Conversion of Potato Starch and Peel Waste to High Value Nanocrystals

The present study aimed to convert starch and potato peel waste to nanocrystals. Starch nanocrystals were prepared using two methodologies: direct acid hydrolysis and enzyme pretreatment followed by acid hydrolysis. Direct hydrolysis broke down the starch granules to nanocrystals in 12 days. Enzyme pretreatment with starch hydrolytic enzymes (α-amylase and amyloglucosidase) reduced the time for preparation of starch nanocrystals by 6 days. Starch nanocrystals of optimum size were obtained with both the treatments and the resultant size ranged from 10 to 50 nm. Nanocrystals were disk-like platelets in appearance. Cellulose nanocrystals were derived from cellulosic material in the potato peel. Cellulose was isolated from peel waste with alkali treatment. Further, cellulose nanocrystals from potato peel and cellulose microcrystalline were prepared by acid hydrolysis. Microscopic images revealed that the aqueous suspension of cellulose nanocrystals derived from potato peel were single rod shaped, whereas those derived from cellulose microcrystalline were rod-like nanoparticles, agglomerated in the form of bundles including some of the rods in single units (well separated). The size of potato peel nanocrystals ranged from 40 to 100 nm (length) and cellulose microcrystalline ranged from 4 to 20 nm (diameter) by 110 to 250, given 4 to 20 nm (length), respectively. As starch nanocrystals as well as cellulose nanocrystals are derived from biopolymer, both can be considered safe for humans and the environment. Moreover, the biodegradable nature of these nanocrystals makes them superior over metallic nanoparticles, particularly in the field of nanocomposites.     

荷正电大豆蛋白和丙烯酸的复合体系研究

通过酶解大豆蛋白获得荷正电大豆蛋白,采用HPLC、Zeta电位、TEM对其酶解行为进行了追踪,进一步将酶解得到的大豆蛋白与丙烯酸复合,对复合物的溶液行为和微结构进行考察研究。结果显示:酶解大豆蛋白后得到荷正电的球形粒子,其能够与丙烯酸通过静电作用形成球形的复合物SPI-AA纳米粒子,该球形粒子在加入引发剂引发聚合反应后粒径变小,在加入交联剂交联后粒径也随之变小。该纳米颗粒在药物负载、生物传感、水处理等领域有较好的应用前景。     

Optimization of phosphoric acid catalyzed fractionation and enzymatic digestibility of flax shives

Flax shives are the woody residue left over from processing flax straw into fiber, and are an abundant renewable lignocellulosic material with a potential for the conversion into bioethanol and other value added products. In this study, prior to enzymatic hydrolysis for the liberation of fermentable sugars, such as glucose and xylose, flax shives were treated with concentrated phosphoric acid. In order to optimize the phosphoric acid pretreatment and enzymatic hydrolysis steps, the effects of three process variables on the fractionation of flax shives, and enzymatic digestibility of pretreated flax shives were evaluated. The optimization process employed a central composite design (CCD), where the variables selected were concentration of phosphoric acid (40.8–86.2%), pretreatment time (9.5–110.5 min), and cellulase loading (13.1–71.9 FPU/g cellulose). Using three-variable and five-level CCD, all tested independent variables were identified to have significant effects (P < 0.05) on the digestibility of pretreated flax shives. It was found that the level of phosphoric acid (P < 0.0001) affects the digestibility most significantly when compared with other variables. When the optimization was conducted under a constrain of minimum cellulase loading, the maximum digestibility of 94.8% was predicted when the phosphoric acid concentration, pretreatment time, and cellulase loading were 86.2%, 110.5 min, and 13.1 FPU/g cellulose at 50 °C and 120 h, respectively. Under these conditions, digestibility of pretreated flax shives in the validation study reached a maximum of 93% at 120 h of incubation, showing good agreement with the values from the validation experiment of 93.4%, indicating high accuracy of the CCD procedure. When triticale straw, pine wood, and poplar wood were pretreated and hydrolyzed under optimum conditions obtained from the flax shives experiment, the digestibility reached 98.2, 74.8, and 95.7%, respectively, suggesting that the modest pretreatment process using phosphoric acid is an effective method for perennial plants as well as hard wood.     

Facile procedure for producing silver nanocoated cotton gauze and antibacterial evaluation for biomedical applications

We present a rapid, simple, convenient and cost-effective method for producing nanosized stable silver particles on cotton fibers with complete control of the silver loading level using a thermal reducing silver carbamate complex. Cotton gauze was coated with silver 2-ethylhexylcarbamate solution. Silver nanoparticles on the cotton gauze were characterized by energy dispersive X-ray spectroscopy and X-ray diffraction. Particle size and lattice image of the silver nanoparticles were studied by scanning electron microscopy. The antibacterial activity of the silver coated cotton gauze against Escherichia coli and Staphylococcus aureus, whole blood clotting and physical properties including vertical wicking test, water retention time and absorption of 0.9 % (w/v) saline were studied. Silver coated cotton gauze showed a faster blood clotting rate than the untreated cotton gauze. Cotton gauzes treated with two different silver concentrations (0.01 %, 0.1 %) showed slightly better saline absorption and they had better vertical wicking and water retention time than pristine cotton gauze.     

Optimization of ethanol production by Saccharomyces cerevisiae UFPEDA 1238 in simultaneous saccharification and fermentation of delignified sugarcane bagasse

Ethanol production by Saccharomyces cerevisiae UFPEDA1238 was performed in simultaneous saccharification and fermentation of delignified sugarcane bagasse. Temperature (32 °C, 37 °C), agitation (80; 100 rpm), enzymatic load (20 FPU/g cellulose and 10%, v/v β-glucosidase or 10 FPU/g cellulose and 5% β-glucosidase) and composition of culture medium were evaluated. Ethanol concentration, enzymatic convertibility of cellulose and volumetric productivity were higher than 25 g/L, 72% and 0.70 g/L h, respectively, after 30 h, when the culture medium 1 and 20 FPU/g cellulose/10%, v/v β-glucosidase or the culture medium 2 and 10 FPU/g cellulose/5% β-glucosidase were used in SSF at 37 °C and 80 rpm. In the SSF with culture medium 2 (supplemented with ammonium, phosphate, potassium and magnesium), 150 L ethanol/t bagasse was achieved, with minimum enzyme loading (10 FPU/g cellulose and 5%, v/v β-glucosidase) for 8%, w/v of solids, which is often an important requirement to provide cost-efficient second generation ethanol processes.     

Ethanol production from alkali- and ozone-treated cotton stalks using thermotolerant Pichia kudriavzevii HOP-1

In the present study, milled cotton stalks were subjected to alkali pretreatment with NaOH at 1-4% (w/v) concentrations at 121 °C for time ranging from 30 to 90 min. Ozone pretreatment was performed by passing 45 mg/L of ozone gas over 2 mm cotton stalks for 150 min at a flow rate of 0.37 L/min. The residual biomass from 4% alkali pretreatment for 60 min showed 46.6% lignin degradation accompanied by 83.2% increase in glucan content, compared with the untreated biomass. Hydrolysis of 4% alkali-treated and ozone-treated cotton stalks was conducted using enzyme combination of 20 filter paper cellulase units/gram dried substrate (FPU/g-ds), 45 IU/g-ds β-glucosidase and 15 IU/g-ds pectinase. Enzymatic hydrolysis of alkali-treated and ozone-treated biomass after 48 h resulted in 42.29 g/L glucose, 6.82 g/L xylose and 24.13 g/L glucose, 8.3 g/L xylose, respectively. About 99% of glucose was consumed in 24 h by Pichia kudriavzevii HOP-1 cells resulting in 19.82 g/L of ethanol from alkali-treated cotton stalks and 10.96 g/L of ethanol from ozone-treated cotton stalks. Simultaneous saccharification and fermentation of the alkali-treated cotton stalks after 12-h pre-hydrolysis resulted in ethanol concentration, ethanol yield on dry biomass basis and ethanol productivity of 19.48 g/L, 0.21 g/g and 0.41 g/L/h, respectively which holds promise for further scale-up studies. To the best of our knowledge, this is the first study employing SSF for ethanol production from cotton stalks.     

Towards an optimal process for gelatinisation and hydrolysis of highly concentrated starch–water mixtures with alpha-amylase from B. licheniformis

The enzymatic hydrolysis of starch is usually carried out with 30–35 w/w% starch in water. Higher substrate concentrations (50–70 w/w%) were reached by using a twin-screw extruder for gelatinisation and for mixing enzyme with gelatinised starch prior to enzymatic hydrolysis in a batch reactor. The aim of this study was to determine which parameters are important for gelatinisation of wheat starch and to investigate the effects of different extrusion conditions on the enzymatic hydrolysis. After extrusion, the degree of gelatinisation was measured. During hydrolysis, the carbohydrate composition, the dextrose equivalent (DE) and the alpha-amylase activity were measured. Gelatinisation measurements showed that mechanical forces lowered the temperature required for complete gelatinisation. During hydrolysis experiments, high DEs were observed even if starch was not completely gelatinised during extrusion. Due to high substrate concentrations, the residual alpha-amylase activity remained high throughout enzymatic hydrolysis, although high temperatures were used. Increased substrate concentrations did not affect the carbohydrate composition of the product. Furthermore, the time required for the batch hydrolysis step could be varied by choosing a different enzyme-to-substrate ratio. This article provides a basis for detailed optimisation of this process to develop an industrial-scale process at high substrate concentrations.     

Hydrolysis of glycoalkaloids fromSolanum tuberosum L. haulm by enzymes present in plant material and by enzyme preparation

Summary This paper deals with the kinetics of enzymatic hydrolysis of glycoalkaloids from potato (Solanum tuberosum L.) haulm. The hydrolysis was carried out by the action of the enzymes present in fresh haulm, juice of fresh haulm and in haulm dried at various temperatures. The highest degree of enzymatic hydrolysis of 90% was obtained during fermentation of haulm dried at 40 °C after 30 h incubation time. The enzyme preparation was obtained from the juice of fresh potato haulm by using capillary dialysator HM 16 (AQM 1681, 1.6 m² Hemofan 8 υ). The best degree of enzymatic hydrolysis by enzyme preparation, 68%, was achieved after 20 h time of incubation. The enzyme preparation from juice of fresh haulm was characterized by K_m of 0.70 mM at pH 5.5 and 35 °C.     

The minimal enzyme cocktail concept for biomass processing

Efficient generation of a fermentable hydrolysate is a primary necessity in the utilization of fibrous plant biomass as a feedstock in bioethanol processes. Enzyme catalyzed hydrolysis of cellulose and heteroxylans in biomass feedstocks each require multiple enzyme activities to achieve degradation to fermentable monosaccharides. The minimal enzyme cocktail concept concerns identification of the minimal number, the minimal levels, and the optimal combination of the best performing key monoactive enzymatic activities to meet this requirement. Two major hypotheses lie behind this concept: 1. That the native multi-component profiles of crude “wild type” cellulolytic and/or xylan degrading enzyme preparations are not optimal for degradation of cellulose in pre-treated lignocellulosic biomass nor for degradation of heteroxylans in hemicellulose-rich product streams; 2. That it is possible to replace crude multienzyme preparations with designed combinations of the minimal number of required enzyme activities for biomass processing. This paper outlines the current strategies employed and the stage of development of minimal enzyme cocktails for enzymatic hydrolysis of cellulose and arabino-xylan in complex, genuine biomass substrates. The available data demonstrate the feasibility of the concept and illustrate the potential efficacy improvements obtainable by use of designed minimal enzyme cocktails for pre-treated lignocellulosic and hemicellulose-rich biomass substrates.     

Preparation and characterization of cellulose nanofiltration membrane through hydrolysis followed by carboxymethylation

Bamboo cellulose (BC) is hydrophilic, biodegradable and inexhaustible. The bamboo cellulose membrane (BCM) is one of the best materials to replace petroleum-based polymer film for water purification. In this study, the N-methylmorpholine-N-oxide (NMMO) was used as a solvent to dissolve cellulose 6 wt.%, and regenerated cellulose membrane was prepared by phase inversion. A new kind of cellulose nanofiltration membrane (BC-NFM) was obtained by the hydrolysis and carboxymethylation of dense cellulose membrane (BCM). The modification was carried out through hydrolysis followed by carboxymethylation. The BC-NFM was characterized by XRD, FT-IR, SEM and thermal analysis. BC-NFM performance evaluation instrument were used to evaluate retention rate and water flux of nanofiltration membrane. BCM was immersed in 1 mol/l NaOH and 3 wt/v.% chloroacetic acid solution to obtain BC-NFM. By calculating, pore size of nanofiltration membrane was 0.63 nm. With a pressure of 0.5 MPa, the water flux of nanofiltration membrane for Na₂SO₄ solution was 10.32 l/m²h, and the retention rate was 68.4 %. The water flux for NaCl solution was 13.12 l/m²h, and the retention rate was 34.9 %. And the retention rates were 93.0 % and 98.9 % for methyl orange and methyl blue, respectively. The stability of the nanofiltration membrane was measured by the thermal analyzer, following the order of BC>BCM>BC-NFM. The prepared cellulose nanofiltration membrane exhibited good stability in water treatment process, and can be used to remove organic compounds in aqueous solutions.     

Green Approach for Multifunctionalization of Cellulose-Containing Fabrics

Development of multifunctional textile and clothing products with improved environmental profiles has been demanded both by textile industry and by consumer. Herein, dialdehyde sodium alginate (DASA) and dialdehyde carboxymethyl cellulose (DACMC) have been prepared, characterized and utilized, as an eco-friendly binding/ macromolecular crosslinking/hand building agents, in functional finishing of cellulose-containing fabrics. Fabric samples were treated with the nominated dialdehyde polysaccharide (DAPS, 10 g/l) along with the reactant resin (DMDHEU, 50 g/l), Ag- or TiO₂-NPs as active ingredients (20 g/l) and ammonium persulfate catalyst (5 g/l) using the padding method. After functional finishing, the finished fabrics demonstrated a remarkable improvement in their antibacterial efficacy, UV-blocking ability, self-cleaning capacity, and surface roughness functionality without adversely affecting fabrics resiliency. The variation in these functional properties is affected by kind of DAPS, type of added nanoparticles as well as the treated substrate. Additionally, FTIR, SEM, EDS, and durability to wash measurements for selected samples were performed. Moreover, pre-oxidation of DAPS, functionalization reactions/interactions among the nominated reactants and the textile materials were also suggested.     

Facile Fabrication of Durable Antibacterial Cotton Fabric Realized by Thioglycolic Acid and Silver Nanoparticles

In this study, durable antibacterial cotton fabrics were prepared by a simple two-step impregnation method. Firstly, thioglycolic acid (TGA) was grafted onto cotton fabric via esterification with the hydroxyl groups of cellulose, then silver nanoparticles (Ag NPs) were immobilized on the cotton fabric surface via coordination bonds with the TGA thiol groups. As a result, the mean size of Ag NPs coating on the cotton fabric is around 74 nm, and these functionalized cotton fabrics show superior antibacterial properties and excellent laundering durability. After withstand 50 laundering cycles, the obtained cotton fabrics still showed outstanding bacterial reduction rates (BR) against both S. aureus and E. coli, and the rates are all higher than 97 %. Therefore, this method to prepare antibacterial cotton fabric shows great potential applications in socks, cosmetic, and medical textiles.     

Process optimization for ethanol production from photoperiod-sensitive sorghum: Focus on cellulose conversion

Photoperiod-sensitive sorghum, as a competitive biomass for ethanol production, was investigated to develop an integrated process for improving ethanol yield. Response surface methodology was employed to study the relationship between pretreatment variables (including temperature, sulfuric acid concentration, and reaction time) and cellulose recovery, as well as efficiency of enzymatic hydrolysis (EEH) in the solid part. Recovery yield decreased and EEH increased as the pretreatment temperature, acidic concentration, and reaction time increased. A model was successfully developed to predict total glucose yield with a maximum value of 82.2%. Conditions of co-fermentation were also optimized, and the optimal ethanol yield was obtained with constant-temperature simultaneous saccharification and fermentation at 38 °C. Acetate buffer at a concentration of 50 mM was found helpful for increasing efficiency of enzymatic hydrolysis, as well as ethanol yield. The maximum ethanol yield was 0.21 g ethanol per dry mass at the conditions of 38 °C, 0.05 g yeast/L, and 50 mM acetate buffer. A complete cellulose balance was provided for the whole process.     

Layer by layer assembly of nanosilver for high performance cotton fabrics

High performance cellulosic fabrics are of increasing attention as a wearable fabric with special functions. The current report deals with preparation of multifunctional cotton fabrics by using simple and facile layer by layer technique. Firstly, silver nitrate was reacted with carboxymethyl cellulose to prepare Ag nanoparticles-carboxymethyl cellulose composite. Multi-layers of the so-obtained composite were applied on the cotton fabrics using pad-dry-cure method. Ag nanoparticles were deposited with mean size of 18.2 nm onto cotton fabrics which served as a cross linker between carboxymethyl cellulose macromolecules and cotton macromolecular blocks. Application of composite multilayers brought new properties for the finished cloths such like coloration, ultraviolet resistance, electrical resistance and biocidal action. The ultraviolet transmission radiation was significantly reduced to 7-10 % after applying ten composite layers. Valuable antibacterial textiles which are required in different medical purposes could be successfully produced, as excellent antibacterial activities were achieved by using the reported method. The developed process can be easily adapted to the existing textile machinery, making it industrially viable to produce fabric’s versatility.     

Sophorolipids: a source for novel compounds

Renewable resources, such as rapeseed oil or oleic acid, combined with glucose were used both in a feed-batch and two-stage continuous process for the production of sophorolipids with the yeast Candida bombicola ATCC 22214. High yields >300 g l⁻¹ and increased productivities of 57 g l⁻¹ d⁻¹ (feed-batch) and 76 g l⁻¹ d⁻¹ (continuous mode), respectively, were obtained by using optimized cultivation conditions. The key-factors for enhanced sophorolipid production are presented. The acidic sophorolipid was used for further modification after alkaline hydrolysis and purification. A novel glucoselipid was synthesized by using the enzyme naringinase (EC 3.2.1.40). A (ω-1)-hydroxyfatty acid, commercially not yet available and difficult to prepare by organic synthesis, was released by acidic hydrolysis, purified and is proposed as a precursor for plastics and flavours.     

Application of acacia natural dyes on cotton by pad dyeing

Coloration of textiles, traditionally achieved using natural dyes, commonly employs synthetic dyes at the industrial level. A revival of commercial interest in natural dyes has opened several research avenues. This paper investigates the application by padding of cotton fabric with 10 g/l of two natural dyes derived from the Acacia plant family. Three mordanting techniques were studied; of which post-mordanting produced the most even shade. Among the two mordants investigated, the use of copper sulfate resulted in a level beige shade at 15 g/l concentration while ferrous sulfate performed best at 5 g/l yielding a yellow-grey shade. An optimum process-sequence for the copper sulfate mordant was “pad (dye)→dry→steam followed by pad (mordant)→steam→dry”, and for ferrous sulfte it was “pad (dye)→steam→dry followed by pad (mordant)→steam→dry”. Typically a change in mordant resulted in a different shade with the same dye. The study concluded that padding is a readily adaptable process for the dyeing of cotton using natural dyes and acceptable fastness in shades can be obtained.     

Effect of enzyme treatment and wood pulp variation on physical characteristics and fabric hand of lyocell fabrics

The purpose of the research was to examine the effect of three different levels of enzyme treatment on the physical characteristics and the end-use suitability of the lyocell fabrics made with four different types of commercial wood pulp. The appropriate enzyme concentration for obtaining an optimum as well as consistent physical characteristics and fabric hand trait was 3 g/l for the concentration levels tested in the present investigation. Weight loss was more affected by higher enzyme concentration than other physical properties. H2 was least affected by enzyme treatment for all three physical properties and fabric hand. 5 g/l concentration exhibited little difference from 3 g/l in the physical characteristics, whereas the KES-FB values indicated a significant loss of fabric hand in most PHVs with the 5 g/l concentration level. Among different garment parameters, all four fabric types were relatively inappropriate for the men’s slacks (MS) fabric due to the lower hand value of koshi required by the MS parameter. However, despite the relatively low koshi values, high fukurami values required for men’s dress shirt (MWDS) resulted in the highest THV among the four garment parmeters. The four fabric types, which represent the usage of four different wood pulps, in general seem to exhibit a higher applicability to women’s winter thin dress (WWTD) than women’s winter suit (WWS) garment parameter.     

Hydrolysis of Fucoidan by Fucoidanase Isolated from the Marine Bacterium,Formosa algae

Intracellular fucoidanase was isolated from the marine bacterium, Formosa algae strain KMM 3553. The first appearance of fucoidan enzymatic hydrolysis products in a cell-free extract was detected after 4 h of bacterial growth, and maximal fucoidanase activity was observed after 12 h of growth. The fucoidanase displayed maximal activity in a wide range of pH values, from 6.5 to 9.1. The presence of Mg²⁺, Ca²⁺ and Ba²⁺ cations strongly activated the enzyme; however, Cu²⁺ and Zn²⁺ cations had inhibitory effects on the enzymatic activity. The enzymatic activity of fucoidanase was considerably reduced after prolonged (about 60 min) incubation of the enzyme solution at 45 °C. The fucoidanase catalyzed the hydrolysis of fucoidans from Fucus evanescens and Fucus vesiculosus, but not from Saccharina cichorioides. The fucoidanase also did not hydrolyze carrageenan. Desulfated fucoidan from F. evanescens was hydrolysed very weakly in contrast to deacetylated fucoidan, which was hydrolysed more actively compared to the native fucoidan from F. evanescens. Analysis of the structure of the enzymatic products showed that the marine bacteria, F. algae, synthesized an α-l-fucanase with an endo-type action that is specific for 1→4-bonds in a polysaccharide molecule built up of alternating three- and four-linked α-l-fucopyranose residues sulfated mainly at position 2.     

Evaluation of thermomechanical pretreatment for enzymatic hydrolysis of pure microcrystalline cellulose and cellulose from Brewers’ spent grain

Microcrystalline cellulose (Avicel PH102) and Brewers’ spent grain (BSG) were subjected to Détente Instantanée Contrôlée (DIC) thermomechanical pre-treatment before exposure to cellulases (Celluclast 1.5 L). In a first part, we showed that the addition of β-glucosidase (Novozym-188) increased the hydrolysis yield of Avicel. A maximal theoretical yield (100%), was obtained for 5 and 10 g/L of Avicel using a mixture of Celluclast 1.5 L/Novozym-188. After DIC pre-treatments, the initial rate and final yield of hydrolysis decreased in comparison with those from untreated microcrystalline cellulose. This phenomenon may be due to the modification of the crystallinity of pure cellulose and the formation of inhibitors during the pre-treatment. In a second part, BSG was thermomechanically pre-treated and hydrolyzed. The results showed that the hydrolysis yield of BSG treated at pressure levels between 2 and 7 bar during 15 min was strongly improved compared to hydrolysis yield of untreated BSG. The optimized hydrolysis process, under intensive DIC conditions, achieved a glucose yield corresponding to 100% of the theoretical cellulose value. The morphology of BSG samples was studied with Scanning Electronic Microscopy (SEM) and highlighted that the structure of pre-treated BSG showed an important disruption compared to the rigid structure of untreated BSG.     

An approach to the influence of particle size distribution of leuco vat dye converted by a reducing agent

Three vat dyes have been applied to regular viscose rayon and their dyeing and wash fastness properties were evaluated. Particle size determination was undertaken to obtain information about the size of dye particles converted by a reducing agent, to see if dye particle size has an affect on dyeing properties of regular viscose rayon. It is observed that viscose rayon exhibits more dyeability with reducing agent concentrations between 5–7.5 g/l. Also, we found that the vat dyeing system is greatly affected by the particle size of the vat dye converted to leuco form by a reducing agent.