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More than 60% of India's population relies on agriculture as their primary source of income, making it the nation's most important economic sector. Rice husk (often abbreviated as RH) is one of the most typical by-products of agricultural production. Every five tonnes of rice that is harvested results in the production of one tonne of husk. The concept of recycling and reusing waste from agricultural production has received interest from a variety of environmental and industrial perspectives. A wide variety of nanomaterials, including nano-zeolite, nanocarbon, and nano-silica, have been discovered in agro-waste. From rice cultivation to the finished product, there was a by-product consisting of husk that comprised 20% of the overall weight, or RH. The percentage of silica in RH ash ranges from 60 to 40%, with the remaining percentage consisting of various minerals. As a direct consequence of this, several distinct approaches to generating and extracting nanomaterial from rice husk have been developed. Because it contains a significant amount of cellulose and lignin, RH is an excellent and economical source of carbon precursor. The goal of this chapter is to produce carbon-based nanomaterials from RH. [ABSTRACT FROM AUTHOR]

Leaf litter decomposition and nutrient release dynamics of Flemingia semialata Roxb. were studied from May 2016 to April 2017 using the litter bag technique. The study on litter dynamics is needed to assess the nutrient release pattern before introduction in degraded or marginal lands or agroforestry systems for soil nutrient management practices in hilly northeast states of India. The initial N concentration, lignin content, and lignin/N ratio of leaf litter had significant positive correlations with decay coefficients. The annual decay rate constant (k) for dry matter was 0.01 day−1 (3.65 year−1) with t50 and t99 values of 96.43 and 695.73 days, respectively, indicating faster leaf litter decomposition. Initial C (51%), N (2.38%), and low lignin concentrations with low C/N (21.53) and lignin/N (4.05) ratios could be important factors in faster mass loss from the litter samples. The P mineralization kP (2.19) rate was higher than kN (0.73), indicating the slower release rate of N. The weight loss during decomposition was positively correlated with rainfall (r = 0.42) and temperature (r = 0.39). The study suggests that F. semialata leaf litter could be useful for regulating soil nutrient pool through faster litter turnover and can therefore be exploited as plantation and/or agroforestry species for soil and water conservation in degraded slopy terrain of the region. [ABSTRACT FROM AUTHOR]

The most common crop in India is rice, which is grown on 43 million planted hectares and produces 746 million tones of grain annually. Due to the fact that straw accounts for 50% of the dry weight of the rice plant, a tremendous amount of straw is produced as a byproduct of rice farming each year. We produce 65% of our biomass on land, according to estimates. Lignin is the most prevalent natural polymer of that biomass after cellulose and a significant renewable supply of aromatic carbon on earth. Since lignin, cellulose, and hemicelluloses make up the structural elements of higher land plant vascular tissues, the biodegradation of these elements is a crucial step in the recycling of terrestrial biosynthetic carbon. This study focus on biochemical analysis of decomposition of paddy straw and find out different fungi present in soil after decomposition. [ABSTRACT FROM AUTHOR]

Plant parts like root, wood, twig and leaf of Cassia siamea, a fast-growing tree in the abandoned mines of Jharkhand, India, have been considered here as a possible fuel source for decentralized power generation. This is a low greenhouse gas emission pathway to cater the electricity need of the adjoining locality. Seasonal availability of the plant parts originated interests of studying the basic combustion characteristics of the plant parts separately. Finding out the roles of cellulose and lignin to regulate the combustion behavior of plant parts was another objective. Cellulose and lignin were extracted from each plant part, and their burning performances were evaluated against those of respective plant parts with the help of DSC-TGA. Cellulose and lignin were found to influence the combustion processes of plant parts differently. Lignin in case of leaf combustion and cellulose for wood combustion regulated the combustion process. Both lignin and cellulose were competitive in regulating the combustion of twig and root. Burning characteristics of cellulose or lignin extracted from different plant parts varied. Higher heating value (HHV) was low for celluloses (~ 16.8 ± 1 MJ kg−1) as compared to lignin (HHV ~ 23.0 ± 1 MJ kg−1). Leaf having substantial lignin and extractives showed the highest HHV around 23.5 MJ kg−1, while the lowest HHV (16.0 MJ kg−1) was observed for wood. Results are interesting for considering each plant part as a single fuel or as a potential component of coal–biomass blended fuel, where locally available low-grade high ash coal may be the other component. [ABSTRACT FROM AUTHOR]

Background: Lignin is a complex polymer of phenyl propanoid units found in the vascular tissues of the plants as one of lignocellulose materials. Many bacteria secrete enzymes to lyse lignin, which can be essential to ease the production of bioethanol. Current research focused on the study of ligninolytic bacteria capable of producing lignin peroxidase (LiP) which can help in lignin biodegradation and bioethanol production. Ligninolytic bacterial strains were isolated and screened from the soil samples of Simlipal Biosphere Reserve (SBR), Odisha (India), for the determination of their LiP activity. Enzymatic assay and optimization for the LiP activity were performed with the most potent bacterial strain. The strain was identified by morphological, biochemical, and molecular methods. Results: In this study, a total of 16 bacteria (Simlipal ligninolytic bacteria [SLB] 1–16) were isolated from forest soils of SBR using minimal salt medium containing lignin. Out of the 16 isolates, 9 isolates showed decolourization of methylene blue dye on LB agar plates. The bacterial isolates such as SLB8, SLB9, and SLB10 were able to decolourize lignin with 15.51%, 16.80%, and 33.02%, respectively. Further enzyme assay was performed using H2O2 as substrate and methylene blue as an indicator for these three bacterial strains in lignin containing minimal salt medium where the isolate SLB10 showed the highest LiP activity (31.711 U/mg). The most potent strain, SLB10, was optimized for enhanced LiP enzyme activity using response surface methodology. In the optimized condition of pH 10.5, temperature 30 °C, H2O2 concentration 0.115 mM, and time 42 h, SLB10 showed a maximum LiP activity of 55.947 U/mg with an increase of 1.76 times from un-optimized condition. Further chemical optimization was performed, and maximum LiP activity as well as significant dye-decolourization efficiency of SLB10 has been found in bacterial growth medium supplemented individually with cellulose, yeast extract, and MnSO4. Most notably, yeast extract and MnSO4-supplemented bacterial culture medium were shown to have even higher percentage of dye decolourization compared to normal basal medium. The bacterial strain SLB10 was identified as Bacillus mycoides according to morphological, biochemical, and molecular (16S rRNA sequencing) characterization and phylogenetic tree analysis. Conclusion: Result from the present study revealed the potential of Bacillus mycoides bacterium isolated from the forest soil of SBR in producing LiP enzyme that can be evaluated further for application in lignin biodegradation and bioethanol production. Scaling up of LiP production from this potent bacterial strain could be useful in different industrial applications. [ABSTRACT FROM AUTHOR]

Lignin is biopolymer synthesized by plants and it consists up to 30% dry mass weight of any woody tissue. It is also known as second most abundant source of carbon after cellulose but still has a major problem, i.e. very tough to degrade. Thus, in present work authors were studied about the degradation of lignin by bacteria. The paper reports isolation, screening and identification of lignin degrading bacteria from collected samples. The bacterial strains were isolated from a cave that is located in the Chhattisgarh state of India in the mountain range of Salewara which have a temperature range between 26-28°C. A total of 32 bacterial isolates were studied and their RAPD analysis was performed and it was observed that Brevundimonas diminuta, Bacillus thuringiensis and Bacillus cereus were isolated in lignin- rich media which showed evidence of high lignin degradation. [ABSTRACT FROM AUTHOR]

According to the global survey, Iran, China, India, and USA are leading producers of pomegranate. Among them, India tops the chart as the highest producer of pomegranate, cultivating 1.14 million tons per annum. Peels cover 50% weight of whole pomegranate fruit and are mostly discarded as waste. This enormous peel waste has innumerable health benefits. Pomegranate peel (PP) constitutes various antioxidants, anthocyanins, and polyphenols such as ellagic acid, pectin, gallic acid, and many others which can be extracted. A detailed process for sequential extraction, with zero discharge, of such valuable chemicals from biorefinery point of view is developed in this study. Major products considered for extraction include ellagic acid (EA), lignin, and pectin. Also, the total phenolic content (TPC) and total reducing sugar (TRS) content are found in the intermediate stages. The percent yield of the products EA, lignin, and pectin is 10%, 13%, and 19% with respect to the weight of pomegranate peels (PP) processed. For the first time, a sequential extraction of products with its detailed process flow diagram, process inventory, and life cycle assessment (LCA) of PP biorefinery is presented. The global warming potential of the PP biorefinery is found to be 4505.8 kg CO2 eq. per ton of PP processed. The intense hydrolysis step contributed majorly to the overall GWP indicator. [ABSTRACT FROM AUTHOR]

Leaf litter decomposition and nutrient release patterns from five common multipurpose tree species—viz., Artocarpus heterophyllus, Mangifera indica, Areca catechu, Citrus sp., and Tamarindus indica, found in homegardens of Mizoram—were evaluated using a litter bag technique. The result of the study indicates a varying pattern of decomposition and nutrient release (N&P) among the species. Citrus sp. and T. indica were found to be the most labile species with comparatively much higher decay constant and faster nutrient release. Initial nitrogen concentration, lignin content, and lignin/N ratio of foliage litter showed significantly higher (p < .01) correlation with the decay coefficient and were found to be the important determinants in the decay process. The initial slow release and immobilization of N in A. heterophyllus and M. indica leaf litter reflect their potential as a source of nitrogen storage and effective mulching material. While litter from T. indica and Citrus sp. can provide the short-term nutrient need, foliage for the other three species may supply the long-term nutrient requirement for the understory crops in such agroforestry systems. [ABSTRACT FROM PUBLISHER]

The article focuses on a research that examines the termite infestation and the resultant damage in bamboo species in Karnataka, India. The study explores reasons why six bamboo species including Dendrocalamus asper, Dendrocalamus stocksii and Guadua angustifolia are susceptible to termite damage. The study found that the exotic species Guadua angustifolia was more susceptible to termite attack than the native species.

Rates of weight loss and nutrient (N and P) release patterns were studied in the leaf litter of the dominant tree species ( Ailanthus grandis, Altingia excelsa, Castanopsis indica, Duabanga sonneriatioides, Dysoxylum binectariferum, Mesua ferrea, Shorea assamica, Taluma hodgsonii, Terminalia myriocarpa and Vatica lancefolia) of a tropical wet evergreen forest of northeast India. Nitrogen and phosphorus mineralization rate and decay pattern varied significantly from species to species. In general, the decay pattern, characterized by using a composite polynomial regression equation, exhibited three distinct phases of decay during litter decomposition—an initial slow decay phase (0.063% weight loss day−1), followed by a rapid decay phase (0.494% weight loss day−1) and a final slow decay phase (0.136% weight loss day−1). The initial chemical composition of the litter affected decomposition rates and patterns. Species like D. sonneriatoides, D. binectariferum, and T. hodgsonii with higher N and P content, lower carbon and lignin content, and lower C:N ratio and lignin:N ratio exhibited relatively faster decomposition rates than the other species, for example M. ferrea, C. indica and A. grandis. A slow decay rate was recorded for species such as M. ferrea, C. indica, and A. grandis. The initial N and P content of litter showed significant positive correlations with decay rates. Carbon and lignin content, lignin:N, and C:N showed significant negative correlations with decay rates. Soil total N and P, and rainfall, soil temperature, and soil moisture had positive correlations with decay rates. The rapid decomposition rates observed in comparison with other different forest litter decay rates confirm that tropical wet evergreen forest species are characterized by faster decomposition rates, indicating a faster rate of organic matter turnover and rapid nutrient cycling. [ABSTRACT FROM AUTHOR]

The decomposition of wood and leaf litter of a dominant tree species, Dipterocarpus tuberculatus Roxb. was studied from March 1999 to June 2000 in a tropical deciduous forest of Manipur, Northeast India. The weight loss pattern and concentration of nitrogen (N) and lignin during decomposition were also evaluated. The monthly weight loss was significantly correlated (P < 0.05) with soil moisture and rainfall in both types of litter. The rate of weight loss was faster in wood litter than leaf litter, probably due to termite-feeding activities. [ABSTRACT FROM AUTHOR]

Biorefineries typically use dry feedstock due to technical and logistic issues, but in unique cases where climatic conditions are unfavorable and where the biomass has to be processed without a holding time, wet processing might be advantageous. The present study evaluated the possibility of using the fresh (non-dried) mixed biomass harvested from Phumdis; which are floating vegetation unique to Loktak lake in Manipur, India, for bioethanol production. Pretreatment with dilute alkali (1.5% at 120 °C for 60 min) resulted in 36% lignin removal and an enhancement of cellulose content to 48% from 37%, and enzymatic hydrolysis released 25 g/L glucose. Fermentation of the hydrolysates was highly efficient at 95%, attained in 36 h and 80% in just 12 h. The new wet processing strategy could help in value addition of mixed phumdi biomass., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Research Highlights: Agroforestry systems in the humid tropics have the potential for high rates of production and large accumulations of carbon in plant biomass and soils and, thus, may play an important role in the global C cycle. Multiple factors can influence C sequestration, making it difficult to discern the effect of a single factor. We used a modeling approach to evaluate the relative effects of individual factors on C stocks in three agricultural systems in Kerala, India. Background and Objectives: Factors such as plant growth form, management, climate warming, and soil texture can drive differences in C storage among cropping systems, but the relationships among these factors and their effects are complex. Our objective was to use CENTURY, a process-based model of plant–soil nutrient cycling, in an experimental mode to evaluate the effects of individual factors on C stocks in soil and biomass in monocultures (annuals or trees) and agroforestry systems. Materials and Methods: We parameterized the model for this region, then conducted simulations to investigate the effects on C stocks of four experimental scenarios: (1) change in growth form; (2) change in tree species; (3) increase in temperature above 20-year means; and (4) differences in soil texture. We compared the models with measured changes in soil C after eight years. Results: Simulated soil C stocks were influenced by all factors: growth form; lignin in tree tissues; increasing temperature; and soil texture. However, increasing temperature and soil sand content had relatively small effects on biomass C. Conclusions: Inclusion of trees with traits that promoted C sequestration such as lignin content, along with the use of best management practices, resulted in the greatest C storage among the simulated agricultural systems. Greater use and better management of trees with high C-storage potential can thus provide a low-cost means for mitigation of climate warming. [ABSTRACT FROM AUTHOR]