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This research evaluates, through microbial dynamics, the use of earthworms Eisenia andrei for maturation of pre-composted pig manure in comparison with maturation under static conditions and with vermicomposting of fresh pig manure. Therefore, two substrates were used (fresh and pre-composted pig manure) and four treatments were developed: fresh manure vermicomposting, control of fresh manure without earthworms, pre-composting followed by vermicomposting and static maturation of pre-composted manure. In order to determine the microbial dynamics, the enzymatic activities and profiles of phospholipid fatty acids (PLFAs) were evaluated over a 112-days period. Physicochemical and biological parameters of the obtained products were also analyzed. The presence of earthworms significantly reduced (p < 0.05) microbial biomass and all the microbial groups (Gram + bacteria, Gram − bacteria, and fungi) in both substrates. The enzymatic activities (cellulase, β-glucosidase and acid phosphatase) behaved in a significantly distinctive manner (p < 0.05) depending on the treatment. Microbial communities had significant correlations (p < 0.05) with hydrolytic activities during static maturation of pre-composted manure. This indicates a direct effect of microbiota evolution on the degradative processes; however, complex earthworm-microbiota interactions were established in the presence of E. andrei. After earthworms’ removal from vermicompost of fresh substrate at 70 day, an increase in Gram + (4.4 times), Gram − (3.8 times) and fungi (2.8 times) were observed and, although the vermicompost achieved quality values, it is necessary to optimize the vermicompost aging phase period to improve the stability. Static maturation presented stability on microbial dynamics that indicated a slow degradation of organic compounds so that, maturation of pre-composted manure through vermicomposting is better option. [ABSTRACT FROM AUTHOR]

A new family of copper(I) complexes of general formula [Cu(dppe)(NN)] + have been synthesized and fully characterized, with dppe = 1.2-bis(diphenylphosphino)ethane and NN representing several bidentate heteroaromatic ligands: 2,2′-bipy = 2.2′-bipyridine (1), Me 2 bpy = 4.4′-dimethyl-2,2′-bipyridine (2), dpytz = 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (3), dpp = 2.3-bis(2-pyridyl)pyrazine (4), and the metallaligand [Ru(η 5 -C 5 H 5 )(PPh 3 )(dpp)] + (5), yielding the bimetallic copper(I)-ruthenium(II) complex [Cu(dppe)(μ-dpp)Ru(η 5 -C 5 H 5 )(PPh 3 )] 2 + (6). The single crystal structures of complexes (2) and (4) were determined by X-ray diffraction studies. All the complexes exhibit high cytotoxicity against the human cancer cells A2780 and MCF7 with IC 50 values far lower than those found for the antitumor drug cisplatin in the same cell lines and even surpassing cisplatin resistance in the A2780cisR cells. They display IC 50 values on the human embryonic kidney HEK293 non-tumoral cells of the same order of magnitude as those found for the tumoral cells. In the ovarian cells the compounds induce rapid production of reactive oxygen species (ROS) probably through mitochondrial pathways. According to the results reported here, these compounds can be considered as prospective antitumoral agents that deserve further evaluation. [ABSTRACT FROM AUTHOR]

During composting, facilities usually exert greater control over the bio-oxidative phase of the process, which uses a specific technology and generally has a fixed duration. After this phase, the material is deposited to mature, with less monitoring during the maturation phase. While there has been considerable study of biological parameters during the thermophilic phase, there is less research on the stabilization and maturation phase. This study evaluates the effects of the type of starting material on the evolution of microbial dynamics during the maturation phase of composting. Three waste types were used: sludge from the fish processing industry, municipal sewage sludge and pig manure, each independently mixed with shredded pine wood as bulking agent. The composting system for each waste type comprised a static reactor with capacity of 600 L for the bio-oxidative phase followed by stabilization and maturation phase in triplicate 200 L boxes for 112 days. Phospholipid fatty acids, enzyme activities and physico-chemical parameters were measured throughout the maturation phase. The evolution of the total microbial biomass, Gram + bacteria, Gram − bacteria, fungi and enzymatic activities (β-glucosidase, cellulase, protease, acid and alkaline phosphatase) depended significantly on the waste type (p < 0.001). The predominant microbial community for each waste type remained present throughout the maturation process, indicating that the waste type determines the microorganisms that are able to develop at this stage. While fungi predominated during fish sludge maturation, manure and municipal sludge were characterized by a greater proportion of bacteria. Both the structure of the microbial community and enzymatic activities provided important information for monitoring the composting process. More attention should be paid to the maturation phase in order to optimize composting. [ABSTRACT FROM AUTHOR]

Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques to reduce its risk to the environment. This research studies vermicomposting and vermicomposting after composting of sewage sludge with the earthworm specie Eisenia andrei . In order to determine the effect that earthworms cause on the microbial dynamics depending on the treatment, the structure and activity of the microbial community was assessed using phospholipid fatty acid analysis and enzyme activities, during 112 days of vermicomposting of fresh and composted sewage sludge, with and without earthworms. The presence of earthworms significantly reduced microbial biomass and all microbial groups (Gram+ bacteria, Gram− bacteria and fungi), as well as cellulase and alkaline phosphatase activities. Combined composting–vermicomposting treatment showed a lesser development of earthworms, higher bacterial and fungal biomass than vermicomposting treatment and greater differences, compared with the control without earthworms, in cellulase, β-glucosidase, alkaline and acid phosphatase. Both treatments were suitable for the stabilization of municipal sewage sludge and the combined composting–vermicomposting treatment can be a viable process for maturation of fresh compost. [ABSTRACT FROM AUTHOR]