Aerobic granules synthesized with EPS and degrading strain Rhodococcus FP1 for industrial wastewater treatment

Aerobic granular sludge-sequencing batch reactors (AGS-SBR) is a promising and innovative wastewater treatment system. AGS is composed of microorganisms embedded in a self-produced extracellular polymeric substances (EPS) matrix, forming spherical sludge aggregates. Although AGS tolerance to toxicity, the indigenous microbial communities may not be effective in removing recalcitrant pollutants. Bioaugmentation strategies (addition of specific microorganisms to the system) can be a solution to overcome the difficulty to eliminate certain compounds in wastewaters. However, it is still not a well-established strategy. EPS was extracted from aerobic granules from Nereda® wastewater treatment plants in Utrecht or Garmerwolde, Netherlands. The extraction procedure is as described by Felz et al., 2016. The synthetic granules were produced using the extrusion technique with CaCl2, by mixing the extracted EPS, a concentrated bacterial suspension of Rhodococcus sp FP1 (OD450 of 67.0), and substances 1 or 2. The produced synthetic granules were subjected to a shear stress test, 400 or 800 rpm in a closed vessel for 1 hour, in order to measure their strength. A specific mixture composed of EPS, bacterial suspension and substance 2 generated strong synthetic granules, similar to Utrecht granules used as a control in the shear stress test. Beads produce only with substance 2 and bacterial suspension showed to be weaker than the granules previously mentioned. Thus, the EPS can be considered a key component to increase the strength of the synthetic granules. However, some inconsistencies were observed for synthetic granules with higher concentration of EPS and substance 2, which could indicate that the composition and crosslinking potential of the EPS could be the limiting factor for the granules strength and not only the EPS concentration. In summary, EPS composition and concentration can be important factors to be considered when synthesizing strong granules able to endure this shear stress test. In the future, the EPS biocompatibility and 2-fluorophenol biodegradation with these synthetic granules will be tested.info:eu-repo/semantics/publishedVersio

Bioaugmentation of Aerobic Granular Sludge with specialized degrading granules treating 2-fluorophenol wastewater

The industry growth has been accompanied by an increase in the amount of industrial chemicals being released into the environment. Indigenous microbial communities in wastewater biotreatment processes are not always effective in removing xenobiotics. This work aimed to evaluate the efficiency of a new bioaugmentation strategy in an aerobic granular sludge sequencing batch reactor (AGS-SBR) system fed with 2-fluorophenol (2-FP). Bioreactor performance in terms of phosphate and ammonium removal, 2-FP degradation and chemical oxygen demand (COD) was evaluated. The new bioaugmentation strategy consisted in producing granules using extracellular polymeric substances (EPS) extracted from AGS as a carrying matrix and a 2-FP degrading strain, Rhodococcus sp. FP1. The produced granules were used for the bioaugmentation of a reactor fed with 2-FP. Shortly after bioaugmentation, the produced granules broke down into smaller fragments inside the bioreactor, but 2-FP degradation occurred. After 8 days of bioaugmentation, 2-FP concentration inside the reactor started to decrease, and stoichiometric fluorine release was observed 35 days later. Phosphate and ammonium removal also improved after bioaugmentation, increasing from 30% to 38% and from 20 to 27%, respectively. Complete ammonium removal was only achieved when 2-FP feeding stopped, and phosphate removal was not recovered during operation time. COD removal also improved after the addition of the produced granules. The persistence of Rhodococcus sp. FP1 in the reactor was followed by qPCR. Rhodococcus sp. FP1 was detected 1 day after in the AGS and up to 3 days after bioaugmentation at the effluent. Nevertheless, the 2-FP degradative ability remained thereafter in the granules. Horizontal gene transfer could have happened from the 2-FP degrading strain to indigenous microbiome as some bacteria isolated from the AGS, 3 months after bioaugmentation, were able to degrade 2-FP. This study presents a promising and feasible bioaugmentation strategy to introduce specialized bacteria into AGS systems treating recalcitrant pollutants in wastewater.N/

LEM-3 is a midbody-tethered DNA nuclease that resolves chromatin bridges during late mitosis

Chromosome segregation and genome maintenance require the removal of DNA bridges that link chromosomes just before cells divide. Here the authors show that the LEM-3/Ankle1 nuclease processes DNA bridges before cells divide and define a previously undescribed genome integrity mechanism

Clinical approach for the classification of congenital uterine malformations

A more objective, accurate and non-invasive estimation of uterine morphology is nowadays feasible based on the use of modern imaging techniques. The validity of the current classification systems in effective categorization of the female genital malformations has been already challenged. A new clinical approach for the classification of uterine anomalies is proposed. Deviation from normal uterine anatomy is the basic characteristic used in analogy to the American Fertility Society classification. The embryological origin of the anomalies is used as a secondary parameter. Uterine anomalies are classified into the following classes: 0, normal uterus; I, dysmorphic uterus; II, septate uterus (absorption defect); III, dysfused uterus (fusion defect); IV, unilateral formed uterus (formation defect); V, aplastic or dysplastic uterus (formation defect); VI, for still unclassified cases. A subdivision of these main classes to further anatomical varieties with clinical significance is also presented. The new proposal has been designed taking into account the experience gained from the use of the currently available classification systems and intending to be as simple as possible, clear enough and accurate as well as open for further development. This proposal could be used as a starting point for a working group of experts in the field

Recovered granular sludge extracellular polymeric substances as carrier for bioaugmentation of granular sludge reactor

An increasing amount of industrial chemicals are being released into wastewater collection systems and indigenous microbial communities in treatment plants are not always effective for their removal. In this work, extracellular polymeric substances (EPS) recovered from aerobic granular sludge (AGS) were used as a natural carrier to immobilize a specific microbial strain, Rhodococcus sp. FP1, able to degrade 2-fluorophenol (2-FP). The produced EPS granules exhibited a 2-FP degrading ability of 100% in batch assays, retaining their original activity after up to 2-months storage. Furthermore, EPS granules were added to an AGS reactor intermittently fed with saline wastewater containing 2-FP. Degradation of 2-FP and stoichiometric fluorine release occurred 8 and 35 days after bioaugmentation, respectively. Chemical oxygen demand removal was not significantly impaired by 2-FP or salinity loads. Nutrients removal was impaired by 2-FP load, but after bioaugmentation, the phosphate and ammonium removal efficiency improved from 14 to 46% and from 25 to 42%, respectively. After 2-FP feeding ceased, at low/moderate salinity (0.6–6.0 g L−1 NaCl), ammonium removal was completely restored, and phosphate removal efficiency increased. After bioaugmentation, 11 bacteria isolated from AGS were able to degrade 2-FP, indicating that horizontal gene transfer could have occurred in the reactor. The improvement of bioreactor performance after bioaugmentation with EPS immobilized bacteria and the maintenance of cell viability through storage are the main advantages of the use of this natural microbial carrier for bioaugmentation, which can benefit wastewater treatment processes.info:eu-repo/semantics/publishedVersio

Production of granules with the degrading strain Rhodococcus FP1 using polymeric immobilizing agents

In an increasingly competitive and demanding world, industrial and population-wise, water has gained an increased value and is more than ever a scarce and valuable resource. As a consequence of civilization development, the variety and amount of industrial chemicals being released into the environment has raised. Indigenous microbial communities in biotreatment processes may not be effective in removing xenobiotic contaminants. This work aims to combine extracted extracellular polymeric substances (EPS) with specialized degrading strain Rhodococcus sp. FP1 for the production of granules capable to degrade 2-fluoropenol - a toxic compound present in several industrial effluents – for further bioreactor bioaugmentation. The strength of the synthetic granules was tested using a shear stress test. This study presents a potential application of a recovered resource from wastewater treatment and will potentially assist the existing industrial processes of wastewater treatment with aerobic granular sludge (AGS).N/

Specialized degrading granules effective for biaugmentation of Aerobic Granular Sludge reactor treating 2-fluorophenol in wastewater

The amount of industrial chemicals being released into the environment has increased. Indigenous microbial communities in wastewater biotreatment processes are not always effective in removing xenobiotics. This work aimed to evaluate the feasibility and efficiency of a promising bioaugmentation strategy in an aerobic granular sludge (AGS) system continuously fed with 2-fluorophenol (2-FP). Bioreactor performance in terms of phosphate and ammonium removal and 2-FP degradation was evaluated. Granules were produced using extracellular polymeric substances (EPS) extracted from AGS as a carrying matrix and a 2-FP degrading strain, Rhodococcus sp. FP1. Afterwards, the produced granules were introduced in the reactor. Shortly after addition, the produced granules broke down into smaller fragments inside the bioreactor, but 2-FP degradation occurred. After 8 days of bioaugmentation, 2-FP concentration inside the reactor started to decrease, and stoichiometric fluorine release was observed 35 days later. 14 Days after the bioaugmentation, phosphate and ammonium removal efficiency improved ca. 36% and 48%, respectively. However, complete phosphorous and ammonium removal was never achieved while the reactor was fed with 2-FP. The persistency of Rhodococcus sp. FP1 in the reactor was followed by qPCR. Rhodococcus sp. FP1 was detected 1 day after in the AGS and up to 3 days after bioaugmentation at the effluent. Nevertheless, the degradative ability remained thereafter in the granules. Degrading strain could have persisted even if at lower numbers. Horizontal gene transfer could have happened from the 2-FP degrading strain to indigenous microbiome as some bacteria isolated from the AGS, 3 months after bioaugmentation, degraded 2-FP.N/