Performance of an anaerobic-oxic-anoxic (AOA) system in the simultaneous removal of nutrients and triclosan and bacterial community.

The constant presence of triclosan (TCS) in surface water and wastewater has been verified due to its application in several pharmaceutical and personal care products. Thus, removing this emerging contaminant is essential to minimize the contamination of water bodies. The anaerobic-aerobic-anoxic (AOA) system is an innovative alternative that combines the removal of nutrients and triclosan. This study focuses on the simultaneous removal of carbonaceous matter, nitrogen, phosphorus, and triclosan in a continuous pilot-scale AOA system from synthetic wastewater. The upflow system, in series, was operated at hydraulic retention time (HRT) of 8 h and a flowrate of 2.40 L h-1. Glucose (190 mg L-1) was added to the anoxic reactor as the external carbon source. Besides that, bacterial community structure was investigated using 16S rRNA sequencing in each reactor. The system achieved average removal efficiencies of 96% (14.03 g d-1) for Chemical Oxygen Demand (COD), 85% (2.64 g d-1) for Total Kjeldahl Nitrogen (TKN), 88% (1.40 g d-1) for Total Ammonia Nitrogen (TAN), 20% (0.12 g d-1) for Total Phosphorus (TP), and 93% (1.87 µg d-1) for Triclosan (TCS). The phyla Proteobacteria, Firmicutes, Bacteroidetes, and Chloroflexi were found in greater abundance. The main genera identified were Anaeromusa, Aeromonas, Azospira, Clostridium, and Lactococcus. The organisms related to phylum and genus corroborate the involved processes and the removal performance achieved. In addition, Lactococcus, Thermomonas, Ferruginibacter, and Dechloromonas were involved in triclosan biodegradation. The anaerobic-oxic-anoxic system successfully removed carbonaceous, nitrogenous matter, and triclosan, with glucose increasing the denitrifying activity.

Ataxia with Ocular Apraxia Type 1 (AOA1) (APTX, W279* Mutation): Neurological, Neuropsychological, and Molecular Outlining of a Heterogenous Phenotype in Four Colombian Siblings.

Hereditary ataxias are a group of devastating neurological disorders that affect coordination of gait and are often associated with poor coordination of hands, speech, and eye movements. Ataxia with ocular apraxia type 1 (AOA1) (OMIM: 606,350.0006) is characterized by slowly progressive symptoms of childhood-onset and pathogenic mutations in APTX; the only known cause underpinning AOA1. APTX encodes the protein aprataxin, composed of three domains sharing homology with proteins involved in DNA damage, signaling, and repair. We present four siblings from an endogamic family in a rural, isolated town of Colombia with ataxia and ocular apraxia of childhood-onset and confirmed molecular diagnosis of AOA1, homozygous for the W279* p.Trp279Ter mutation. We predicted the mutated APTX with AlphaFold to demonstrate the effects of this stop-gain mutation that deletes three beta helices encoded by amino acid 270 to 339 rescinding the C2H2-type zinc fingers (Znf) (C2H2 Znf) DNA-binding, the DNA-repair domain, and the whole 3D structure of APTX. All siblings exhibited different ages of onset (4, 6, 8, and 11 years old) and heterogeneous patterns of dysarthria (ranging from absence to mild-moderate dysarthria). Neuropsychological evaluation showed no neurocognitive impairment in three siblings, but one sibling showed temporospatial disorientation, semantic and phonologic fluency impairment, episodic memory affection, constructional apraxia, moderate anomia, low executive function, and symptoms of depression. To our knowledge, this report represents the most extensive series of siblings affected with AOA1 in Latin America, and the genetic analysis completed adds important knowledge to outline this family's disease and general complex phenotype of hereditary ataxias.

Influence of HRT and carbon source on the enhancement of nutrient removal in an Anaerobic-Oxic-Anoxic (AOA) system.

The eutrophication and increase in toxicity promoted by the continuous or abundant supply of nutrients in water bodies threaten the safety of drinking water and human health. In this regard, this study proposes the investigation of wastewater treatment focusing on the simultaneous removal of nitrogen and phosphorus in the anaerobic-oxic-anoxic (AOA) system. The AOA system was operated in three different stages to verify the influence of the external carbon source addition in the anoxic reactor and the reduction of hydraulic retention time (HRT) in the anaerobic and oxic reactors for nutrient removal optimization. Results showed that the best performance of the AOA system on nutrient removal was obtained in Stage 3, with the reduction of the HRT in the anaerobic and oxic reactors (HRT = 4 h) while maintaining HRT of 6.4 h in the anoxic reactor with no addition of the external carbon source. Under these conditions, the average removal efficiencies reached 98% for Chemical Oxygen Demand (COD), 88% for Total Ammonia Nitrogen (TAN), 81% for Total Kjeldahl Nitrogen (TKN), and 70% for Total Phosphorus (TP). The results also demonstrate that the highest phosphorus removal efficiency was achieved in the anoxic reactor, thus indicating the occurrence of denitrifying phosphorous removal by Denitrifying Phosphate Accumulating Organisms (DNPAOs). This configuration was efficient regarding the simultaneous removal of nitrogen and phosphorus; besides, the advantages of this system include robust configuration and excellent performance on the nutrient removal.

Purple Sulfur Bacteria Dominate Microbial Community in Brazilian Limestone Cave.

The mineralogical composition of caves makes the environment ideal for inhabitation by microbes. However, the bacterial diversity in the cave ecosystem remains largely unexplored. In this paper, we described the bacterial community in an oxic chamber of the Sopradeira cave, an iron-rich limestone cave, in the semiarid region of Northeast Brazil. The microbial population in the cave samples was studied by 16S rDNA next-generation sequencing. A type of purple sulfur bacteria (PSB), Chromatiales, was found to be the most abundant in the sediment (57%), gravel-like (73%), and rock samples (96%). The predominant PSB detected were Ectothiorhodospiraceae, Chromatiaceae, and Woeseiaceae. We identified the PSB in a permanently aphotic zone, with no sulfur detected by energy-dispersive X-ray (EDX) spectroscopy. The absence of light prompted us to investigate for possible nitrogen fixing (nifH) and ammonia oxidizing (amoA) genes in the microbial samples. The nifH gene was found to be present in higher copy numbers than the bacterial-amoA and archaeal-amoA genes, and archaeal-amoA dominated the ammonia-oxidizing community. Although PSB dominated the bacterial community in the samples and may be related to both nitrogen-fixing and ammonia oxidizing bacteria, nitrogen-fixing associated gene was the most detected in those samples, especially in the rock. The present work demonstrates that this cave is an interesting hotspot for the study of ammonia-oxidizing archaea and aphotic PSB.

The polynucleotide kinase 3'-phosphatase gene (PNKP) is involved in Charcot-Marie-Tooth disease (CMT2B2) previously related to MED25.

Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of hereditary peripheral neuropathies. We previously reported a CMT locus on chromosome 19q13.3 segregating with the disease in a large Costa Rican family with axonal neuropathy and autosomal recessive pattern of inheritance (CMT2B2). We proposed a homozygous missense variant in the Mediator complex 25 (MED25) gene as causative of the disease. Nevertheless, the fact that no other CMT individuals with MED25 variants were reported to date led us to reevaluate the original family. Using exome sequencing, we now identified a homozygous nonsense variant (p.Gln517ter) in the last exon of an adjacent gene, the polynucleotide kinase 3'-phosphatase (PNKP) gene. It encodes a DNA repair protein recently associated with recessive ataxia with oculomotor apraxia type 4 (AOA4) and microcephaly, seizures, and developmental delay (MCSZ). Subsequently, five unrelated Costa Rican CMT2 subjects initially identified as being heterozygous for the same MED25 variant were found to be also compound heterozygote for PNKP. All were heterozygous for the same variant found homozygous in the large family and a second one previously associated with ataxia (p.Thr408del). Detailed clinical reassessment of the initial family and the new individuals revealed in all an adult-onset slowly progressive CMT2 associated with signs of cerebellar dysfunction such as slurred speech and oculomotor involvement, but neither microcephaly, seizures, nor developmental delay. We propose that PKNP variants are the major causative variant for the CMT2 phenotype in these individuals and that the milder clinical manifestation is due to an allelic effect.

Z-Isomers of (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=OH. Conformational properties, electronic structure and aqueous solvent effects.

Procyanidins are highly hydroxylated polymers known as antioxidant compounds, thereby exhibiting beneficial effects. These compounds are protective agents against oxidative stress and the damage induced by free radicals in membranes and nucleic acids. This paper describes a study of the conformational space of (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=OH as part of a larger study of similar structures with different substitutions. The relationships between aqueous solution-vacuum variations of some properties were studied, as well as the stabilization and reactivity of (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=H, R'=H, R=OH, R'=R=OH, and (+)-catechin. The variations in geometric parameters and electronic properties due to conformational changes, as well as the effects of substituents and polar solvents, were evaluated and analyzed. Bader's theory of atoms in molecules was applied to characterize intramolecular interactions, along with a natural bond orbital analysis for each conformer described. The molecular electrostatic potential was rationalized by charge delocalization mechanisms and interatomic intramolecular interactions, relating them to the structural changes and topological properties of the electron charge density. Molecular polarizability and permanent electric dipole moment values were estimated. The results show the importance of a knowledge of the conformational space, and values for each conformer. Based on our previous results, we showed the existence of electron charge delocalization mechanisms acting cooperatively as "delocalization routes", showing interactions between different rings not even sharing the same plane. These "delocalization routes" were more effective for (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=OH than for (+)-catechin, and are proposed as adding insight into the structure-antioxidant activity relationship of flavans.

Ataxia with oculomotor apraxia type 2 fibroblasts exhibit increased susceptibility to oxidative DNA damage.

Ataxia with oculomotor apraxia type 2 (AOA2) is an autosomal recessive cerebellar ataxia associated with mutations in SETX, which encodes the senataxin protein, a DNA/RNA helicase. We describe the clinical phenotype and molecular characterization of a Colombian AOA2 patient who is compound heterozygous for a c.994 C>T (p.R332W) missense mutation in exon 7 and a c.6848_6851delCAGA (p.T2283KfsX32) frameshift deletion in SETX exon 21. Immunocytochemistry of patient-derived fibroblasts revealed a normal cellular distribution of the senataxin protein, suggesting that these mutations do not lead to loss or mis-localization of the protein, but rather that aberrant function of senataxin underlies the disease pathogenesis. Furthermore, we used the alkaline comet assay to demonstrate that patient-derived fibroblast cells exhibit an increased susceptibility to oxidative DNA damage. This assay provides a novel and additional means to establish pathogenicity of SETX mutations.