Processing of materials derived from sweet sorghum for biobased products

Sweet sorghum (Sorghum bicolor (L.) Moench) is particularly suitable as a feedstock for a variety of bioprocesses, largely because of its high yields of both lignocellulosic biomass and fermentable saccharides. Sweet sorghum is less economically important for refined sugar production than other sugar crops, e.g., sugar beet and sugarcane, but can produce more raw fermentable sugar under marginal conditions than those crops. In this review, the agronomic requirements of sorghum (viz., water, soil, and nutrient requirements), cultural practices, and plant morphology are discussed from a bioprocessing perspective. Historically, sugar extraction from the plant in the form of juice has been of primary interest; these methods, along with modern developments are presented. Recently, the direct yeast fermentation of sorghum juice for ethanol production has been studied. Additionally, the bagasse resulting from the juice extraction has been used for a variety of potential products: forage, silage, combustion energy, synthesis gas, and paper. The bagasse contains high levels of relatively low crystallinity cellulose, along with relatively labile lignin, and so is itself of interest as a fermentation feedstock. Whole sorghum stalk, and its bagasse, have been subjected to studies of a wide array of pretreatment, enzymatic hydrolysis, and fermentation processes. The potential fermentation products of sweet sorghum are wide ranging; those demonstrated include ethanol, acetone, butanol, various lipids, lactic acid, hydrogen, and methane. Several potential native products of the plant, in addition to cellulose for paper production, are also identified: waxes, proteins, and allelopathic compounds, such as sorgoleone.     

Evaluation Method of Solubility of Wheat Straw in LiCl/DMSO Solvent北大核心CSCD

In order to solve the quantitative problem of the solubility of lignocellulosic biomass in the solvent system, wheat straw was studied as raw material for a ball milling time on its dissolution behavior in the LiCl/DMSO system. The dissolution performance was evaluated by visual method, optical microscopy and turbidity method respectively. By comparison of visual colorimetry method and the optical microscopy method at the condition of wheat straw dissolved in 8% LiCl/DMSO, it was found that the turbidimetric method is accurate, simple and quantitative. The turbidimetric method can be used to evaluate the dissolution behavior of lignocellulosic biomass during pretreatment and refining. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

木质基高吸水树脂的合成

采用木质纤维材料与丙烯酰胺接枝共聚合成高吸水树脂，考察了原料配比，引发剂，反应温度和反应时间对接枝共聚物性能的影响，探讨了接 枝共聚物皂化水解反应条件，实验表明，此部分水解的接枝共聚物是一种较好的高吸水材料，其吸去离子水量可达1200g/g。     

Biogas digestates based on lignin-rich feedstock – potential as fertilizer and soil amendment

With advances in biogas technology, lignocellulosic material may be increasingly included in feedstock due to the abundance of raw materials. The main goal of this study was to evaluate fertilizing and soil amendment effects of digestates based on lignin-rich feedstock. The digestates originated from reactors fed with manure co-digested with Salix, wheat straw or sugarcane bagasse, respectively. In pot experiments with three different soils, Italian ryegrass and reed canary grass were grown with 120 kg ha^?1 total nitrogen or 150 kg ha^?1 available nitrogen, respectively, given as either mineral fertilizer or digestate. Soil chemical and physical characteristics were determined after ended experiments. Additionally, an incubation study was carried out to estimate N mineralization from one digestate over time. Digestate addition resulted in similar yields compared to mineral fertilizer, varying from 0.5 (loam) to 1 kg dry matter m^?2 (silt) for Italian ryegrass and 1.2 (loam) to 2.3 kg m^?2 (silt) for reed canary grass. Digestates contributed to a favourable pH for plant growth, reduced bulk density in the loam and improved water retention characteristics in the sand. Biogas digestates based on lignin-rich feedstock appear promising as fertilizers and for soil amelioration but results have to be verified in field experiments.     

Effect of supplementation of rice straw with biogas residual slurry manure on the yield, protein and mineral contents of oyster mushroom

Popularity of oyster mushroom is increasing for its ease of cultivation, high yield potential as well as its high nutritional value. Laboratory experimentation followed by farm trial with a typical oyster mushroom Pleurotus sajor caju revealed that the yield potential of these mushrooms can be increased significantly when grown on a lignocellulosic crop residue—rice straw supplemented with biogas residual slurry manure in 1:1 ratio as substrate. Residual slurry manures obtained from biogas plants utilising either cattle dung, poultry litter, jute caddis or municipal solid waste as substrates for biogas production were all effective in increasing the yield of Pleurotus sajor caju significantly although to different extents. Disinfection of straw and manure by means of 0.1% KMnO₄ plus 2% formalin solution in hot water caused 42.6% increase in yield of Pleurotus sajor caju over control, i.e., when disinfection done with hot water. In addition to increased yield, the above treatments caused significant increase in protein content, reduction in carbohydrate and increase in essential mineral nutrients in mushroom sporophores. Thus, it is concluded from the study that supplementation of rice straw with biogas residual slurry manure has strong impact in improving the yield potential, protein and mineral nutrient contents of Pleurotus sajor caju mushroom in Indian subcontinent or similar climatic conditions.     

Life Cycle Assessment and sustainability methodologies for assessing industrial crops, processes and end products

Providing food, energy and materials for the rising global population is a challenge which is compounded by increased pressure on natural resources such as land, water and fossil sources of raw materials. Greenhouse gas (GHG) emissions from human activities have increased with industrial development and population expansion, and it is anticipated that resulting climate change might further limit agricultural productivity, through changes to weather patterns and global availability/distribution of agriculturally productive land. Growing crops as feedstocks for industrial uses is seen as one way of reducing GHG emissions and dependency on fossil resources. However, determining the extent to which the development of crops for industrial use will effect GHG balances and provide for a more energy efficient manufacturing system requires the development and use of appropriate calculation methodologies.Research at the Porter Institute has identified over 250 different scenarios for bioenergy production systems using commodity crops. In order to rationalise this complexity and diversity, a modular approach to Life Cycle Assessment (LCA) and sustainability analysis has been taken. This allows characterisation of discrete sections of supply chains and enables comparisons to be made between different crop production systems, different process systems and different end product uses. The purposes of this paper are to introduce the concepts of biofuel GHG and sustainability metrics, to introduce the approach taken by our organization and to use the example of UK grown willow in a lignocellulosic ethanol production system to demonstrate how GHG emission outcomes can be reviewed for “new” crops and technologies.The results show a range of variation, in both growing and process systems and how outcomes such as energy and GHG balances can be affected by various activities.LCA methodologies provide data to inform governments and industry of the potential specific supply chains may have for energy and GHG saving. However, methodological approaches can also affect assessment outcomes. Unresolved issues in LCA methodology must also be evaluated e.g. impacts resulting from land use change. Sustainability assessments of crop growing systems, irrespective of the end use, also assist in the assessment of environmental impacts of supply chains. However, it is critical that data continue to be collected, analysed and reviewed, to ensure that the most appropriate crops are grown and processed for the most appropriate end use.     

添加不同浓度黑曲霉菌液对饲用苎麻混合青贮品质影响

为了解决苎麻（Boehmeria nivea）木质纤维素含量过多的问题,本试验设计了4个处理,在每千克混合青贮（80%苎麻+18%麦麸+2%蔗糖）中添加不同浓度的黑曲霉（Aspergillus niger）菌液（添加50 mL黑曲霉菌液+150 mL无菌水为处理Ⅰ、添加100 mL黑曲霉菌液+100 mL无菌水为处理Ⅱ、添加150 mL黑曲霉菌液+50 mL无菌水为处理Ⅲ、添加200 mL黑曲霉菌液为处理Ⅳ、添加200 ml无菌水为对照组（CK））,发酵30 d后开包取样分析各项指标。结果显示,添加黑曲霉菌液显著提高了青贮中可溶性碳水化合物、干物质、乳酸和乙酸含量（P<0.05）,显著降低了青贮中pH和氨态氮/总氮比值（P<0.05）;处理Ⅱ、处理Ⅲ和处理Ⅳ组显著降低了青贮中中性洗涤纤维、酸性洗涤纤维及酸性不溶木质素含量（P<0.05）;对处理Ⅱ组样品进行酶活检测发现,随着发酵时间的延长,羧甲基纤维素酶、锰过氧化物酶、漆酶和木聚糖酶4种酶酶活都有不同程度降低。从节约成本角度考虑,处理Ⅱ组是进行木质纤维素降解、青贮品质提高的最佳处理。     

Dissolving lignocellulosic biomass in a 1-butyl-3-methylimidazolium chloride-water mixture

An ionic liquid (IL)-water mixture employed to treat lignocellulosic biomass is promising. The addition of water decreases viscosity and process cost so as to improve the IL practical application. In this work, effects of temperature (50-170 °C), water content (0-80 wt%), treating duration (0.5-4 h) and pressure (0.1-3.2 MPa) on treating legume straw process using a 1-butyl-3-methylimidazolium chloride ([C₄mim]Cl)-water mixture were experimentally investigated. Legume straw was found to be partially dissolved, and the dissolved substances can be flocculated by adding the coagulating agent—water (equal to volume of the solution). For this process at 0.1 MPa, the maximum 29.1 wt% legume straw is dissolved in the [C₄mim]Cl-water mixture with water content of 20 wt% at 150 °C during 2 h, which is much higher than 9.8 wt% using pure [C₄mim]Cl. A hemicellulose-free lignin-rich material (64.0 wt% lignin and 35.3 wt% cellulose) is obtained by adding the water. Even for 0.5 h, 22.3 wt% of legume straw is dissolved in the case of water content of 20 wt%, 150 °C and 0.1 MPa. High pressure favors the dissolution of legume straw but lignin content in the residue has no obvious change. The addition of proper amount of water facilitates the dissolution of legume straw and a relative rapid dissolving rate can be achieved in a [C₄mim]Cl-water mixture. There are great differences in chemical and physical properties between legume straw and the obtained samples (residue and floc) due to the dissolution and reconstitution.     

不同添加剂对饲用苎麻与麦麸混合青贮品质的影响

为了解决饲用苎麻（Boehmeria nivea L.）木质纤维素过多的问题,本试验设计了4个处理,在混合青贮（80%苎麻+18%麦麸+2%蔗糖）中分别添加不同的添加剂,各处理发酵30 d后开包取样分析各项指标。结果显示,4个处理组都显著提高了青贮中可溶性碳水化合物、干物质、粗蛋白和乳酸含量（P<0.05）;都显著降低了乙酸含量、中性洗涤纤维含量、pH和氨态氮/总氮比值（P<0.05）。添加黑曲霉菌液处理组和添加黑曲霉菌液+纤维素酶处理组酸性洗涤纤维及酸性洗涤木质素降解效果明显优于另外两个处理组（P<0.05）。添加黑曲霉菌液可有效进行木质纤维素降解,提高青贮品质,并且节约成本,为最佳处理。     

Cellulase production by Aspergillus unguis in solid state fermentation

Lignocellulosic substrates are a good carbon source and provide rich growth media for a variety of microorganisms which prodLuce industrially important enzymes. Cellulases are a group of hydrolytic enzymes such as filter paperase (FPase), carboxymethyl cellulase(CMCase) andβ-glucosidase-responsible for release of sugars in the bioconversion of the lignocellulosic biomass into a variety of value-added products. This study examined cellulase production by a newly isolated Aspergillus unguis on individual lignocellulosic substrates in solid state fermentation (SSF). The maximum peak production of enzymes varied from one substrate to another, however,based on the next best solid support and local availability of groundnut fodder supported maximum enzyme yields compared with other solid supports used in this study.Groundnut fodder supported significant production of FPase (5.9 FPU/g of substrate), CMCase (1.1 U/g of substrate) andβ-glucosidase activity (6.5 U/g of substrate) in SSF. Considerable secretion of protein (27.0 mg/g of substrate) on groundnut fodder was recorded. Constant increment of protein content in groundnut fodder due to cultivation of A. unguis is an interesting observation and it has implications for the improvement of nutritive value of groundnut fodder for cattle.