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Parthenium hysterophorous, a widespread weed in India, contributes a substantial amount of lignocellulosic biomass. The key objective of this study is to evaluate the feasibility of producing xylanase enzyme from P. hysterophorus weed biomass using the fungus Aspergillus niger. The impact of various physiological factors was confirmed through a two-step approach: first, a one-factor-at-a-time (OFAT) investigation, and subsequently, employing the RSM-based CCD method in statistical design. This research revealed that the RSM-based model led to the optimization of enzyme activity, resulting in a value of 2098.08 IU/gds for xylanase. This was achieved with an incubation time of 4.5 days, a medium pH of 6, and a cultivation temperature of 32.5 °C. Additionally, a pretreatment involving 1% NaOH and a 30-min autoclave treatment was found to alter the chemical composition of lignocellulose substrates (cellulose 43.87% and xylan 28.7%), thereby enhancing the efficiency of enzymatic hydrolysis. Moreover, fermentable sugars were produced by autoclave-assisted alkali pretreatment (NaOH-1.0% w/v) at rates of 219.6 ± 2.05 mg/gds−1 by utilizing the crude xylanase from A. niger and 291.3 ± 1.2 mg/gds−1 from commercial xylanase enzyme. Our study revealed that P. hysterophorus served as a viable and affordable substrate for fermentable sugar liberation, and xylanase is a rate-limiting enzyme in enzymatic saccharification. [ABSTRACT FROM AUTHOR]

The efficient removal of lignin and silica from paddy straw is essential for its volarization into biofuels and other value-added products. In this work, different chemical pre-treatments viz. acid/alkali, organosolv and deep eutectic solvents were carried out to assess the extent of delignification and desilication of paddy straw. Maximum lignin and silica removal of 96.08 and 95.51% was observed with two step acid (0.5% sulphuric acid) followed by alkali (4% sodium hydroxide) pre-treatment with significantly low total lignin (2.30%) and silica content (0.80%) of the treated straw residue. The treated straw residue contained significantly high holocellulose (91.65%), cellulose (75.01%) and hemicellulose content (16.64%). Among the four indigenous fungal isolates, Penicillium mallochii (JS17) cellulase showed better accessibility for the treated straw residue with maximum release of 504.18 mg g−1 of reducing sugars and saccharification efficiency of 56.90%. The two-step acid/alkali pre-treatment of paddy straw was highly effective for removing lignin and silica from paddy straw, thereby, resulting in enhanced enzymatic accessibility of the substrate and more efficient hydrolysis of cellulose into fermentable sugars. [ABSTRACT FROM AUTHOR]

This study evaluates certain pre-treatment methods for Lantana camara stem for efficient conversion to fermentable sugars. The composition analysis of L. camara stem showed 66.8% (w/w) holocellulose, 34.9% (w/w) cellulose and 17% (w/w) hemicellulose. Comparative analysis of various chemical, physical or physico-chemical pre-treatments on L. camara stem was performed. Of all pretreatment methods used, pre-treatment with 1% (v/v) H2SO4 assisted autoclaving gave maximum total reducing sugar yield 132.7 mg/g (13.2 g/L) of raw biomass in pretreated hydrolysate. Major contribution to total reducing sugar was from hemicellulosic fraction, because total pentose sugar yield was 119.4 mg/g of raw biomass whereas, glucose released was only 10 mg/g of untreated biomass. The enzymatic saccharification of pre-treated L. camara stem by 1% (v/v) H2SO4 assisted autoclaving was performed with partially purified carboxymethylcellulase from Bacillus amyloliquefaciens SS35. Enzymatic saccharification at 30 °C for 48 h gave total reducing sugar yield, 63.3 mg/g of pre-treated biomass in the hydrolysate, while untreated biomass gave 43.3 mg/g of untreated biomass. The total sugar yield i.e. the sum of pre-treated biomass hydrolysate total reducing sugar (132.7 mg/g of raw biomass) and enzymatic hydrolysate total reducing sugar (63.3 mg/g of pre-treated biomass) was 196.0 mg/g of raw biomass, indicating the effectiveness of pre-treatment method. Field emission scanning electron microscopy, Fourier transform infrared and X-ray diffraction analyses displayed enhanced porosity, removal of non-cellulosic sugars and increased cellulose crystallinity, respectively, in pre-treated L. camara stem, showing the effectiveness of acid assisted autoclaving pre-treatment. [ABSTRACT FROM AUTHOR]

Nocardiopsis sp. KNU was found to degrade various lignocellulosic waste materials, namely, sorghum husk, sugarcane tops and leaves, wheat straw, and rice husk very efficiently. The strain was found to produce high amounts of cellulase and hemicellulase. Augmentation of cotton seed cake as an organic nitrogen source revealed inductions in activities of endoglucanase, glucoamylase, and xylanase up to 70.03, 447.89, and 275.10 U/ml, respectively. Nonionic surfactant Tween-80 addition was found to enhance the activity of endoglucanase enzyme. Cellulase produced by Nocardiopsis sp. KNU utilizing sorghum husk as a substrate was found to retain its stability in various surfactants up to 90%. The produced enzyme was further tested for saccharification of mild alkali pretreated rice husk. The changes in morphology and functional group were analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. Enzymatic saccharification confirmed the hydrolytic potential of crude cellulase. The hydrolysate products were analyzed by high-performance thin layer chromatography. [ABSTRACT FROM AUTHOR]

A large amount of cotton stalk waste biomass with high cellulose content are incinerated by the farmers causing air pollution. The high cellulose content of cotton stalks can be converted to fermentable sugars by fungal delignification pretreatment of lignocellulosic biomass and enzymatic saccharification. The effect of particle size, moisture content, and media supplements was studied for delignification of cotton stalks by Daedalea flavida MTCC 145 (DF-2) in solid-state fermentation. The highest lignolytic enzyme activities, optimal lignin degradation 29.88 ± 0.97% (w/w) with cellulose loss 11.70 ± 1.30% (w/w), were observed in cotton stalks at particle size 5 mm with 75% moisture content after 20 days. Cellulolytic enzyme activity increased with decrease in particle size and increased moisture content. The addition of Cu, gallic acid, and veratryl alcohol enhanced the lignolytic enzyme production and the lignin degradation. In addition to increased laccase activity, Cu inhibited the cellulolytic activity. Supplements Cu at 0.5 mM/g gave the best results of lignin degradation 33.74 ± 1.17% (w/w) and highest selectivity value (SV) 3.15 after pretreatment. The glucose yield increased to 127.44 ± 4.56 mg/g from 20 day pretreated cotton stalks with Cu supplements, ~threefolds higher than untreated cotton stalks. The study is important for the production of fermentable sugars from cotton stalks residues which can further be utilized in production of bioethanol and other applications. [ABSTRACT FROM AUTHOR]