus trees, bioprocess engineering and biosynthesis of secondary metabolites (e.g., paclitaxel) is a crucial step due to the restrictions associated with extinction of these species. However, extraction of intact genomic DNA from these plants still demands a rapid, easy and efficient protocol. To pursue such aim, in the current work, we report on the development of a simple and highly efficient method for the extraction of DNA from Taxus baccata. Based upon our protocol, interfering phenolic compounds were removed from extraction using polyvinylpyrrolidone and RNA contamination was resolved using LiCl. By employing this method, high quality genomic DNA was successfully extracted from leaves of T. baccata. The quality of extracted DNA was validated by various techniques such as RAPD marker, restriction digestions and pre-AFLP. Upon our findings, we propose this simple method to be considered for extraction of DNA from leathery plant tissues.     

Comparison of DNA extraction methods for analysis of turkey cecal microbiota

AIM: As a prelude to long-term studies to characterize the microbiota of the turkey ceca, 14 DNA isolation protocols were evaluated for their ability to reproducibly characterize microbial diversity. METHODS AND RESULTS: Eight commercially available DNA extraction kits were assessed. DNA quantity and quality were assessed and competitive PCR was used to quantify the 16S bacterial rRNA genes. The Invitrogen Easy-DNA Kit extraction method for large samples yielded over eight times more DNA than any other method (3144 +/- 873 microg g(-1) of sample, P < 0.05). Bacterial and fungal species richness was estimated by Automated Ribosomal Intergenic Spacer Analysis. The Invitrogen Easy-DNA Kit generated the greatest bacterial species richness (46 +/- 7 peaks) while Bio-Rad Aquapure yielded the highest fungal species richness (71 +/- 9.5 peaks). CONCLUSION: Cluster analysis indicated different DNA extraction methods generated different microbial community compositions using the same cecal matrix from a single donor bird. SIGNIFICANCE AND IMPACT OF THE STUDY: Optimized DNA extraction protocols Invitrogen Easy-DNA Kit extraction method for large samples and Bio-Rad Aquapure outperform other methods for extraction of DNA from poultry fecal samples, although these methods do not necessarily recover all available DNA. They will be used in future studies to monitor the dynamics of microbial communities of the avian ceca.     

Comparison of three DNA extraction methods for Mycobacterium bovis, Mycobacterium tuberculosis and Mycobacterium avium subsp. avium

Aims:  To compare three methods for DNA extraction from Mycobacterium bovis , Mycobacterium tuberculosis and Mycobacterium avium subsp. avium .
Methods and Results:  The DNA was extracted from mycobacterial cultures using enzymatic extraction, combined bead beating and enzymatic extraction and cetyltrimethylammonium bromide (CTAB) extraction. The yield and quality of DNA were compared by spectrophotometry, agarose gel electrophoresis, restriction endonuclease analysis and PCR. The combined bead beating and enzymatic extraction method yielded more DNA. However, that method produced some sheared DNA, visible either by agarose gel electrophoresis or by restriction endonuclease analysis. All methods were appropriate for PCR amplification of a 123 bp fragment of IS 6110 in M. bovis and M. tuberculosis , and of a 1700 bp fragment of FR300 region in M. avium avium .
Conclusions:  Combined bead beating and enzymatic extraction method was the most efficient and easy method for extracting DNA from bacteria of the M. tuberculosis complex.
Significance and Impact of the Study:  The results reveal important differences among the DNA extraction methods for mycobacteria, which are relevant for the success of further downstream molecular analysis.     

Finding flies in the mushroom soup: Host specificity of fungus‐associated communities revisited with a novel molecular method

Fruiting bodies of fungi constitute an important resource for thousands of other taxa. The structure of these diverse assemblages has traditionally been studied with labour‐intensive methods involving cultivation and morphology‐based species identification, to which molecular information might offer convenient complements. To overcome challenges in DNA extraction and PCR associated with the complex chemical properties of fruiting bodies, we developed a pipeline applicable for extracting amplifiable total DNA from soft fungal samples of any size. Our protocol purifies DNA in two sequential steps: (a) initial salt–isopropanol extraction of all nucleic acids in the sample is followed by (b) an extra clean‐up step using solid‐phase reversible immobilization (SPRI) magnetic beads. The protocol proved highly efficient, with practically all of our samples—regardless of biomass or other properties—being successfully PCR‐amplified using metabarcoding primers and subsequently sequenced. As a proof of concept, we apply our methods to address a topical ecological question: is host specificity a major characteristic of fungus‐associated communities, that is, do different fungus species harbour different communities of associated organisms? Based on an analysis of 312 fungal fruiting bodies representing 10 species in five genera from three orders, we show that molecular methods are suitable for studying this rich natural microcosm. Comparing to previous knowledge based on rearing and morphology‐based identifications, we find a species‐rich assemblage characterized by a low degree of host specialization. Our method opens up new horizons for molecular analyses of fungus‐associated interaction webs and communities. Fruiting bodies of fungi constitute an important resource for thousands of other taxa. The structure of these diverse assemblages has traditionally been studied with labour‐intensive methods involving cultivation and morphology‐based species identification, to which molecular information might offer convenient complements. To overcome challenges in DNA extraction and PCR associated with the complex chemical properties of fruiting bodies, we developed a pipeline applicable for extracting amplifiable total DNA from soft fungal samples of any size. Our protocol purifies DNA in two sequential steps: (a) initial salt–isopropanol extraction of all nucleic acids in the sample is followed by (b) an extra clean‐up step using solid‐phase reversible immobilization (SPRI) magnetic beads. The protocol proved highly efficient, with practically all of our samples—regardless of biomass or other properties—being successfully PCR‐amplified using metabarcoding primers and subsequently sequenced. As a proof of concept, we apply our methods to address a topical ecological question: is host specificity a major characteristic of fungus‐associated communities, that is, do different fungus species harbour different communities of associated organisms? Based on an analysis of 312 fungal fruiting bodies representing 10 species in five genera from three orders, we show that molecular methods are suitable for studying this rich natural microcosm. Comparing to previous knowledge based on rearing and morphology‐based identifications, we find a species‐rich assemblage characterized by a low degree of host specialization. Our method opens up new horizons for molecular analyses of fungus‐associated interaction webs and communities.     

Polymerase chain reaction in diagnosis of toxoplasmosis of the central nervous system: effect of methods for isolating DNA from samples of cerebrospinal fluid on results of the reaction

We examined influence of the method of isolation of DNA from cerebrospinal fluid samples on results of PCR in the diagnosis of toxoplasmosis of the central nervous system. Three different protocols of DNA isolation were used for DNA extraction from 360 samples made of cerebrospinal fluid spiked with tachyzoites of Toxoplasma gondii: thermic, enzymatic and enzymatic-filtering. Purified DNA samples were tested by PCR with primers T15 and T16 designed for the B1 gene of the parasite. Enzymatic method of DNA isolation appeared most effective allowing detection of T. gondii DNA in 50% of samples containing single parasite cell.     

DNA Extraction from Activated Sludges

To optimize the cell lysis step for DNA extraction from activated sludge samples, two floc dispersion methods (sonication versus stirring with a cation exchange resin), and three cell lysis treatments (lysozyme + SDS, sonication in a water bath, and thermal shock) were tested. For dispersion, stirring with cation exchange resin was more efficient than sonication. The cell lysis procedures were applied in two sequences, and DNA was quantified after each cell lysis treatment. Lysozyme + SDS was the most effective step in the cell lysis procedures. The cell lysis treatment sequences giving the highest DNA yields were not the same for all the sludges. The differences in sludge microbial compositions and floc structures required specifically adapted cell lysis protocols. The proposed protocols were highly efficient for DNA extraction, yielding about 50 mg DNA g⁻¹ volatile suspended solids, and allowed PCR amplification of 16S rDNA. Received: 26 September 1998 / Accepted: 13 February 1999     

一种快速高效提取病原真菌DNA作为PCR模板的方法

真菌rDNA-ITS序列分析适合于较高等级水平的生物群体间的系统分析。真菌DNA的提取采用传统的方法,步骤繁琐,需要较长时间。采用Chelex-100法提取真菌DNA,使用PCR扩增rDNA-ITS序列评价提取核酸的质量。结果显示,该方法具有经济、简便、快速、高效的特点,是一种比较理想的提取真菌基因组DNA作为PCR模板的方法。     

Comparative analysis of fecal DNA extraction methods with phylogenetic microarray: Effective recovery of bacterial and archaeal DNA using mechanical cell lysis

Several different protocols are used for fecal DNA extraction, which is an integral step in all phylogenetic and metagenomic approaches to characterize the highly diverse intestinal ecosystem. We compared four widely used methods, and found their DNA yields to vary up to 35-fold. Bacterial, archaeal and human DNA was quantified by real-time PCR, and a compositional analysis of different extracts was carried out using the Human Intestinal Tract Chip, a 16S rRNA gene-based phylogenetic microarray. The overall microbiota composition was highly similar between the methods in contrast to the profound differences between the subjects (Pearson correlations > 0.899 and 0.735, respectively). A detailed comparative analysis of mechanical and enzymatic methods showed that despite their overall similarity, the mechanical cell disruption by repeated bead beating showed the highest bacterial diversity and resulted in significantly improved DNA extraction efficiency of archaea and some bacteria, including Clostridium cluster IV. By applying the mechanical disruption method a high prevalence (67%) of methanogenic archaea was detected in healthy subjects (n = 24), exceeding the typical values reported previously. The assessment of performance differences between different methodologies serves as a concrete step towards the comparison and reliable meta-analysis of the results obtained in different laboratories.     

Isolation of high molecular weight DNA from wholeEuglena cells

Summary A method for isolating high quality DNA from wholeEuglena cells is described. The procedure consists in: the weakening of the cell pellicle in glycerol avoiding the mechanical disruption of cells and shearing damage in DNA molecules; the decondensation ofEuglena compact chromatin directly inside the cells; the complete dissociation of cells and nucleoproteins in sarkosyl detergent; the optional digestion of proteins and RNA with DNase-free enzymes and the final purification of DNA by isopycnic banding in CsCl gradients. Degradation of DNA is prevented all along the extraction procedure by glycerol, antioxydants, EDTA and sarkosyl detergent. Using the enzymatic digestion step, DNA containing few single-stranded nicks is obtained with a yield approaching 100%. DNA with no single-stranded nick could be obtained with a 35% yield when the enzymatic digestion step was omitted. In both cases, the double-stranded DNA has an average molecular weight equal or greater than 6×10⁷. It is free of contaminants and could be easily digested with restriction enzymes. After digestion with Eco RI and size-fractionation in agarose gel this DNA has permitted specific hybridization of the rDNA sequences with a radioactive rRNA probe.Abbreviations Kbp kilobasepairs - Kb kilobases     

一种快速提取丝状真菌染色体DNA的方法

介绍了一种适用于丝状真菌染色体DNA大片段的快速提取方法,该方法以(100mM Tris,100mM NaGl,50mM EDTA-Na2 2%SDS,pH值9.0)为提取液,经石英砂研磨破壁.应用该方法成功地提取了粗糙脉胞菌(Neurospora crassa)、米曲霉(Aspergillus oryzae)、产黄青霉(Penicillium chrysogenum)和头孢霉菌(Cep- halosporium sp.)等4种不同丝状真菌的染色体DNA大片段,且所提DNA片段均大于20kb,可直接用于限制性酶切、PCR等分子生物学研究.     

Comparison of the utility of five commercial kits for extraction of DNA from Aspergillus fumigatus spores

The aim of this study was to compare the efficiency of DNA extraction from water as well as from blood samples spiked with A. fumigatus spores, using selected commercial kits. Extraction of DNA according to manufacturer's protocols was preceded by blood cells lysis and disruption of fungal cells by enzymatic digestion or bead beating. The efficiency of DNA extraction was measured by PCR using Aspergillus-specific primers and SYBR Green I dye or TaqMan probes targeting 28S rRNA gene. All methods allowed the detection of Aspergillus at the lowest tested density of water suspensions of spores (101 cells/ml). The highest DNA yield was obtained using the ZR Fungal/Bacterial DNA kit, YeastStar Genomic DNA kit, and QIAamp DNA Mini kit with mechanical cell disruption. The ZR Fungal/Bacterial DNA and YeastStar kits showed the highest sensitivity in examination of blood samples spiked with Aspergillus (100 % for the detection of 102 spores and 75 % for 101 spores). Recently, the enzymatic method ceased to be recommended for examination of blood samples for Aspergillus, thus ZR Fungal/Bacterial DNA kit and QIAamp DNA Mini kit with mechanical cell disruption could be used for extraction of Aspergillus DNA from clinical samples.     

A simple method of genomic DNA extraction suitable for analysis of bulk fungal strains

Aims: A simple and rapid method (designated thermolysis) for extracting genomic DNA from bulk fungal strains was described. Methods and Results: In the thermolysis method, a few mycelia or yeast cells were first rinsed with pure water to remove potential PCR inhibitors and then incubated in a lysis buffer at 85°C to break down cell walls and membranes. This method was used to extract genomic DNA from large numbers of fungal strains (more than 92 species, 35 genera of three phyla) isolated from different sections of natural Ophiocordyceps sinensis specimens. Regions of interest from high as well as single‐copy number genes were successfully amplified from the extracted DNA samples. The DNA samples obtained by this method can be stored at ?20°C for over 1 year. Conclusions: The method was effective, easy and fast and allowed batch DNA extraction from multiple fungal isolates. Significance and Impact of Study: Use of the thermolysis method will allow researchers to obtain DNA from fungi quickly for use in molecular assays. This method requires only minute quantities of starting material and is suitable for diverse fungal species.     

A Hybrid DNA Extraction Method for the Qualitative and Quantitative Assessment of Bacterial Communities from Poultry Production Samples

The efficacy of DNA extraction protocols can be highly dependent upon both the type of sample being investigated and the types of downstream analyses performed. Considering that the use of new bacterial community analysis techniques (e.g., microbiomics, metagenomics) is becoming more prevalent in the agricultural and environmental sciences and many environmental samples within these disciplines can be physiochemically and microbiologically unique (e.g., fecal and litter/bedding samples from the poultry production spectrum), appropriate and effective DNA extraction methods need to be carefully chosen. Therefore, a novel semi-automated hybrid DNA extraction method was developed specifically for use with environmental poultry production samples. This method is a combination of the two major types of DNA extraction: mechanical and enzymatic. A two-step intense mechanical homogenization step (using bead-beating specifically formulated for environmental samples) was added to the beginning of the “gold standard” enzymatic DNA extraction method for fecal samples to enhance the removal of bacteria and DNA from the sample matrix and improve the recovery of Gram-positive bacterial community members. Once the enzymatic extraction portion of the hybrid method was initiated, the remaining purification process was automated using a robotic workstation to increase sample throughput and decrease sample processing error. In comparison to the strict mechanical and enzymatic DNA extraction methods, this novel hybrid method provided the best overall combined performance when considering quantitative (using 16S rRNA qPCR) and qualitative (using microbiomics) estimates of the total bacterial communities when processing poultry feces and litter samples.     

Statistical assessment of DNA extraction methodology for culture-independent analysis of microbial community associated with diverse environmental samples

Cost-effectiveness, quality, time-effectiveness and ease of the methodology are the most crucial factors in isolating quality DNA from wide variety of samples. Thus, research efforts focusing on the development of an efficient DNA extraction protocol is the need of the hour. The present study therefore, focuses on development of an efficient, rapid and free of inhibitory substances based methodology for extracting metagenomic DNA from diverse environmental samples viz. anaerobic biogas digesta, ruminant stomach, human feces, soil, and microbial starter cultures used for preparation of fermented food. PCR–DGGE based analysis and quality metagenomic library preparation, using DNA extraction methodology, validates the developed protocol. The developed protocol is cost effective, capable of isolating DNA from small sample size (100–1000 µl), time efficient (1.5–2.0 h protocol) and results in significantly higher DNA yield (4–8 times increased yield) when compared to previously available DNA extraction method and a commercial DNA extraction kit. The DNA extracted from the samples using different protocols was evaluated based on its ability to identify diverse microbial species using PCR–DGGE profiles targeting variable region within the 16S rRNA gene. The results of microbial community analysis revealed comparability of the developed protocol to commercial kits, in effectively identifying dominant representatives of the microbial community in different samples. Using the DNA extracted from the presented methodology, metagenomic libraries were prepared, which were found suitable for sequencing on Illumina platform.     

A simple method for extraction of fungal genomic DNA

We have developed a new, simple and effective method for extraction of fungal genomic DNA. The initial steps involved suspension of freeze-dried mycelium in buffer containing sodium dodecyl sulphate, detachment of DNA from polysaccharides by mild shearing, NaCl precipitation of polysaccharides and protein, chloroform extraction and ethanol precipitation. The ethanol precipitate was then subjected to a second round of mild shearing, NaCl precipitation, chloroform extraction and ethanol precipitation. The procedure required approximately 1 h to perform. The method yielded 8-32 microg of high molecular weight DNA per 30 mg of freeze-dried mycelium when tested on six fungal species: Aspergillus niger, A. flavus, Fusarium graminarum, Neotyphodium lolii, Penicillium citrinum and Rhizopus nigricanes. The DNA was digestible with EcoRI, HindIII, SalI and BamHI. For the slow-growing N. lolii, a modification of the method was developed that removed the agar residue from colonies grown on agar plates by centrifugation at 13 000 rev min(-1) in the presence of CsCl. The modified method yielded 1.5-2 microg of high molecular weight DNA per colony.     

工业化废水处理反应器污泥总DNA提取方法

根据工业化废水处理反应器污泥特性,对常规的溶菌酶-SDS-酚/氯仿环境样品总DNA提取方法进行改进,增强样品预处理,强化细胞裂解,提高杂质去除效率,获得了一种工业化污泥总DNA提取的通用方法,并采用该方法对石家庄若干实际运行的工业化厌氧、好氧反应器的污泥样品进行了总DNA提取研究.结果表明,该方法对所选污泥样品均有效,具有普适性.提取的污泥总DNA杂质含量少,纯度高,A260/A280在1.8左右;提取效率较高.总DNA产率都在0.7 mg/g以上,最大产率可达0.85 mg/g.所提取的污泥总DNA可以直接作为模板进行PCR反应,PCR产物直接进行变性梯度凝胶电泳(DGGE),能够得到较好的DGGE谱图,表明该方法提取的污泥总DNA样品可满足后续分析研究的要求.