Xiaoyu Tang

Spent mushroom substrate (SMS) is defined as the biomass waste generated during industrial mushroom cultivation. Utilization of SMS has been extensively researched and has immense potential as a sustainable substrate for generating biogas that can offset fossil fuel use. This closed loop energy generation process that can be set up in mushroom plants will reduce the dependence on fossil fuels and has the potential to reduce greenhouse gas emissions, which will benefit the environment. Anaerobic co-digestion of SMS with different agricultural wastes such as livestock manure would result in enhanced biogas production. In this study, the anaerobic co-digestion of SMS was carried out by combing yellow back fungus SMS along with chicken, dairy and pig manure. SMS combined with chicken manure yielded a slightly higher cumulative methane yield when compared with the combination of dairy manure and pig manure. Factors such as the total solids (TS) and the relative ratio of manure to SMS loading had a significant impact on the cumulative methane yield, volatile solids removal, with a particularly prominent synergistic effect. The synergistic effect was also closely related to the C/N ratio, and under experimental conditions (TS = 15%, SMS relative ratio of 50% and C/N ratio = 25.6), the cumulative methane yield of SMS with chicken manure (CM) was increased by 414% compared with that obtained using SMS or CM separately. We carried out a multiple linear regression (MLR) analysis, a statistical technique that uses several explanatory variables to predict the outcome of a response variable. Our analysis concluded that by using operating conditions (TS = 15%, and SMS ratio = 38.9), we were able to achieve the maximum cumulative methane yield (CMY).

[Purpose] The development of agriculture and animal husbandry in Tibet is basically based on the interlaced development of agriculture and animal husbandry in mountainous areas. The interlaced agricultural and animal husbandry areas in mountainous areas are the unity of special, harmonious and harmonious regional small environment. The special attributes of mountainous areas determine the rich agricultural and animal husbandry resources, ecological development cycle areas, characteristic agricultural products areas and tourism. The division and regionalization of recreational zones and the optimal combination and utilization of agricultural and animal husbandry resources in mountainous ecotone have very important effects on promoting the benign cycle of regional agricultural and animal husbandry economic development, the development of urban integration and the protection of industrial ecological environment. How to develop and construct a new type of "environment-friendly and resource-saving" agricultural and animal husbandry areas is very important. It is of great practical significance to promote the development of regional agriculture and animal husbandry industry, to establish an efficient production system of agriculture and animal husbandry and to speed up the increase of farmers' and herdsmen's income. Rational and effective utilization of various beneficial resources can effectively solve the problems of material shortage, resource shortage and contradiction between supply and demand, and ensure the interlaced agriculture and animal husbandry economy in Tibet's mountainous areas. Sustainable development. [Method]On the basis of domestic and foreign literatures, this paper analyses and evaluates in detail the optimal combination and utilization mode of agricultural and animal husbandry resources in mountainous ecotone area by means of management induction, [Result]that is, the modern high-efficiency utilization mode of new energy, the green integration development mode of "chain fusion" in seed and culture, and the multi-level agricultural capital. Four basic modes, i.e. the mode of efficient utilization of resources and the mode of recreational sightseeing and sightseeing in mountainous agriculture and animal husbandry. [Conclusion] The above four modes of optimal combination and utilization of agricultural and animal husbandry resources are the basic macro-combination modes of agricultural and animal husbandry resources in the mountainous ecotone of Tibet. They are discussed in detail from the perspectives of natural resources utilization, agricultural products production and processing, agricultural and animal husbandry production and construction, and eco-tourism development in order to provide better services. Development and construction of agricultural and animal husbandry circular economy in Tibet. Finally, according to the characteristics of Tibet's own development, this paper puts forward to promote the integration of scientific concepts, the strength of scientific and technological support, and the fund guarantee system in the basic fields, and to strengthen the integration of farmer-herdsman cooperatives and market organizations in practical application. Reference and extension of the model, incentive and compensation security system, etc., for the future development of mountain-type interlaced agriculture and animal husbandry in Tibet circular agricultural and animal husbandry and resource optimization and combination of construction to provide a reference and research results.

Sweetcane (Erianthus arundinaceus [Retzius] Jeswiet) is an ecologically dominant warm‐season perennial grass native to southern China. It traditionally plays an important role in sugarcane breeding due to its excellent biological traits and genetic relatedness to sugarcane. Recent studies have shown that sweetcane has a great potential in bioenergy and environmental remediation. The objective of this paper is to review the current research on sweetcane biology, phenology, biogeography, agronomy, and conversion technology, in order to explore its development as a bioenergy crop with environmental remediation potential. Sweetcane is resistant to a variety of stressors and can adapt to different growth environments. It can be used for ecological restoration, soil and water conservation, contaminated land repairing, nonpoint source pollutants barriers in buffer strips along surface waters, and as an ornamental and remediation plant on roadsides and in wetlands. Sweetcane exhibits higher biomass yield, calorific value and cellulose content than other bioenergy crops under the same growth conditions, thereby indicating its superior potential in second‐generation biofuel production. However, research on sweetcane as a bioenergy plant is still in its infancy. More works need be conducted on breeding, cultivation, genetic transformation, and energy conversion technologies.

Kitchen waste oil (KWO) from catering industries or households was used as a low-cost carbon source for producing biosurfactants by self-isolated Pseudomonas aeruginosa. Fermentation performance with KWO was superior to those with four other carbon sources, with higher optical density (OD₆₀₀) of 2.33 and lower interfacial tension of 0.57 mN/m. Culture conditions for biosurfactant production were optimized, with optimal pH of 8.0 and nitrogen source concentration of 2.0 g/L, respectively. The results of infrared spectroscopy and liquid chromatography-mass spectrometry (LC-MS) showed that the biosurfactant was a mixture of six rhamnolipid congeners, among which Rha-Rha-C₁₀-C₁₀ and Rha-C₁₀-C₁₀ were the main components, with mass fraction of approximately 34.20 and 50.86%, respectively. The critical micelle concentration (CMC) obtained was 55.87 mg/L. In addition, the rhamnolipids exhibited excellent tolerance to temperature (20–100 °C), pH (6.0–12.0), and salinity (2–20%; w/v) in a wide range, thereby showing good stability to extreme environmental conditions. The rhamnolipids positively affected oil removal from oil sludge and KWO-contaminated cotton cloth, with removal rate of 34.13 and of 30.92%, respectively. Our results demonstrated that biosurfactant production from KWO was promising, with advantages of good performance, low cost and environmental safety.

Plants can suffer ammonium (NH4 +) toxicity, particularly when NH4 + is supplied as the sole nitrogen source. However, our knowledge about the underlying mechanisms of NH4 + toxicity is still largely unknown. Lemna minor, a model duckweed species, can grow well in high NH4 + environment but to some extent can also suffer toxic effects. The transcriptomic and physiological analysis of L. minor responding to high NH4 + may provide us some interesting and useful information not only in toxic processes, but also in tolerance mechanisms. The L. minor cultured in the Hoagland solution were used as the control (NC), and in two NH4 + concentrations (NH4 + was the sole nitrogen source), 84 mg/L (A84) and 840 mg/L (A840) were used as stress treatments. The NH4 + toxicity could inhibit the growth of L. minor. Reactive oxygen species (ROS) and cell death were studied using stained fronds under toxic levels of NH4 +. The malondialdehyde content and the activities of superoxide dismutase and peroxidase increased from NC to A840, rather than catalase and ascorbate peroxidase. A total of 6.62G nucleotides were generated from the three distinct libraries. A total of 14,207 differentially expressed genes (DEGs) among 70,728 unigenes were obtained. All the DEGs could be clustered into 7 profiles. Most DEGs were down-regulated under NH4 + toxicity. The genes required for lignin biosynthesis in phenylpropanoid biosynthesis pathway were up-regulated. ROS oxidative-related genes and programmed cell death (PCD)-related genes were also analyzed and indicated oxidative damage and PCD occurring under NH4 + toxicity. The first large transcriptome study in L. minor responses to NH4 + toxicity was reported in this work. NH4 + toxicity could induce ROS accumulation that causes oxidative damage and thus induce cell death in L. minor. The antioxidant enzyme system was activated under NH4 + toxicity for ROS scavenging. The phenylpropanoid pathway was stimulated under NH4 + toxicity. The increased lignin biosynthesis might play an important role in NH4 + toxicity resistance.

The fermentation inhibition of yeast or bacteria by lignocellulose-derived degradation products, during hexose/pentose co-fermentation, is a major bottleneck for cost-effective lignocellulosic biorefineries. To engineer microbial strains for improved performance, it is critical to understand the mechanisms of inhibition that affect fermentative organisms in the presence of major components of a lignocellulosic hydrolysate. The development of a synthetic lignocellulosic hydrolysate (SH) media with a composition similar to the actual biomass hydrolysate will be an important advancement to facilitate these studies. In this work, we characterized the nutrients and plant-derived decomposition products present in AFEX™ pretreated corn stover hydrolysate (ACH). The SH was formulated based on the ACH composition and was further used to evaluate the inhibitory effects of various families of decomposition products during Saccharomyces cerevisiae 424A (LNH-ST) fermentation. The ACH contained high levels of nitrogenous compounds, notably amides, pyrazines, and imidazoles. In contrast, a relatively low content of furans and aromatic and aliphatic acids were found in the ACH. Though most of the families of decomposition products were inhibitory to xylose fermentation, due to their abundance, the nitrogenous compounds showed the most inhibition. From these compounds, amides (products of the ammonolysis reaction) contributed the most to the reduction of the fermentation performance. However, this result is associated to a concentration effect, as the corresponding carboxylic acids (products of hydrolysis) promoted greater inhibition when present at the same molar concentration as the amides. Due to its complexity, the formulated SH did not perfectly match the fermentation profile of the actual hydrolysate, especially the growth curve. However, the SH formulation was effective for studying the inhibitory effect of various compounds on yeast fermentation. The formulation of SHs is an important advancement for future multi-omics studies and for better understanding the mechanisms of fermentation inhibition in lignocellulosic hydrolysates. The SH formulated in this work was instrumental for defining the most important inhibitors in the ACH. Major AFEX decomposition products are less inhibitory to yeast fermentation than the products of dilute acid or steam explosion pretreatments; thus, ACH is readily fermentable by yeast without any detoxification.