Bacterial control promoted by bacteriophages (phages) is an attractive tool in the face of the antibiotic crisis triggered by the exacerbated use of these drugs. Despite the growing interest in using these viruses, some gaps still need answers, such as the protection and delivery of phages. Some limitation points involve the degradation of phage proteins by enzymes or inactivation in low-pH environments. In this review, a literature search using keywords related to the field of virus delivery formulations was done to understand the current scenario of using delivery techniques and phage formulations. A total of 2096 raw results were obtained, which resulted in 140 publications after refinement. These studies were analyzed for main application techniques and areas, keywords, and countries. Of the total, 57% of the publications occurred in the last five years, and the encapsulation technique was the most used among the articles analyzed. As excipient agents, lactose, trehalose, mannitol, PEG, and Leucine stand out. The development of phage formulations, protection approaches, their delivery routes, and the knowledge about the best application strategy enables the use of these organisms in several sectors. It can act as a powerful tool against antibiotic-resistant bacteria.
Bacteriophages , Bacteriophages/physiology , Anti-Bacterial Agents/pharmacology , Bacteria , Lactose
In swine farming, antibiotics are often used to reduce disease and promote animal growth. Part of these compounds is not absorbed by the swine body, being excreted and later reaching the treatment systems, soil, and nearby waterbodies. This research sought to investigate the influence of adding ciprofloxacin (CIP) on the anaerobic digestion of swine wastewater. For that, a bench-scale anaerobic sequential batch reactor (ASBR) was used, with 5 L of working volume in six different phases, with volumetric organic loading rate (VOLR) and CIP dosage variation. According to the results, the optimal VOLR for the reactor was 0.60 ± 0.11 gSV L-1 d-1, resulting in biogas productivity of 0.51 ± 0.03 Lbiogas L-1 d-1. After initial stability, adding substrate with 0.5 mgCIP L-1 resulted in an abrupt drop of 82% in the productivity from the 7th to 11th day of addition, coinciding with volatile acids accumulation. Afterward, the reactor recovered and reached apparent stability, with productivity similar to the previous step without the drug. For 2.5 mgCIP L-1 in the substrate, the biogas productivity at equilibrium was 11.8% lower than in the phases with the same VOLR and 0.0 and 0.5 mgCIP L-1. Organic matter removals near 80% were achieved for both dosages. The 16S rRNA metagenomic analyses showed an increase in the relative abundance of most of the phyla found, indicating that the dosages used allowed the acclimatization of microorganisms and possibly the compound biodegradation.
Microbiota , Wastewater , Animals , Swine , Anaerobiosis , Biofuels , Bioreactors , Ciprofloxacin/pharmacology , RNA, Ribosomal, 16S/genetics , Methane
The anaerobic digestion (AD) of a high diversity blend of fruit and vegetable waste (FVW) generated in tropical conditions as a single substrate was performed. A continuously stirred tank reactor (CSTR) operated in semi-continuous regime was used for AD. The reactor performance was monitored with gradually increasing organic loading rates (OLRs) from 0.5 up to 5.0â gVSâ L-1â d-1. The biochemical methane potential (BMP) of FVW determined by batch bottles was 360â LNâ CH4â kgVS-1, with a biodegradability of 79%. A stable pH with an adequate level of buffering capacity was observed during the entire experiment. Methane yield indicated the best performance at an OLR of 3.0â gVSâ L-1â d-1, with 285â LNâ CH4â kgVS-1 added, reaching 79% of BMP. At an OLR over 3.0â gVSâ L-1â d-1 accumulation of volatile fatty acids (VFA) was detected; in particular, propionic acid was monitored, and a decreased methane yield was detected. Biogas production rate was 1.55â LNâ L-1â d-1 and showed linear increase according to increases in the OLR.
Methane , Vegetables , Anaerobiosis , Biofuels , Bioreactors , Fruit
This study investigates the influence of chemical composition on the biochemical methane potential (BMP) of twelve different batches of fruit and vegetable waste (FVW) with different compositions collected over one year. BMP ranged from 288 to 516LNCH4kgVS-1, with significant statistical differences between means, which was explained by variations in the chemical composition over time. BMP was most strongly correlated to lipid content and high calorific values. Multiple linear regression was performed to develop statistical models to more rapidly predict methane potential. Models were analysed that considered chemical compounds and that considered only high calorific value as a single parameter. The best BMP prediction was obtained using the statistical model that included lipid, protein, cellulose, lignin, and high calorific value (HCV), with R2 of 92.5%; lignin was negatively correlated to methane production. Because HCV and lipids are strongly correlated, and because HCV can be determined more rapidly than overall chemical composition, HCV may be useful for predicting BMP.
Methane/analysis , Waste Management , Anaerobiosis , Bioreactors , Fruit , Lignin , Linear Models , Vegetables
O objetivo principal deste trabalho foi avaliar o estado geral da qualidade das águas do rio Belém a partir de duas abordagens complementares: o uso do Índice de Qualidade das Águas da National Sanitation Foundation e de protocolos perceptivos (Indicador de Intensidade Antrópica e Indicador de Valor de Habitat). Para o monitoramento, foram selecionados 10 pontos no seu canal principal além da foz dos 13 tributários principais. Os resultados do IQA nsf mostraram perda progressiva da qualidade das águas da nascente para a foz em razão do aporte de esgotos domésticos oriundos das regiões mais densamente habitadas próximas ao centro da cidade. A aplicação dos protocolos perceptivos mostrou maior variabilidade dos resultados, mas com tendência esperada em relação ao IQAnsf, indicando seu uso potencial como instrumento de avaliação complementar.
The main purpose of this work was to evaluate the water quality of Belem River with two complementary strategies: the use of the National Sanitation Foundation Water Quality Index and the application of perceptive protocols (Human Intensity Index and Habitat Value Index). To access the water quality, 10 points at the main river channel as well as the estuary of its 13 main tributaries were selected. The WQInsf results showed a gradual loss of the water quality from the headwater to its mouth mainly due the presence of domestic effluents from the more densely populated areas located near the center of the city. The application of perceptive protocols showed more variable but predictable results indicating its potential as complementary methods of evaluation.
