RESUMO
Polyhydroxybutyrate (PHB) is known for wide applications, biocompatibility, and degradability; however, it cannot be commercialized due to conventional recovery using solvents. The present study employed mechanical cell-disruption methods, such as Pestle and mortar, sonication, and glass bead vortexing, for solvent-free extraction of PHA from Bacillus sp. Different time intervals were set for grinding (5, 10, 15 min), sonicating (1, 3 and 5 min), and vortexing (2, 5 and 8 g glass beads with 5, 10 and 15 min each) hence studying their effect on cell lysis to release PHA. Tris buffer containing phenylmethyl sulfonyl fluoride (PMSF) (20 mM Tris-HCl, pH 8.0, 1 mM PMSF) was employed as a lysis buffer to study its action over Bacillus cells. Its presence was checked with the above methods in cell lysis. Sonicating cells for 5 min in the presence of lysis buffer achieved a maximum PHA yield of 45%. Cell lysis using lysis buffer yielded 35% PHA when vortexing with 5 g glass beads for 15 min. Grinding cells for 15 min showed a maximum yield of 34% but lacked a lysis buffer. The overall results indicated that the action of lysis buffer and physical extraction methods improved PHA yield by %. Therefore, the study sought to evaluate the feasibility of applying laboratory methods for cell disruption. These methods can showcase possible opportunities in large-scale applications. The polymer yield results were compared with standard sodium hypochlorite extraction. Confirmation of obtained polymers as polyhydroxy butyrate (PHB) was made through FTIR and 1HNMR characterization.
RESUMO
Contemporary research in epidemiology has found that being exposed to air pollution at an early stage of life has associations with both acute and chronic conditions of the multi-organs. Nevertheless, the reasons for this have yet to be fully explained. Because of this there is a need for a robust investigation into the damaging toxic influence of diesel particulate matter (PM2.5) on living organisms. This study is aimed to investigate the developmental toxicity of PM2.5 by using zebrafish (Danio rerio) embryo/larvae as a disease model and to understand the toxicity effects of PM2.5 on ecological environment more thoroughly. This research demonstrates that being exposed to PM2.5 leads to a significant increase in mortality, effective developmental morphology, reductions in hatching rates and lower heart rates in zebrafish. Additionally, it leads to increases in the length of string heart, area of pericardium, and apoptosis, reduces the number of normal intersegmental vessels (ISVs) and motor neurons in the trunk region and liver formation defects in zebrafish embryos. Investigation employing a scanning electron microscope demonstrates that being exposed to PM2.5 leads to damage in zebrafish larvae skin cell layers. Histological analysis demonstrates that when these larvae are treated with PM2.5 then abnormalities occur in the neurons, liver, heart, gills, brain, and eyes, and remarkable increase in in the cellular/subcellular levels of organelle dissolution. These findings are useful to help us understand the pathophysiological influence of being exposed to PM2.5 on the multi-organ defects of zebrafish. More research into which particular elements that make up diesel pollution contribute to this toxicity is needed so that the dangers to development can be further analysed.
