No abstract

A novel acidotolerant and moderately thermophilic sulfur-reducing bacterium was isolated from sediments of the Tinto River (Spain), an extremely acidic environment. Strain TR1T stainedGram-negative, and was obligately anaerobic, non-spore-forming and motile. Cells were short rods (1.5-260.5-0.7 mm), appearing singly or in pairs. Strain TR1 T was catalase-negative and slightly oxidase-positive. Urease activity and indole formation were absent, but gelatin hydrolysis was present. Growth was observed at 20-52 8C with an optimum close to 50 8C, and a pH range of 3-7 with optimum between pH 6 and 6.5. Yeast extract was essential for growth, but extra vitamins were not required. In the presence of sulfur, strain TR1 T grew with acetate, formate, lactate, pyruvate, stearate, arginine and H 2 /CO 2 . All substrates were completely oxidized and H 2 S and CO 2 were the only metabolic products detected. Besides elemental sulfur, thiosulfate was used as an electron acceptor. The isolate also grew by disproportionation of elemental sulfur. The predominant cellular fatty acids were saturated components: C 16 : 0 , anteiso-C 17 : 0 and C 18 : 0 . The only quinone component detected was menaquinone MK-7(H 2 ). The G+C content of the genomic DNA was 34 mol%. The isolate is affiliated to the genus Desulfurella of the class Deltaproteobacteria, sharing 97 % 16S rRNA gene sequence similarity with the four species described in the genus Desulfurella. Considering the distinct physiological and phylogenetic characteristics, strain TR1 T represents a novel species within the genus Desulfurella, for which the name Desulfurella amilsii sp. nov. is proposed. The type strain is TR1 T (5DSM 29984Respiratory growth with elemental sulfur has been reported for phylogenetically diverse micro-organisms. They belong to about 69 bacterial genera falling into nine phyla and 37 archaeal genera from two phyla (Florentino et al., 2016). Sulfidogenic micro-organisms can be potentially applied for the treatment of acidic and metal-rich effluents from the mining and metallurgical industries (Johnson, 1998;Koschorreck, 2008); the sulfide that they produce can precipitate metals as insoluble metal sulfides that can be recovered. Bacteria that thrive at low pH are of special ecological and biotechnological interest due to their higher proton resistance. Sequences belonging to the sulfur-reducing genus Desulfurella have been detected in acid mine drainage environments (Brito et al., 2014; Sánchez-Andrea et al., 2011). Selective enrichments for sulfur reducers at low pH using sediments from the acidic Tinto River led to the isolation of strain TR1 T (Florentino et al., 2015), which is described and characterized here.Sediment samples were collected in March 2013 from three sampling sites in the Tinto River basin. Briefly, strain TR1 T was isolated by combining growth on solid media with a serial dilution technique and addition of vancomycin. Details on the isolation process and basal media preparation can be found in Florentino et al. (2015). Cell morphology...

Anaerobic digestion of nitrogen (N) rich substrates might be hindered when ammonia (NH 3 ) formation reaches toxic levels for methanogenic microorganisms. One possible strategy to avoid inhibiting conditions is the removal of NH 3 from digestate by stripping and scrubbing technology and by recirculating N depleted digestate back to the digester. This study aimed to i) monitor the performance (mass and energy balances) of a full scale digestate processing cascade that includes an innovative vacuum side stream NH 3 stripping and scrubbing system, ii) assess the production cost of ammonium sulphate (AS) solution and iii) evaluate its fertiliser quality. The use of gypsum to recover NH 3 in the scrubbing unit, instead of the more common sulphuric acid, results in the generation of AS and a fertilising liming substrate. Mass and nutrient balances indicated that 57% and 7.5% of ammonium N contained in digestate was recovered in the form of a 22% AS and liming substrate, respectively. The energy balance showed that about 3.8 kWh el and 59 kWh th were necessary to recover 1 kg of N in the form of AS. Furthermore, the production cost of AS, including both capital and operational costs, resulted to be 5.8 € t −1 of digestate processed. According to the fertiliser quality assessment, this technology allows for the recovery of NH 3 in the form of salt solutions that can be utilised as a substitute for synthetic mineral nitrogen fertilisers.

No abstract

The research was undertaken as part of the project called SYSTEMIC: 'Systemic large scale ecoinnovation to advance circular economy and mineral recovery from organic waste in Europe'. This project has received funding from the European Union's H2020 research and innovation programme under the grant agreement No: 730400. SYSTEMIC started on 1 June 2017 and continued for 4 years.