Cellulase Enzyme Research Articles

Enhanced crystalline cellulose degradation by a novel metagenome-derived cellulase enzyme

Metagenomics has revolutionized access to genomic information of microorganisms inhabiting the gut of herbivorous animals, circumventing the need for their isolation and cultivation. Exploring these microorganisms for novel hydrolytic enzymes becomes unattainable without utilizing metagenome sequencing. In this study, we harnessed a suite of bioinformatic analyses to discover a novel cellulase-degrading enzyme from the camel rumen metagenome. Among the protein-coding sequences containing cellulase-encoding domains, we identified and subsequently cloned and purified a promising candidate cellulase enzyme, Celcm05-2, to a state of homogeneity. The enzyme belonged to GH5 subfamily 4 and exhibited robust enzymatic activity under acidic pH conditions. It maintained hydrolytic activity under various environmental conditions, including the presence of metal ions, non-ionic surfactant Triton X-100, organic solvents, and varying temperatures. With an optimal temperature of 40 °C, Celcm05-2 showcased remarkable efficiency when deployed on crystalline cellulose (> 3.6 IU/mL), specifically Avicel, thereby positioning it as an attractive candidate for a myriad of biotechnological applications spanning biofuel production, paper and pulp processing, and textile manufacturing. Efficient biodegradation of waste paper pulp residues and the evidence of biopolishing suggested that Celcm05-2 can be used in the bioprocessing of cellulosic craft fabrics in the textile industry. Our findings suggest that the camel rumen microbiome can be mined for novel cellulase enzymes that can find potential applications across diverse biotechnological processes.

Green ecofriendly enhancement of cellulase productivity using agricultural wastes by Aspergillus terreus MN901491: statistical designs and detergent ability on cotton fabrics

BackgroundCellulase is considered a group member of the hydrolytic enzymes, responsible for catalyzing the hydrolysis of cellulose and has various industrial applications. Agricultural wastes are used as an inexpensive source for several utilizable products throughout the world. So, searching for cellulase enzymes from fungal strains capable of utilizing agricultural wastes to increase productivity, reduce costs and overcome waste accumulation in the environment is very important to evaluate its potency as a bio-additive to detergent agents.ResultsIn the current study, the previously identified fungal strain Aspergillus terreus MN901491 was screened and selected for cellulase production. Medium parameters were optimized using one-factor-at-a-time (OFAT) and multi-factorial (Plackett-Burman and Box-Behnken) design methods. OFAT showed the ability of the fungal strain to utilize agricultural wastes (corn cob and rice straw) as a substrate. Also, yeast extract was the best nitrogen source for enhancing cellulase productivity. The most significant variables were determined by Plackett-Burman Design (PBD) and their concentrations were optimized by Response Surface Methodology (RSM) using Box-Behnken Design (BBD). Among eleven independent variables screened by PBD, malt extract, (NH4)2SO4, and KCl were the most significant ones followed by rice straw which affected cellulase production positively. The ANOVA results particularly the R2-value of PBD (0.9879) and BBD (0.9883) confirmed the model efficiency and provided a good interpretation of the experiments. PBD and BBD improved cellulase productivity by 6.1-fold greater than that obtained from OFAT. Medium optimization using OFAT and statistical models increased cellulase production from A. terreus MN901491 by 9.3-fold compared to the non-optimized medium. Moreover, the efficiency of cellulase activity on cotton fabrics as a bio-additive detergent was evaluated and estimated using whiteness and scanning electron microscope (SEM) that affirmed its potential effect and remarkable detergent ability to improve whiteness by 200% in comparison with non-washed fabric and by 190% in comparison with fabric washed by water.ConclusionThe presented work was stabilized as a multi-efficiency in which wastes were used to produce cellulase enzyme from the fungal strain, Aspergillus terreus MN901491 as a bio-additive to detergent applications that involved ecofriendly and green processes.

Full utilization of poplar sawdust with chemical-mechanical pretreatment for coproduction of xylooligosaccharides, fermentable sugars and porous carbon materials

In recent decades, one of the major challenges of biorefinery is the full utilization of lignocellulosic components for coproduction of value-added materials. In this context, we proposed an integrated process of acetic acid (AC) pretreatment, Papir Forsknings Institutet (PFI) refining and enzymatic hydrolysis to coproduce xylooligosaccharides, fermentable sugars and lignin-based porous carbon materials. Results showed AC pretreatment (170 ºC, 60 min, 5 w/v % acetic acid and 5% 2-naphthol addition based on dry mass of biomass) resulted in maximum xylooligosaccharids (XOS) yield of 51.08%. The integrated process of AC pretreatment assisted by 2-naphthol-7-sulfonate addition and PFI post-refining led to cellulose hydrolysis yield of 98.20% and lignin-based porous carbon materials with methylene blue adsorption capacity of up to 749.17 mg/g. Moreover, it was found lignin repolymerization inhibitors (i.e. 2-naphthol, 2-naphthol-7-sulfonate) in acid pretreatment helped increase the specific surface area of substrate and decrease surface lignin coverage, which enhanced cellulose accessibility to cellulase enzymes. Moreover, they enhanced lignin detaching during enzymatic hydrolysis, which reduced cellulase aggregation and promoted the ease of cellulose hydrolysis. Results demonstrated an efficient pretreatment strategy to maximize coproduction of xylooligosaccharids, fermentable sugars and lignin materials from lignocellulosic biomass for full utilization.

Ficus hookeri tree leaves as herbal feed additives to enhance ruminal fermentation and reduced protozoal population in growing crossbred cattle

An experiment was conducted to evaluate the effect of dietary supplementation of Ficus hookeri leaf meal as herbal feed additive on rumen protozoal population, enzyme profile and fermentation characteristics in growing crossbred calves. Ten growing male crossbred (Jersey × Tharparker) calves with similar initial body weight of 91.8+1.37 kg, were randomly divided into two equal groups (T1 and T2) and fed individually under stall feeding for 140 days on a mixed ration containing rice straw and concentrate mixture in 50:50 ratio. Two types (C1 and C2) of iso-nitrogenous concentrate mixtures were prepared. Wheat bran in concentrate mixture (C2) of test group (T2) was partially replaced (4 parts w/w) with Ficus hookeri leaf meal. Daily dry matter intake between two experimental groups was similar. Rumen pH, NH3-N concentration and total rumen protozoal population decreased while ruminal TVFA and propionic acid production increased due to dietary supplementation of Ficus hookeri leaf meal as herbal feed additive. Activity of carboxymethyl cellulase, xylanase and b-glucosidase enzymes were significantly higher in the rumen liquor of calves fed Ficus hookeri leaf meal. It could be concluded that dietary supplementation of Ficus hookeri leaf meals as herbal feed additive have a potential for reducing rumen protozoal population and ammonia nitrogen concentration with improving ruminal TVFA and propionate production in growing crossbred calves.

Biohydrogen Production and Quantitative Determination of Monosaccharide Production Using Hyperthermophilic Anaerobic Fermentation of Corn Stover

Second-generation biofuels from lignocellulosic biomass remain critical and require several challenges due to lignin compounds’ inefficient degradation and recalcitrate characteristics. In this regard, this study focuses on enzymatic technology as a promising treatment that is beneficial in breaking down the biomass’s hemicellulose and cellulosic parts. Thermostable bacterial species owe thermostable enzymes that are able to degrade complex carbohydrate compounds and produce efficient hydrogen production. The present study investigates the direct utilization of ligninolytic enzymes such as cellulase and xylanase derived from the hyperthermophilic bacteria Thermotoga maritima (ATCC 43589 strain). The results show that xylanase and cellulase enzymes extracted from Thermotoga maritima could depolymerize the lignin bonds of corn stover substrate and release monomers such as Galactose in the media. In conclusion, this study can open a new advanced research window on directly applying a hyperthermophilic consortium of enzymes capable of hydrolyzing lignocellulose material toward hydrogen production.

Study of hydrolysis efficiency of isoflavones from soy germ extracts by cellulase enzyme

Study of hydrolysis efficiency of isoflavones from soy germ extracts by cellulase enzyme

Effect of medium supplementations and extraction conditions on cellulase production through solid state fermentation of oil palm empty fruit bunches

In this study, cellulase enzyme was produced through solid state fermentation (SSF), employing oil palm empty fruit bunches (EFB) as the primary substrate. Two key aspects were explored to enhance crude enzyme yield, which are medium supplementation effects during SSF and cellulase recovery. During medium supplementation, glucose and/or Tween 80 were added alongside EFB substrate and other nutrients. Enzyme yield was determined using a filter paper assay and expressed as enzyme activity. The initial addition of glucose during fermentation led to increased crude enzyme activity, as measured by the filter paper assay. The peak crude enzyme activity was observed with the addition of 3 mg of glucose, with higher amounts showing no further increase in activity. Conversely, the addition of Tween 80 did not yield any significant increase in crude enzyme activity across all concentrations tested. The extraction conditions were varied to study cellulase recovery, specifically by adjusting the solid‐to‐solvent ratio and the number of extraction stages. Higher enzyme activity was achieved with lower solid‐to‐liquid ratios, as the increased solvent volume facilitated greater enzyme extraction. However, increasing the number of extraction steps did not significantly affect the resulting cellulase activity. Overall, this research underscores the need for further process optimization for cellulase production via SSF, utilizing the widely available EFB in Indonesia.

Isolation and molecular characterization of cellulase-producing bacteria from waste dump site

Cellulases are collections of extracellular enzymes and a complex mixture of enzyme proteins with various specificities. Cellulases work together to hydrolyze glycosidic bonds and generate monomers of glucose for fermentation. This investigation aims to isolate and molecularly characterize Bacillus species with cellulolytic ability. Bacillus species were isolated from soil samples retrieved from a dump site and screened for cellulolytic ability on carboxyl methylcellulose (CMC) agar. The percentage hydrolysis efficiency of isolates was determined and cellulase produced was quantified using CMC assay method. Biochemical identification was by Analytical Profile Index (API) Kit 50CHB/20E and API web software while molecular characterization employed 16S rRNA gene sequencing and blast search analysis. Bacillus megaterium (FSP1) and Bacillus zanthoxyli (FSP4) exhibited their cellulolytic potentials by presenting zones of clearance of about 21 ± 2.08 and 7 ± 1.00 mm on CMCA with hydrolysis efficiency of 250 and 600 % respectively. Quantification of crude cellulase revealed cellulase activity of 85 and 74μmol/ml for both bacteria species. Biochemically, the cellulolytic bacteria were identified as Bacillus megaterium (FSP1) and Bacillus zanthoxyli (FSP4) while molecularly, they were identified as Bacillus megaterium 14581 (FSP1) and Bacillus zanthoxyli 1433 (FSP4) with Reference Sequence (RefSeq) accession numbers NR_116873 and NR_164882, and showing maximum sequence similarity of 99 and 96 % respectively. Results obtained from this investigation, suggests that both bacteria species characterised, possesses good cellulolytic ability and hence can be utilized for the production of the enzyme cellulase which has a wide range of industrial application.

Bioplastic films from cassava peels: Enzymatic transformation and film properties

Annually, millions of tons of cassava peels are generated as agro-waste. This research repurposed entire cassava peels into biodegradable films as a sustainable alternative to single-use plastics. Enzymes (cellulase, xylanase, and glucanase) were employed to catalyze the process, and cassava peels were effectively converted into films, which exhibited comparable or even better mechanical properties and water resistance to commercial packaging materials. The films also presented high water solubility of 44–50% and good light barrier properties, with 15–23% transmittance values for visible light and less than 3% for UV light. Extended enzymatic treatment time resulted in films characterized by increased elasticity, solubility, water resistance, transparency, and smoother surfaces, which can be attributed to the enzymatic breakdown of cassava peel fibers into smaller saccharide units. The optimal enzymatic treatment time was found to be 4 h which produced films with favorable mechanical characteristics, barrier properties, and solubility. A sustainable and ecologically-friendly approach is provided to fully harness cassava peels in fabricating packaging films, particularly suited for food items necessitating dissolution in water.

Elucidation of enhanced cellulase immobilization onto synthetic magnetic nickel nanomaterials for lignocellulosic biomass hydrolysis

The immobilization of cellulase enzymes for the conversion of lignocellulosic biomass into sustainable biochemical products is essential for the stability and recovery of the enzymes. In this study, nickel nanoparticles (NiNPs) were synthesized and coated with 3-aminopropyl triethoxysilane (APTES) to serve as cellulase enzyme carriers. Cellulase enzyme immobilization on the prepared NiNPs was achieved using glutaraldehyde as a cross-linker. The physicochemical properties of the carrier were determined before and after enzyme immobilization using X-ray Powder Diffraction (XRD), Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Vibrating-Sample Magnetometer (VSM), and Field Emission Scanning Electron Microscopy (FESEM). The impacts of different experimental factors on the performance of the cellulase enzymes immobilized on the synthesized NiNPs and commercial nickel nanoparticles were compared. The results showed comparable optimal cellulase enzyme immobilization conditions on both substrates in terms of the immobilization time, pH, and cellulase enzyme concentration. However, the recommended temperatures for cellulase enzyme immobilization on the synthesized and commercial NiNPs were 50 °C and 40 °C, respectively. Under these optimum conditions, the immobilized cellulase enzyme on the synthesized NiNPs had an activity of about 99.1% (in comparison to the activity of free cellulase enzyme), while the activity of the enzyme upon immobilization on commercial NiNPs was about 93%. The particle size of the NiNPs was found to be crucial for enzyme immobilization efficiency and its magnetic strength. Therefore, cellulase enzyme immobilization on tunable NiNPs could be a sustainable and eco-friendly approach towards high recovery of cellulose from lignocellulosic materials.

Functionalized magnetic nanoparticles for Cellic Ctec2 cellulase immobilization: Allowing reusability of enzyme in the conversion of cellulosic biomass

The method of enzyme immobilization can ameliorate the overall stability and restoration of enzymes, hence facilitating their broader application in several sectors. This investigation utilized cellulase as a hydrolytic enzyme. In order to enhance the stability and performance of the cellulase enzyme, the research employed immobilization technology to secure the Cellic Ctec2 cellulase to the synthesized Cs@Fe3O4 nanocomposites. Fe3O4 nanoparticles (NPs) were coated with chitosan obtained from co-precipitation method that served as enzyme carrier. The NPs (Cs@ Fe3O4) were observed under XRD; VSM (vibrating-sample magnetometer) shows saturation magnetizations (Ms), UV–vis, field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FT-IR). Response surface approach was applied to optimize the conditions for immobilization of cellulase. The optimum immobilization of cellulase reaches to 99.1% of loading efficiency and 69.7% of recovery activity with 2.5% of glutaraldehyde concentration. Furthermore, under ideal circumstances the immobilized enzyme’s thermostability, pH stability, temperature tolerance and reusability, were studied with respect to free cellulase. Higher relative activity of cellulase enzyme was observed at pH 5 with 50 °C temperature than free enzyme. One percent CMC hydrolysis is considered for reusability of free and immobilized enzyme and releases 222 mg glucose/g substrate at 24 h, showing great quiescence in cellulosic biomass conversion. Immobilized cellulase demonstrated high reusability by retaining almost 61.2% up to the 5th cycles and 51.2% of activity-maintained 10th cycle of hydrolysis. Reusability of cellulase enzyme can attain a gradual decrease in relative activity as number of repeats of the cycle increases to 10 during hydrolysis and increases in glucose yield after hydrolysis.

Enhancing Kojic Acid Production in Aspergillus oryzae: Leveraging Crude Cellulase from Achatina fulica for Strain Improvement via Protoplasting and UV Mutagenesis

This study aims to prove the ability of crude cellulase enzymes from snails for protoplasting Aspergillus oryzae cells and its application for strain improvement with UV mutagenesis. Snail enzyme was obtained from Achatina fulica by dissolving its digestion track and fractionating it with ammonium sulfate. The activity of fractions was measured Spectrophotometrically and used for cell protoplasting for 2 hours, then irradiated with UV for 10, 15, and 20 minutes, respectively, with 5 cm in the distance. Screening of mutants is carried out with 1% FeCl3, and the potential mutant strain was tested for kojic acid production in an aerobic state and determined by Spectrophotometry at 268 nm. The cellulase activity in crude snail enzyme was 11.5807 U/ml and increased to 16.3984 U/ml after fractionation. The best protoplast formation was obtained with a 60% fraction, which showed transparent performance under the microscope. The UV mutagenesis of protoplasts showed that the highest number of potential mutants was obtained from UV treatment for 15 minutes (41.67%). The potential mutants look dark brown (DBC), such as strain 10H3, and produced higher kojic acid concentration than the parent strain. In conclusion, UV mutagenesis of Aspergillus oryzae through protoplasting by crude cellulase of snail enzyme was effective and improved kojic acid concentration.

Investigation of the effect of enzymatic and alkali treatments on the physico-chemical properties of Sambucus ebulus L. plant fiber

The investigation aims to determine the effect of enzymatic and alkali treatments on Sambucus ebulus L. stem fiber. For this purpose, Sambucus ebulus L. stem fibers were treated with alkali, cellulase, and pectinase enzymes. An image processing technique was developed and implemented to calculate the average thicknesses of Sambucus ebulus L. fibers. The thickness of alkali, cellulase and pectinase enzyme treated fibers was determined as 478.62 μm, 808.28 μm and 478.20 μm, respectively. Scanning electron microscopy analysis illustrated that enzymatic and alkali treatments lead to the breakage of fiber structure. Furthermore, enzymatic and alkali treatments induce variations in elemental ingredients. All treatments increased the crystallinity index of Sambucus ebulus L. fiber from 72 % (raw fiber) to 83 % (alkali treated), 75.2 % (cellulase enzyme treated) and 86.3 % (pectinase enzyme treated) due to the hydrolysis of hemicellulose. Fourier transform infrared analysis indicated that there are no significant differences in functional groups. Thermogravimetric analysis shows that enzymatic and alkali treatments improve final degradation temperature of the fiber. Mechanical behaviors of cellulase enzyme-treated fiber decrease compared to raw fiber, while pectinase enzyme and alkali treatment cause to improve mechanical properties. Tensile strength of samples was determined as 76.4 MPa (cellulase enzyme treated fiber), 210 MPa (pectinase enzyme treated fiber) and 240 MPa (alkali treated fiber). Young's modules of cellulase enzyme, pectinase enzyme and alkali treated fibers were predicted as 5.5 GPa, 13.1 GPa and 16.6 GPa. Elongation at break of samples was calculated as 5.5 % (cellulase enzyme treated fiber), 6.5 % (pectinase enzyme treated fiber) and 6 % (alkali treated fiber). The results suggest that enzymatic and alkali treatments can modify the functional and structural attributes of Sambucus ebulus L. fiber.

Surface-Enhanced Raman Spectroscopy for Monitoring the Biochemical Changes Due to DNA Mutations Induced by CRISPR-Cas9 Genome Editing in the Aspergillus niger Fungus.

In this study, surface-enhanced Raman spectroscopy (SERS) technique, along with principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA), is used as a simple, quick, and cost-effective analysis method for identifying biochemical changes occurring due to induced mutations in the Aspergillus niger fungus strain. The goal of this study is to identify the biochemical changes in the mutated fungal cells (cell mass) as compared to the control/nonmutated cells. Furthermore, multivariate data analysis tools, including PCA and PLS-DA, are used to further confirm the differentiating SERS spectral features among fungal samples. The mutations are caused in A. niger by the clustered regularly interspaced palindromic repeat CRISPR-Cas9 genomic editing method to improve their biotechnological potential for the production of cellulase enzyme. SERS was employed to detect the changes in the cells of mutated A. niger fungal strains, including one mutant producing low levels of an enzyme and another mutant producing high levels of the enzyme as a result of mutation as compared with an unmutated fungal strain as a control sample. The distinctive features of SERS corresponding to nucleic acids and proteins appear at 546, 622, 655, 738, 802, 835, 959, 1025, 1157, 1245, 1331, 1398, and 1469 cm-1. Furthermore, PLS-DA is used to confirm the 89% accuracy, 87.7% precision, 87% sensitivity, and 88.9% specificity of this method, and the value of the area under the curve (AUROC) is 0.67. It has been shown that surface-enhanced Raman spectroscopy is an effective method for identifying and differentiating biochemical changes in genome-modified fungal samples.

Effects of enzymatic hydrolysis technology on the physicochemical properties and biological activities of American ginseng beverages.

American ginseng (Panax quinquefolius L.) contains various biological macromolecules, such as polysaccharides, saponins, and proteins, which have various pharmacological activities, including antioxidant, anti-inflammatory, and hypoglycemic effects. Consequently, the utilization of novel processing technologies developed an American ginseng beverage to meet people's health needs and the preferences of young people. This study was the first to use American ginseng as a primary raw material, utilizing a three-step enzymatic hydrolysis approach with cellulase, pectinase, amylase, maltase, and flavor protease enzymes to prepare an American ginseng beverage. The basic nutritional and active ingredient contents of the product were determined. The antioxidant activity of enzymatic beverages was evaluated by calculating the free radical clearance rates of DPPH and ABTS, and the effect of enzymatic beverages on α-glucosidase activity was also tested. The anti-inflammatory activity of RAW264.7 cells induced by LPS was evaluated by measuring the production of NO, TNF-α, and IL-6 during the enzymatic hydrolysis process. The results indicated that the nutritional components of American ginseng beverage products met the beverage industry standards. Moreover, the application of enzymatic hydrolysis technology had improved the antioxidant and anti-inflammatory activities of American ginseng beverages. In addition, the enzymatic beverage of American ginseng exhibited certain hypoglycemic activity. Consequently, the established enzymatic hydrolysis technology provided a reference for the production of other beverage products.

Oral Microbial Diversity Among Nepalese Individuals Across Various Geographical Regions

A comprehensive study encompassed the collection of 153 samples derived from oral patients across 17 diverse locations throughout Nepal. The assortment of samples included extracted teeth, dental plaque, and dental calculus, procured from dental clinics, dental hospitals, and dental camps. Employing six distinct culture media, namely nutrient agar (NA), Muller Hilton agar (MHA), mannitol salt agar (MSA), blood agar (BA), brain heart infusion agar (BHA), and potato dextrose agar (PDA) for potential fungal strains, plates were meticulously incubated at 37°C for 5-7 days. The ensuing bacterial colonies were judiciously isolated, and their morphological and biochemical traits were scrutinized. The microscopic structures of the bacterial cells were examined, considering shape, size, colour, opacity, and texture. Gram-staining was employed, and each colony's biochemical attributes were assessed for protease, pectinase, cellulase, and lipase enzymes. From the 1200 colonies isolated from dental samples, 300 diverse colonies, distinguished by morphological and biochemical characteristics, were chosen for further taxonomic identification. Subsequent sequencing revealed the identification of 60 distinct species within 21 genera of bacterial isolates, including Achromobacter, Bacillus, Chryseobacterium, Citrobacter, Curtobacterium, Enterobacter, Enterococcus, Escherichia, Flavobacterium, Klebsiella, Kocuria, Lyinibacillus, Novosphingobium, Ochrobactrum, Proteus, Pseudomonas, Sporosarcina, Staphylococcus, Stenotrophomonas, Serratia and Streptococcus. The research underscored the presence of various pathogenic bacterial species in oral samples.

KARAKTERISASI SELULASE TERMOSTABIL ASAL ISOLAT BAKTERI TANAH PERTANIAN PASANG SURUT

Cellulase is an enzyme that can break up β - (1→4) glycosidic bonds of cellulose. Generally, cellulases are classified into three major groups, i.e., endoglucanase (EC 3.2.1.4), exoglucanase (EC 3.2.1 .91), and β glucosidase (EC 3.2.1.21). Meanwhile, five isolates of tidal swamp soil have been isolated; thus, in this research step, we are acquainted with cellulase activity and the characterization of cellulase enzymes on various temperatures, pH, and specific substrates. The activity of an enzyme was measured using the modified Miller and Bradford methods to detect the specific characteristics of the isolate. The results showed that five isolates namely ATP-1 BKP-5, HAMML-2, PKL-2, and SPBKK-3 have activities 0.025 nKat.ml-1, 0.032 nKat.ml-1, 0.296 nKat.ml-1, 0.114 nKat.ml-1, and 0.087 nKat.ml-1, respectively. Furthermore, cellulase from isolates ATP 1, BKP-5, and PKL 2 have an optimum activity at pH 7,0; 50 oC. The isolate HAMML-2 has an optimum activity at pH 5,0; 60 oC. SPBK 3 has an optimum activity at pH 5,0; 50 oC. All of those isolates can degrade CMC, Avicell, and Whatman paper No.1 and retain the activity relative to the temperatures 50 and 60 0C as the characteristics of the thermostable enzyme.

Evaluating the effects of chitosan incorporated with seabuckthorn leaf extract composite edible coatings on the shelf life of peach (Prunus persica L.) fruits

Peaches are highly nutritious and delicious fruits with a limited shelf life. The present study was aimed to test the efficiency of chitosan (CHI) coatings incorporated with seabuckthorn leaf extract (ST) in extending the shelf life of peach fruits at refrigerated temperature. Peach fruits of ‘Elberta’ cultivar were coated with one of the following treatment combinations: distilled water (control), CHI (1.0%), CHI (1%) + ST (0.5%), CHI (1%) + ST (1.0%), CHI (1%) + ST (1.5%) and CHI (1%) + ST (2.0%) and then stored at 4 °C for 25 days. The combined treatment of CHI and ST showed a synergistic effect in significantly decreasing the skin browning and maintaining the firmness during the storage period, corroborated by the decline in the polyphenol oxidase, cellulase and pectinase enzyme activity. In particular, fruits treated with CHI (1%) + ST (1.5%) and CHI (1%) + ST (2.0%) showed maximum efficiency in retaining the physico-chemical attributes, increasing the antioxidant potential and controlling the browning during post harvest period upto 25 days under refrigerated temperature at 4 °C. Furthermore, besides maintaining the quality parameters, the treated fruits showed a significant reduction in microbial spoilage and maintaining the acceptable sensory attributes. Therefore, the study employing the incorporation of Seabuckthorn leaf extract into chitosan edible coating could be a valuable addition and promising approach to different existing preservation techniques towards extending the shelf life of peach fruits.

Effects of Cellulase and Xylanase on Fermentation Characteristics, Chemical Composition and Bacterial Community of the Mixed Silage of King Grass and Rice Straw.

This study was to investigate the effects of cellulase and xylanase on fermentation characteristics, nutrient composition and the bacterial community of the mixed silage of king grass and rice straw. Lab-scale bag silage was produced and seven groups were studied: blank control (CK); added 1%, 2% cellulase (CE1, CE2); added 1%, 2% xylanase (XY1, XY2); and added 0.5% cellulase +0.5% xylanase, 1% cellulase +1% xylanase (CX1, CX2). The results showed that the application of additives in six treated groups exerted a positive effect on lactic acid (LA) content and their pH values decreased significantly (p < 0.05). The addition of cellulase and xylanase decreased (p < 0.05) the content of neutral detergent fiber (NDF) and acid detergent fiber (ADF) significantly and increased (p < 0.01) the crude protein (CP) and water-soluble carbohydrate (WSC) content. Filter paper enzyme activity (FPA) declined and xylanase activity (XA) intensified (p < 0.05) as ensiling was prolonged, where most of the enzymatic treatments (especially XY2, CX2) resulted in increased enzyme activities. Moreover, the addition of cellulase and xylanase reduced the abundance of harmful bacteria such as Acinetobacter and Klebsiella and increased the abundance of lactic acid bacteria such as Lacticaseseibacillus, Lactiplantibacillus. In conclusion, the addition of cellulase and xylanase would improve fermentation quality and nutrient preservation via altering the bacterial community, with 1% cellulase or complex enzyme best.

Comparative Measurements of Cellulase Enzymes in Qualitative and Quantitative activity in some Trichoderma spp.

Comparative Measurements of Cellulase Enzymes in Qualitative and Quantitative activity in some Trichoderma spp.