Increased resistance of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp. (ESKAPE) pathogens against various drugs has enhanced the urge for the development of alternate therapeutics. Quorum sensing (QS) is a density dependent cell-to-cell communication mechanism responsible for controlling pathogenicity with the regulation of gene expression. Thus, QS is considered a potential target for the development of newer anti-biofilm agents that do not depend on the utilization of antibiotics. Compounds with anti-QS effects are known as QS inhibitors (QSIs), and they can inhibit the QS mechanism that forms the major form in the development of bacterial pathogenesis. A diverse array of natural compounds provides a plethora of anti-QS effects. Over recent years, these natural compounds have gained importance as new strategies for combating the ESKAPE pathogens and inhibiting the genes involved in QS. Different pharmacognostical and pharmacological studies have been carried out so far for identification of novel drugs or for the discovery of their unique structures that may help in developing more effective anti-biofilm therapies. The main objective of this review is to discuss the various natural compounds, so far identified and their employed mechanisms in hindering the genes responsible for QS leading to bacterial pathogenesis.

The treatment of stabilized landfill leachate (SLL) by conventional biological treatment is often inefficient due to the presence of bio-recalcitrant substances. In this study, the feasibility of coagulation-flocculation coupled with the Fenton reaction in the treatment of SLL was evaluated. The efficiency of the selected treatment methods was evaluated through total organic carbon (TOC) removal from SLL. With ferric chloride as the coagulant, coagulation-flocculation was found to achieve the highest TOC removal of 71% at pH 6. Then, the pretreated SLL was subjected to the Fenton reaction. Nearly 50% of TOC removal was achieved when the reaction was carried out at pH 3, H₂O₂:Fe²⁺ ratio of 20:1, H₂O₂ dosage of 240 mM and 1 h of reaction time. By coupling the coagulation-flocculation with the Fenton reaction, the removal of TOC, COD (chemical oxygen demand) and turbidity of SLL were 85%, 84% and 100%, respectively. The ecotoxicity study performed using zebrafish revealed that 96 h LC₅₀ for raw SLL was 1.40% (v/v). After coagulation-flocculation, the LC₅₀ of the pretreated SLL was increased to 25.44%. However, after the Fenton reaction, the LC₅₀ of the treated SLL was found to decrease to 10.96% due to the presence of H₂O₂ residue. In this study, H₂O₂ residue was removed using powdered activated charcoal. This method increased the LC₅₀ of treated effluent to 34.48% and the removal of TOC and COD was further increased to 90%. This finding demonstrated that the combination of the selected treatment methods can be an efficient treatment method for SLL.

There has been a surge in interest in using food waste (FW) as an insect-rearing substrate in recent years. We examine the effect of protein-based food waste (leftover boneless chicken, LBC), carbohydrate-based food waste (overnight rice, OR), and fruit-based food waste (rotten banana, RB) on the following parameters: substrate reduction (SR), waste reduction index (WRI), bioconversion rate (BCR) and relative growth rate (RGR). BSFL reared on OR feed substrate had the highest biomass (0.23±0.01) g at d9 followed by RB (0.22±0.00) g and LBC (0.16±0.00) g. Larvae from OR-fed BSFL were the longest, averaging 20.53±0.46 mm in length on d12. The SR calculated for all feed substrates were as followed: RB (95.35 ± 0.33)% > OR (85.29 ± 0.80)% > LBC (83.17 ± 0.27)%. The WRI for control (C) and BSFL-fed on all feeds were in the following manner: (RBC:8.90±0.00 g days-1, RBBSFL:9.53±0.00 g days-1) > (ORC:7.35±0.00 g days-1, ORBSFL:8.53±0.09 g days-1) > (LBCC:6.90±0.00 g days-1, LBCBSFL: 8.32±0.03 g days-1). OR-fed BSFL showed the highest BCR (76.0±1.0) % and RGR (0.32±0.01) days-1. The FW’s self-composting (as in control) influenced the BSFL’s SR and WRI in all diets. Overall, the BSFL’s growth and development are affected by the nature, quality, and type of diet of the feed substrates.