The corncob is an agricultural waste generated in huge quantities during corn processing. In this paper, we tested the capacity of corncob particles for water purification by removing the azo dye Direct Yellow 27 (DY27) via biosorption. The biosorption process was investigated in terms of the kinetics, equilibria, and thermodynamics. Batch biosorption studies showed that the biosorption performance has strong inverse correlations to the solution pH and the corncob particle size, and it increases quickly with increasing contact time and initial dye concentration. The pseudo-second-order kinetic model provides the best fit to the experimental data, whereas the Redlich-Peterson isotherm model is most suitable for describing the observed equilibrium biosorption. The biosorption process is exothermic, spontaneous, and physisorption in character. Fourier transform infrared (FTIR) spectroscopy and confocal scanning laser microscopy (CSLM) studies suggest that lignocellulose and proteins play key roles in the biosorption of DY27 from aqueous solutions by corncob. Furthermore, after biosorption onto the corncob, the dye can be effectively desorbed using 0.1 M NaOH solution. Therefore, the corncob can be used as a promising biosorbent to remediate DY27-contaminated water and wastewater.
The candidiasis caused by C. albicans is a public health problem. The abuse of antifungals has contributed to the development of resistance. B. morelensis has demonstrated antibacterial and antifungal activities. In this work the activity of the essential oil of B. morelensis was evaluated and for its two pure compounds with analysis of the different mechanisms of pathogenesis important for C. albicans. The essential oil was obtained by the hydro-distillation method and analyzed using GC–MS. The anti-Candida activity was compared between to essential oil, α-Pinene and γ-Terpinene. GC–MS of the essential oil demonstrated the presence of 13 compounds. The essential oil showed antifungal activity against four C. albicans strains. The most sensitive strain was C. albicans 14065 (MFC 2.0 mg/mL and MIC50 0.125 mg/mL) with α-Pinene and γ-Terpinene having MFCs of 4.0 and 16.0 mg/mL respectively. The essential oil inhibited the growth of the germ tube in 87.94% (8.0 mg/mL). Furthermore, it was observed that the essential oil diminishes the transcription of the gene INT1. This work provides evidence that confirms the anti-Candida activity of the B. morelensis essential oil and its effect on the growth of the germ tube and transcription of the gene INT1.