Considering biomass production on marginal lands as one of the important ways for climate change mitigation, ecological restoration and biodiversity conservation and livelihood, the development of high-diversity tall perennial grass-based biomass production system is getting special attention. Although such grasses (e.g., Arundo donax L., Desmostachya bipinnata L. Stapf., Panicum antidotale Retz., Saccharum species, Vetiveria zizanioides L.) are widely distributed in India and naturally grow on marginal lands without external inputs, these are neglected and underutilized. On the other hand, similar species like Panicum virgatum L. and Miscanthus × giganteus Greef and Deuter ex Hodkinson and Renvoize are significantly contributing in bioenergy production in the USA, Europe and Australia. The unavailability of appropriate plant species that can be grown on marginal lands for consistent biomass production, restoration of soil fertility and to support several socioeconomic and ecological services has shifted the attention of policy makers more toward solar and wind energy than bioenergy as evident from India’s Intended Nationally Determined Contributions submitted to United Nations Framework Convention on Climate Change (UNFCCC 2015). It is, therefore, important to identify appropriate plant species which produce high biomass in various stressful environments without intensive agricultural inputs and have a range of ecological services. This review, therefore, briefly provides information on biomass and bioenergy production, ecological restoration, biodiversity conservation, environmental remediation and cultural perspectives of various tall perennial grasses those are otherwise neglected and underutilized so far in India in the lack of primary research. The major research gaps and opportunities for developing multifunctional cropping systems involving these grasses for harnessing various economic and ecological services have also been identified.
The efficacy of ionic liquid (IL)-based pretreatment of lignocellulosic biomass (LB) can be enhanced by simultaneous application of surfactants/salts/deep eutectic solvent (DES) systems which may realize more effectual biorefining of LB to biofuels or other commodities. However, due to inhibitory nature of IL, IL-stable saccharification enzymes (cellulase/xylanase) are desired for enzymatic hydrolysis of IL-pretreated biomass. Bacillus spp. are considered as the super microbial factories for production of commercially important robust enzymes. The current study presents the enhanced production (1.438-fold) of an IL-stable cellulase from a newly isolated IL-tolerant Bacillus amyloliquefaciens SV29 by statistical optimization using agroindustrial residues as carbon (groundnut shell) and nitrogen source (mustard cake). The process variables such as groundnut shell and mustard cake, incubation time, and inoculum size were optimized. The enzyme preparation (cellulase/xylanase) was evaluated for its saccharification potential of Prosopis sp. (twigs/pods) biomass that was pretreated either with IL (1-ethyl-3-methylimidazolium methanesulfonate, EMIMS) standalone or IL along with surfactants/salts/DES systems in a consolidated bioprocess (CBP), i.e., one pot consolidated bioprocess, due to several technoeconomic advantages of the latter. No reported studies are available on bioconversion of Prosopis sp. biomass using IL or CBP. Sugar yield was enhanced when IL was used along with either DES choline chloride glycerol (54.4%) or with FeSO4 (51%). Thus, the pretreatment efficacy of EMIMS is substantially enhanced when used in combination with choline chloride glycerol or FeSO4 for getting increased sugar yield upon enzymatic hydrolysis of Prosopis sp. biomass with IL-stable enzymes.
Low-density polyethylene (LDPE) is a conventionally used polymer and possesses diverse applications in various industries due to its low cost, excellent strength, and numerous mechano-thermal properties. Unfortunately, the deliberate and unconscious release of excess polythene in the environment causes serious ecological threat. To deal with this issue, biodegradation of LDPE was considered using different fungal strains, namely Aspergillus flavus, Aspergillus versicolor, and Fusarium solani isolated from local municipal dump yard in Chennai, India. For degradation study, the polymers were subjected to microbial cultures for 60 days under laboratory conditions. The extent of the degradation was quantified in terms of the weight loss of the LDPE films, pH changes of the culture medium, mineralization, and analysed by field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR) spectroscopy. FESEM micrographs revealed the fungal colonization on the polythene matrix due to their metabolic activities, whereas FTIR spectra showed the changes in chemical nature of the polymer films and confirmed the biodegradation of LDPE. By comparing the reduction in dry weight of LDPE strips and Sturm test results, A. versicolor strain was found to be a potential LDPE-degrading candidate than A. flavus and F. solani and, hopefully, can address the global issue of polymer pollution.
BaFe2O4 spinel-type ferrite is synthesized by a simple auto-combustion method. The ferrites are based on spinel structure. The ideal spinel structure consists of the cubic close packing of oxygen anions with the tetrahedral (A site) and octahedral (B site) holes available for metal cation occupancy. Spinel ferrites have combined the both interesting magnetic properties and high electrical resistivity. The barium nitrate and ferric nitrate are taken as raw material, and combustion process is adopted for synthesis. The resultant ash was collected after combustion, and it is annealed at 700 and 900 °C. The synthesized products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectrum and vibrating sample magnetometer. BaFe2O4 nanoparticles exhibit good magnetic property and also possess gas sensing ability. This material is more suitable for high-temperature gas sensor to support for clean environment.
In the present study, sugar beet pulp (SBP) was subjected to bioconversion by earthworm Eisenia fetida in a vermicomposting process. SBP and cattle dung were mixed in different ratios of 0:100 (SBP0) 10:90 (SBP10), 20:80 (SBP20), 40:60 (SBP40) and 80:20 (SBP80). Allium cepa L. genotoxicity bioassay test was used to check the reduction of toxicity of waste during vermicomposting. The results revealed the increase in the root length and mitotic index (MI) values of final vermicomposted mixtures. The maximum root length (cm) and MI (%) values were found in the final feed mixtures of SBP0 (control) (7.52 ± 0.33 cm) and SBP10 (16.7 ± 0.29%) concentrations, respectively. The vermicomposted feed mixtures of sugar beet pulp showed 34–62% reduction in the chromosomal aberrations with maximum decline (62.0%) in SBP20 concentration. The study indicated that the earthworms have the potential to minimize the toxicity of SBP waste. Scanning electron microscopy analysis of SBP40 feed mixture revealed that the final product was more fragmented and scattered in nature than the initial raw waste.