Mechanism and kinetic model of microalgal enzymatic hydrolysis for prospective bioethanol conversion.

Tetraselmis chuii is a potential microalgae that is in consideration for producing bioethanol owing to its large content of carbohydrates. The glucose production from T. chuii through an enzymatic process with cellulase and xylanase (pretreatment process) and α-amylase and glucoamylase (saccharification process) was studied. The mechanism of the enzymatic process was developed and the kinetic models were then evaluated. For the pretreatment process, enzymes with 30% concentration reacted at 30 °C for 40 min resulted in 35.9% glucose yield. For the saccharification process, the highest glucose yield of 90.03% was obtained using simultaneous α-amylase (0.0006%) and glucoamylase (0.01%) enzymes at 55 °C and for 40 min. The kinetic models fitted well with the experimental data. The model also revealed that the saccharification process performed better than the pretreatment process with a higher kinetic constant and lower activation energy. The proposed kinetic model plays an important role in implementing processes at a larger scale.

The Amine Functionalized Sugarcane Bagasse Biocomposites as Magnetically Adsorbent for Contaminants Removal in Aqueous Solution.

The method of solvothermal by one-step operation has been performed to synthesize of magnetic amine-functionalized sugarcane bagasse biocomposites (SB-MH). The obtained SB-MH contains 62.34% of Fe, 17.8 mmol/g of amine, and a magnetic property of 19.46 emu/g. The biocomposite surface area increased significantly from 1.617 to 25.789 m2/g after amine functionalization. The optimum condition of SB-MH used for Pb(II) ion removal was achieved at pH 5 for 360 min with adsorption capacity of 203.522 mg/g. The pseudo 2nd order was well-fitted to the model of Pb(II) ion adsorption. Meanwhile, other contaminant parameters number of Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and dye in wastewater were also remarkably reduced by about 74.4%, 88.0%, and 96.7%, respectively. The reusability of SB-MH with 4th repetitions showed only a slight decrease in performance of 5%. Therefore, the proposed magnetic amine-functionalized sugarcane bagasse biocomposites lead to a very potential adsorbent implemented in high scale due to high surface area, easy separation, stable materials and capability to adsorb contaminants from aqueous solution.

The green synthesis of a palm empty fruit bunch-derived sulfonated carbon acid catalyst and its performance for cassava peel starch hydrolysis.

A sulfonated carbon acid catalyst (C-SO3H) was successfully generated from palm empty fruit bunch (PEFB) carbon via hydrothermal sulfonation via the addition of hydroxyethylsulfonic acid and citric acid. The C-SO3H catalyst was identified as containing 1.75 mmol g-1 of acid and 40.2% sulphur. The surface morphology of C-SO3H shows pores on its surface and the crystalline index (CrI) of PEFB was decreased to 63.8% due to the change structure as it became carbon. The surface area of the carbon was increased significantly from 11.5 to 239.65 m2 g-1 after sulfonation via hydrothermal treatment. The identification of -SO3H, COOH and -OH functional groups was achieved using Fourier-transform infrared spectroscopy. The optimal catalytic activity of C-SO3H was achieved via hydrolysis reaction with a yield of 60.4% of total reducing sugar (TRS) using concentrations of 5% (w/v) of both C-SO3H and cassava peel starch at 100 °C for 1 h. The stability of C-SO3H shows good performance over five repeated uses, making it a good potential candidate as a green and sulfonated solid acid catalyst for use in a wide range of applications.

Prospective production of fructose and single cell protein from date palm waste

BACKGROUND: Fructose and single cell protein are important products for the food market. Abundant amounts of low-grade dates worldwide are annually wasted. In this study, highly concentrated fructose syrups and single cell protein were obtained through selective fermentation of date extracts by Saccharomyces cerevisiae. RESULTS: The effect of air flow (0.1, 0.5, 0.75, 1, 1.25 and 1.5 vvm) and pH (4.5, 4.8, 5, 5.3 and 5.6) was investigated. Higher air flow led to lower fructose yield. The optimum cell mass production of 10 g/L was achieved at air flow of 1.25 vvm with the fructose yield of 91%. Similar cell mass production was obtained in the range pH of 5.0­5.6, while less cell mass was obtained at pH less than 5. Controlling the pH at 4.5, 5.0 and 5.3 failed to improve the production of cell mass which were 5.6, 5.9 and 5.4 g/L respectively; however, better fructose yield was obtained. CONCLUSIONS: Extension of the modified Gompertz enabled excellent predictions of the cell mass, fructose production and fructose fraction. The proposed model was also successfully validated against data from literatures. Thus, the model will be useful for wide application of biological processes.

Aluminum leaching from water treatment sludge using hydrochloric acid and kinetic study.

Water treatment sludge (WTS) is abundantly produced in the world; the waste contributes to the environmental problems. Therefore, for WTS utilization, aluminum leaching was employed using hydrochloric acid in this study. Al leaching efficiency increased from 72% to 80% as hydrochloric acid concentration increased from 1 to 4 M. Decreasing the particle size and increasing the temperature increased Al leaching efficiency. The proposed kinetic model revealed that the rate-controlling step followed a series of two leaching mechanisms: initially controlled by product-layer diffusion and then by a chemically controlled reaction. For instance, at 70 °C, the initial stage is well fitted by product-layer diffusion (R2 = 0.87) compared to R2 = 0.60 for chemical reaction; while for the second stage, R2 = 0.95 was observed via chemical reaction compared to R2 = 0.74 for product-layer diffusion. The activation energies in these two stages were 9.58 kJ/mol and 10.73 kJ/mol, respectively. The proposed model was well validated by using data from literature and thus will be useful for other applications of leaching and extraction processes.

Biodiesel production from waste cooking oil using heterogeneous catalyst: Biodiesel product data and its characterization.

The biodiesel production from waste cooking oil in this data collection process was focused on the utilization of the heterogeneous catalyst of CaO/silica. The CaO was obtained from eggshell after preparation process and the silica was successfully extracted from peat clay using sodium hydroxide with various molarities. The CaO/silica catalyst was formed by the impregnation of the CaO catalyst on the support of silica. The FTIR, SEM and XRD characterization for the various formed catalysts were presented. The generated catalysts were further used for the production of biodiesel. The GCMS chromatogram with the type of methyl esters for each data was presented. The data presented here are related to the previous research article [1].

Kinetic modeling of the simultaneous production of ethanol and fructose by Saccharomyces cerevisiae

Background: Ethanol and fructose are two important industrial products that enjoy many uses. In this contribution, their production via selective fermentation of date extract using Saccharomyces cerevisiae was studied. Scaling up the process for possible commercialization was investigated in three fermentors with working volume ratio of 1:40:400. Results: Higher ethanol concentration was obtained in the larger fermentor due to conversion of fructose. Fructose yields in the 0.5-L, 7.5-L and 80-L fermentors were 99, 92 and 90%, respectively. Good fitting was obtained with the modified Monod kinetics; however, a better fit of cell mass was obtained with the modified Ghose­Tyagi model which accounts for ethanol inhibition. Conclusions: The modified Gompertz model was expanded to facilitate prediction of products' formation and fructose fractions in all three fermentors. Such expansion will be beneficial in industrial applications.

Dataset on potential large scale production of biosurfactant using Bacillus sp.

Surfactants are very important in industry. The cost of commercial surfactant production is still high and the surfactant demand is constantly increasing. Microbial production of surfactant known as biosurfactant shows commercial potency. Utilization of Bacillus sp. strain on glucose fermentation for biosurfactant production was then studied. This type of microbe was isolated from soil contaminated with palm oil. The selection of the strain was based on its ability to form emulsifying zone around the colony and its capability to grow compared with those for commercial bacteria of Bacillus pumilus JCM 2508. The results showed a potentially promising strain with high biosurfactant yields and low surface tension. For further scale-up development, the microbe performance in a fermentor was compared with those in a flask and a proposed model to predict the kinetic profiles of cell mass, biosurfactant and surface tension were also described. The data presented here are related to the research article entitled "Kinetic study and modeling of biosurfactant production using Bacillus sp." (Heryani and Putra, 2017) [1].

Kinetic study and modeling of biosurfactant production using Bacillus sp

Background: Surfactants are one of the most important raw materials used in various industrial fields as emulsifiers, corrosion inhibitors, foaming agents, detergent products, and so on. However, commercial surfactant production is costly, and its demand is steadily increasing. This study aimed to evaluate the performance of typical strains of Bacillus sp. to produce biosurfactants through fermentation. It also included the investigation of the effect of initial glucose concentration and the carbon to nitrogen ratio. Results: The biosurfactant yield was in the range of 1­2.46 g/L at initial glucose concentrations of 10­70 g/L. The optimum fermentation condition was achieved at a carbon to nitrogen ratio of 12.4, with a decrease in surface tension of up to 27 mN/m. Conclusions: For further development and industrial applications, the modified Gompertz equation is proposed to predict the cell mass and biosurfactant production as a goodness of fit was obtained with this model. The modified Gompertz equation was also extended to enable the excellent prediction of the surface tension.

Production of fructose from highly concentrated date extracts using Saccharomyces cerevisiae.

Large amounts of low-quality dates produced worldwide are wasted. Here, highly concentrated fructose syrups were produced via selective fermentation of date extracts with Saccharomyces cerevisiae. Syrups with 95.4-99.9 % (w/w) fructose yields were obtained from date extracts having an initial sugar range of 49-374 g/l without media supplementation; the corresponding ethanol yields were between 69 and 52 % (w/w). At 470 g initial sugars/l, fructose and ethanol yields were 84 and 47 % (w/w), respectively, and the product contained 62 % (w/w) fructose, which is higher than the widely available commercial 42 and 55 % (w/w) high fructose corn syrups. The commercial potential for conversion of waste dates to high-value products is thus demonstrated.