Determination of Anaerobic and Anoxic Biodegradation Capacity of Sulfamethoxasole and the Effects on Mixed Microbial Culture

status: publishe

Understanding how micro-organisms respond to acid pH is central to their control and successful exploitation

Microbes from the three domains of life, bacteria, archaea and eukarya, share the need to sense and respond to changes in the external and internal concentrations of protons. When the proton concentration is high, acidic conditions prevail and cells must respond appropriately to ensure that macromolecules and metabolic processes are sufficiently protected to sustain life. While we have learned much in recent decades about the mechanisms that microbes use to cope with acid, including the unique challenges presented by organic acids, there is still much to learn and much to be gained from developing a deeper understanding of the effects and responses to acid in microbes. In this perspective article, we survey the key molecular mechanisms that are known to be important for microbial survival during acid stress. We discuss the research approaches that have been taken to investigate the problem and highlight promising new avenues. We highlight the importance of understanding acid stress in controlling spoilage and pathogenic microbes in the food chain. We discuss the influence of acid on pathogens during the course of infections and highlight the potential of using organic acids in treatments for some types of infection. We explore the influence of acid stress on photosynthetic microbes, and on biotechnological and industrial processes, including those needed to produce organic acids. Finally, we invite colleagues with an interest in microbial responses to low pH to participate in the EU-funded COST Action project called EuroMicropH and contribute to a comprehensive database of literature on this topic that we are making publicly available

Opinion paper about organic trace pollutants in wastewater: Toxicity assessment in a European perspective

This opinion paper focuses on the role of eco- toxicological tools in the assessment of possible impacts of emerging contaminants on the aquatic ecosystem, hence, on human health. Indeed, organic trace pollutants present in raw and treated wastewater are the pivot targets: a multidisciplinary approach allows defining the basic principles for managing this issue, from setting a proper monitoring campaign up to evaluating the optimal process treatment. Giving hints on trace pollutants fate and behavior, attention is focused on the choice of the bioassay( s), by analyzing the meaning of possible biological answers. Data interpretation and exploitation are detailed with the final goal of providing criteria in order to be able to select the best-targeted treatment options. The manuscript deals with conventional and innovative analytical approaches for assessing toxicity, by reviewing laboratory and field assays ; illustrative real scale and laboratory applications integrate and exemplify the proposed approach

A review of nature-based solutions for resource recovery in cities

Our modern cities are resource sinks designed on the current linear economic model which recovers very little of the original input. As the current model is not sustainable, a viable solution is to recover and reuse parts of the input. In this context, resource recovery using nature-based solutions (NBS) is gaining popularity worldwide. In this specific review, we focus on NBS as technologies that bring nature into cities and those that are derived from nature, using (micro)organisms as principal agents, provided they enable resource recovery. The findings presented in this work are based on an extensive literature review, as well as on original results of recent innovation projects across Europe. The case studies were collected by participants of the COST Action Circular City, which includes a portfolio of more than 92 projects. The present review article focuses on urban wastewater, industrial wastewater, municipal solid waste and gaseous effluents, the recoverable products (e.g., nutrients, nanoparticles, energy), as well as the implications of source-separation and circularity by design. The analysis also includes assessment of the maturity of different technologies (technology readiness level) and the barriers that need to be overcome to accelerate the transition to resilient, self-sustainable cities of the future

Bio-Based Processes for Material and Energy Production from Waste Streams under Acidic Conditions

The revolutionary transformation from petrol-based production to bio-based production is becoming urgent in line with the rapid industrialization, depleting resources, and deterioration of the ecosystem. Bio-based production from waste-streams is offering a sustainable and environmentally friendly solution. It offers several advantages, such as a longer operation period, less competition for microorganisms, higher efficiency, and finally, lower process costs. In the current study, several bio-based products (organic acids, biomethane, biohydrogen, and metal leachates) produced under acidic conditions are reviewed regarding their microbial pathways, processes, and operational conditions. Furthermore, the limitations both in the production process and in the scale-up are evaluated with future recommendations

從貿易自由化看糧食安全

In this study, microbial community dynamics were assessed in two lab-scale anaerobic sequencing batch reactors (ASBRs). One of the reactors was fed by synthetic pharmaceutical industry wastewater with sulfamethoxazole (SMX) as the test reactor and the other without sulfamethoxazole as the control reactor. DNA based DGGE results indicated that Clostiridum sp. became dominant in the SMX reactor while the inoculum was dominated with Firmicutes (61%) and Methanomicrobiales (28%). However their abundances in active community decreased through the last phase. Also the abundance of hydro-genotrophs was high in each phase, while acetoclastic methanogens disappeared in the last phase. Q-PCR analysis revealed that there is a significant reduction in the bacterial community approximately 84%, while methanogens increased to 97% through the operation. Additionally an increase in the expression level of bacterial and methanogenic 16S rRNA (60% and 20%, respectively) was detected. Significant correlation between microbial community and the reactor operation data was found. The study demonstrated that the microbial community maintains the system stability under high antibiotic concentration and long-term operation by homoacetogenesis coupled with hydrogenotrophic methanogenesis.QC 20191007</p

The effects of pH on the production of volatile fatty acids and microbial dynamics in long-term reactor operation

Volatile fatty acids, intermediate products of anaerobic digestion, are one of the most promising biobased products. In this study, the effects of acidic (pH 5), neutral (without pH adjustment) and alkali (pH 10) pH on production efficiency and composition of volatile fatty acids (VFAs) and bacterial community profile were analyzed. The anaerobic sequencing batch reactors were fed cheese production wastewater as substrate and inoculated by anaerobic granular seed sludge. The results showed that acidic pH improved VFA production yield (0.92 at pH 5; 0.42 at pH 10 and 0.21 gCOD/gVS at neutral pH). Furthermore, propionic acid was dominant under both pH 10 (64 ± 20%) and neutral pH (72 ± 8%), whereas, acetic acid (23 ± 20%4), propionic acid (22 ± 3%), butyric acid (21 ± 4%) and valeric acid (15 ± 8%) were almost equally distributed under pH 5. Adaptation of bacterial community to different pH conditions might steer the acid profile: Bacteroidetes (50.07 ± 2%) under pH 10, Proteobacteria (40.74 ± 7%) under neutral pH and Firmicutes (47.64 ± 9%) under pH 5 were the most dominant phylum, respectively. Results indicated pH plays a significant role in VFA production, acid composition, and bacterial community structure. However, in order to gain a concrete understanding effects of pH, characterization of intracellular and extracellular metabolites with dynamics of the microbial community is required