Fermentable Reducing Sugars Research Articles

Improving the Quality of Low-grade Tobacco by Enzymatic Treatment and Co-fermentation with Yeast and Lactic Acid Bacteria.

Enzymatic treatment is a promising method to modulate the chemical composition, flavoring substances and to enhance the sensory quality of cigarettes. This study investigates the feasibility of enzymatic treatment in conjunction with co-fermentation with yeast and lactic acid bacteria to improve the quality of low-quality cigarettes. Amylase, flavourzyme, glucoamylase, protease, and their combinations were used for the enzymatic treatment of tobacco-sorghum by using the liquid-state fermentation method. The biochemical components and flavor substances of the fermented products were analyzed. The findings show that amylase and glucoamylase can effectively degrade starch into fermentable reducing sugars, facilitate microbial growth and proliferation, and significantly enhance the levels of flavoring alcohols and esters. Flavourzyme and glucoamylase, either individually or combined with amylase, achieved a more balanced distribution of flavor substances in the products. Additionally, flavourzyme was capable of increasing the content of guaiacol, solanesol, and 2-acetylpyrrole in the fermented products, thereby improving the richness and depth of the cigarette flavor. While the protease treatment group showed fewer flavor substances and higher nicotine content, which was detrimental to the quality of cigarettes. When integrating the fermentation products into low-quality cigarettes, flavourzyme and glucoamylase combined with amylase treatment received higher scores in sensory quality evaluations. This study provides a beneficial strategy for effectively improving the quality of low-quality cigarettes.

Comparative study of chemical and enzymatic pre-treatments of Kitchen waste (KW) to generate fermentable sugars for the production of polyhydroxyalkanoates (PHA)

Kitchen waste (KW) production is anticipated to rise because of accelerated urban and economic growth, particularly in Asian nations. Therefore, applications/recycling of KW should be explored for its effective utilization to generate a sustainable source of energy that will ultimately avoid massive economic and energy losses. The main goal of this study was to investigate the combinational effect of thermochemical and enzymatic pre-treatment on synthetic KW to enhance the release of fermentable sugars for the synthesis of value-added products such as polyhydroxyalkanoates (PHAs). The thermochemical pre-treatment of KW samples was performed using 4 N HCl, 4 N H2SO4, and 4 N NaOH at a concentration of 0–30% (v/v), 30–100 °C for 0–120 min. Furthermore, to enhance the total fermentable sugars, variable enzyme dosages were added after acidic or alkaline pre-treatments (0–1% v/v α-amylase and 0–1% v/v amyloglucosidase-AMG) while maintaining a constant pH 5, temperature 50 °C, and time 30 min. Pre-treatment of KW with acid (15% v/v 4 N HCl in water) at temperature 100 °C, followed by enzymatic hydrolysis, i.e., 0.6% (v/v) α-amylase and 0.4% (v/v) amyloglucosidase (at pH 5, 50 0C and 60 min) resulted in the maximum concentration of fermentable reducing sugars (46.13 g/L) in the hydrolysate.

Obtaining fermentable reducing sugars by chemical hydrolysis of mesquite pod fractions

Obtaining fermentable reducing sugars by chemical hydrolysis of mesquite pod fractions

Application of a novel biological-nanoparticle pretreatment to Oscillatoria acuminata biomass and coculture dark fermentation for improving hydrogen production

BackgroundEnergy is the basis and assurance for a world's stable development; however, as traditional non-renewable energy sources deplete, the development and study of renewable clean energy have emerged. Using microalgae as a carbon source for anaerobic bacteria to generate biohydrogen is a clean energy generation system that both local and global peers see as promising.ResultsKlebsiella pneumonia, Enterobacter cloacae, and their coculture were used to synthesize biohydrogen using Oscillatoria acuminata biomass via dark fermentation. The total carbohydrate content in O. acuminata was 237.39 mg/L. To enhance the content of fermentable reducing sugars, thermochemical, biological, and biological with magnesium zinc ferrite nanoparticles (Mg-Zn Fe2O4-NPs) pretreatments were applied. Crude hydrolytic enzymes extracted from Trichoderma harzianum of biological pretreatment were enhanced by Mg-Zn Fe2O4-NPs and significantly increased reducing sugars (230.48 mg/g) four times than thermochemical pretreatment (45.34 mg/g). K. pneumonia demonstrated a greater accumulated hydrogen level (1022 mLH2/L) than E. cloacae (813 mLH2/L), while their coculture showed superior results (1520 mLH2/L) and shortened the production time to 48 h instead of 72 h in single culture pretreatments. Biological pretreatment + Mg-Zn Fe2O4 NPs using coculture significantly stimulated hydrogen yield (3254 mLH2/L), hydrogen efficiency)216.9 mL H2/g reducing sugar( and hydrogen production rate (67.7 mL/L/h) to the maximum among all pretreatments.ConclusionThese results confirm the effectiveness of biological treatments + Mg-Zn Fe2O4-NPs and coculture dark fermentation in upregulating biohydrogen production.

Assessment of indigenous fungal biocatalysts towards valorization of delignified physico‐chemically pretreated corn cobs and sugarcane bagasse

AbstractThe conversion of plant‐based lignocellulosic materials into alternative fuels entails various pretreatment strategies (chemical, physico‐chemical or enzymatic) to boost the release of sugar constituents from biomass. This investigation reports the influence of different pretreatment techniques such as acid, alkali and steam treatment followed by enzymatic hydrolysis in single and (or) consolidated system, for releasing fermentable reducing sugars from sugarcane bagasse (SB) and corn cobs (CC) (major agricultural residues). Alkaline pretreatment facilitated maximal lignin removal, 83.2 and 69.4% from CC and SB, respectively, thereby expediting enzymatic hydrolysis by in‐house xylanases produced from indigenously isolated Aspergillus tubingensis strains, AUMS60 (Xyn60) and AUMS64 (Xyn64A, B). The major operating conditions for enzymatic treatment of raw and pretreated residues were set at a substrate loading of 2% (w/v), an enzyme loading of 100–500 U g−1 substrate and incubation at 40°C, 140 rpm for 72 h. Treatment with Xyn60 and Xyn64A, B resulted in 81.4% (72 h) and 75.9% (24 h) saccharification of delignified SB and CC, respectively. Scanning electron micrographs and Fourier transform infrared spectra corroborated structural deformations induced by physico‐chemical pretreatment processes, thereby validating the maximal enzymatic hydrolysis of delignified substrates. The analysis of enzyme hydrolysis products suggested higher saccharification of hemicellulosic fraction as compared with cellulose. The observations of the present study signify that the thermotolerant in‐house enzymes show great potential in the saccharification of lignocelluloses within a short span of time and may open a new vista for biomass valorization in the bioenergy sector. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

Experimental investigation on simultaneous production of bioethanol and biodiesel from macro-algae

The present work compares the biofuel production efficiency of Padina tetrastromatica and Sargassum swartzii macro-algae biomass by fermentation with Saccharomyces cerevisiae and Zymomonas Mobilis. The optimal pretreatment factors were identified by studying the effect of temperature, pH, and enzyme concentration on the conversion of macroalgae biomass to fermentable reducing sugars. The Low concentration of enzyme did not help conversion of biomass to reducing sugars even after 15 h of treatment with enzyme, but when the enzyme concentration was increased, the desired conversion was completed within 4 h of enzyme treatment. Both Padina tetrastromatica and Sargassum swartzii had an ethanol yield of above 80% irrespective of the difference in the species used for the fermentation. The highest possible ethanol yield (95.12%) was achieved for Padina tetrastromatica biomass when it was fermented with Zymomonas Mobilis. From the above results, it is clear that both Padina tetrastromatica and Sargassum swartzii have the potential to be used as reliable feedstock for biofuel production. The spent biomass after the fermentation process was used for the lipid extraction process and the extracted lipid was used for biodiesel production. The percentage of biodiesel yield obtained by means of the Soxhlet extraction process from Padina tetrastromatica and Sargassum swartzii macro-algae with the conventional NaOH catalyst was found to be 84% and 89% respectively. MgO.La2O3 was synthesized by means of the co-precipitation method. With the introduction of MgO.La2O3 nano-catalyst biodiesel yield was improved up to 88% and 92% for Padina tetrastromatica and Sargassum swartzii macro-algae, respectively.

Proximate Analysis and Production of Bio-ethanol from Sweet Potato (Ipomoea batatas) White Cultivars obtained from Samaru Zaria

This study entails the production of bioethanol from the peels of sweet potato of white cultivar variety obtained in Zaria, Kaduna State Nigeria. Fresh cultivar with the proximate composition of 72% moisture content, 9.71% ash content, 24.52% crude fiber, 78.74% total carbohydrate and crude protein of 6.42% were hydrolyzed with 3% sulphuric acid solution at 130oC and 60 minutes in an improvised reactor to generate 54.5ml of hydrolyzate after steam pretreatment step. The fermentable reducing sugar of 10.68% was achieved through glucose standardization with UV-spectrophotometer at 540nm wavelength. The fermentation of the hydrolyzate –yeast/media mixture (155ml) at 30oC for 72hours was achieved by commercial grade saccharomyces cerevisiae to yield 20.5g/54.5ml, which corresponds to 0.8198g/ml specific gravity and 93.6% ethanol concentration. The molecular sieve was eventually adopted in dehydrating the bioethanol to 99.9% (0.8072g/ml) concentration and the final yield of 1.61% per 50g of w. cultivar. FTIR spectrum that declares the ethanolic identity with the stretching vibrations of O-H, C-O and C-H at 3391, 1055 and 2981cm-1 respectively with the symmetric stretching vibration of the methyl groups at 2930cm-1.

An integrated ionic liquid hybrid polymeric fixed-bed reactor with a porous sponge-like structure for biomass hydrolysis

Biomass hydrolysis into fermentable reducing sugars is essential for the bioethanol production. Novel integrated ionic liquid (IL) hybrid polymeric fixed-bed reactor with porous sponge-like structure was constructed for inulin hydrolysis. The acidic IL, [(CH2)3SO3HVIm]HSO4 was covalently grafted on polysulfone (PSF). The PSF-ILs integrated porous fixed beds were elaborately prepared by famous non-solvent induced phase separation approach. Effects of coagulation bath composition and temperature, fixed bed height, permeation flux, feed temperature and concentration on inulin hydrolysis were explored intensively. The porous sponge-like structure and chemical binding of ILs endowed the fixed beds with excellent catalytic performance, stability, and reusability. Under optimized conditions, once the inulin aqueous solution permeated through the fixed beds, the yield of total reducing sugar (TRS) reached up to 98.82%. Compared with the catalytic membrane, the hydrolysis reaction time was drastically shortened by 92.5%. These findings provided a new strategy on developing high-performance fixed-bed reactors for biomass conversion.

Intensification of delignification and enzymatic hydrolysis of orange peel waste using ultrasound for enhanced fermentable sugar production

The present study focuses on using orange peel as a lignocellulosic substrate for fermentable reducing sugar production with intensification studies for delignification and enzymatic hydrolysis steps. The orange peel exposed to conventional and ultrasound-assisted alkaline pretreatment under ambient temperature for delignification resulted in around 86% delignification and 92% delignification in 4 h respectively. Subsequently, the effect of the enzyme concentration, ultrasonic power and duty cycle on reducing sugar production in the enzymatic hydrolysis has been investigated. Maximum concentration of reducing sugar as 1.30 g/L was obtained in 6 h treatment under 60W as power and 70% duty cycle, which was higher and much faster as compared to the conventional method where the sugar concentration was 0.814 g/L in 24 h. Studies involving advanced oxidation pretreatment based on hydrogen peroxide, Fenton, and ozone performed under ambient temperature demonstrated that the optimum conditions for best pretreatment efficacy are 3% H2O2 loading, 0.5g as FeSO4 loading and 2 L/min as the ozone flow rate as applicable, yielding a sugar concentration of 1.528 g/L, 2.069 g/L and 0.472 g/L respectively. Overall, the work has established that application of ultrasound and advanced oxidation pretreatment benefits the delignification and subsequent enzymatic hydrolysis of orange peel waste.

Cellulases and animal feed production by solid-state fermentation by Aspergillus fumigatus NRCF-122 mutant

A high cellulase-producing fungus was isolated from agricultural waste compost, purified, identified genetically as Aspergillus fumigatus NRCF-122 (accession no. MT318341), and improved by UV-irradiation for cellulase production (named as A. fumigatus mutant-17). Optimal cellulase production conditions were studied using sugar beet pulp “SBP” as the substrate of solid-state fermentation technique. The optimal conditions were: initial moisture content ratio (1:2 w/v), incubation temperature (30°C), initial pH of solid culture (10), incubation period (4 days), aeration area (1:100 ratio ((1%)), SBP substrate weight : flask volume of moistened SBP in a 250 mL Erlenmeyer flask, fungal inoculum (seeding) culture age (3 days) and inoculum size (20%, v/w). Studies were also involved the effect of different nitrogen sources where urea is the best nitrogen source for cellulase production. Concerning the application of bioethanol production from yeast, using rice straw cellulose as a source of fermentable reducing sugars), the lingo-cellulosic waste rice straw was first pretreated (with NaOH 1.5%) to reduce crystallinity of cellulose & removing lignin and other inhibitors, enhancing the subsequent process (saccharification) of rice straw cellulose. Then, its cellulose was saccharified enzymatically by cellulases (produced from SBP as substrate (under SSF condition) as substrate under the optimum conditions) resulting in reducing sugars. one of the largest livestock production operating costs is the feed bill. In our study we evaluated the resulted crude protein content of the fermented SBP and the results declared that, the total digest nutrient (TDN) and gross energy performance were increased, where as crude fiber, acid detergent fiber ADF & neutral detergent fiber NDF were decreased, thereby upgrading the feed quality of biologically treated SBP.

Environmental-friendly pretreatment and process optimization of macroalgal biomass for effective ethanol production as an alternative fuel using Saccharomyces cerevisiae

Abstract Fossil fuel depletion and gas limitations require tremendous efforts to the production of renewable energy from environmental-friendly and sustainable sources. The third-generation bioethanol from non-lignocellulosic biomass of macroalgae is an effective candidate for renewable and sustainable fuel–making that mainly involves pretreatment, enzyme hydrolysis, and microbial fermentation. Therefore, the purpose of this research was to develop a consolidated process for the effective conversion of macroalgal biomass into third-generation bioethanol. The pretreatment of two macroalgae biomasses (namely Ulva rigida and Ulva intestinalis) was optimized using a steam explosion, compared with ultrasonication, to maximize the fermentable reducing sugars yield. A condition of pressure at 25 psi and pretreatment time of 15 min by steam explosion pretreatment of U. intestinalis was the best condition for maximizing fermentable reducing sugars up to 5.41 g/L, generating 86.6 kJ/L of energy. In subsequent enzyme hydrolysis of pretreated biomass, using commercial cellulose enhanced the fermentable reducing sugars up to 6.18 g/L. Fermentation of the hydrolysate using yeast Saccharomyces cerevisiae produced 0.12 g–ethanol/g–fermentable reducing sugar in a short time with ethanol productivity of 2.54 mg–ethanol/g–fermentable reducing sugar/h. Interestingly, the produced ethanol can be converted into energy up to 21.91 kJ/L. This study demonstrates the macroalgal biomass is a suitable feedstock of non-lignocellulosic biomass for third-generation bioethanol production and the developed process confirmed the practical, low-cost, and non-polluting conversion of macroalgal biomass into bioethanol based renewable energy.

Orange Bagasse Pellets as a Carbon Source for Biobutanol Production.

Due to the environmental concerns, the conversion of lignocellulosic waste can be the key to produce bioproducts and biofuels such as butanol. This study aimed to present and evaluate orange bagasse pellets (OBP) as a carbon source to produce butan-1-ol production via ABE fermentation using Clostridium beijerinckii. These bagasse pellets were characterized, holocellulose (18.99%), alfacellulose (5.37%), hemicellulose (13.62%), lignin (6.16%), pectin (7.21%), protein (3.14%), and was tested under three different pretreatments, which were the following: (a) ultrasound, (b) autohydrolysis, and (c) acid-diluted hydrolysis followed by enzymatic hydrolysis to verify an amount of fermentable total reducing sugars. ANOVA was used and pretreatments followed by enzymatic hydrolysis do not enhance a significant amount of available sugars compared to raw bagasse. The ABE fermentation was carried out in batch reactors at 37°C under agitation of 160rpm and anaerobic conditions, using OBP without treatment followed by enzymatic hydrolysis. Using a non-mutant microorganism, the fermentation achieved butyric acid yields of 3762.68mgL-1 for control and 2488.82mgL-1 for OBP and the butanol production was 63.86mgL-1 and 196.80mgL-1 for OBP and the control (glucose) assay, respectively. The results of this solvent's production have shown that OBP has the potential for ABE fermentation and a promising feedstock.

Unraveling the camel rumen microbiome through metaculturomics approach for agriculture waste hydrolytic potential.

Cellulose is the most abundant natural polymer present on Earth in the form of agriculture waste. Hydrolysis of agriculture waste for simple fermentable reducing sugars is the bottleneck in the area of biofuel generation and other value-added products. The present study aims to utilize the camel rumen as a bioreactor for potent cellulolytic and hemicellulolytic bacteria by altering the feed types with varying cellulosic concentrations. A total of 6716 bacterial cultures were subjected to three layers of screening, where plate zymography and chromophoric substrate screening served as primary screeningmethod for cellulolytic and hemicellulolytic potential. The potential isolates were genetically grouped using RAPD, and 51 representative isolates from each group were subjected to molecular identification through 16S rDNA sequencing, followed by quantification of various cellulolytic and hemicellulolytic enzymes. Out of 51 potent isolates, 5 isolates had high endoglucanase activity ranging from 0.3 to 0.48U/ml. The selected five key isolates identified as Pseudomonas, Paenibacillus, Citrobacter, Bacillus subtilis, and Enterobacter were employed for hydrolyzing the various agriculture residues and resulted in approximately 0.4mg/ml of reducing sugar. Furthermore, the metaculturomics approach was implemented to deduce the total cultured diversity through 16S rRNA amplicon library sequencing. The metaculturomics data revealed the dominance of proteobacteria and unidentified bacterial population in all four feed types, which indicates the possibility of culturing novel cellulose-deconstructing bacteria. Moreover, the presence of diverse hydrolytic enzymes in cultured isolates supports the usage of these bacteria in bio-processing of agriculture waste residues and obtaining the biofuels and other value-added products.

Enhanced biochemical characteristics of β-glucosidase via adsorption and cross-linked enzyme aggregate for rapid cellobiose hydrolysis.

With proper design, immobilization can be useful tool to improve the stability of enzymes, and in certain cases even their activity, selectivity, productivity and economic viability. An immobilized β-glucosidase (BGL, EC 3.2.1.21) through matrix adsorption and cross-linked enzyme aggregate (ad-CLEA) technology is presented in this work. After adsorption and precipitation, BGL was immobilized to poly(glycidyl methacrylate-co-ethylenedimethacrylate) (PGMA/EDMA) microparticles using glutaraldehyde as the cross-linker. Immobilized BGL exhibits lower apparent Km but much higher Vmax than that of the soluble enzyme, suggesting greater enzyme-substrate affinity and rapid velocity. Besides, ad-CLEA-BGL presents better thermostability retaining activity nearly 70% for 3h and approximately 50% for 5h at 70°C, high operational reusability remaining more than 90% activity after nine uses and excellent storage stability holding about 95% activity after 45days. Furthermore, the cellobiose is completely hydrolyzed within 1h with ad-CLEA-BGL, which is significantly more efficient than soluble enzyme (about 4h). Therefore, BGL was successfully immobilized on PGMA/EDMA microparticles with an ad-CLEA technology and the immobilization greatly enhances the biochemical characteristics. This work indicates promising application for ad-CLEA-BGL in utilizing agricultural remnants, bio-converting cellobiose to fermentable reducing sugar and ethanol production.

Selection of Microorganisms Possessing Thermostable Lignocellulolytic Enzymes and Application of the Enzymes for Saccharification of Pretreated Palm Oil Mill Wastes

This study attempted to find potential effective thermotolerant microorganisms producing complex enzymes for use in the hydrolyzing empty fruit bunch (EFB) to reduce cost of enzyme and enhance the efficiency of saccharification. The enrichment process at 45 °C was employed as a strategy to obtain four effective thermotolerant microorganisms. Streptomyces thermocarboxydus ME742, Bacillus subtilis ME751 and Bacillus amyloliquefaciens ASB/TRE produced the highest activity of xylanase (226.2 U/mL), CMCase (3.84 U/mL) and FPase (69.55 U/mL), respectively, while Aspergillus fumigatus A4112 exhibited the highest specific activity of xylanase (637.9 U/mg), CMCase (5.55 U/mg) and FPase (21.58 U/mg). Xylanase of isolated ME742 and A4112, CMCase of isolated ASB/TRE, FPase of isolated ME742, ME751 and ASB/TRE possessed thermostability with 80% remaining activity at 60 °C after 1 h incubation. These four strains were capable to reduce 49–78% (w/w) lignin in raw EFB with simultaneous enzyme production. The EFB residue was reused as substrate for saccharification with the highest amount of reducing sugar using the crude enzymes from S. thermocarboxydus ME742 (9.24 mg/g EFB). The sugar was 3.76 and 3.61 fold higher than that obtained from saccharification of acid- and alkaline-pretreated EFB, respectively. Moreover, the crude enzymes from A. fumigatus A4112 and B. amyloliquefaciens ASB/TRE hydrolyzed palm oil mill effluent (POME) to generate high yield of reducing sugar (61.01–64.63 mg/g TS-POME). Therefore, these selected strains were considered as the potent biological tool applicable in the bioconversion of oil palm biomass to fermentable reducing sugars.

Production of dextranase by aspergillus fumigatus NRC-F103 and its application in cane juice treatment and enhancing ethanol production from sugarcane molasses

Background and objectives One of the important applications of dextranase enzyme is preventing dextran accumulation in sugarcane juice as well as, consequently, for enhancing the resultant fermentable reducing sugars and ethanol yield in the fermentation of sugarcane molasses by yeasts. Materials and methods Different materials and methods were used for fungal strains [screening, mutation ultraviolet (UV), inoculum preparation, cultivation type ‘solid-state fermentation,’, culture substrates], dextranase (production, assay, soluble protein determination), purification, characterization, application in ethanol production by fermentation from sugarcane molasses, dextran estimation, and determination of reducing sugars. Results and conclusion Six fungal strains (namely Aspergillus oryzae FK-923, Aspergillus niger F-93, A. niger F-258, Aspergillus awamori NRC-F18, Aspergillus fumigatus NRC-F103, and Trichoderma viride NRC-F107) were screened on sorghum, sugar beet pulp, wheat bran, and orange peels using the solid-state fermentation technique to produce dextranase enzyme. The fungus A. fumigatus NRC-F103 cultivated on orange peels showed promising enzyme yield than other tested fungal strains. Then, optimization of culture conditions for dextranase production was carried out. Moisture content, initial pH value, incubation temperature, and incubation period were optimized to be 2 : 1 (v/w), 5.0, 35°C and 96 h, respectively. Five inorganic nitrogen sources were trailed at equivalent levels as sole nitrogen in the fermentation medium did not result in any increase in enzyme activity. Subjecting the fungal to UV resulted in a 75% increase in enzyme activity corresponding to the mother strain before subjecting to UV. Under the above conditions, 118 U/g original substrate was obtained. Isopropanol 1 : 1 (v/v) was applied for precipitation enzyme protein, as 32% of total protein involving 68% of total enzyme activity was obtained and specific activity was 42.94 U/mg protein compared with 16.4 U/mg protein in the culture supernatant. A study on obtained dextranase showed that it has an optimum that pH ranged from 4.5 to 5.5 as well as it gave the highest activity when incubated between 35 and 40°C. Promising results were obtained when the enzyme was applied in cane juice to prevent accumulation of dextran. Enzyme supplementation to diluted sugarcane molasses (26%, w/v) resulted in an increase in reducing sugars by 2.64%. Ethanol was increased by about 2.36% (v/v) in the fermentation medium supplemented with an enzyme compared with the unsupplemented medium and the fermentation efficiency increased from 89 to 92.5%.

Investigation of pickled baby corn (Zea mays L.) fermentation

Baby corn (Zea mays L.) is a monoic annual plant belonging to maideas tribe and the grass family of Gramineae. It is a vegetable with good nutritional characteristics with a short post-harvest shelf-life in the ambient environment. Baby corn is rich source of fibre, protein, vitamin C, potassium, phosphorus, magnesium and calcium. It has high content of fermentable reducing sugars such as glucose, sucrose and fructose could serve as substrates for lactic acid fermentation thus transforming from a perishable product to more stable and value-added one. Baby corn has a great potential and great demand in international market mainly because of its freshness, taste, nutrition, free from pesticides and its multiuse. The consumption of lactic acid fermented vegetables helps enhance balanced human nutrition. Lactic acid fermentation retains all the natural plant ingredients while improving the quality, taste and aroma. Objective of this study focused on a lactic acid fermentation from baby corn by penetrating on the effect of various parameters such as blanching pre-treatment, salt: sugar immersion, fermentation to physico-chemical, microbial and sensory characteristics of pickled baby corn. Results showed that baby corn should be blanched in hot water at 95°C in 5 sec with 0.20% citric acid; fermentation in 8.0%: 2.0% salt: sugar solution in 12 days to achieve a pleasant flavour and firmness of pickled baby corn. Pickled baby corn would be easily accepted in cuisine. Production of pickle from this vegetable can improve the added value as well as to reduce post-harvest losses from this valuable source.

Combination of xylanase and cellulase hydrolysis for enhanced saccharification of poplar chips: Process optimization

Removing xylan from the outer surface of cellulose could promote the accessibility of cellulase to cellulose. Under this premise, in order to develop an efficient pretreatment method to obtain fermentable reducing sugar from poplar fiber, a response surface methodology was created via the combination of the Plackett-Burman design and the Box-Behnken design and was utilized by the Design-Expert software. The optimum conditions were as follows: a liquid-solid ratio of 4.95 to 1 (mL/g), a pre-hydrolysis xylanase temperature of 70.3 °C, and a total hydrolysis time of cellulase of 52.9 h. Under these conditions, the maximum amount of reducing sugars converted from poplar fiber was 159.6 mg/g. The average amount from the validation results was 160.1 mg/g, which was in agreement with the predicted value. Meanwhile, the poplar fiber hydrolyzed via a xylanase-aided two-stage pretreatment was compared with the poplar fiber hydrolyzed via only a cellulase pretreatment, using scanning electron microscopy. The xylanase-aided treatment revealed a surface with a more damaged structure, indicating that the utilization of xylanase could further improve the effects of hydrolysis on poplar fibers.

Pretreatment of lignocellulosic feedstock to produce fermentable sugars for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production using activated sludge

The goal of this research was to release fermentable reducing sugar from lignocellulose (poplar) by hot water pretreatment, and then employed to synthesize poly(3-hydroxybutyrate-co-3-hydroxy-valerate) (PHBV) using activated sludge to replace traditional petroleum-based polymers. The orthogonal experiment was used to optimize the conditions of different pretreatment temperature, pretreatment time, enzymatic hydrolysis temperature and enzymatic hydrolysis time and the optimal condition for producing sugars was pretreated at 200 °C for 30 min and enzymatic hydrolysis at 45 °C for 3d. A maximum yield was 530.3 mg/g of reduced sugar, while the furfural and 5-HMF produced in the optimum conditions were 512.61 mg/L and 239.34 mg/L. Moreover, the effects of increasing concentration of hot water pretreated poplar hydrolysates (500–1700 mg/L) on PHBV production were investigated. Poplar hydrolysate (1700 mg/L) exhibited maximum PHBV concentration of 637.556 mg/L.

Degradation of bamboo lignocellulose by bamboo snout beetle Cyrtotrachelus buqueti in vivo and vitro: efficiency and mechanism

BackgroundAs an important biomass raw material, the lignocellulose in bamboo is of significant value in energy conversion. The conversion of bamboo lignocellulose into fermentable reducing sugar, i.e. the degradation of bamboo lignocellulose, is an important step in lignocellulose conversion. However, little research has focussed on excavating the enzymes and microbes that are related to the degradation of bamboo lignocellulose, which is important for its utilisation. This study used Cyrtotrachelus buqueti (bamboo snout beetle) to evaluate the efficiency of bamboo lignocellulose degradation.ResultsRNA sequencing was conducted to sequence the transcriptome of the insect before and after feeding on bamboo shoots. The expression levels of genes encoding several carbohydrate-active enzymes, such as endoglucanase (evgtrinloc27093t1 and evgtrinloc16407t0) and laccase (evgtrinloc15173t0 and evgtrinloc11252t0), were found to be upregulated after feeding. Faecal component analysis showed that the degradation efficiencies of cellulose, hemicellulose and lignin were 61.82%, 87.65% and 69.05%, respectively. After 6 days of co-culture with crude enzymes in vitro, the degradation efficiencies of cellulose, hemicellulose and lignin in bamboo shoot particles (BSPs) were 24.98%, 37.52% and 26.67%, respectively. These results indicated that lignocellulosic enzymes and related enzymes within the insect itself co-degraded bamboo lignocellulose. These finding can potentially be used for the pre-treatment and enzymatic hydrolysis of bamboo lignocellulose.ConclusionOur results showed that intestinal digestive enzymes from C. buqueti degraded bamboo shoot lignocellulose both in vivo and in vitro. In addition, the expression levels of many carbohydrate-active enzyme (CAZyme) genes were upregulated in the transcriptome, including those for cellulase, xylanase and ligninase genes. Therefore, we proposed a scheme for applying the lignocellulolytic enzymes from C. buqueti to degrade bamboo lignocellulose using genetic, enzymatic and fermentation engineering techniques to overexpress the lignocellulolytic enzymes genes in vitro and obtain large quantities of enzymes that could efficiently degrade bamboo lignocellulose and be used for lignocellulose bioconversion.