Potential of Fermentable Sugar Production from Napier cv. Pakchong 1 Grass Residue as a Substrate to Produce Bioethanol

AbstractBioethanol is one of the most significant renewable fuels. The major sources of bioethanol production are food crops such as corn, sugarcane, rice, wheat and sugar beet. However, utilization of food crops to produce bioethanol could affect the food sources and disrupt the food to population ratio. To overcome these issues, the utilization of lignocellulosic materials such as wheat straw, grass and crop residues to produce bioethanol has been developed for second-generation fuel, since those resources are abundant, cheap and renewable. Napier Pakchong 1 grass (NPG) residue is a lignocellulosic waste obtained from the process of biogas production that can be used as an alternative material for bioethanol production. This research aims to study on the potential of fermentable sugar production from NPG residue. The materials were pretreated with different concentrations of sodium hydroxide (NaOH), followed by enzymatic hydrolysis for saccharification. The results suggested that pretreatment with 3.0% (w/v) NaOH solution at 121̊C for 60 minutes provided the highest lignin removal of 86.1% (w/w) and enriched cellulose fraction from 36.4 to 75.6% (w/w). The enzymatic hydrolysis was conducted by varying enzyme loading volume and total solid contents (TS) at pH 4.8, 50̊C for 72h. The hydrolysis with enzyme loading volume of 2.0 ml/g of substrate and 10% (w/v) of TS were optimal for saccharification giving the reducing sugar yield of 768 mg/g of pretreated biomass or equal to 64 g/L and glucose yield of 522 mg/g of pretreated biomass or equal to 43 g/L. The reducing sugar will be used as a starting material for yeast to produce bioethanol

A novel CuInS2/m-BiVO4 p-n heterojunction photocatalyst with enhanced visible-light photocatalytic activity

Novel CuInS2/m-BiVO4 composites with different mass ratios (CuInS2 to m-BiVO4 = 1:3, 1:1, and 3:1) were synthesized and their potential visible-light photocatalytic applications for photodegradation of some organic dyes (methylene blue, rhodamine B, and methyl orange) and inactivation of bacteria (Pseudomonas aeruginosa) were investigated. CuInS2/m-BiVO4 with a mass ratio of 1:3 exhibited better photocatalytic degradation of methylene blue and antibacterial activity than those of either pure CuInS2 or m-BiVO4. Moreover, this composite photocatalyst showed different photocatalytic selectivity in terms of the organic dye degradation. Salicylic acid was also used to test the photocatalytic activity of this composite to clarify the dye sensitization effect. The photoelectrochemical (PEC) properties of the CuInS2/m-BiVO4 photoelectrode, evaluated by linear sweep voltammetry (LSV) measurement, revealed that the composite photoelectrode exhibited higher current density and onset potential in comparison with the m-BiVO4 photoelectrode. In addition, the electrochemical impedance spectroscopy (EIS) measurement also proved a faster rate of charge transfer at the electrode/electrolyte interface. The enhancement of photocatalytic and PEC activities of the CuInS2/m-BiVO4 composite was revealed not only that the CuInS2/m-BiVO4 composite extended light absorption in the visible light region, but also that the formation of a p-n heterojunction could promote photogenerated charges as well as facilitate effective charge separation and transportation between the CuInS2 and m-BiVO4 contact interface

Chemical diversity and anti-acne inducing bacterial potentials of essential oils from selected Elsholtzia species

Essential oils from the aerial parts of four Elsholtzia species; Elsholtzia stachyodes, Elsholtzia communis, Elsholtzia griffithii and Elsholtzia beddomei were obtained by steam distillation and their chemical components were analysed by gas chromatography-mass spectrometry (GC-MS). Principle Component Analysis was used to identify the chemical variations in the essential oils from these plants, which could be categorised into two groups according to their main chemical components which are acylfuran derivatives and oxygenated monoterpenes. Additionally, the anti-acne inducing bacterial activity against Staphylococcus aureus and Staphylococcus epidermidis were evaluated. The oil from E. stachyodes was the most efficacious against the growth of S. aureus and S. epidermidis having MIC values of 0.78 and 1.56 μL/mL, respectively, and exhibited five times more effective than erythromycin (standard antibiotic)

Chemical diversity and anti-acne inducing bacterial potentials of essential oils from selected <i>Elsholtzia</i> species

<p>Essential oils from the aerial parts of four <i>Elsholtzia</i> species; <i>Elsholtzia stachyodes</i>, <i>Elsholtzia communis</i>, <i>Elsholtzia griffithii</i> and <i>Elsholtzia beddomei</i> were obtained by steam distillation and their chemical components were analysed by gas chromatography-mass spectrometry (GC-MS). Principle Component Analysis was used to identify the chemical variations in the essential oils from these plants, which could be categorised into two groups according to their main chemical components which are acylfuran derivatives and oxygenated monoterpenes. Additionally, the anti-acne inducing bacterial activity against <i>Staphylococcus aureus</i> and <i>Staphylococcus epidermidis</i> were evaluated. The oil from <i>E. stachyodes</i> was the most efficacious against the growth of <i>S. aureus</i> and <i>S. epidermidis</i> having MIC values of 0.78 and 1.56 μL/mL, respectively, and exhibited five times more effective than erythromycin (standard antibiotic).</p