Acid Pretreatment Research Articles

Enhancing enzymatic hydrolysis of industrial hemp hurds (Cannabis sativa L.) by combination of soaking in dilute acid and steam pretreatment

Enhancing enzymatic hydrolysis of industrial hemp hurds (Cannabis sativa L.) by combination of soaking in dilute acid and steam pretreatment

Pre-Treatment of Rice Plants with ABA Makes Them More Tolerant to Multiple Abiotic Stress.

Multiple abiotic stress is known as a type of environmental unfavourable condition maximizing the yield and growth gap of crops compared with the optimal condition in both natural and cultivated environments. Rice is the world's most important staple food, and its production is limited the most by environmental unfavourable conditions. In this study, we investigated the pre-treatment of abscisic acid (ABA) on the tolerance of the IAC1131 rice genotype to multiple abiotic stress after a 4-day exposure to combined drought, salt and extreme temperature treatments. A total of 3285 proteins were identified and quantified across the four treatment groups, consisting of control and stressed plants with and without pre-treatment with ABA, with 1633 of those proteins found to be differentially abundant between groups. Compared with the control condition, pre-treatment with the ABA hormone significantly mitigated the leaf damage against combined abiotic stress at the proteome level. Furthermore, the application of exogenous ABA did not affect the proteome profile of the control plants remarkably, while the results were different in stress-exposed plants by a greater number of proteins changed in abundance, especially those which were increased. Taken together, these results suggest that exogenous ABA has a potential priming effect for enhancing the rice seedlings' tolerance against combined abiotic stress, mainly by affecting stress-responsive mechanisms dependent on ABA signalling pathways in plants.

Biohydrogen production from kitchen organic waste via effective pre-treatment process of dark fermentation

This research aims to highlight the effective pre-treatment process for biohydrogen production from kitchen organic waste in dark fermentation. The complexity of the fermentation process through the competing of the metabolic living bacteria requires a dynamical control of the process through the pre-treatment of the substrate’s mixtures. In this research the pre-treatment process parameters and inoculum condition that affect biohydrogen production via dark fermentation process were investigated. The parameter that affects biohydrogen production via the dark fermentation process have also been analysed. The performance of two inoculums from food waste and cow manure were tested with three different pre-treatment processes: thermal, acid and alkaline. Based on the results, the cow manure inoculum was the best-performing inoculum, producing more H2 compared to food waste inoculum. Furthermore, the substrate and inoculum with thermal shock pre-treatment approaches has increased the biohydrogen generation compared to acid and alkaline pre-treatment.

Coffee pulp pretreatment methods: A comparative analysis of hydrolysis efficiency

The Vietnamese food industry produces a lot of coffee pulp, which is a valuable and abundant source of agricultural by-products. It contains a lot of cellulose, which can be converted into bioethanol. However, coffee pulp needs an extensive pretreatment to reduce the amount of lignin and hemicellulose while retaining the initial cellulose composition. This study compared several pre-hydrolysis and pre-fermentation pretreatment methods which involved H2SO4, NaOH, microwaves, and white rot fungus Phanerochaete chrysosporium.
 The hemicellulose dropped by 43.8% after the acidic pretreatment, by 47.1% after the alkaline pretreatment, and by 12.8% after the microbial pretreatment. The lignin contents dropped by 4.2, 76.6, and 50.2% after acidic, alkaline, and microbial pretreatment, respectively. The removal of hemicellulose and lignin in the coffee pulp was much more efficient when two or three of the pretreatment methods were combined. The microwave-assisted acid and alkaline pretreatment was the most efficient method: it removed 71.3% of hemicellulose and 79.2% of lignin. The combined method also had the highest amount of reducing sugars and glucose in hydrolysate. Additionally, concentrations of such yeast inhibitors as 5-hydroxymethyl-2-furaldehyde (HMF) and furfural were 2.11 and 3.37 g/L, respectively.
 The acid pretreatment was effective only in removing hemicellulose while the alkaline pretreatment was effective in lignin removal; the fungal pretreatment had low results for both hemicellulose and lignin removals. Therefore, the combined pretreatment method was found optimal for coffee pulp.

Chemical pretreatment of corncob for the selective dissolution of hemicellulose and lignin: influence of pretreatment on the chemical, morphological and thermal features

The aim of this work was to remove the hemicellulose and lignin fraction from corncob using chemical pretreatments, and to stablish the effect of that on the composition, microstructure, and thermal properties of corncob. The biomass was pretreated with H2SO4 and NaOH solution to dissolve hemicellulose and lignin portion. Likewise, the biomass pretreated was characterized by scanning electron microscope, IR spectroscopy and TGA methods. It was found that the acid pretreatment disrupt the hemicellulose structure by hydrolysis of glycoside bonds. Moreover, the corncob morphology becomes flaky after acid pretreatment due to dissolution of hemicellulose. The lignin is removed during alkaline pretreatment by solvation of aryl groups. In addition, the crystalline morphology of cellulose fibers was disrupted, increasing the surface area. The pretreatment of corncob with 1.0% H2SO4 and 0.1 M NaOH solubilized ∼42.6% and ∼20.9% of the biomass, respectively. The soluble products were analyzed by FTIR, Fehling test, and calorimetric analysis, to stablish their composition and heat content. The hydrolysis of hemicellulose leads to the release of the monomeric sugars and soluble oligomers. Moreover, the lignin of corncob releases more energy per unit of mass, making it an energy-denser component of corncob.

Comprehensive Treatment Strategy for Banana Inflorescence Bract to Synthesize Biodiesel and Bioethanol Through Fungal Biorefinery

Banana inflorescence bract (BIB), an agro-waste is sporadically explored for second-generation biofuel production in spite of having considerable holocellulosic composition (cellulose-35.56%, w/w; hemicellulose-22.41%, w/w). In this study, an attempt has been made to utilize this substrate for fermentable sugars (pentose-C5 and hexose-C6) extraction which were employed for the co-production of microbial lipids and ethanol using Rhodosporidium toruloides NCIM 3547 and Saccharomyces cerevisiae respectively. Since, a considerable amount of lignin (8.78%, w/w) is present in BIB, a hybrid pretreatment and carbohydrate hydrolysis through microwave (160 W) assisted mild H2SO4 acid 2.5% (v/v) was adopted. The resultant liquor contains holocellulosic sugars (C5 and C6 sugars), out of which xylose (10.40 ± 0.49 g/L) and glucose (51.48 ± 1.14 g/L). Hence, it was used as the growth medium for R. toruloides to produce lipids i.e., single cell oil (SCO). The maximum lipid content was found to be 44.89 ± 1.25 (%, w/w) containing total saturated fatty acids of 89.07% which justifies its potential application in biodiesel production. On the other hand, the pretreated solid fraction containing cellulose was saccharified using cellulolytic enzyme produced by Aspergillus sp. with saccharification (%) of 69.99 ± 0.30 (%, v/w) and yield of 27.22 ± 0.33 g/L of reducing sugar. This enzymatic hydrolysate was used for ethanol production by Saccharomyces cerevisiae resulting in an ethanol yield of 12.70 ± 0.09 g/L and productivity of 0.132 g/L/h. Based on this outcome, a sustainable route for agro-waste management of BIB was laid by favouring the integrated production of biodiesel and bioethanol towards a biorefinery approach. Exploration and utilization of an agro-waste, banana inflorescence bract is established as a potent feedstock for the co-production of single cell oil and bioethanol is reported for the first time. Microwave-assisted mild acid pretreatment was performed for effective delignification and hydrolysis of holocellulosic components. The resultant liquid hydrolysate consisting of lignin degradatory compounds, pentose (xylose) and hexose (glucose) sugars was used as a growth medium for producing single cell oil, proving its potential application in biodiesel production. Further, the pretreated solid cellulosic fraction was saccharified using crude cellulolytic enzymes and an enzymatic hydrolysate was used for the production of bioethanol through two different fermentative strategies. This study reveals that banana inflorescence bract could act as suitable biomass towards the biorefinery approach. Its complete utilization paved the way for agro-waste management that is not in existence so far according to the authors’ knowledge

An innovative and efficient hydrogen peroxide-citric acid pretreatment of bamboo residues to enhance enzymatic hydrolysis and ethanol production

Organic peracids has attracted widespread attention from researchers in biomass pretreatment. As a weak acid with high production, low price and toxicity, citric acid (CA) was mixed with hydrogen peroxide at the room temperature to generate peroxy-citric acid with strong oxidative functions. An innovative and efficient pretreatment method using peroxy-citric acid (HPCA) was proposed to enhance enzymatic hydrolysis and bioethanol production of bamboo residues. After D. giganteus (DG) was pretreated with HPCA at 80 °C for 3 h, lignin of 95.36% and xylan of 55.41% was effectively removed, and the enzymatic saccharification yield of HPCA-treated DG enhanced by about 8–9 times compared with CA pretreated DG. The ethanol recovery of 17.18 g/L was achieved. This work provided a reference for mild biomass pretreatment, which will promote the large-scale application of organic peracids system in biorefinery processes.

Investigation of the effect of preparation processes on CO2 laser-faded denim fabric quality

Purpose In the denim industry, enzyme washing and its combination with stone washing are generally used to get the desired worn-out look. However, these conventional methods include high water, energy and time consumption. Nowadays, laser fading, which is a computer-controlled, dry, ecological finishing method, is preferred in the denim fading process. The purpose of this study is to observe the effects of chemical pretreatment applications on laser-faded denim fabric in terms of color and mechanical properties. To eliminate the enzyme washing process in denim fading and to minimize the disadvantages of laser fading, such as decreased mechanical properties and increased fabric yellowness, various chemical pretreatment applications were applied to the denim fabric before laser fading, followed by simple rinsing instead of enzyme washing. Design/methodology/approach Two different indigo-dyed, organic cotton denim fabrics with different unit weights were exposed to pretreatment processes and then laser treatment, followed by simple rinsing. Polysilicic acid, boric acid, borax and bicarbonate were used for pretreatment processes, and laser treatment was carried out under optimized laser parameters (40 dpi resolution and 300 µs pixel time). Tensile strength was tested, and color values (CIE L*, a*, b*, ΔE*, C* and h), color yield (K/S), yellowness and whiteness indexes were measured to identify the color differences. Findings Before laser fading, 30 g/L and 40 g/L polysilicic acid pretreatments for sulfur-indigo-dyed fabric and a mixture of 10 g/L boric acid and 10 g/L borax pretreatments for the fabric only indigo-dyed were recommended for the laser fading with sufficient mechanical properties and good color values. Originality/value With the chemical pretreatments defined in this study, it was possible to reduce yellowness and maintain the mechanical properties after laser fading, thus minimizing the disadvantages of laser treatment and also eliminating enzyme washing.

Enhancing catalytic performance of red mud for palmitic acid hydrodeoxygenation by acid pretreatment-induced structural modification

Red mud (RM) is a metal oxide-enriched solid waste material that was subjected to various acid treatments to assess their effect on catalytic performance for hydrodeoxygenation (HDO). Acid pretreatment induces structural changes in RM, which enhances its stability and catalytic performance for HDO. Among the different acid treatments, acetic acid-treated RM catalyst (Ni/RM-HAC) exhibited superior catalytic performance and stability, yielding 81% cetane selectivity and maintaining efficient conversion for up to 400 h. The acetic acid treatment increased the Fe2O3 content in the catalyst, removed inert components such as Na2O and CaO that block pore channels, and greatly improved specific surface area and pore size. Moreover, the acetic acid treatment increased medium acid sites and oxygen vacancy in the catalyst, enhancing its catalytic performance. The increase of Fe3+ makes the catalyst have better stability. These results are expected to aid in the development of efficient, sustainable, and cost-effective catalysts for the production of the second-generation biodiesel.

Assessing the future of second-generation bioethanol by 2030 – A techno-economic assessment integrating technology learning curves

Lignocellulosic biomass is the most abundant source of renewable biomass and is seen as a high-potential replacement for petroleum-based resources. The conversion technologies to advanced biofuels are still at a low maturity level, thus allowing for future cost reductions through technological learning. This fact is barely considered in state-of-the-art techno-economic assessments and a structured approach to account for technological learning in techno-economic assessments is needed. In this study, a framework for techno-economic assessments of advanced biofuels, integrating learning curves, is proposed. As a validation of this framework, the economic feasibility of the valorization of corn stover for the production of second-generation bioethanol in Belgium is studied. Process flowsheet simulations in Aspen Plus are developed, with an emphasis on the comparison of four different pretreatment technologies and two plant capacities at 156 dry kt biomass/y and 667 dry kt/y. The dilute acid pretreatment model of the large-scale biorefinery required the lowest minimum learning rate to reach an economically feasible biorefinery by 2030, being 3.9%, almost half as the one calculated for the smaller scale plant. This learning rate seems to be achievable based on learning rates commonly estimated in literature. We conclude that there is a potential for advanced ethanol production in Belgium under the current state of technology for large-scale biorefineries, which require additional biomass imports, when accounting for future cost reductions through learning.

Biohydrogen production coupled with wastewater treatment using selected microalgae

Microalgae such as Chlorella pyrenoidosa, Scenedesmus obliquus and Chlorella sorokiniana were cultivated in domestic wastewater for biohydrogen production. The comparison between the microalgae was executed based on biomass productions, biochemical yields and nutrient removal efficiencies. S. obliquus showed the possibility of growing in domestic wastewater reaching maximum biomass production, lipid, protein, carbohydrate yield and nutrient removal efficiency. All the three microalgae reached high biomass production of 0.90, 0.76 and, 0.71 g/L, respectively for S. obliquus, C. sorokiniana and C. pyrenoidosa. A higher protein content (35.76%) was obtained in S. obliquus. A similar pattern of lipid yield (25.34–26.23%) and carbohydrate yield (30.32–33.21%) was recorded in all selected microalgae. Chlorophyll-a content was higher in synthetic media-grown algae compared algae grown in wastewater. The maximum nutrient removal efficiencies achieved were 85.54% of nitrate by C. sorokiniana, 95.43% of nitrite by C. pyrenoidosa, ∼100% of ammonia and 89.34% of phosphorus by C. sorokiniana. An acid pre-treatment was applied to disintegrate the biomass of microalgae, followed by dark fermentation in batch mode to produce hydrogen. During fermentation process, polysaccharides, protein and lipids were consumed. Maximum hydrogen production of 45.50 ± 0.32 mLH2/gVS, 38.43 ± 0.42 mLH2/gVS and 34.83 ± 1.82 mL/H2/gVS was achieved by C. pyrenoidosa, S. obliquus and C. sorokiniana respectively. Overall, the results revealed the potential of microalgal cultivation in wastewater coupled with maximum biomass production lead to biohydrogen generation for environmental sustainability.

Selective saccharification of crude glycerol pretreated sugarcane bagasse via fast pyrolysis: Reaction kinetics and life cycle assessment

Saccharification is a pivotal step in the conversion of lignocellulose to biofuels and chemicals. In this study, crude glycerol derived from biodiesel production was used in pretreatment to facilitate efficient and clean pyrolytic saccharification of sugarcane bagasse. Delignification, demineralization, destruction of lignin-carbohydrate complex structure, and cellulose crystallinity improvement in crude glycerol pretreated biomass could enhance levoglucosan producing reactions against competitive reactions, and therefore facilitate a kinetically controlled pyrolysis with apparent activation energy increased by 2-fold. Accordingly, selective levoglucosan production (44.4%) was promoted by 6-fold whilst light oxygenates and lignin monomers were limited to <25% in bio-oil. Owing to the high-efficiency saccharification, life cycle assessment suggested that the environmental impacts of the integrated process were less than those of typical acid pretreatment and petroleum-based processes, especially on the acidification (8-fold less) and global warming potential. This study provides an environmentally benign approach to efficient biorefinery and waste management.

Fermentative valorisation of xylose-rich hemicellulosic hydrolysates from agricultural waste residues for lactic acid production under non-sterile conditions

Lactic acid (LA) is a platform chemical with diverse industrial applications. Presently, commercial production of LA is dominated by microbial fermentation using sugary or starch-based feedstocks. Research pursuits emphasizing towards sustainable production of LA using non-edible and renewable feedstocks have accelerated the use of lignocellulosic biomass (LCB). The present study focuses on the valorisation of xylose derived from sugarcane bagasse (SCB) and olive pits (OP) through hydrothermal and dilute acid pretreatment, respectively. The xylose-rich hydrolysate obtained was used for LA production by homo-fermentative and thermophilic Bacillus coagulans DSM2314 strain under non-sterile conditions. The fed-batch mode of fermentation resulted in maximum LA titers of 97.8, 52.4 and 61.3 g/L with a yield of 0.77, 0.66 and 0.71 g/g using pure xylose, xylose-rich SCB and OP hydrolysates, respectively. Further, a two-step aqueous two-phase system (ATPS) extraction technique was employed for the separation and recovery of LA accumulated on pure and crude xylose. The LA recovery was 45 – 65% in the first step and enhanced to 80–90% in the second step.The study demonstrated an efficient integrated biorefinery approach to valorising the xylose-rich stream for cost-effective LA production and recovery.

Using citric acid to suppress lignin repolymerization in the organosolv pretreatment of corn stalk

The esterification reactions that occur between citric acid (CA) and lignin on hydroxyl groups of side chains can inhibit the formation of reactive intermediates in acid-catalyzed pretreatments. The effects of CA on dilute hydrochloric acid (1.0%) pretreatments of corn stalk in hydrated 1,4–dioxane were investigated with sodium hypophosphite (0.5%) as the catalyst at 95 °C for 3.5 h. The resulting cellulose recovery (62.5–80.9%) and lignin removal (72.5–85.0%) after adding CA were significantly higher than those in the pretreatment without CA. Water content influenced pretreatment and delignification when CA was added into the treatment systems. The highest yield of total reducing sugar (97.1%) was achieved during the enzymatic hydrolysis of cellulose-rich materials obtained from the pretreatment with 11.4% water content. Meanwhile, β–O–4′ in the extracted lignin increased from 22.4/100Ar to 41.2/100Ar with increasing water content from 11.4% to 25.9%. These findings implied that CA as a stabilization agent could inhibit the repolymerization of degraded lignin fragments due to the esterification between CA and lignin and then improved the enzymatic saccharification of cellulose.

Efficient co-production of xylo-oligosaccharides and probiotics from corncob by combined lactic acid pretreatment and two-step enzymatic hydrolysis

Lactic acid (LA) is efficient in xylo-oligosaccharides (XOS) production from poplar. However, the role of LA in XOS production from corncob has not been carefully elucidated, and the co-production of probiotics of Bacillus subtilis from corncob residue has not been reported. In this study, LA pretreatment was combined with enzymatic hydrolysis to produce XOS and monosaccharides from corncob. An XOS yield of 69.9% was obtained from corncob by combining 2% LA pretreatment and xylanase hydrolysis. Yields of 95.6% glucose and 54.0% xylose were obtained from corncob residue via cellulase, and the resulting cellulase hydrolysate was used to culture Bacillus subtilis YS01. The resulting viable count of the strain was 6.4×108 CFU/mL, and the glucose and xylose utilization were 99.0% and 89.8%, respectively. This study demonstrated a green, efficient, and mild process for producing XOS and probiotics from corncob by combining LA pretreatment and enzymatic hydrolysis.

Renewable deep eutectic solvents pretreatment improved the efficiency of anaerobic digestion by lignin extraction from willow

Lignin extraction from lignocellulosic biomass can enhance its bioconversion efficiency, whilst the recovered lignin can provide added economic value. This study comprehensively investigated the impacts of short-chain carboxylic acid-based deep eutectic solvents (DESs) pretreatments on lignin extraction from willow and assessed subsequent biomethane production through anaerobic digestion. Process parameters (including the DESs type, molar ratios of DESs components, temperature and reaction time) in the DESs pretreatments of willow for lignin extraction were optimized using the central composite surface response methodology. Results showed that lactic acid-based DES pretreatment outperformed acetic acid and propionic acid-based DES pretreatments in terms of lignin removal efficiency and methane production. Under the optimal conditions (choline chloride:lactic acid with a molar ratio of 1:10 at 160 °C for 15 min) lactic acid-based DES pretreatment retained over 94% of the glucan content in the raw willow whilst achieved the highest lignin removal of 80%. The recovered lignin showed a purity of above 81%. Compared with the biomethane production of 89.9 mL/g total solid from raw willow, the biomethane production significantly increased by 36.3% after the lactic acid-based DES pretreatment. The optimal condition reduced the digestion time from 22 to 10 days. The overall energy conversion efficiency of 62.7% demonstrated that lactic acid-based DES pretreatment of lignocellulose could be a promising method to co-produce renewable gaseous fuels and lignin in a sustainable approach.

Converting and valorizing heavy metal-laden post-harvest hyperaccumulator (Pteris vittate L.) into biofuel via acid-pretreated pyrolysis and gasification

Not only should post-harvest hyperaccumulators rich in heavy metals (HMs) be properly disposed to avoid secondary HMs pollution, but also they should be valorized to enhance circular economy. This study aimed to characterize how As-hyperaccumulator (Pteris vittate L.) (PV) pretreated with HCl or H3PO4 affected its physicochemical, HMs, decomposition, and volatile characteristics. The HCl-pretreated PV retained its original main components, physical properties, and chemical structures but introduced Cl to carbon chain, induced O loss, increased C content, and removed most minerals, in particular, alkali/alkaline earth metals. The favorable pyrolysis and gasification behaviors of PV were maintained via the HCl-pretreated PV, with the raised and narrowed temperature range of mass loss but with the increased energy demand for the decomposition. Compared with PV (276.74 kJ/mol), 5% HCl-pretreated PV reduced activation energy of its pyrolysis (260.62 kJ/mol). The H3PO4 pretreatment destroyed carbon chain, loaded phosphorus oxygen group, and removed more organics and minerals in PV than did the HCl-pretreated PV. This in turn allowed for an earlier start and finish of devolatilization stage, an easier breaking of potential energy barrier, and improvement of reaction favorability. Unlike the two atmospheres, the acid pretreatments changed the temperature dependency of volatile products during the main reaction-temperature range. The volatile products which released from the pyrolysis and gasification at the temperature of maximum mass loss peak or 350 °C were collected. HCl-pretreated PV reduced the formation of ring-opening products, while H3PO4-pretreated PV emitted more aromatic compounds and selectively generated ketone, such as levoglucanone. More HMs were dissolved with the increased acid concentration, with HMs in HCl-pretreated PV being at a higher leaching concentration than those in the other treatments. H3PO4-pretreated PV retained As, Cd, and Pb at a low leachable rate. The best joint optimization was achieved with the combined settings of 5% HCl-pretreated PV or 10% H3PO4-pretreated PV at 10 °C/min in the N2 atmosphere. Overall, findings provide new insights into how to best manage and valorize post-harvest and HM-laden hyperaccumulators.

Implementing dilute acid pretreatment coupled with solid acid catalysis and enzymatic hydrolysis to improve bioconversion of bamboo shoot shells

Exploiting bamboo shoot shells (BSS) as feedstocks for biorefining is a crucial scheme to advance the bioavailability of bamboo shoots. This work applied traditional dilute sulfuric acid pretreatment (DAP) to treat BSS and simultaneously prepared the solid-acid-catalyst by using BSS as carbon-based carriers. The biocatalysis of the prehydrolysate from DAP and enzymatic hydrolysis of pretreated BSS was subsequently performed to achieve efficient bioconversion of its carbohydrates. The results displayed that 0.1 g/L H2SO4 employed in DAP was the optimal condition for furfural conversion of BSS during biocatalysis, reaching the maximum of 41%. Meanwhile, the enzymatic hydrolysis efficiency of the pretreated BSS also reached the maximum of 97%. This increment of efficiency was ascribed to the enhancement of accessibility and cellulosic crystal size, and also the reduction of surface area of lignin in BSS. Ultimately, the efficient bioutilization of BSS and bioconversion of its carbohydrates were realized by DAP technology.

Pharmacokinetics of Marbofloxacin Following Oral Administration in Lactic Acid Pretreated Broiler Chickens

Background: It is hypothesized that feeding lactic acid as a feed additive has the potential to alter the pharmacokinetics of many antimicrobial drugs being used for the treatment of infectious disease in general and marbofloxacin in particular; leading to either increased or decreased efficiency. Hence, the present study was planned to explore the effects of lactic acid pre-treatment on the pharmacokinetics of marbofloxacin after oral administration in broiler chickens. Methods: The pharmacokinetics of marbofloxacin was investigated following single dose oral administration (5 mg/kg) in lactic acid pre-treated (8 gm/l each, oral, 10 days) broiler chickens. The plasma concentration of marbofloxacin was determined by ultra-high-performance liquid chromatography to workout pharmacokinetic profile of marbofloxacin using non compartment model. Result: The AUC (area under curve) of marbofloxacin declined from 14.70 ìg·h/mL to 6.16 ìg·h/mL after pre-treatment of lactic acid. Similarly, the average values of maximum plasma concentration (Cmax) of drug decreased from 2.11 ìg/mL to 0.98 ìg/mL and mean body clearance (ClB) increased from 0.47 L/h/kg to 1.03 L/h/kg. The average elimination half-lives (t½â) of marbofloxacin before and after pre-treatment with lactic acid were 4.89 h and 2.81 h, respectively. Furthermore, the investigation revealed alteration of pharmacokinetic parameters evident in lactic acid pre-treated broiler chickens (as compared to non pre-treated birds) requiring adjustment of dosage regimens.

Rapid and mild fractionation of hemicellulose through recyclable mandelic acid pretreatment

The development of organic acid pretreatments from biological sources is essential to facilitate the progress of green and sustainable chemistry. In this study, the effectiveness of mandelic acid pretreatment (MAP) was analyzed for eucalyptus hemicellulose separation. 83.66% of xylose was separated under optimal conditions (temperature: 150 °C; concentration: 6.0 wt%; time: 80 min). The hemicellulose separation selectivity is higher than acetic acid pretreatment (AAP). The stable and effective separation efficiency (56.55%) is observed even after six reuses of the hydrolysate. Higher thermal stability, larger crystallinity index and optimized surface element distribution in the samples were demonstrated by MAP. Lignin condensation is effectively inhibited through MAP, as determined from the structural of different lignin. In particular, the demethoxylation of lignin by MA was found. These results open up a new way to construct a novel organic acid pretreatment for separating hemicellulose with high efficiency.