Effectiveness of Green Chemical Solvent-based on Triethylammonium Methanesulfonate Ion Liquid for the OPEFB Pretreatment Process.

Many studies have explored the pretreatment of lignocellulosic biomass based on oil palm empty fruit bunch (OPEFB) which is categorized as potential biomass waste for bioethanol production. Before proceeding further to obtain bioethanol, several steps such as pretreatment to increase organic constituents are needed. The ionic liquids (ILs) were commonly investigated by many researchers for lignocellulosic pretreatment because it is easy solubilization property, non-toxic, and not harmful impacts on the environment. Therefore in this study, the hypothesis and main objective were to observe the effectiveness of triethylammonium methanesulfonate ion liquid (TMS IL) in the OPEFB lignocellulose pretreatment process. Three variations were studied to obtain optimization of the pretreatment process, such as times duration, IL composition, and temperature. Based on these results, we observed the effectiveness of the time duration for OPEFB pretreatment of 20 hours. Furthermore, it was applied to determine the optimization of IL composition and temperature showing that using 91% (1:1:10) at 120°C for 20 hours has provided good performance for the OPEFB lignocellulose pretreatment process. TMS IL has exhibited the ability to reduce hemicellulose and lignin contents to 7.35% and 17.80%, whereas cellulose was increased by 54.24%. This has the opportunity to be projected to a larger scale for bioethanol production based on OPEFB lignocellulose.

Ecotoxicity of the Adipate Plasticizers: Influence of the Structure of the Alcohol Substituent.

A significant increase in the production of plastic materials and the expansion of their areas of application contributed to the accumulation of a large amount of waste of polymeric materials. Most of the polymer composition is made up of plasticizers. Phthalate plasticizers have been recognized as potentially hazardous to humans and the environment due to the long period of their biodegradation and the formation of persistent toxic metabolites. It is known that the industrial plasticizer dioctyl adipate is characterized by reduced toxicity and a short biodegradation period. The paper describes the synthesis of a number of new asymmetric esters based on adipic acid and ethoxylated butanol by azeotropic esterification. The receipt of the products was confirmed by IR spectra. The physicochemical properties of the synthesized compounds were investigated. The glass transition temperatures of PVC composites plasticized with alkyl butoxyethyl adipates were determined using DSC analysis. The ecological safety of esters was assessed by the phytotesting method. Samples of adipates were tested for fungal resistance, and the process of their biodegradation in soil was also studied. It is shown that the synthesized esters have good plasticizing properties and are environmentally safe. When utilized under natural conditions, they can serve as a potential source of carbon for soil microorganisms and do not form stable toxic metabolites; therefore, they are not able to accumulate in nature; when the plasticizers under study are disposed of in the soil, toxic substances do not enter.

A facile reaction to access novel structural sulfonyl-hybridized imidazolyl ethanols as potential DNA-targeting antibacterial agents.

A novel type of sulfonyl-hybridized imidazolyl ethanols as potential DNA-targeting antibacterial agents was constructed via the unique ring-opened reaction of oxiranes by imidazoles for the first time. Some developed target hybrids showed potential antimicrobial potency against the tested microbes. Especially, imidazole derivative 5f could strongly suppressed the growth of MRSA (MIC = 4 µg/mL), which was 2-fold and 16-fold more potent than the positive control sulfathiazole and norfloxacin. This compound exhibited quite low propensity to induce bacterial resistance. Antibacterial mechanism exploration indicated that compound 5f could embed in MRSA DNA to form steady 5f-DNA complex, which possibly hinder DNA replication to exert antimicrobial behavior. Molecular docking showed that molecule 5f could bind with dihydrofolate synthetase through hydrogen bonds. These results implied that imidazole derivative 5f could be served as a promising molecule for the exploration of novel antibacterial candidates.

Seaweed-based cellulose: Applications, and future perspectives.

Cellulose is a naturally occurring organic polymer extracted mainly from lignocellulosic biomass of terrestrial origin. However, the increasing production of seaweeds for growing global market demands has developed the opportunity to use it as an additional cellulose source. This review aims to prepare comprehensive information to understand seaweed cellulose and its possible applications better. This is the first review that summarizes and discusses the cellulose from all three types (green, red, and brown) of seaweeds in various aspects such as contents, extraction strategies, and cellulose-based products. The seaweed cellulose applications and future perspectives are also discussed. Several seaweed species were found to have significant cellulose content (9-34% dry weight). The review highlights that the properties of seaweed cellulose-based products were comparable to products prepared from plant-based cellulose. Overall, this work demonstrates that cellulose could be economically extracted from phycocolloids industrial waste and selected cellulose-rich seaweed species for various commercial applications.

Ethanol-assisted kneading of apigenin with arginine for enhanced dissolution rate of apigenin: development of rapidly disintegrating tablets.

Apigenin is a natural flavonoid which is claimed to have many pharmacological activities ranging from simple anti-inflammatory to anticancer action. However, poor dissolution slowed the advancement of this drug through the development pipelines. The objective of this work was to probe ethanol-aided kneading of apigenin with arginine as a new strategy for enhanced dissolution rate. The work was extended to develop rapidly disintegrating tablets of apigenin. Apigenin was mixed with increasing molar ratios of arginine before ethanol-aided kneading. The resulting products were examined using Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction in addition to probing the dissolution characteristics of apigenin. The analytical techniques highlighted the existence of new crystalline species with a possibility of salt formation. The recorded alterations in the crystalline properties were associated with a significant enhancement in the dissolution rate of apigenin. The presence of arginine did not have any negative effect of the cytotoxic power of apigenin. Optimum formulation was successfully prepared as rapidly disintegrating tablets which showed fast liberation of apigenin. The study introduced arginine as a potential excipient for enhanced dissolution of apigenin after ethanol-assisted kneading.

Ethanol: Unlocking an Abundant Renewable C2 -Feedstock for Catalytic Enantioselective C-C Coupling.

With annual production at >85 million tons/year, ethanol is the world's largest-volume renewable small molecule carbon source, yet its use as a C2 -feedstock in enantioselective C-C coupling is unknown. Here, the first catalytic enantioselective C-C couplings of ethanol are demonstrated in reactions with structurally complex, nitrogen-rich allylic acetates incorporating the top 10 N-heterocycles found in FDA-approved drugs.

Designing Efficient Processes for Sustainable Bioethanol and Bio-Hydrogen Production from Grass Lawn Waste.

The effect of thermal, acid and alkali pretreatment methods on biological hydrogen (BHP) and bioethanol production (BP) from grass lawn (GL) waste was investigated, under different process schemes. BHP from the whole pretreatment slurry of GL was performed through mixed microbial cultures in simultaneous saccharification and fermentation (SSF) mode, while BP was carried out through the C5yeast Pichia stipitis, in SSF mode. From these experiments, the best pretreatment conditions were determined and the efficiencies for each process were assessed and compared, when using either the whole pretreatment slurry or the separated fractions (solid and liquid), the separate hydrolysis and fermentation (SHF) or SSF mode, and especially for BP, the use of other yeasts such as Pachysolen tannophilus or Saccharomyces cerevisiae. The experimental results showed that pretreatment with 10 gH2SO4/100 g total solids (TS) was the optimum for both BHP and BP. Separation of solid and liquid pretreated fractions led to the highest BHP (270.1 mL H2/g TS, corresponding to 3.4 MJ/kg TS) and also BP (108.8 mg ethanol/g TS, corresponding to 2.9 MJ/kg TS) yields. The latter was achieved by using P. stipitis for the fermentation of the hydrolysate and S. serevisiae for the solid fraction fermentation, at SSF.

Use of cellulose acetate butyrate as a carrier for preparation of alcohol-resistant matrix tablet.

The objective of this study was to investigate cellulose acetate butyrate (CAB) as a carrier for extended-release alcohol-resistant matrix tablet. Powder blends were either directly compressed or granulated before compression. The drug release from CAB matrix tablet was robust to formulation/process parameters such as compression force (10-20 kN), granular size (0.15-1.40 mm), and drug content (50-70%). In addition, release medium variables such as ionic strength, pH, and agitation rate had no effect on the drug release. CAB matrix tablet was more robust than ethylcellulose matrix tablet; the release from CAB matrix tablet was not affected by ethanol content (up to 20% v/v) in the release medium irrespective of agitation. CAB is a promising polymer for formulating of alcohol-resistant extended-release matrix tablet.

Immobilization of invertase in calcium alginate and calcium alginate-kappa-carrageenan beads and its application in bioethanol production.

Invertase from Saccharomyces cerevisiae was entrapped in Ca-alginate and Ca-alginate-kappa-carrageenan matrix. Optimum pH for the free and immobilized invertase was found to be 4.5 and 5.5, respectively. The optimum hydrolysis temperature was 55 °C for both the free and immobilized forms. Km values for free invertase and invertase entrapped in Ca-alginate and Ca-alginate-kappa-carrageenan beads were 15, 21, and 19 mM, respectively. Values of Vmax for free invertase and invertase entrapped in Ca-alginate and Ca-alginate-kappa-carrageenan beads were 238, 186, and 197 mM min-1, respectively. Invertase entrapped in Ca-alginate-kappa-carrageenan matrix had the highest pH and thermal stability, higher reusability with 71% retention in activity after nine batches of reuse and higher storage stability with 86% activity retention after 12 weeks at 4 °C, pH 4.5. Fermentation of cane molasses by yeast for bioethanol formation in the presence of free invertase at 30 °C, pH 5.0, led to an increase in ethanol production by 3%. However, the production increased by 9% when invertase entrapped in Ca-alginate-kappa-carrageenan was used as a catalyst.HighlightsInvertase from Saccharomyces cerevisiae was entrapped in Ca-alginate beads.For efficient encapsulation of invertase, kappa-carrageenan was used in combination with alginate as a matrix.Entrapment in Ca-alginate-kappa-carrageenan increased pH and thermal stability of invertase.Invertase entrapped in Ca-alginate-kappa-carrageenan was used for bioethanol production from cane molasses.

An overview on bioethanol production from lignocellulosic feedstocks.

Lignocellulosic ethanol has been proposed as a green alternative to fossil fuels for many decades. However, commercialization of lignocellulosic ethanol faces major hurdles including pretreatment, efficient sugar release and fermentation. Several processes were developed to overcome these challenges e.g. simultaneous saccharification and fermentation (SSF). This review highlights the various ethanol production processes with their advantages and shortcomings. Recent technologies such as singlepot biorefineries, combined bioprocessing, and bioenergy systems with carbon capture are promising. However, these technologies have a lower technology readiness level (TRL), implying that additional efforts are necessary before being evaluated for commercial availability. Solving energy needs is not only a technological solution and interlinkage of various factors needs to be assessed beyond technology development.

Adaptive evolution and selection of stress-resistant Saccharomyces cerevisiae for very high-gravity bioethanol fermentation

Background: In industrial yeasts, selection and breeding for resistance to multiple stresses is a focus of current research. The objective of this study was to investigate the tolerance to multiple stresses of Saccharomyces cerevisiae obtained through an adaptive laboratory evolution strategy involving a repeated liquid nitrogen freeze­thaw process coupled with multi-stress shock selection. We also assessed the related resistance mechanisms and very high-gravity (VHG) bioethanol production of this strain. Results: Elite S. cerevisiae strain YF10-5, exhibiting improved VHG fermentation capacity and stress resistance to osmotic pressure and ethanol, was isolated following ten consecutive rounds of liquid nitrogen freeze­thaw treatment followed by plate screening under osmotic and ethanol stress. The ethanol yield of YF10-5 was 16% higher than that of the parent strain during 35% (w/v) glucose fermentation. Furthermore, there was upregulation of three genes (HSP26, HSP30, and HSP104) encoding heat-shock proteins involved in the stress response, one gene (TPS1) involved in the synthesis of trehalose, and three genes (ADH1, HXK1, and PFK1) involved in ethanol metabolism and intracellular trehalose accumulation in YF10-5 yeast cells, indicating increased stress tolerance and fermentative capacity. YF10-5 also showed excellent fermentation performance during the simultaneous saccharification and fermentation of VHG sweet potato mash, producing 13.40% (w/ v) ethanol, which corresponded to 93.95% of the theoretical ethanol yield. Conclusions: A multiple-stress-tolerant yeast clone was obtained using adaptive evolution by a freeze­thaw method coupled with stress shock selection. The selected robust yeast strain exhibits potential for bioethanol production through VHG fermentation.

Improvement of ethanol production from birch and spruce pretreated with 1-H-3-methylmorpholinium chloride

Background: Pretreatment is the critically important step for the production of ethanol from lignocelluloses. In this study, hardwood birch (Betula pendula) and softwood spruce (Norway spruce) woods were pretreated with a newly synthesized morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]), followed by enzymatic hydrolysis and fermentation to ethanol. Results: [HMMorph][Cl] was synthesized using inexpensive raw materials, i.e., hydrochloric acid and N-methyl morpholine, following a simple process. The influence of pretreatment time (2, 3, 5, and 8 h) and temperature (120 and 140°C) in terms of hydrolysis efficiency was investigated. Glucose yields from enzymatic hydrolysis were improved from 13.7% to 45.7% and 12.9% to 51.8% after pretreatment of birch and spruce woods, respectively, under optimum pretreatment conditions (i.e., at 140°C for 3 h) as compared to those from pristine woods. Moreover, the yields of ethanol production from birch and spruce were increased to 34.8% and 44.2%, respectively, while the yields were negligible for untreated woods. Conclusions: This study demonstrated the ability of [HMMorph][Cl] as an inexpensive agent to pretreat both softwood and hardwood.

Green synthesis of enantiopure (S)-1-(benzofuran-2-yl)ethanol by whole-cell biocatalyst.

Optically active aromatic alcohols are valuable chiral building blocks of many natural products and chiral drugs. Lactobacillus paracasei BD87E6, which was isolated from a cereal-based fermented beverage, was shown as a biocatalyst for the bioreduction of 1-(benzofuran-2-yl) ethanone to (S)-1-(benzofuran-2-yl) ethanol with highly stereoselectivity. The bioreduction conditions were optimized using L. paracasei BD87E6 to obtain high enantiomeric excess (ee) and conversion. After optimization of the bioreduction conditions, it was shown that the bioreduction of 1-(benzofuran-2-yl)ethanone was performed in mild reaction conditions. The asymmetric bioreduction of the 1-(benzofuran-2-yl)ethanone had reached 92% yield with ee of higher than 99.9% at 6.73 g of substrate. Our study gave the first example for enantiopure production of (S)-1-(benzofuran-2-yl)ethanol by a biological green method. This process is also scalable and has potential in application. In this study, a basic and novel whole-cell mediated biocatalytic method was performed for the enantiopure production of (S)-1-(benzofuran-2-yl)ethanol in the aqueous medium, which empowered the synthesis of a precious chiral intermediary process to be converted into a sophisticated molecule for drug production.

Minimalist approach meets green chemistry: Synthesis of 18 F- labeled (hetero)aromatics in pure ethanol.

The application of toxic solvents and additives is inevitable for most of the described protocols for 18 F-labeling. Herein, a novel "green" procedure for nucleophilic aromatic radiofluorination of highly activated (hetero)aromatic substrates in pure EtOH is described. Using this method a series of 18 F-labeled (hetero)arenes have been synthesized in radiochemical yields (RCYs) of up to 97%.

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.

Cytocompatible Fabrication of Yeast Cells/Fabrics Composite Sheet for Bioethanol Production.

Entrapment of living cells into a polymer network has significant potential in various fields such as biomass conversion and tissue engineering. A crucial challenge for this strategy is to provide a mild enough condition to preserve cell viability. Here, a facile and cytocompatible method to entrap living yeast cells into a poly(ethylene glycol) (PEG) network grafting from polypropylene nonwoven fabrics via visible-light-induced surface living graft crosslinking polymerization is reported. Due to the mild reaction conditions and excellent biocompatibility of PEG, the immobilized yeast cells could maintain their viability and proliferate well. The obtained composite sheet has excellent long-term stability and shows no significant efficiency loss after 25 cycles of repeated batch bioethanol fermentation. The immobilized yeast cells exhibit 18.0% higher bioethanol fermentation efficiency than free cells. This strategy for immobilization of living cells with high viability has significant potential application.

Transfection efficiencies of α-tocopherylated cationic gemini lipids with hydroxyethyl bearing headgroups under high serum conditions.

Herein, five new α-tocopheryl cationic gemini lipids with hydroxyethyl bearing headgroups (THnS, n = 4, 5, 6, 8, 12) have been synthesized for efficient plasmid DNA (pDNA) delivery into cancer cells. Among these gemini lipid formulations, the lipid with an octamethylene [-(CH2)8] spacer (TH8S) showed the highest transfection efficiency (TE) that was comparable to that of the commercial standard lipofectamine 2000 (L2K) in terms of luciferase expression in HepG2 (liver hepatocellular carcinoma) cells. The addition of the helper lipid DOPE (1,2-dioleoyl phosphatidyl ethanolamine) with cationic lipids in mixed liposomes further enhanced the TE and the optimized molar ratio was 2 : 1 (DOPE : cationic lipid). The optimized co-liposomal formulation of TH8S (DOPE : TH8S = 2 : 1) showed a higher TE in HepG2, A549 (human lung carcinoma) and MCF7 (human breast adenocarcinoma) cells than other optimized co-liposomal formulations and was also significantly more potent than L2K. The comparison of the TE of DOPE-TH8S (2 : 1) with the gemini lipid T8T (the headgroup devoid of the hydroxyl group) further demonstrated the importance of the hydroxyethyl functionality at the level of the headgroup. Relatively good binding efficiency and easy release of pDNA (pGL3) were also observed with DOPE-TH8S (2 : 1) in the ethidium bromide (EB)-exclusion and re-intercalation assay, which may be the plausible reason for high TE. The lipoplexes were also characterized by atomic force microscopy (AFM), dynamic light scattering (DLS), zeta potential and small angle X-ray diffraction experiments. Greater cellular internalization of fluorescein tagged pDNA was also observed with DOPE-TH8S (2 : 1) lipoplexes compared to that with L2K. Retention of the TE of DOPE-TH8S (2 : 1) lipoplexes under high serum conditions was conferred by the presence of the tocopherol backbone and also the hydroxyethyl functionalities. The cellular internalization pathway of the lipoplexes was characterized by performing transfection experiment in the presence of inhibitors of different endocytic pathways and it was found to be caveolae mediated. An MTT based cell viability assay indicated that the lipoplex mediated gene delivery vectors exhibited low toxicity in all the three cancer cell lines studied.

A new approach for bioethanol production from sugarcane bagasse using hydrodynamic cavitation assisted-pretreatment and column reactors.

Hydrodynamic cavitation (HC) was adopted to assist alkaline-hydrogen peroxide pretreatment of sugarcane bagasse (SCB). In the following condition: 0.29 M of NaOH, 0.78% (v/v) of H2O2, 9.95 min of process time and 3 bar of inlet pressure, 95.4% of digestibility of cellulosic fraction was achieved. To take the best use of the pretreated biomass, the overall process was intensified by way of employing a packed bed flow-through column reactor and thus enabling to handle a high solid loading of 20%, thereby leading to cellulose and hemicellulose conversions to 74.7% and 75%, respectively. In the fermentation step, a bubble column reactor was introduced to maximize ethanol production from the pretreated SCB by Scheffersomyces stipitis NRRL-Y7124, resulting in 31.50 g/L of ethanol, 0.49 g/g of ethanol yield and 0.68 g/L.h of productivity. All this showed that our HC-assisted NaOH-H2O2 pretreatment strategy along with the process intensification approach might offer an option for SCB-based biorefineries.

Identification of stable fly attractant compounds in vinasse, a byproduct of sugarcane-ethanol distillation.

The stable fly, Stomoxys calcitrans (Diptera: Muscidae), is a worldwide pest of livestock. Recent outbreaks of stable flies in sugarcane fields in Brazil have become a serious problem for livestock producers. Larvae and pupae found inside sugarcane stems after harvesting may indicate that stable flies use these stems as potential oviposition or larval development sites. Field observations suggest that outbreaks of stable flies are associated with the vinasse and filter cake derived from biomass distillation in sugarcane ethanol production that are used as fertilizers in sugarcane fields. Adult stable flies are attracted to vinasse, which appears to present an ideal larval development site. The primary goal of the present study is to demonstrate the role of vinasse in influencing the sensory physiological and behavioural responses of stable flies, and to identify its associated volatile attractant compounds. Both laboratory and field studies showed that vinasse is extremely attractive to adult stable flies. Chemical analyses of volatiles collected revealed a wide range of carboxylic acids, alcohols, phenols and aldehydes as potential attractant compounds. These newly identified attractants could be used to develop a tool for the attractant-baited mass trapping of stable flies in order to reduce infestations.

Feeding a sustainable chemical industry: do we have the bioproducts cart before the feedstocks horse?

A sustainable chemical industry cannot exist at scale without both sustainable feedstocks and feedstock supply chains to provide the raw materials. However, most current research focus is on producing the sustainable chemicals and materials. Little attention is given to how and by whom sustainable feedstocks will be supplied. In effect, we have put the bioproducts cart before the sustainable feedstocks horse. For example, bulky, unstable, non-commodity feedstocks such as crop residues probably cannot supply a large-scale sustainable industry. Likewise, those who manage land to produce feedstocks must benefit significantly from feedstock production, otherwise they will not participate in this industry and it will never grow. However, given real markets that properly reward farmers, demand for sustainable bioproducts and bioenergy can drive the adoption of more sustainable agricultural and forestry practices, providing many societal "win-win" opportunities. Three case studies are presented to show how this "win-win" process might unfold.