China National Bamboo Research Center

BACKGROUND: Salt stress is a major factor limiting plant growth and productivity. Salicylic acid (SA) has been shown to ameliorate the adverse effects of environmental stress on plants. To investigate the protective role of SA in ameliorating salt stress on Torreya grandis (T. grandis) trees, a pot experiment was conducted to analyze the biomass, relative water content (RWC), chlorophyll content, net photosynthesis (Pn), gas exchange parameters, relative leakage conductivity (REC), malondialdehyde (MDA) content, and activities of superoxide dismutase (SOD) and peroxidase (POD) of T. grandis under 0.2% and 0.4% NaCl conditions with and without SA. METHODOLOGY/PRINCIPAL FINDINGS: The exposure of T. grandis seedlings to salt conditions resulted in reduced growth rates, which were associated with decreases in RWC and Pn and increases in REC and MDA content. The foliar application of SA effectively increased the chlorophyll (chl (a+b)) content, RWC, net CO2 assimilation rates (Pn), and proline content, enhanced the activities of SOD, CAT and POD, and minimized the increases in the REC and MDA content. These changes increased the capacity of T. grandis in acclimating to salt stress and thus increased the shoot and root dry matter. However, when the plants were under 0% and 0.2% NaCl stress, the dry mass of the shoots and roots did not differ significantly between SA-treated plants and control plants. CONCLUSIONS: SA induced the salt tolerance and increased the biomass of T. grandis cv. by enhancing the chlorophyll content and activity of antioxidative enzymes, activating the photosynthetic process, and alleviating membrane injury. A better understanding about the effect of salt stress in T. grandis is vital, in order gain knowledge over expanding the plantations to various regions and also for the recovery of T. grandis species in the future.

Developing an easily recyclable and reusable biosorbent for highly efficient removal of very toxic Hg(II) ions from bodies of water is of special significance. Herein, a thiol-functionalized nanocellulose aerogel-type adsorbent for the highly efficient capture of Hg(II) ions was fabricated through a facile freeze-drying of bamboo-derived 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized nanofibrillated cellulose (TO-NFC) suspension in the presence of hydrolyzed 3-mercaptopropyl-trimethoxysilane (MPTs) sols. Notably, the modified aerogel was able to effectively and selectively remove more than 92% Hg(II) ions even in a wide range of Hg(II) concentrations (0.01–85 mg/L) or coexistence with other heavy metals. Besides, the adsorption capacity of the aerogel was not compromised much by the variation in pH values of Hg(II) solutions over a wide pH range. The fitting results of adsorption models suggested the monolayer adsorption and chemisorptive characteristics with the maximal uptake capacity as high as 718.5 mg/g. The adsorption mechanism of the MPTs-modified TO-NFC aerogel toward Hg(II) was studied in detail. For the simulated chloralkali wastewater containing Hg(II) ions, the novel aerogel-type adsorbent exhibited a removal efficiency of 97.8%. Furthermore, its adsorption capacity for Hg(II) was not apparently deteriorated after four adsorption/desorption cycles while almost maintaining the original structural integrity.

Knot detection is a challenging problem for the wood industry. Traditional methodologies depend heavily on the features selected manually and therefore were not always accurate due to the variety of knot appearances. This paper proposes an automated framework for addressing the aforementioned problem by using the state-of-the-art YOLO-v5 (the fifth version of You Only Look Once) detector. The features of surface knots were learned and extracted adaptively, and then the knot defects were identified accurately even though the knots vary in terms of color and texture. The proposed method was compared with YOLO-v3 SPP and Faster R-CNN on two datasets. Experimental results demonstrated that YOLO-v5 model achieved the best performance for detecting surface knot defects. F-Score on Dataset 1 was 91.7% and that of Dataset 2 was up to 97.7%. Moreover, YOLO-v5 has clear advantages in terms of training speed and the size of the weight file. These advantages made YOLO-v5 more suitable for the detection of surface knots on sawn timbers and potential for timber grading.

Bamboo is an important forest resource in many countries that serves as an excellent substitute for timber products and provides a multitude of other food and non-food uses. This societal and economic significance has led to increased bamboo cultivation globally. This review describes the rapid expansion of bamboo hectarage, both intentional and by encroachment, in native and non-native countries. Also presented are details of the influence of bamboo invasion on biodiversity and soil processes as well as potential ecological risk. Finally, we suggest some strategies for controlling bamboo invasion and needs for further research.

Structural colored nanocomposites with photonic liquid crystal structures are desirable owing to their excellent optical performances, unique structural features and intelligent responsive behaviors.

To illuminate the lignin evolution after hydrogen peroxide presoaking prior to ammonia fiber expansion (H-AFEX) pretreatment and enzymatic hydrolysis, ball-milled wood lignins were separated from untreated corn stover, H-AFEX-treated corn stover, and enzymatic hydrolyzed residue, labeled as UN-L, HA-L, and EH-L, respectively. The structural features of EH-L were compared with HA-L and UN-L by elemental analysis, GPC, FT-IR, and NMR. The inhibition deriving from lignin loading and the structure were assessed by adding UN-L/HA-L in enzymatic hydrolysis. The thermogravimetric analysis and thermal degradation kinetics analysis of EH-L were performed to evaluate its industrial utilization. The results showed that a significant decline in molecular weight was observed in EH-L, while the polydispersity index was almost unchanged. The decrease of the G unit and the increase of the S unit were shown in EH-L when comparing to UN-L. The G unit had the strongest inhibition to enzymatic hydrolysis, and the increasing relative proportion of S/G in lignin was beneficial for enzymatic hydrolysis. The resinol structure in lignin was relatively stable after pretreatment and enzymatic hydrolysis. The thermogravimetry analysis indicated that the EH-L exhibited better thermal stability than that of UN-L, offering potential to prepare lignin-based heat-resistant epoxy resin and new flame-resistant materials.

A versatile and highly efficient method was proposed to fabricate durable, superhydrophobic surfaces on various substrates, including wood, lignocellulosic fibers, cotton textiles, sponge, glass, and metals.

The hydrogen peroxide presoaking prior to ammonia fiber expansion (H-AFEX) pretreatment is an effective and promising method for agricultural residues to decrease biomass recalcitrance and enhance enzyme accessibility. To illuminate the structural changes of lignin after the H-AFEX process, ball-milled wood lignins were isolated from raw material and H-AFEX-treated corn stover. The features and structures of the obtained lignins were characterized by elemental analysis, gel permeation chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The results demonstrated that the H-AFEX-treated lignins had higher oxygen and nitrogen contents while lower carbon and hydrogen contents when compared to those of untreated lignin. A remarkable decrease in molecular weight of H-AFEX-treated lignin was observed. Ammonolysis, hydrolysis, and oxidation reactions were major chemical modifications to lignin, and the cleavages of ferulate and p-coumarate ester bonds, alkyl ether bonds, and aryl ether bonds were observed during the H-AFEX process. G unit lignin was more easily degraded through demethoxylation, while the interunit linkages of resinol and phenylcoumaran were relatively stable. The study on lignin structural changes during the H-AFEX process could reveal the pretreatment mechanism and develop of a new pretreatment method, with a perspective of reducing biomass recalcitrance and improving the bioconversion of biomass to biofuels or biomaterials.

BACKGROUND: During the dilute acid pretreatment process, the resulting pseudo-lignin and lignin droplets deposited on the surface of lignocellulose and inhibit the enzymatic digestibility of cellulose in lignocellulose. However, how these lignins interact with cellulase enzymes and then affect enzymatic hydrolysis is still unknown. In this work, different fractions of surface lignin (SL) obtained from dilute acid-pretreated bamboo residues (DAP-BR) were extracted by various organic reagents and the residual lignin in extracted DAP-BR was obtained by the milled wood lignin (MWL) method. All of the lignin fractions obtained from DAP-BR were used to investigate the mechanism for interaction between lignin and cellulase using surface plasmon resonance (SPR) technology to understand how they affect enzymatic hydrolysis RESULTS: The results showed that removing surface lignin significantly decreased the yield for enzymatic hydrolysis DAP-BR from 36.5% to 18.6%. The addition of MWL samples to Avicel inhibited its enzymatic hydrolysis, while different SL samples showed slight increases in enzymatic digestibility. Due to the higher molecular weight and hydrophobicity of MWL samples versus SL samples, a stronger affinity for MWL (KD = 6.8-24.7 nM) was found versus that of SL (KD = 39.4-52.6 nM) by SPR analysis. The affinity constants of all tested lignins exhibited good correlations (r > 0.6) with the effects on enzymatic digestibility of extracted DAP-BR and Avicel. CONCLUSIONS: This work revealed that the surface lignin on DAP-BR is necessary for maintaining enzyme digestibility levels, and its removal has a negative impact on substrate digestibility.

ABSTRACT The production of nanocellulose with controlled structure from plant sources with easy availability and good sustainability is very important in science and engineering. In this work, the isolation of cellulose from bamboo and the effects of the hydrolysis of different acids on the morphology, structure, and properties of the resultant cellulose and cellulose nanocrystals were investigated. Bamboo cellulose (PHC) was first isolated from raw bamboo powder by alkali and consecutive bleaching treatments. Cellulose crystallites were then prepared by the controlled hydrolysis of PHC in acid solutions. The samples were characterized by using thermogravimetric analysis, Fourier transform infrared spectroscopy, powder X‐ray diffraction, laser particle size analyzer, Scanning electron microscopy, and Transmission electron microscopy. Cellulose nanocrystals prepared from the hydrolysis of the isolated bamboo cellulose in the sulfate acid, hydrochloric acid, phosphoric acid, or acetic acid solution had the length of 3–200 nm, 20–85 nm, 20–40 nm, and 6.5–20 nm, respectively. Nanocrystals made by the uses of sulfuric acid and phosphoric acid possessed higher crystallinity and lower thermal stability than those by the uses of hydrochloric acid and a mixture of acetic acid and nitric acid. Results suggested the type of acids significantly influenced the structure, morphology, and thermal stability of cellulose crystallites. The anions in the acid solution also contributed to those differences because they affected the swelling of cellulose chains and breakage of hydrogen bonds in cellulose. The findings indicate that a judicious choice of pretreatment of the cellulose and its moieties can be used for the production of different cellulose nanocrystals. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.

Abstract Black carbon (BC) not only warms the atmosphere but also affects human health. The nationwide lockdown due to the Coronavirus Disease 2019 (COVID‐19) pandemic led to a major reduction in human activity during the past 30 years. Here, the concentration of BC in the urban, urban‐industry, suburb, and rural areas of a megacity Hangzhou were monitored using a multiwavelength Aethalometer to estimate the impact of the COVID‐19 lockdown on BC emissions. The citywide BC decreased by 44% from 2.30 to 1.29 μg/m 3 following the COVID‐19 lockdown period. The source apportionment based on the Aethalometer model shows that vehicle emission reduction responded to BC decline in the urban area and biomass burning in rural areas around the megacity had a regional contribution of BC. We highlight that the emission controls of vehicles in urban areas and biomass burning in rural areas should be more efficient in reducing BC in the megacity Hangzhou.

Natural fiber composites are receiving more and more attention because of their greenness and low cost. Among natural fibers, bamboo is characterized by fast growth, a short cultivation period, high strength and good toughness, and is one of the strongest natural fibers in the world. A bamboo-fiber-reinforced polymer composite (BFRPC) has the characteristics of high mechanical strength, low density, degradability, etc. It has the industrial applicability comparable to metal materials, the same strong corrosion resistance as composites such as glass and carbon fibers, and the same immunity to electromagnetic interference and low thermal conductivity as natural materials. Its unidirectional specific strength and unidirectional specific modulus is higher than that of glass fiber, second only to the extremely high price of carbon fiber, which is playing an increasingly important role in the field of composite materials, and can be widely used in the fields of wind power, construction, aviation, automotive, medical care and so on. At present, it has been initially used in packaging, automotive and transportation fields, and is expected to replace petroleum-based plastics in various fields. In addition to their environmental protection and green production, they have excellent physical properties. This paper provides an overview of the mechanical properties of bamboo-fiber-reinforced thermoplastic composites and thermoset composites that have been developed so far, such as tensile strength, flexural properties and impact strength. In addition, the prospects of bamboo-fiber-reinforced thermoplastic composites for automotive, packaging and agricultural applications are presented.

The previous study in our team found that supplementation of probiotic Bacillus amyloliquefaciens (Ba) instead of antibiotics growth performance of piglets. Hence, the present study was carried out to further demonstrate the effect of Ba replacement of antibiotics on digestive and absorption enzyme activity and intestinal microbiota population of piglets. A total of 90 piglets were selected and divided into three groups: G1 group was fed with basal diet supplemented with 150 mg/Kg aureomycin, G2 group was fed with 1 × 108 cfu/Kg Ba and half dose of aureomycin, G3 group was used the diet with 2 × 108 cfu/Kg Ba replaced aureomycin. Each treatment had three replications of ten pigs per pen. Results indicated that Ba replacement significantly increased the activities of amylase, disaccharides and Na+/K+-ATPase. And chymotrypsin activity in different section of intestine was dramatically enhanced in half replacement of aureomycin with Ba. Moreover, Ba replacement maintained the intestinal integrity with the significantly decreased activity of DAO compared with aureomycin group. Besides, supplementation with Ba increased the β-diversity of intestinal microbiota. Taken together, the current study indicated that diet supplementation with Ba instead of aureomycin increased the growth performance of piglets by improving the digestive and absorb enzyme activities, enhancing the intestinal integrity and regulating the population of intestinal micrbiota.

The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar, straw, and chemical fertilizers compared with chemical fertilization alone. Five soil fertilization treatments were evaluated: regular chemical fertilizers (RF), straw+regular chemical fertilizers (SRF), straw biochar+regular chemical fertilizers (SCRF), bamboo biochar (BC)+regular chemical fertilizers (BCRF), and straw biochar+70% regular chemical fertilizers (SC+70%RF). Their effects were investigated after approximately 1.5 years. The soil pH and cation exchange capacity (CEC) were significantly higher in biochar-treated soils. The soil phosphorous (P) and potassium (K) contents increased with biochar application. The soil Colwell P content was significantly increased with the addition of straw biochar in the treatments of SCRF and SC+70%RF. The oxygen (0):carbon (C) ratio doubled in BC picked from the soil. This indicated that BC underwent a significant oxidation process in the soil. The denaturing gradient gel electrophoresis (DGGE) fingerprints of microbial communities differed among the treatments. Soils with added biochar had higher Shannon diversity and species richness indices than soils without biochars. The results suggest that biochar can improve soil fertility.

Bamboo delignification is a common method for studying its functional value-added applications. In this study, bamboo samples were delignified by treatment with sodium chlorite. The effects of this treatment on the bamboo’s microstructure, surface chemical composition, and pyrolysis behaviour were evaluated. Field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were conducted to evaluate these parameters. The FTIR results demonstrated that the lignin peak decreased or disappeared, and some hemicellulose peaks decreased, indicating that sodium chlorite treatment effectively removed lignin and partly decomposed hemicellulose, although cellulose was less affected. The XPS results showed that, after treatment, the oxygen-to-carbon atomic ratio of delignified bamboo increased from 0.34 to 0.45, indicating a lack of lignin. XRD revealed increased crystallinity in delignified bamboo. Further pyrolysis analysis of treated and untreated bamboo showed that, although the pyrolysis stage of the delignified bamboo did not change, the maximum thermal degradation rate (Rmax) and its corresponding temperature (from 353.78 to 315.62 °C) decreased significantly, indicating that the pyrolysis intensity of the bamboo was weakened after delignification. Overall, this study showed that delignified bamboo develops loose surfaces, increased pores, and noticeable fibres, indicating that alkali-treated bamboo has promising application potential due to its novel and specific functionalities.

Abstract The aim of this study was to explore whether nutrition supply can improve the drought tolerance of Moso bamboo under dry conditions. One-year-old seedlings were exposed to two soil water content levels [wellwatered, 70 ± 5% soil-relative-water-content (SRWC) and drought stress, 30 ± 5% SRWC] and four combinations of nitrogen (N) and phosphorus (P) supply (low-N, low-P, LNLP; low-N, high-P, LNHP; high-N, high-P, HNHP; and high-N, low-P, HNLP) for four months. Plant growth, photosynthesis, chlorophyll fluorescence, water use efficiency and cell membrane stability were determined. The results showed that drought stress significantly decreased total biomass, net-photosynthesis (Pn), stomatal-conductance (g s ), leaf-chlorophyll-content (Chl leaf ), PSII-quantum-yield (Φ PSII ), maximum-quantum-yield-of-photosynthesis (Fv/Fm), photochemical-quenching-coefficient (qP), leaf-instantaneous-water-use efficiency (WUE i ), relative-water-content (RWC), photosynthetic-N-use-efficiency (PNUE), and photosynthetic-P-use-efficiency (PPUE). N and P application was found to be effective in enhancing the concentration of leaf N, g s , and Pn while reducing the production of reactive oxygen species under both water regimes. Under LNHP, HNHP and HNLP treatments, the decreases in total biomass, Pn, Chl leaf and Fv/Fm of drought-stressed were less evident than the decreases under LNLP. The study suggests that nutrient application has the potential to mitigate the drastic effects of water stress on Moso bamboo by improving photosynthetic rate, water-use efficiency, and increasing of membrane integrity.

Catalytic glycerol dehydration provides a sustainable route to produce acrolein because glycerol is a bioavailable platform chemical. However, in this process catalysts are rapidly deactivated due to coking. This paper examines and discusses recent insights into coking of catalysts during catalytic glycerol dehydration. The nature and location of coke and the rate of coking depend on feedstock, operating conditions, and the acidity and pore structure of the solid catalysts. Several methods have been suggested for inhibiting the coking and slowing the deactivation of catalyst, including (1) cofeeding of oxygen, (2) tuning of the pore size of the solid acid catalysts, (3) doping noble metals (Ru, Pt, Pd) into the solid acid catalysts, and (4) designing new reactors. The present methods for inhibiting coking are still unsatisfactory. The deactivated catalysts can be regenerated by removing coke. Nevertheless, the rapid deactivation of the regenerated catalyst remains problematic. The literature survey indicates that the exact chemical compositions of the coke on the catalyst during glycerol dehydration remain elusive. The thermodynamics, kinetics, and mechanism of coking need to be probed so as to advance the development of a catalyst with high activity, selectivity, and resistance to coking to put the catalytic glycerol dehydration into practice.

With the increasing emphasis on sustainable development, bamboo is receiving an increasing attention as a kind of forest resource. But bamboo is readily discoloured by mould fungi, which greatly limits the applications of bamboo. In this research, ZnO nanoparticles were successfully fabricated on the surface of bamboo timber by a simple low-temperature wet chemical method. The morphology, chemical structure, and crystalline structure of the samples were characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). XRD studies confirmed that the as-prepared ZnO nanoparticles were wurtzite. The microstructure and hydroxyl groups in the bamboo timber surface at the wet state provided cavities and affinity for the creation and the immobilization of ZnO nanoparticles on the bamboo timber surface through electrostatic and hydrogen bonding interactions. Moreover, the mould-resistance of ZnO coated bamboo timber was also in focus on the present study. The results indicated that bamboo timber treated with ZnO had a better resistance against Aspergillus niger V. Tiegh (A. niger) and Penicillium citrinum Thom (P. citrinum), but poor against Trichoderma viride Pers. ex Fr (T. viride). Keywords: Bamboo timber, ZnO nanoparticles, Wet chemical method, Surface, Mould-resistance

ABSTRACT In this study, ultrafine bamboo‐char (BC) was introduced into poly(lactic acid) (PLA) matrix to improve mechanical and thermal properties of PLA based biodegradable composites. PLA/BC biocomposites were fabricated with different BC contents by weight. Uniform dispersion of BC in the PLA matrix and good interaction via physical and chemical interfacial interlocks were achieved. The maximum tensile strength and tensile modulus values of 14.03 MPa and 557.74 MPa were obtained when 30% BC was used. Impact strength of the biocomposite with 30% BC was increased by 160%, compared to that of pure PLA. DSC analysis illustrated that PLA/BC biocomposites had a better thermal property. Crystallization temperature decreased and maximal crystallinity of 30.30% was observed with 30% BC load. We did not notice significant thermal degradation differences between biocomposites with different BC loadings from TGA. Better water resistance was obtained with the addition of BC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43425.

Obesity and the related liver diseases are prevalent around the world. Although probiotics have been shown to prevent obesity through multiple ways, only few researches investigated the lipid-lowering effects of probiotic Bacillus. Moreover, the limited results consistently suggested that Bacillus regulated genes related to lipogenesis and oxidation, but no further exploration was made. Our previous study revealed that Bacillus amyloliquefaciens SC06 has potent antioxidant capacity in vitro. The aim of this study is to investigate the effects of SC06 on obesity and the associated liver injury of high-fat diet (HFD)-fed-mice and its underlying mechanism. By feeding normal chow (NC), NC+SC06, HFD and HFD+SC06 to mice, we found that SC06 improved body weight gain, hepatic steatosis, and glucose metabolism of HFD-mice. Further, SC06 also increased the antioxidant capacity of mice through Nrf2/Keap1 signaling pathway. High-throughput sequencing of 16S rRNA gene showed that HFD changed the gut microbiota dramatically, while HFD+SC06 decreased the ratio of Firmicutes/Bacteroidetes and increased TM7 abundance. More differences were also found in lower taxa. Altogether, SC06 is a potential probiotic that decreases HFD-related lipid accumulation and liver injury via regulating the antioxidant capacity and host gut microbiota.