2022, Vol. 7, No. 2

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Mini Review
Is engineered wood China's way to carbon neutrality?
Christian Sonne, Changlei Xia, Su Shiung Lam
2022, 7(2): 83-84. doi: 10.1016/j.jobab.2022.03.001
Sources, production and commercial applications of fungal chitosan: A review
Tanzina Huq, Avik Khan, David Brown, Natasha Dhayagude, Zhibin He, Yonghao Ni
2022, 7(2): 85-98. doi: 10.1016/j.jobab.2022.01.002
Chitosan is a type of biopolymer that can be obtained from animal/marine sources, and it can also be extracted or produced from agriculture waste products like mushroom or different fungal sources after the chitin deacetylation. Depending on the size of mushroom farm, the amount of waste ranges between 5% and 20% of the production volume. The cell wall of the filamentous fungi, a good source of chitin, offers an easy way to extract chitin. The physicochemical characteristics such as molecular weight and degree of deacetylation of fungal chitosan can be controlled compared to chitosan obtained from crustacean sources. Fungal sourced chitosan can be used in food, pharmaceutical or biomedical applications for different applications, for example, as an antimicrobial agent, coating material, water purification or bio-pesticide. This review mainly focused on the extraction of chitin from mushroom or different fungal sources and also showed some applications of commercial chitosan products.
A mixed acid methodology to produce thermally stable cellulose nanocrystal at high yield using phosphoric acid
Khairatun Najwa Mohd Amin, Alireza Hosseinmardi, Darren J. Martin, Pratheep K. Annamalai
2022, 7(2): 99-108. doi: 10.1016/j.jobab.2021.12.002
Cellulose nanocrystal (CNC) with distinctive shape-morphology, enhanced thermal stability and dispersibility is essential for overcoming the challenges in processing polymer/CNC nanocomposites through melt compounding at elevated temperatures. This study shows a mixed acid hydrolysis method to produce CNC with improved thermal stability and high productivity. The use of phosphoric acid (H3PO4), as a mild acid, in combination with a strong acid either sulphuric acid (H2SO4) or hydrochloric acid (HCl) leads to reduced use of strong acids and low impact on our environment. The influences of acid combination and sequence of addition on the production yield were investigated by retaining the proportion of H3PO4 to corrosive acid (H2SO4 and HCl) 4 to 1, and solid to liquid ratio 1:75. This methodology has enabled to isolate CNC with higher thermal stability, dispersibility and productivity in terms of amount acid used 1 g of CNC, as compared with single acid hydrolysis. The CNC produced using the combination of H3PO4 and HCl exhibits high thermal stability, dispersibility and rod-like shape morphology with length and width of (424 ± 86) and (22 ± 3) nm, respectively. Moreover, this approach has reduced H3PO4 consumption by 54% as compared with single acid hydrolysis method for the production of same amount of CNC.
Biochar derived from non-customized matamba fruit shell as an adsorbent for wastewater treatment
Gotore Obey, Munodawafa Adelaide, Rameshprabu Ramaraj
2022, 7(2): 109-115. doi: 10.1016/j.jobab.2021.12.001
This study of Matamba shell reviled them as material with outstanding surface morphology, elemental and kinetic mechanism characteristics. Mutamba biochar revealed irregular honeycomb morphological transformation from the field emission scanning electron microscope after pyrolysis at 600 ℃ for 2 h. Energy dispersive X-ray spectroscopy revealed high content of carbon (72.68wt%), nitrogen (14.14wt%) and oxygen (10.35wt%) on the biochar surface. The available oxygen composition provides enough polarization ability for high iodine adsorption (43.65 mmol/g) from the experimental data which were significantly induced by weak van der Waals forces and π-π and π-stacking interaction on the biochar surface and its micropores. The carbon content above 50% in ash rich biochar with an increase in pyrolysis can be ascribed to elements incorporated into aromatic or heterocyclic ring system established through preferential loss of oxygen at 600 ℃ pyrolysis. The adsorption kinetics were conducted to evaluate the equilibrium adsorption of the novel material and Elovich and Intra particle diffusion better described well the kinetic adsorption through Iodine adsorption than pseudo first order and pseudo second order models. Elovich was the best model to fit the adsorption kinetics with 45.41 mmol/(g·min) adsorption rate. The second order Akaike Information Criterion (38.26), adjusted correlation coefficient R2 (0.9898) and sum of squares error (1.442) were used to fit the data. Consequently, the biochar in this study can serve as a promising green material for efficiently removing organic and inorganic contaminants from the environmental water ecosystem. The environmental significance of biochar will be of fundamental meaning to rural areas in developing countries in aquatic contaminants immobilization for water reuse. These results indicate that the Matamba fruit shells has the possibility to be used as an eco-friendly and low-cost effective adsorbent for anionic dye removal from the water environment. They also demonstrate the immense potential of the fruit shell waste to produce high performance biochar as an alternative green carbonaceous material that can be applied to adsorb organic and inorganic unwanted constituencies from wastewater as well as improvement of waste management in developing countries at a low cost. Its application as a pathway mitigation for diminishing greenhouse gasses and reducing the global warming potential could not be underestimated.
Hydrochar-embedded carboxymethyl cellulose-g-poly(acrylic acid) hydrogel as stable soil water retention and nutrient release agent for plant growth
Yufei Zhang, Xinyue Tian, Qiuyue Zhang, Huifang Xie, Bingyu Wang, Yanfang Feng
2022, 7(2): 116-127. doi: 10.1016/j.jobab.2022.03.003
The cellulose-based hydrogel has been widely applied for soil water retention and nutrient re-lease agents for several decades. Embedding the inorganic materials into hydrogels is an excellent strategy to improve the inherent limits of the cellulose-based hydrogel. Notably, municipal sludge-derived hydrochar (HC) has reduced the environmental burden and offered a potential hydrogel carrier to control water-retention and nutrient-release. However, the above function for plant growth of hydrochar-embedded carboxymethyl cellulose-g-poly(acrylic acid) (CMC-g-PAA/HC) is unknown, and relevant reports are lacking. This study investigated the water retention, nutri-ent release behavior, and effect of germination and plant growth of CMC-g-PAA/HC hydrogel. Characterization results showed that HC was successfully incorporated into CMC-g-PAA/HC with 6.0% higher thermostability, 7.2-21.0% lower swelling ratio (SR) in water, and substantial SR in phosphate solution (P-solution). The water loss rate of CMC-g-PAA/HC in P-solution or wa-ter owned a more significant temperature response (7.9-15.0 folds) than CMC-g-PAA (8.2-10.0 folds). Moreover, 4.0% higher n value and more 18.5% released P for CMC-g-PAA/HC were also observed. These phenomena were due to restricting the polymer chains movement and the wa-ter molecules diffusion inside the hydrogels with HC. Phytotoxicity assessments showed that HC in CMC-g-PAA/HC could effectively alleviate the inhibition effects on rape germination retained with 78.3% germination vigor and 80.0% germination ratio, even dramatically improved plant growth to 28 d. The results of this study demonstrated a new route for developing eco-friendly CMC-g-PAA/HC hydrogel, advantageous as a water retention agent and nutrient carrier in arid and semiarid regions.
Comparative phytochemical, thin layer chromatographic profiling and antioxidant activity of extracts from some Indian herbal drugs
Md Sohail Akhtar, Mohamed Rafiullah, Wegdan Aly Shehata, Amzad Hossain, Mohammed Ali
2022, 7(2): 128-134. doi: 10.1016/j.jobab.2022.01.001
Natural antioxidants play a significant role to prevent cell breaking and regenerate cells. Three plants native to India named dwarf morning-glory (Evolvulus alsinoides), Indian banyan (Ficus bengalensis) and chicory (Chicorium intybus) are used as medicine in India traditionally to treat diseases. The aim of this study is to evaluate and compare the antioxidant activity as well as to compare phytochemical profiles of the aqueous extracts of the selected three plants. The dried plant powder was extracted with ethanol individually by using the Soxhlet method for eight hours and the solvent was evaporated under reduced pressure. Similarly, the air-dried powder was ex-tracted with water, and the water was evaporated. The thin layer chromatography (TLC) profile of the extracts was determined by using TLC densitometer and the antioxidant activity was deter-mined by the conventional 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method. The TLC profile shows that there are no similarities of retention factor (Rf) values among the plant extracts which means all three plants contain different chemical compounds. The antioxidant activities of the aqueous extracts at different concentrations show different antioxidant activities. Percentage inhibition is dose dependent, as doses are increasing then percentage inhibition is also increasing for all three plant extracts. Among the selected plants, the highest activity was found in C. intybus and the lowest was in E. alsinoides. The order of the antioxidant activity among the selected plants was C. intybus < F. bengalensis < E. alsinoides. Based on the TLC profile and antioxidant activities, the highest activity of the selected plant species was evaluated.
Improvement of quality of Ginkgo biloba seeds powder by solid-state fermentation with Eurotium cristatum for developing high-value ginkgo seeds products
Minmin Zou, Jiarui Cao, Wen Zhang, Chao Tang, Fuliang Cao, Erzheng Su
2022, 7(2): 135-144. doi: 10.1016/j.jobab.2021.10.002
In this study, we investigated the feasibility of Ginkgo biloba seeds powder by solid-state fermentation with Eurotium cristatum for developing high-value ginkgo seeds products. The optimum fermentation medium was consisted of 10 g of 40-mesh ginkgo seeds powder loaded in 100 mL Erlenmeyer flask with 50% (w/w) of water content, 4% (w/w) of MgSO4 and 5% (w/w) of KH2PO4 addition. The optimum fermentation conditions were pH 5.0, 2 × 108 CFU/g of inoculum size, 3 mL of sterilized water supplemented every two days during the four days of fermentation. Through fermentation, the spore number of E. cristatum was improved by about 36 times with the production of lovastatin reaching (54.10±0.16) μg/g. The antioxidant activity of fermented ginkgo seeds powder also got obvious enhancement, which could help eliminate excess free radicals produced by normal metabolism. The content of free amino acids increased by 82.32%. Except that the sugar was consumed in some degree, the other nutritional and functional components were well preserved while the content of detrimental ginkgolic acids was reduced by 44.97%. In addition, fermented ginkgo seeds powder possessed better digestibility and showed pleasant orange-like smelling. In conclusion, the quality of ginkgo seeds powder was remarkably improved through solid-state fermentation by using E. cristatum, which could be a promising way for functional applications of ginkgo seeds.