Effect of SGLT-2 inhibitors as an add-on therapy to metformin on P wave indices and atrial electromechanics in type 2 diabetes mellitus patients.

INTRODUCTION: Sodium-glucose co-transporter 2 (SGLT-2) inhibitors have been shown to reduce the risk of atrial fibrillation (AF) occurrence in patients with diabetes mellitus (DM). In this prospective study, we aimed to analyze the effect of SGLT-2 inhibitors as an add-on therapy to metformin on P wave indices and atrial electromechanics in patients with type 2 DM. METHODS: A total of 144 patients enrolled. Electrocardiographic indices were recorded on admission and at 3rd and 6th month of the combination therapy. P wave indices and atrial electromechanical coupling intervals were measured and compared. RESULTS: Although decrease in P wave dispersion (62.78 ± 9.59 vs. 53.62 ± 10.65; p = .002) became significant at 6th month of combination therapy, significant decreases in P wave terminal force in V1 (37.79 ± 3.45 vs. 32.01 ± 5.74; p = .035), left atrial volume index (35.87 ± 6.57 vs. 31.33 ± 7.31; p = .042), left sided intra-atrial electromechanical delay (32.09 ± 9.17 vs. 27.61 ± 8.50; p = .016), right sided intra-atrial electromechanical delay (31.82 ± 4.92 vs. 27.65 ± 8.05; p = .042), and interatrial electromechanical delay (29.65 ± 7.52 vs. 25.96 ± 4.30; p = .044) were seen as early as 3rd month of treatment. Besides, there was no statistically significant difference between Empagliflozin and Dapagliflozin subgroups in terms of mentioned parameters. CONCLUSION: SGLT-2 inhibitors as an add-on therapy to metformin were shown to significantly improve P wave indices and atrial electromechanics in type 2 DM patients as early as the 3rd month of treatment. It was thought that this may be one of the underlying mechanisms of the decrease in the frequency of AF with the use of SGLT2 inhibitors.

Prognostic significance of serum galectin-3 in hospitalized patients with COVID-19.

BACKGROUND: There are no major tools that could predict disease severity in COVID-19. The aim of this study is to evaluate if serum galectin-3 levels can identify disease progression in COVID-19. METHODS: Patients that were hospitalized due to COVID-19 between March and June 2020 were included in this cross-sectional prospective study. Baseline demographic and clinical data in addition to levels of serum parameters including galectin-3 were measured at the time of hospital admission. Patients with COVID-19 were categorized into two groups (non-severe and severe illness). The need for ICU during hospital stay, duration from hospital admission to the transfer to the ICU, and the total length of hospital stay were recorded. RESULTS: A total of 175 patients were included in the study and among these, 64 patients formed the severe illness group whereas 111 comprised the non-severe illness group. There was statistically significant difference in terms of galectin-3 levels between groups (1.07 ± 0.75 vs 0.484 ± 0.317, p < 0.0001, respectively). Our results showed that galectin-3, IL-6 and CRP levels at admission were independent risk factors associated with transfer to the ICU whereas only galectin-3 was an independent factor for the need for advanced ventilatory support. Also, galectin-3 and IL-6 were independent risk factors related to in-hospital mortality. CONCLUSION: In conclusion, our results indicated that galectin-3 had moderate power in outlining disease severity and the need for ICU transfer throughout the clinical course in COVID-19.

The Prognostic Value of C-Reactive Protein/Albumin Ratio in Acute Pulmonary Embolism.

Background: Serum C-reactive protein (CRP) to albumin ratio (CAR) has been defined as an inflammation-based prognostic marker. We evaluated the association and prognostic value of CRP/albumin ratio in patients with pulmonary embolism (PE). Methods: A total of 256 patients with acute PE who were hospitalized between March 2016 and December 2020 were retrospectively reviewed. PE severity index (PESI) was calculated. Serum levels of CRP and albumin that were obtained at the time of admission were used for calculation. CAR was evaluated for correlation with PESI, and thus, foresee the risk of death due to PE. Results: There were 186 patients eligible for inclusion. 54 patients were in intermediate, 34 patients were in high risk and 98 patients were in very high-risk group according to PESI score. In the correlation analysis, we observed moderate positive correlations between CRP/albumin ratio, troponin and PESI score (r = 0.584, p < 0.0001; r = 521, p < 0.0001, respectively). Regression analysis revealed that only CRP/albumin ratio and PESI score were independent risk factors associated with 6-month mortality of acute PE patients. The AUC for CRP/albumin ratio was 0.643, 0.751, and 0.763 for 30-day, 90-day, and 6-month mortality, respectively (95% CI: 0.550-0.737, 0.672-0.830, 0.687-0.838]. A cut-off value of 5.33 for CRP/albumin ratio was associated with 65.3% sensitivity and 65.6% specificity in predicting 6-month mortality. Conclusion: The CRP/albumin ratio, an inexpensive and easily measurable laboratory variable, may be a useful prognostic marker of PE, especially when other causes that alter serum levels are excluded from the study.

Contrasting the Water Quality and Bacterial Community Patterns in Shallow and Deep Lakes: Manyas vs. Iznik.

The objectives of this study are to monitor the physicochemical properties of two freshwater lakes with different chemical characteristics and trophic status over a year (2019) and assess the bacterial diversity by a high-throughput sequencing method for a certain time. Carlson Trophic Index analysis revealed that, whereas the deep lake, Iznik Lake, (TSImean = 48.9) has mesotrophic characteristics, the shallow lake Manyas Lake (TSImean = 74.2) was found at a hypertrophic status. The most important parameters controlling water qualities in the lakes were temperature, alkalinity, and phosphate levels. Although the bacterial communities were dominated by the same phyla (Cyanobacteria, Bacteroidetes, Actinomicrobia, Proteobacteria, and Verrucomicrobia) in both lakes, the communities differed distinctly at the lower levels. Whereas Sporichthyaceae in Manyas Lake accounted for 10% of the total reads, the major share of the sequences was assigned to Cyanobacteria Family I (8%) in Iznik Lake. The hypertrophic Manyas Lake had a more diverse bacterial community rather than Iznik Lake and contained higher numbers of unique Operational Taxonomic Units.

Higher Copeptin Levels are Associated with the Risk of Atrial Fibrillation in Patients with Rheumatic Mitral Stenosis.

BACKGROUND: Correlations between increased copeptin levels and various cardiovascular diseases have been described. In this study, we aimed to investigate the correlation between increased copeptin levels and paroxysmal atrial fibrillation (PAF) in rheumatic mitral stenosis (MS). METHODS: Patients with mild/moderate rheumatic MS and sinus rhythm were consecutively recruited from an echocardiography laboratory. Patients with a history of PAF and those with PAF on 24-48-hour ambulatory electrocardiography (ECG) monitoring constituted the study group, and those without PAF on ambulatory ECG monitoring constituted the control group. Clinical characteristics, echocardiographic parameters and levels of copeptin, plasma N-terminal proBNP (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) were evaluated. RESULTS: Twenty-nine patients with PAF and 124 control MS patients were studied. Patients in the PAF group were older, but the mitral valve areas and transmitral gradients were not different between the groups. In the PAF group, hs-CRP (1.2 vs. 0.8 mg/L, p < 0.001), NT-proBNP (335 vs. 115 pg/mL, p < 0.001) and copeptin (6.9 vs. 4.0 pmol/L, p < 0.001) levels were significantly higher than in the control group. Multivariable logistic regression analysis revealed that age [odds ratio (OR) 1.19, 95% confidence interval (CI) 1.04-1.38; p = 0.024], left atrial volume index (OR 1.23, 95% CI 1.06-1.41; p = 0.032), copeptin levels (OR 2.81, 95% CI 1.30-5.29; p < 0.001) and hs-CRP levels (OR 15.5, 95% CI 1.41-71.5; p = 0.012) were independent predictors of PAF. CONCLUSIONS: In patients with mild/moderate rheumatic MS, higher copeptin and hs-CRP levels predicted a higher risk of developing atrial fibrillation.

Electrocardiographic Ccharacteristics of metastatic cardiac tumors presenting with ST-segment elevation.

INTRODUCTION: ST segment elevation (STE) in the standard 12­lead surface electrocardiography (ECG) is a well-known finding in patients with metastatic cardiac tumors. It is important to identify the specific characteristics of STE among those patients to prevent unnecessary aggressive treatments. In the present study, we aimed to demonstrate the ECG characteristics of patients with metastatic cardiac tumors who has STE. MATERIAL AND METHODS: Medical literature was searched from Pubmed database with key words "metastatic cardiac tumors" or "cardiac tumors" and "ST segment elevation" or "ST elevation". In addition, remaining articles were explored using the references of case reports which were obtained during former screening (snowball procedure). RESULTS: Thirty six of 46 case reports were included and ECG characteristics of each case were evaluated. Convex- shaped STE was observed in all patients and it showed a specific coronary territory in 35 of 36 patients (97.2%). Pathologic Q wave and/or loss of R wave progression were observed in only one patient. T wave inversion following STE was detected in 34 patients (94.4%). STE evolution was absent in 32 of 36 patients while the information regarding STE evolution were not provided in the remaining cases. CONCLUSION: STE due to tumor invasion has certain characteristics which could help clinicians in the differential diagnosis.

The effect of P wave indices on new onset atrial fibrillation after trans-catheter aortic valve replacement.

OBJECTIVES: Data is scarce regarding the relation between P wave indices and new onset atrial fibrillation (NOAF) after trans-catheter aortic valve replacement (TAVR). AIMS: The present study aimed to find out certain characteristics of P wave that may predict NOAF after TAVR procedure. METHOD: Patients with severe calcific aortic stenosis who had undergone TAVR procedure between 2013 and 2019 in two centers were investigated. P wave abnormalities that have been resumed to reflect impaired atrial conduction; partial and advanced inter atrial block (IAB), P-wave terminal force in lead V1, P wave dispersion, reduced amplitude of P- wave in lead I, P wave peak time in D2 and V1 were evaluated on pre- procedural 12 derivation surface electrocardiography (ECG). The relationship between these parameters and incidence of NOAF during index hospitalization was evaluated. RESULTS: A total of 227 consecutive patients (median age 79 [74-83]; 134 [59%] female) were included in the study. NOAF occurred in 46 (20.3%) patients. P wave duration, P wave dispersion, number of patients with partial and advanced IAB, left atrium diameter, STS score were higher in NOAF patients. Use of general anesthesia and history of prior open heart surgery were also more frequent in NOAF group. In multivariable logistic regression analysis; advanced IAB (OR 6.413 [2.555-16.095] p < 0.01), P wave dispersion (OR 3.544 [1.431-8.780] p = 0.006) and use of general anesthesia (OR 2.736 [1.225-6.109] p = 0.014) were independent predictors of NOAF. CONCLUSION: Among P wave abnormalities evaluated on pre-procedural 12-derivation surface ECG, advanced IAB and P wave dispersion may predict NOAF after TAVR procedure.

Could fragmented QRS predict mortality in aortic stenosis patients after transcatheter aortic valve replacement?

BACKGROUND: Fragmented QRS evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. The prognostic value of that marker has been demonstrated, particularly, in cardiac diseases that accompany myocardial scar and fibrosis. Myocardial fibrosis is also an issue in patients with aortic stenosis. In this study, we wanted to determine whether fragmented QRS could predict all-cause mortality in aortic stenosis patients after transcatheter aortic valve replacement (TAVR). METHOD: In this study, we evaluated a total of 116 eligible patients on whom we performed TAVR between 2014 and 2018. Patients' demographic and clinical findings, echocardiography results, in-hospital and 30-day mortality, long-term survival statuses were noted. Patient's ECGs before the procedure were evaluated in regard to the occurrence of fragmented QRS. Predictors of mortality were evaluated using univariable and multivariable Cox regression analysis. RESULTS: The study population consisted of 116 patients of median age 79 (IQR 75-83), 64 females (55.2%). Mortality occurred in 27 (23%) patients; median follow-up time was 319 (IQR 122-719) days. Fragmented QRS was observed in 44 out of 116 (37.9%) patients. The presence of a fragmented QRS (HR = 2.178, 95% CI 0.999-4.847, p = 0.050), a history of stroke (HR = 3.463, 95% CI 1.276-9.398, p = 0.015), and the creatinine levels at admission (HR = 2.198, 95% CI 1.068-4.520, p = 0.030) were associated with the long-term mortality in multivariable Cox regression analysis. CONCLUSION: Like in the case of the other diseases associated with myocardial fibrosis, fragmented QRS could also predict mortality in aortic stenosis patients after TAVR procedure.

Enrichment of lignocellulose-degrading microbial communities from natural and engineered methanogenic environments.

The aim of this study was to develop an effective bioaugmentation concept for anaerobic digesters treating lignocellulosic biomass such as straw. For that purpose, lignocellulose-degrading methanogenic communities were enriched on wheat straw from cow and goat rumen fluid as well as from a biogas reactor acclimated to lignocellulosic biomass (sorghum as mono-substrate). The bacterial communities of the enriched cultures and the different inocula were examined by 454 amplicon sequencing of 16S rRNA genes while the methanogenic archaeal communities were analyzed by terminal restriction fragment length polymorphism (T-RFLP) fingerprinting of the mcrA gene. Bacteroidetes was the most abundant phylum in all samples. Within the Bacteroidetes phylum, Bacteroidaceae was the most abundant family in the rumen-derived enrichment cultures, whereas Porphyromonadaceae was the predominant one in the reactor-derived culture. Additionally, the enrichment procedure increased the relative abundance of Ruminococcaceae (phylum: Firmicutes) in all cultures. T-RFLP profiles of the mcrA gene amplicons highlighted that the ruminal methanogenic communities were composed of hydrogenotrophic methanogens dominated by the order Methanobacteriales regardless of the host species. The methanogenic communities changed significantly during the enrichment procedure, but still the strict hydrogenotrophic Methanobacteriales and Methanomicrobiales were the predominant orders in the enrichment cultures. The bioaugmentation potential of the enriched methanogenic cultures will be evaluated in further studies.

Operating conditions influence microbial community structures, elimination of the antibiotic resistance genes and metabolites during anaerobic digestion of cow manure in the presence of oxytetracycline.

The way that antibiotic residues in manure follow is one of the greatest concerns due to its potential negative impacts on microbial communities, the release of metabolites and antibiotic resistant genes (ARGs) into the nature and the loss of energy recovery in anaerobic digestion (AD) systems. This study evaluated the link between different operating conditions, the biodegradation of oxytetracycline (OTC) and the formation of its metabolites and ARGs in anaerobic digesters treating cow manure. Microbial communities and ARGs were determined through the use of quantitative real-time PCR. The biodegradation of OTC and occurrence of metabolites were determined using UV-HPLC and LC/MS/MS respectively. The maximum quantity of resistance genes was also examined at the beginning of AD tests and concentration was in the order of: tetM >tetO. The numbers of ARGs were always higher at high volatile solids (VS) content and high mixing rate. The results of the investigation revealed that relationship between mixing rate and VS content plays a crucial role for elimination of ARGs, OTC and metabolites. This can be attributed to high abundance of microorganisms due to high VS content and their increased contact with elevated mixing rate. An increased interaction between microorganisms triggers the promotion of ARGs.

Application of next-generation sequencing methods for microbial monitoring of anaerobic digestion of lignocellulosic biomass.

The anaerobic digestion of lignocellulosic wastes is considered an efficient method for managing the world's energy shortages and resolving contemporary environmental problems. However, the recalcitrance of lignocellulosic biomass represents a barrier to maximizing biogas production. The purpose of this review is to examine the extent to which sequencing methods can be employed to monitor such biofuel conversion processes. From a microbial perspective, we present a detailed insight into anaerobic digesters that utilize lignocellulosic biomass and discuss some benefits and disadvantages associated with the microbial sequencing techniques that are typically applied. We further evaluate the extent to which a hybrid approach incorporating a variation of existing methods can be utilized to develop a more in-depth understanding of microbial communities. It is hoped that this deeper knowledge will enhance the reliability and extent of research findings with the end objective of improving the stability of anaerobic digesters that manage lignocellulosic biomass.

Assessment of the horizontal transfer of functional genes as a suitable approach for evaluation of the bioremediation potential of petroleum-contaminated sites: a mini-review.

Petroleum sludge contains recalcitrant residuals. These compounds because of being toxic to humans and other organism are of the major concerns. Therefore, petroleum sludge should be safely disposed. Physicochemical methods which are used by this sector are mostly expensive and need complex devices. Bioremediation methods because of being eco-friendly and cost-effective overcome most of the limitations of physicochemical treatments. Microbial strains capable to degrade petroleum hydrocarbons are practically present in all soils and sediments and their population density increases in contact with contaminants. Bacterial strains cannot degrade alone all kinds of petroleum hydrocarbons, rather microbial consortium should collaborate with each other for degradation of petroleum hydrocarbon mixtures. Horizontal transfer of functional genes between bacteria plays an important role in increasing the metabolic potential of the microbial community. Therefore, selecting a suitable degrading gene and tracking its horizontal transfer would be a useful approach to evaluate the bioremediation process and to assess the bioremediation potential of contaminated sites.

Effect of bioaugmentation by cellulolytic bacteria enriched from sheep rumen on methane production from wheat straw.

The aim of this study was to determine the potential of bioaugmentation with cellulolytic rumen microbiota to enhance the anaerobic digestion of lignocellulosic feedstock. An anaerobic cellulolytic culture was enriched from sheep rumen fluid using wheat straw as substrate under mesophilic conditions. To investigate the effects of bioaugmentation on methane production from straw, the enrichment culture was added to batch reactors in proportions of 2% (Set-1) and 4% (Set-2) of the microbial cell number of the standard inoculum slurry. The methane production in the bioaugmented reactors was higher than in the control reactors. After 30 days of batch incubation, the average methane yield was 154 mLN CH4 gVS-1 in the control reactors. Addition of 2% enrichment culture did not enhance methane production, whereas in Set-2 the methane yield was increased by 27%. The bacterial communities were examined by 454 amplicon sequencing of 16S rRNA genes, while terminal restriction fragment length polymorphism (T-RFLP) fingerprinting of mcrA genes was applied to analyze the methanogenic communities. The results highlighted that relative abundances of Ruminococcaceae and Lachnospiraceae increased during the enrichment. However, Cloacamonaceae, which were abundant in the standard inoculum, dominated the bacterial communities of all batch reactors. T-RFLP profiles revealed that Methanobacteriales were predominant in the rumen fluid, whereas the enrichment culture was dominated by Methanosarcinales. In the batch rectors, the most abundant methanogens were affiliated to Methanobacteriales and Methanomicrobiales. Our results suggest that bioaugmentation with sheep rumen enrichment cultures can enhance the performance of digesters treating lignocellulosic feedstock.

Development of a fast and low-cost qPCR assay for diagnosis of acute gas pharyngitis.

BACKGROUND: Group A streptococci (GAS) are the most common bacterial cause of acute pharyngitis and account for 15-30 % of cases of acute pharyngitis in children and 5-10 % of cases in adults. In this study, a real-time quantitative PCR (qPCR) based GAS detection assay in pharyngeal swab specimens was developed. METHODS: The qPCR assay was compared with the gold standard bacterial culture and a rapid antigen detection test (RADT) to evaluate its clinical performance in 687 patients. The analytical sensitivity of the assay was 240 cfu/swab. Forty-five different potential cross-reacting organisms did not react with the test. Four different laboratories for the reproducibility studies were in 100 % (60/60) agreement for the contrived GAS positive and negative swab samples. RESULTS: The relative sensitivities of the RADT and the qPCR test were 55.9 and 100 %; and the relative specificities were 100 and 96.3 %, respectively. Duration of the total assay for 24 samples including pre-analytical processing and analysis changed between 42 and 55 min depending on the type of qPCR instrument used. A simple DNA extraction method and a low qPCR volume made the developed assay an economical alternative for the GAS detection. CONCLUSION: We showed that the developed qPCR test is rapid, cheap, sensitive and specific and therefore can be used to replace both antigen detection and culture for diagnosis of acute GAS pharyngitis.

Changes in microbial community structures due to varying operational conditions in the anaerobic digestion of oxytetracycline-medicated cow manure.

Management of manure containing veterinary antibiotics is a major concern in anaerobic treatment systems because of their possible adverse effects on microbial communities. Therefore, the aim of study was to investigate how oxytetracycline (OTC) influences bacteria and acetoclastic and hydrogenotrophic methanogens under varying operational conditions in OTC-medicated and non-medicated anaerobic cow manure digesters. Concentrations of OTC and its metabolites throughout the anaerobic digestion were determined using ultraviolet-high-performance liquid chromatography (UV-HPLC) and tandem liquid chromatography-mass spectrometry (LC/MS/MS), respectively. Fluorescent in situ hybridization, denaturing gradient gel electrophoresis, cloning, and sequencing analyses were used to monitor changes in microbial community structures. According to the results of analytical and molecular approaches, operating conditions highly influence active microbial community dynamics and associate with biogas production and elimination of OTC and its metabolites during anaerobic digestion of cow manure in the presence of an average initial concentration of 2.2 mg OTC/L. The impact of operating conditions has a drastic effect on acetoclastic methanogens than hydrogenotrophic methanogens and bacteria.

Evaluation of microbial population and functional genes during the bioremediation of petroleum-contaminated soil as an effective monitoring approach.

This study investigated the abundance and diversity of soil n-alkane and polycyclic aromatic hydrocarbon (PAH)-degrading bacterial communities. It also investigated the quantity of the functional genes, the occurrence of horizontal gene transfer (HGT) in the identified bacterial communities and the effect that such HGT can have on biostimulation process. Illumina sequencing was used to detect the microbial diversity of petroleum-polluted soil prior to the biostimulation process, and quantitative real-time PCR was used to determine changes in the bacterial community and functional genes (alkB, phnAc and nah) expressions throughout the biostimulation of petroleum-contaminated soil. The illumine results revealed that γ-proteobacteria, Chloroflexi, Firmicutes, and δ-proteobacteria were the most dominant bacterial phyla in the contaminated site, and that most of the strains were Gram-negative. The results of the gene expression results revealed that gram-negative bacteria and alkB are critical to successful bioremediation. Failure to maintain the stability of hydrocarbon-degrading bacteria and functional gene will reduce the extend to which alkanes and PAHs are degraded. According to the results of the study, the application of a C:N:P ratio of was 100:15:1 in the biodegradation experiment resulted in the highest rate at which petroleum hydrocarbons were biodegraded. The diversity of pollutant-degrading bacteria and the effective transfer of degrading genes among resident microorganisms are essential factors for the successful biostimulation of petroleum hydrocarbons. As such, screening these factors throughout the biostimulation process represents an effective monitoring approach by which the success of the biostimulation can be assessed.

Degradation of oxytetracycline and its impacts on biogas-producing microbial community structure.

The effect of veterinary antibiotics in anaerobic digesters is a concern where methane production efficiency is highly dependent on microbial community structure. In this study, both anaerobic degradation of a common veterinary antibiotic, oxytetracycline (OTC), and its effects on an anaerobic digester microbial community were investigated. Qualitative and quantitative molecular tools were used to monitor changes in microbial community structure during a 60-day batch incubation period of cow manure with the addition of different concentrations of the antibiotic. Molecular data were interpreted by a further redundancy analysis as a multivariate statistics approach. At the end of the experiment, approximately 48, 33, and 17 % of the initially added 50, 100, and 200 mg l(-1) of OTC was still present in the serum bottles which reduced the biogas production via accumulation of some of the volatile fatty acids (VFAs). Biogas production was highly correlated with Methanobacteriales and Methanosarcinales gene copy numbers, and those parameters were negatively affected with oxytetracycline and VFA concentrations.

The joint acute effect of tetracycline, erythromycin and sulfamethoxazole on acetoclastic methanogens.

In this study, we aimed to develop an understanding of the triple effects of sulfamethoxazole-erythromycin-tetracycline (ETS) and the dual effects of sulfamethoxazole-tetracycline (ST), erythromycin-sulfamethoxazole (ES) and erythromycin-tetracycline (ET) on the anaerobic treatment of pharmaceutical industry wastewater throughout a year of operation. Concentrations of the antibiotics in the influent were gradually increased until the metabolic collapse of the anaerobic sequencing batch reactors (SBRs), which corresponded to ETS (40 + 3 + 3 mg/L) and ST (25 + 2.5 mg/L), ET (4 + 4 mg/L) and ES (3 + 40 mg/L). Acetate accumulation in the anaerobic SBRs, acetoclastic activity of the anaerobic sludge taken from different antibiotic feeding stages and also expression of acetyl-coA synthetase from the acetoclastic methanogenic pathway on the mRNA level were assessed. The results indicated that, while acetate accumulation and decrease of acetoclastic activity were observed after stage 3 in the ST and ES reactors, and stage 7 in the ETS and ET reactors, the expression of acetyl-coA synthetase was mostly decreased in the last stages in all SBRs, in which antibiotic mixture feeding was terminated. It might be speculated that acetoclastic methanogens have an important role in acetate degradation by expressing acetyl-coA synthetase.

Inhibitory effect of erythromycin, tetracycline and sulfamethoxazole antibiotics on anaerobic treatment of a pharmaceutical wastewater.

Pharmaceuticals enter ecosystems, which causes changes to microbial community structure and development of resistant genes. Anaerobic treatments can be an alternative application for treatment of pharmaceutical wastewaters, which has high organic content. This study aims to develop an understanding of the effects of sulfamethoxazole-erythromycin-tetracycline (ETS), sulfamethoxazole-tetracycline (ST), erythromycin-sulfamethoxazole (ES) and erythromycin-tetracycline (ET) combinations on the anaerobic treatment of pharmaceutical industry wastewater. The results of this investigation revealed that bacteria have a competitive advantage over archaea under all antibiotic combinations. The ET reactor showed a better performance compared to other reactors; this could be due to antagonistic effects of sulfamethoxazole. Acute inhibition in the microbial community was also strongly affected by antibiotics concentrations. This indicated that the composition of the microbial community changed in association with anaerobic sequencing batch reactor performances. The results of this research support the idea that an acute test could be used to control and improve the anaerobic treatment system.

Bioenergy production from diluted poultry manure and microbial consortium inside Anaerobic Sludge Bed Reactor at sub-mesophilic conditions.

In this study, anaerobic treatability of diluted chicken manure (with an influent feed ratio of 1 kg of fresh chicken manure to 6 L of tap water) was investigated in a lab-scale anaerobic sludge bed (ASB) reactor inoculated with granular seed sludge. The ASB reactor was operated at ambient temperature (17-25°C) in order to avoid the need of external heating up to higher operating temperatures (e.g., up to 35°C for mesophilic digestion). Since heat requirement for raising the temperature of incoming feed for digestion is eliminated, energy recovery from anaerobic treatment of chicken manure could be realized with less operating costs. Average biogas production rates were calculated ca. 210 and 242 L per kg of organic matter removed from the ASB reactor at average hydraulic retention times (HRTs) of 13 and 8.6 days, respectively. Moreover, average chemical oxygen demand (COD) removal of ca. 89% was observed with suspended solids removal more than 97% from the effluent of the ASB reactor. Influent ammonia, on the other hand, did not indicate any free ammonia inhibition due to dilution of the raw manure while pH and alkalinity results showed stability during the study. Microbial quantification results indicated that as the number of bacterial community decreased, the amount of Archaea increased through the effective digestion volume of the ASB reactor. Moreover, the number of methanogens displayed an uptrend like archaeal community and a strong correlation (-0.645) was found between methanogenic community and volatile fatty acid (VFA) concentration especially acetate.