The present study was aimed to evaluate the suitability of agro-wastes and crude vegetable oils for the cost-effective production of poly-β-hydroxybutyrate (PHB), to evaluate growth kinetics and PHB production in Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1 with these carbon substrates and to study the biodegradation of PHB accumulated by these cultures. Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1 accumulates higher amounts of PHB corn (79.90% of dry cell mass) and rice straw (66.22% of dry cell mass) medium respectively. The kinetic model suggests that the Pseudomonas sp. RZS1 follows the Monod model more closely than A. faecalis RZS4. Both the cultures degrade their PHB extract under the influence of PHB depolymerase. Corn waste and rice straw appear as the best and cost-effective substrates for the sustainable production of PHB from Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1. The biopolymer accumulated by these organisms is biodegradable in nature. The agro-wastes and crude vegetable oils are good and low-cost sources of nutrients for the growth and production of PHB and other metabolites. Their use would lower the production cost of PHB and the low-cost production will reduce the sailing price of PHB-based products. This would promote the large-scale commercialization and popularization of PHB as an ecofriendly bioplastic/biopolymer.
The present study examined the vascular effects of peppermint or mint (Mentha longifolia L.) using an abdominal aortic rings model. Concentration-response curves for mint oil were generated after precontracting isolated mouse aorta with phenylephrine. The effect of different receptor antagonists and ion channel or enzyme inhibitors on the vasorelaxant potential of mint oil were studied. Molecular docking studies were conducted using computational techniques to investigate the potential interactions between the bioactive constituents of mint oil and key vascular targets. The tension of aortic rings, which had been contracted by phenylephrine, relaxed as a function of the concentration of mint oil (0.0002-2 mg/mL). Pretreatment of the rings with the nitric oxide synthase inhibitor (L-NAME), a nonselective β-blocker (propranolol), and a muscarinic receptor blocker (atropine) didn't show significant resistance to the vasodilatory effects of the mint oil. The vasodilatory effects of mint oil were significantly diminished when the rings were pretreated with glibenclamide, an inhibitor of ATP-sensitive K+ channels. In addition, indomethacin, a cyclooxygenase (COX) inhibitor, did influence mint oil's tension in the preparations precontracted with phenylephrine. The present findings imply that ATP-sensitive K+ channels activation, blocking of Ca2+ channels, and inhibition of COX play a role in mediating the mint oil-induced vasorelaxation. Molecular docking studies of mint oil constituents showed that β-Elemene and Aromadendrene can interact with K+ and Ca2+ channels through various hydrophobic interactions with key amino acid residues. Additional work is needed to confirm the possible beneficial application of mint oil or its constituents in regulating the vascular tone.
Crystal violet (CV) dye, because of its non-biodegradability and harmful effects, poses a significant challenge for wastewater treatment. This study addresses the efficiency of easily accessible coal fly ash (CFA)-based adsorbents such as raw coal fly ash (RCFA) and surface enhanced coal fly ash (SECFA), in removing CV dye from waste effluents. Various analytical techniques such as FTIR, XRD, SEM, TEM, BET, zeta sizer and zeta potential were employed for the characterization of the adsorbents and dye-loaded samples. BET revealed that RCFA possesses a surface area of 19.370 m2 g-1 and SECFA of 27.391 m2 g-1, exhibiting pore volumes of 0.1365 cm3 g-1 and 0.1919 cm3 g-1 respectively. Zeta-sizer and potential analysis showed the static charges of RCFA as -27.3 mV and SECFA as -28.2 mV, with average particle sizes of 346.6 and 315.3 nm, respectively. Langmuir and Freundlich adsorption isotherms were also employed for adsorption studies. Employing central composite design (CCD) of response surface methodology (RSM), the maximum CV removal was 81.52% for RCFA and 97.52% for SECFA, providing one minute contact time, 0.0125 g adsorbent dose and 10 ppm dye concentration. From the thermodynamic studies, all the negative values of ΔG° showed that all the adsorption processes of both adsorbents were spontaneous in nature.