Isolation Of Bacterial DNA Research Articles

Identification of a Lactococcus lactis Isolated from a Fresh Local Cheese of the Western Algerian Steppe “J’ben of Naama”

Background: The purpose of the study is to evaluate the diversity of lactococci, lactic bacteria, recovered from “J’ben”, a local cheese made from the milk of the Rembi sheep breed, a product of exploitation in the Algerian steppe regions of Naama.Methods: The bacterial species were isolated from samples of the recovered cheese exploitation and analyzed using genotypic methods. The isolation of bacterial DNA from purified Lactococcus cultures has been established by an amplification of ribosomal DNA 16s using the specific universal primers of prokaryotes. Result: The 16s DNA sequencing of all isolates, for genotypic identification, confirmed the predominance of Lactococcus lactis. This lactic dominance determines the quality and distinctiveness of this cheese in the region. The results obtained from acidification and proteolysis kinetics met the technological requirements and good functionality, from the strains used individually and in mixed culture to the cheese processing.

Tryptamine-functionalized magnetic nanoparticles for highly sensitive detection of Salmonella typhimurium.

There is significant demand for the development of rapid, sensitive, and specific methods for detecting bacterial pathogens in order to identify the causes of food poisoning. Nucleic acid amplification tests (NAATs) allow for the culture-free detection of bacterial pathogens and are not as labor intensive and time consuming as culture-based detection methods. However, suitable sample preparation methods must be developed for the realization of simple, rapid, and sensitive NAATs. To resolve this problem, we developed a new sample preparation method that integrates bacterial pathogen enrichment and DNA extraction. We engineered magnetic nanoparticles (MNPs) with a physicochemical probe (tryptamine) for single-tube sample preparation with minimal sample loss. The tryptamine-functionalized MNPs (Indole@MNPs) showed inherent hydrophobicity owing to the indole side chain and a change in their zeta potential with a decrease in the pH. Because of their physicochemical characteristics, the Indole@MNPs could adsorb bacterial pathogens, thus allowing sample enrichment and DNA binding and release through weak electrostatic interactions via pH control. We successfully detected Salmonella enterica serovar Typhimurium, a common cause of bacterial food poisoning, at a concentration of 10 CFU/10 mL in milk samples using quantitative PCR. Thus, the proposed method allows for the simple and sensitive detection of Salmonella typhimurium and can be used for nontyphoidal salmonella detection to ensure food safety.

Quantification of Bacterial Colonization in Dental Hard Tissues Using Optimized Molecular Biological Methods.

Bacterial infections of root canals and the surrounding dental hard tissue are still a challenge due to biofilm formation as well as the complex root canal anatomy. However, current methods for analyzing biofilm formation, bacterial colonization of root canals and dental hard tissue [e.g., scanning electron microscopy, confocal laser scanning microscopy (CLSM) or determination of colony forming units (CFU)] are time-consuming and only offer a selective qualitative or semi-quantitative analysis. The aim of the present study is the establishment of optimized molecular biological methods for DNA-isolation and quantification of bacterial colonization via quantitative PCR (qPCR) from dental hard tissue. Root canals of human premolars were colonized with Enterococcus faecalis. For isolation of DNA, teeth were then grinded with a cryo mill. Since the hard tissues dentin and especially enamel belong to the hardest materials in the human organism, the isolation of bacterial DNA from root dentin is very challenging. Therefore, treatment steps for the isolation of DNA from grinded teeth were systematically analyzed to allow improved recovery of bacterial DNA from dental hard tissues. Starting with the disintegration of the peptidoglycan-layer of bacterial cells, different lysozyme solutions were tested for efficacy. Furthermore, incubation times and concentrations of chelating agents such as EDTA were optimized. These solutions are crucial for the disintegration of teeth and hence improve the accessibility of bacterial DNA. The final step was the determination of prior bacterial colonization of each root canal as determined by qPCR and comparing the results to alternative methods such as CFU. As a result of this study, optimized procedures for bacterial DNA-isolation from teeth were established, which result in an increased recovery rate of bacterial DNA. This method allows a non-selective and straightforward procedure to quantify bacterial colonization from dental hard tissue. It can be easily adapted for other study types such as microbiome studies and for comparable tissues like bones.

Comparison of intestinal permeability, morphology, and ileal microbial communities of commercial hens housed in conventional cages and cage-free housing systems

The gastrointestinal health of poultry can be impacted by a variety of factors including their environment. As egg production moves from conventional cage housing (CC) toward cage-free housing (CF), it is important to understand this impact on intestinal health. This study was conducted to determine if housing type impacted intestinal permeability, morphology, and microbial communities in commercial hens across housing systems. Hens were randomly selected from 2 rooms of CC (n = 25) and CF (n = 25) at a commercial facility. Birds were given fluorescein isothiocyanate dextran (FITC-D) by oral gavage to measure intestinal permeability. Jejunal and ileal samples were collected to evaluate villus height, crypt depth, and their ratio. Ileal contents were collected for bacterial DNA isolation and 16S rRNA gene sequencing. Serum FITC-D was similar between housing type (P = 0.709). Hens housed in the CF had increased jejunal villus height and crypt depth compared with hens from the CC (P < 0.002). Hens from the CC tended to have a greater villus height to crypt depth ratio in both the jejunum and ileum compared with the CF (P = 0.064; P = 0.091, respectively). Microbial community diversity measurements favored hens housed in the CC as ileal contents tended to have increased species richness (P = 0.059), had greater alpha diversity (P = 0.044), and had an increased number of over represented operational taxonomic units (46/64), including Romboutsia sp. (30.80%), Lactobacillus kitasatonis (17.16%), and Lactobacillus aviarius (11.15%). Correlations between microbial communities with intestinal traits identified significant association with the greatest number of correlations with FITC-D and ileal morphology. Many of these correlations identified microbial communities associated with expected traits; thus, providing limited functional data to microbial communities with limited information. The greater number of correlations of ileal morphology with ileal microbial communities suggesting local microbial communities contribute to the intestinal environment distant. In this limited study, several parameters favored hens from CC suggesting an advantage of this system for intestinal health. However, the lower intestinal health parameters observed in CF were not at levels to indicate detrimental effects.

Comparative Evaluation of qnrA, qnrB, and qnrS Genes in Enterobacteriaceae Ciprofloxacin-Resistant Cases, in Swine Units and a Hospital from Western Romania.

Excessive use of antimicrobials and inadequate infection control practices has turned antimicrobial resistance (AMR) into a global, public health peril. We studied the expression of qnrA, qnrB, and qnrS plasmid in ciprofloxacin (CIP)-resistant strains of Escherichia coli in swine and humans from Romania, using the Polymerase Chain Reaction (PCR) technique. Antibiotic Susceptibility Testing (AST) for human subjects (H) on 147 samples and 53 swine (S) was ascertained as well as the isolation of bacterial DNA (E. coli) as follows: bacteriolysis, DNA-binding, rinsing, elution, amplification, and nucleic acids’ migration and U.V. visualization stages. From 24 samples of E. coli resistant to CIP collected from H subjects and 15 from S, for PCR analysis, 15 H and 12 S were used, with DNA purity of 1.8. The statistically analyzed results using the Crosstabs function (IBM SPSS Statistics-Ver. 2.1.), revealed the qnrS (417 bp) gene in 13 human subjects (52.0%), as well as in all swine samples studied. The qnrB (526 bp) gene was exposed in 9 of the human patients (36.0%) and in all swine isolates, and the qnrA (516 bp) gene was observed only in 3 of the isolates obtained from human subjects (12.0%) and was not discovered in pigs (p > 0.05). The presence of plasmids qnrA, qnrB, and qnrS in the human samples and of qnrB and qnrS in swine, facilitates the survival of pathogens despite the CIP action. The long-term use of CIP could cause a boost in the prevalence of qnr resistance genes, and resistance in the pigs destined for slaughter, a perturbing fact for public health and the human consumer.

DETEKSI Liberibacter spp. PADA JERUK SIAM BERGEJALA KLOROSIS DISERTAI BERCAK HITAM DENGAN Polymerase Chain Reaction

Liberibacter bacteria are one of the pathogenic bacteria in citrus plants. Siam Citrus Plant in Setapok Village, Singkawang City, suspected to be infected with Liberibacter spp. bacteria by showing patterns of symptoms of chlorosis accompanied by patches. This study aims to detect Liberibacter spp. on Siam Citrus leaves with symptomatic chlorosis with patches. Leaf sampling uses the roaming method in one of the citrus plantations in Setapok Village, Singkawang City. Detection of Liberibacter spp. done by PCR (Polymerase Chain Reaction) technique. Detection of bacterial DNA through several stages namely, isolation of bacterial plasmid DNA, 16S rDNA gene amplification with a thermocycler machine, and visualization using a set of electrophoresis devices. Electrophoresis results show the presence of DNA band lines, with a size of around 1100 bp for OI1 and OI2c primers, and DNA bands of 703 bp for A2 and J5 specifics. The results showed that there were Liberibacter spp. in the symptomatic chlorosis of Siam Citrus leaves accompanied by patches.

Changes in the Gut Microbiota are Associated with Hypertension, Hyperlipidemia, and Type 2 Diabetes Mellitus in Japanese Subjects.

The human gut microbiota is involved in host health and disease development. Therefore, lifestyle-related diseases such as hypertension (HT), hyperlipidemia (HL), and type 2 diabetes mellitus (T2D) may alter the composition of gut microbiota. Here, we investigated gut microbiota changes related to these diseases and their coexistence. This study involved 239 Japanese subjects, including healthy controls (HC). The fecal microbiota was analyzed through the isolation of bacterial genomic DNA obtained from fecal samples. Although there were no significant differences in the microbial structure between groups, there was a significant difference in the α-diversity between HC and the patients in whom two diseases coexisted. Moreover, Actinobacteria levels were significantly increased, whereas Bacteroidetes levels were significantly decreased in all disease groups. At the genus level, Bifidobacterium levels were significantly increased in the HL and T2D groups, as were those of Collinsella in all disease groups. In contrast, Alistipes levels were significantly lower in the HL group. Furthermore, metabolic enzyme families were significantly increased in all disease groups. Interestingly, the structure and function of the gut microbiota showed similar profiles in all the studied diseases. In conclusion, several changes in the structure of the gut microbiota are associated with T2D, HT, and HL in Japanese subjects.

Two possible candidate enzymes from Ulva lactuca-associated epiphytic bacteria obtained through PCR and functional evaluation

Epiphytic bacteria from marine macroalgae synthesize enzymes of industrial and biotechnological interest. In this study, we obtained two DNA candidate fragments for lipid-degrading enzymes from the total DNA of Ulva lactuca-associated epiphytic bacteria. First, we evaluated a method for total bacterial DNA isolation from the surface of U. lactuca thalli. Then, we designed sets of primers and used them directly for PCR amplification. The resulting PCR products were sequence-analyzed and used for expression and functional evaluation with the Escherichia coli pBAD-TOPO system. We obtained high molecular weight and good quality total bacterial DNA that served as a template to identify a fragment corresponding to an Acetyl-CoA C-Acetyltransferase (or Thiolase), and a candidate fragment for a versatile “true” lipase. We expressed the possible “true” lipase gene fragment heterologously in Escherichia coli and obtained proof of hydrolytic activity on Tributyrin, Tween-20, and Olive-oil media. This study resulted in new knowledge on U. lactuca-associated epiphytic bacteria as possible brand-new sources of enzymes such as thiolases and “true” lipases. However, future studies are required to describe the characteristics and important applications of these candidate enzymes.

Boiling Extraction Method VS Commercial Kits for Bacterial DNA Isolation from Food Samples

Background: In recent years, the development of commercial Kits for DNA extraction, combined with the use of molecular technologies have been utilized for the understanding of microbial ecosystems. DNA extraction considered being a critical step for molecular techniques such as Polymerase Chain Reaction. Several different methods and commercial kits for this purpose are nowadays available. The aim of this study was to compare five commercially available kits and, a cheap, rapid, non-commercial method, the boiling method for isolating bacterial DNA from different food matrixes.

Application of end-point PCR technique to detect bacteria encoding tyrosine decarboxylase (TDC) gene in scombridae fish

Tuna, little tuna, and skipjack can form tyramine from decarboxylation of tyrosine by tyrosine decarboxylase (TDC) enzyme. High tyramine level in fish could cause toxicological effects. Early detection of the tyramine-forming bacteria by using DNA-based methods is needed for seafood safety assurance because it is more sensitive, specific, and faster. This study was aimed to obtain bacterial isolates, detection of TDC and 16S rRNA genes and identifying species of bacteria that encode TDC and 16S rRNA genes. The methods of this study included several steps including bacterial cultivation, DNA isolation and amplification of TDC and 16S rRNA gene markers as well as sequencing of amplicons. Bacterial DNA isolates were successfully obtained from samples by cultivation method. The TDC gene was successfully amplified and identified as belong to Carnobacterium genus, whereas the 16S rRNA gene belong to Enterobacter tabaci, E. hormaechei, Escherichia marmotae, and Peptoniphilus genus. The DNA-based method targeted tyrosine decarboxylase gene can be applied for early detection of biogenic amine accumulation in fishery products.

P4610Gut microbiome and atherosclerotic plaque instability: does choline consumption in red meat influence plaque stability?

Abstract Background Myocardial infarction is the major cause of deaths worldwide. Gut bacteria can process choline as abundant in red meat and subsequently converted by flavin containing monooxygenase in the liver to trimethylamin-N-oxide (TMAO) metabolite, which is strongly associated with cardiovascular events. Aim To investigate the gut microbiome and its association with atherosclerotic plaque instability. Methods Forty-eight Apolipoprotein E deficient mice were randomly divided into two groups and two time points, fed with a high fat diet (containing either 0.4% choline or 3% choline) at 12 weeks of age, for 7 weeks or for 14 weeks. All mice underwent Tandem Stenosis (TS) surgery to induce the development of unstable plaques. Stool samples were collected directly from the colon. Measurements of gut microbes were performed by AGRF diversity profiling. After bacterial genomic DNA isolation, 16S rRNA were sequenced by targeting 27F-519R (V1-V3) and 341F-806R (V3-V4) on the Illumina MiSeq platform. Vessel segments of TS were histologically processed and plaque composition of lipid, collagen, and intraplaque hemorrhage (marker of unstable plaques) were performed by a series of chemical staining and immunohistochemistry. Results Monocytes and granulocytes in mouse blood were significantly increased in the high choline group (p&lt;0.05, unpaired t-test) after 7 weeks of high fat diet (21% fat, 0.15% Cholesterol, 3% Choline). Profiling of gut microbiota showed that Fimicutes were down regulated in the high choline group (p&lt;0.05, unpaired t-test). Within Phylum Fimicutes, only Clostridia (class) Clostridiales (order) were significantly downregulated. Interestingly, histological analysis of TS segments showed that TER-119 (intraplaque haemorrhage marker) and CD42c (platelet marker) were significantly increased in the high choline group, indicating atherosclerotic plaques are more unstable and prone to rupture (p&lt;0.05, unpaired t-test). Nevertheless, CD68 (Foam cells) in plaques, and total atherosclerotic plaque burden in the aortic sinus and aortic arch were not affected by the elevated levels of choline consumption. Conclusion Choline intake increases circulating monocytes and granulocyte numbers in the blood but not in the atherosclerotic plaque itself. Whereas the total plaque burden is not changed by an increased choline intake, the reduction of Fimicutes, Clostridia and Clostridiales seems to contribute to atherosclerotic plaque instability. Acknowledgement/Funding Heart Foundation 2018 Future Leader Fellowship (2018 FLF) ID: 102068 Chen

Insights From a Short-Term Protein-Calorie Restriction Exploratory Trial in Elective Carotid Endarterectomy Patients.

Open vascular surgery interventions are not infrequently hampered by complication rates and durability. Preclinical surgical models show promising beneficial effects in modulating the host response to surgical injury via short-term dietary preconditioning. Here, we explore short-term protein-calorie restriction preconditioning in patients undergoing elective carotid endarterectomy to understand patient participation dynamics and practicalities of robust research approaches around nutritional/surgical interventions. We designed a pilot prospective, multicenter, randomized controlled study in patients undergoing carotid endarterectomy. After a 3:2 randomization to a 3-day preoperative protein-calorie restriction regimen (30% calorie/70% protein restriction) or ad libitum group, blood, clinical parameters, and stool samples were collected at baseline, pre-op, and post-op days 1 and 30. Subcutaneous and perivascular adipose tissues were harvested periprocedurally. Samples were analyzed for standard chemistries and cell counts, adipokines. Bacterial DNA isolation and 16S rRNA sequencing were performed on stool samples and the relative abundance of bacterial species was measured. Fifty-one patients were screened, 9 patients consented to the study, 5 were randomized, and 4 completed the trial. The main reason for non-consent was a 3-day in-hospital stay. All 4 participants were randomized to the protein-calorie restriction group, underwent successful endarterectomy, reported no compliance difficulties, nor were there adverse events. Stool analysis trended toward increased abundance of the sulfide-producing bacterial species Bilophila wadsworthia after dietary intervention (P = .08). Although carotid endarterectomy patients held low enthusiasm for a 3-day preoperative inpatient stay, there were no adverse effects in this small cohort. Multidisciplinary longitudinal research processes were successfully executed throughout the nutritional/surgical intervention. Future translational endeavors into dietary preconditioning of vascular surgery patients should focus on outpatient approaches.

Identification of pathogenic bacteria on the salted fish Lutjanus vivanus in Sorong City of West Papua

Fisheries-based food is needed by humans as a protein source, one of which is salted fish Lutjanus vivanus. Market demand for this product in Indonesia is quite high. The aim of the study was to identify pathogenic bacteria in salted fish L. vivanus. The method used in this study was descriptive method including pathogenic test, bacterial genomic DNA isolation based on 16 sRNA gene using prokaryotic specific primers, namely 63f forward primer (5′-CAGGCC TAA CAC ATG CAA GTC-3′) and reverse 1387r primer (5′-GGG CGG WGT GTA CAA GGC-3′). The results of this study indicated pathogenic bacteria in salted fish L. vivanus with pathogenic activity of α hemolytic and β hemolytic. The bacteria were identified as Serratia marcescens strain ZK2 16S for isolate KS and Bacillus altitudinis strains A-19 16S for isolate LG. In salted fish L. vivanus in the Sorong city, West Papua, it was obtained Serratia marcescens strain ZK2 16S with total hemolytic activity and B. altitudinis A-19 16S strain with partial hemolytic activity.

Penapisan dan Identifikasi Bakteri Penghasil Enzim Xilanase pada Peuyeum Singkong dengan Metode Penanda Gen 16S rRNA

Peuyeum comes from cassava which is an agricultural commodity that is widely grown in Indonesia as a food which is source of carbohydrates. The types of polysaccharides that compose cassava are starch, cellulose and hemicellulose in the form of xylan. Xylanase is a xylanolytic enzyme that can hydrolyze xylan. The bacteria producing xylanase enzyme has been isolated from peuyeum which is thought to affect the fermentation process. Peuyeum contains starch so that it is one of the sources of the amylase enzyme. But there has never been a study of peuyeum's xylanase enzyme screening. The purpose of this study was to isolate xylanase-producing bacteria on peuyeum and identify these bacterial species by analyzing the 16S rRNA gene so that it could become a new source in the search for enzymes. This study consisted of several stages, namely bacterial isolation, xylanase enzyme screening, morphological testing, bacterial DNA isolation, sequencing, bacterial identifikation with the phylogenetic tree method. Xylanase enzyme producing bacteria in peuyeum has been successfully isolated. Based on the results of phylogenetic tree analysis it was found that XF1 bacteria had the closest homology to Bacillus cereus with 99% similarity.

Development of a multiplex PCR for identification of mastitis causing organisms

In the present study, a de novo multiplex polymerase chain reaction using genus specific primers for four organisms’ viz., E. coli, Klebsiella pneumoniae, Staphylococcus aureus and Streptococcus agalactiae were designed to identify and differentiate all the four organisms in a single reaction. Further, DNA was extracted from mastitic milk using three different methods and was subjected to multiplex polymerase chain reaction to compare and identify the best method out of these three methods based on the amplification results of multiplex polymerase chain reaction. It was observed from the study that multiplex PCR was able to amplify three organisms (Streptococcus agalactiae, Klebsiella pneumoniae and E. coli) successfully whereas was unable to amplify Staphylococcus aureus in the multiplex PCR. Mutiplex PCR when evaluated on the field samples using mastitic milk revealed SDS Triton DNA extraction method to be superior to Power Food Microbial DNA isolation Kit and Milk Bacterial DNA isolation kit method in isolating the bacterial DNA from the mastitic milk as indicated by amplification in multiplex PCR reaction.

The Impact of Dietary Grape Seed Meal on Healthy and Aflatoxin B1 Afflicted Microbiota of Pigs after Weaning.

The study investigated the effect of grape seed (GS) meal, aflatoxin (AFB1), or their combination on the large intestine microbiota of weanling piglets. Twenty-four piglets were allocated into four groups based on diet composition: (1) Control group; (2) AFB1 (320 g/kg feed) group; (3) GS group (8% inclusion in the diet); (4) AFB1 + GS group. After 30 days of experiment, the colon content was used for microbiota analyses; after isolation of total bacterial genomic DNA, V3/V4 regions of the 16S rRNA amplicons were sequenced using the Illumina MiSeq platform. The raw sequences were analyzed using the v.1.9.1 QIIME pipeline software. 157 numbers of OTUs were identified among all four dietary groups with 26 of them being prevalent above 0.05% in the total relative abundance. GS and AFB1 increase the relative abundance of phylum Bacteroidetes and Proteobacteria, while decreasing the Firmicutes abundance in a synergic manner as compared with the individual treatments. An additive or synergistic action of the two treatments was identified for Lactobacillus, Prevotella and Campylobacter, while rather an antagonistic effect was observed on Lachnospira. The action mechanisms of aflatoxin B1 and grape seed meal that drive the large intestine microbiota to these changes are not known and need further investigations.

Deteksi Bakteri Patogen Salmonella typhi pada Sayuran yang dikonsumsi Mentah Menggunakan Metode nested Polymerase Chain Reaction

Salmonella typhi (S. typhi) infection is a zoonotic infection and known as salmonellosis. In the human body, salmonellosis causes an increase in high body temperature or known as typhoid fever that cause high morbidity and mortality in developing countries, especially Indonesia. It was found that out of 22 million cases of typhoid fever, 200 thousand of them ended in death. S. typhi often contaminates food that was consumed raw or not perfectly cooked, for example meat, eggs, dairy products, fruits and vegetables. The conventional method for detecting these bacteria is culture method which time consuming and need BSL 2 facilities. PCR was one of DNA based detection method that could overcome the culture method weakness. In this study conducted detection of Salmonella bacteria in raw vegetables which are usually consumed as fresh by using nested PCR method. The detection procedures were sample preparation; bacterial DNA isolation; amplification by using two sets of primer, ST1-ST2 in first round PCR and ST3-ST4 in second round PCR; and the characterization by using agarose electrophoresis. The results indicated that two of nine raw vegetables, tomatos and cabbages have been contaminated with Salmonella. We conclude that nested PCR could detect Salmonella contamination in raw vegetables.

Isolation of bacterial DNA followed by sequencing and differing cytokine response in peritoneal dialysis effluent help in identifying bacteria in culture negative peritonitis.

The treatment of peritoneal dialysis related culture negative peritonitis is empirical which increases the cost of therapy and moreover antibiotic resistance. We aimed the study to isolate bacterial DNA from PD effluent and indentify bacteria causing peritonitis in culture negative situations. We have also studied the cytokine response with different bacteria causing peritonitis. We have isolated bacterial DNA from PD effluent of culture negative and culture positive peritonitis patients. Bacterial DNA was subjected to polymerase chain reaction using universal bacteria specific primers and subsequently to Gram type specific primers for the differentiation of the etiologic agents into Gram-positive and Gram-negative. The amplified products were sequenced and subjected to blast search to identify agent at genus/ species level. Of the 30 molecular method positive samples, 16 (53.33%) samples were positive for Gram-negative bacteria and 4 (13.33%) for Gram-positive, while the remaining10 (33.33%) were positive for both Gram-positive and Gram-negative bacteria. We have found organisms that usually do not grow on normal culture methods. TNF-α was significantly associated with Gram-positive peritonitis and regulatory cytokine IL-10 with Gram-negative peritonitis. The molecular techniques are helpful in detecting and identifying organisms from culture negative PD effluent.

Chemically synthesized silver nanoparticles as cell lysis agent for bacterial genomic DNA isolation

Silver nanoparticles (AgNPs) have seen a recent spurt of use in varied fields of science. In this paper, we showed a novel application of AgNP as a promising microbial cell-lysis agent for genomic DNA isolation. We utilized chemically synthesized AgNPs for lysing bacterial cells to isolate their genomic DNA. The AgNPs efficiently lysed bacterial cells to yield good quality DNA that could be subsequently used for several molecular biology works.

Characterization of Microbial Communities in Acidified, Sulfur Containing Soils.

Over a period of three years, microbial communities in acidified soil with high sulfur content were analyzed. In soil water extracts ureolytic, proteolytic, oxidoreductive, and lipolytic activity were detected. The presented results indicate that the enzymatic activity of soil microbial communities varied considerably over time. Isolated 26 (80%) bacterial strains belonged to genus Bacillus sp. and were identified by cultivation and 16S rRNA methods. The commercially available procedures for bacterial DNA isolation from acidified soil failed, therefore a new, specific DNA isolation method was established. Ureolytic activity, detected in soil extracts as well as in isolated Bacillus sp. strains may be considered as a tool for the bioremediation of acidified soils with high sulfate content.