Deciphering the biochemical and functional characterization of rice straw cultivars for industrial applications.

As an agricultural state, Haryana (India) produces about six million metric tons (mt) of rice straw every year from rice cultivation. Currently, rice straw is either burned or ploughed into the field without being turned into a functional product. Burning of paddy straw release green house gases and particulate matter (2.5 and 10 µm), which leads to air pollution and considerable loss of soil property viz. nutrients, organic matter, productivity and biodiversity, and on and off-farm humans and animals' health. The biochemically and functionally specified potential for optimal alternative use of the rice straw of 13 most widely produced rice varieties from Haryana's eastern and western agro-climate zones was undertaken. Pusa-1401 variety had the highest cellulose (46.55%) and silica content (13.70%), while Pusa-1718 had hemicellulose (28.25%) and lignin (11.60%), respectively. Maximum nitrogen (0.81%), phosphorus (0.32%) and potassium (2.78%) were found in rice variety Pusa-1509, Pusa-1401 and Rice-6129. The findings seemed to be statistically significant (p < 0.05). The biochemical profiles of rice straw cultivars were classified into distinct structural groups (C-H alkalanes, O-H alcohol, C[bond, double bond]O, C-H alkanes) based on the FTIR spectrum in order to find the best alternative possibilities for bioethanol and compost production. According to the study, these rice straw varieties could be used to make lucrative industrial products.

Prospecting the significance of methane-utilizing bacteria in agriculture.

Microorganisms act as both the source and sink of methane, a potent greenhouse gas, thus making a significant contribution to the environment as an important driver of climate change. The rhizosphere and phyllosphere of plants growing in natural (mangroves) and artificial wetlands (flooded agricultural ecosystems) harbor methane-utilizing bacteria that oxidize methane at the source and reduce its net flux. For several decades, microorganisms have been used as biofertilizers to promote plant growth. However, now their role in reducing net methane flux, especially from flooded agricultural ecosystems is gaining momentum globally. Research in this context has mainly focused on taxonomic aspects related to methanotrophy among diverse bacterial genera, and environmental factors that govern methane utilization in natural and artificial wetland ecosystems. In the last few decades, concerted efforts have been made to develop multifunctional microbial inoculants that can oxidize methane and alleviate greenhouse gas emissions, as well as promote plant growth. In this context, combinations of taxonomic groups commonly found in rice paddies and those used as biofertilizers are being explored. This review deals with methanotrophy among diverse bacterial domains, factors influencing methane-utilizing ability, and explores the potential of novel methane-utilizing microbial consortia with plant growth-promoting traits in flooded ecosystems.

Plant Secondary Metabolites as Defense Tools against Herbivores for Sustainable Crop Protection.

Plants have evolved several adaptive strategies through physiological changes in response to herbivore attacks. Plant secondary metabolites (PSMs) are synthesized to provide defensive functions and regulate defense signaling pathways to safeguard plants against herbivores. Herbivore injury initiates complex reactions which ultimately lead to synthesis and accumulation of PSMs. The biosynthesis of these metabolites is regulated by the interplay of signaling molecules comprising phytohormones. Plant volatile metabolites are released upon herbivore attack and are capable of directly inducing or priming hormonal defense signaling pathways. Secondary metabolites enable plants to quickly detect herbivore attacks and respond in a timely way in a rapidly changing scenario of pest and environment. Several studies have suggested that the potential for adaptation and/or resistance by insect herbivores to secondary metabolites is limited. These metabolites cause direct toxicity to insect pests, stimulate antixenosis mechanisms in plants to insect herbivores, and, by recruiting herbivore natural enemies, indirectly protect the plants. Herbivores adapt to secondary metabolites by the up/down regulation of sensory genes, and sequestration or detoxification of toxic metabolites. PSMs modulate multi-trophic interactions involving host plants, herbivores, natural enemies and pollinators. Although the role of secondary metabolites in plant-pollinator interplay has been little explored, several reports suggest that both plants and pollinators are mutually benefited. Molecular insights into the regulatory proteins and genes involved in the biosynthesis of secondary metabolites will pave the way for the metabolic engineering of biosynthetic pathway intermediates for improving plant tolerance to herbivores. This review throws light on the role of PSMs in modulating multi-trophic interactions, contributing to the knowledge of plant-herbivore interactions to enable their management in an eco-friendly and sustainable manner.

Biostimulation of Anaerobic Digestion Using Iron Oxide Nanoparticles (IONPs) for Increasing Biogas Production from Cattle Manure.

The effect of synthesised IONPs employing a nontoxic leaf extract of Azadirachta indica as a reducing, capping, and stabilizing agent for increasing biogas and methane output from cattle manure during anaerobic digestion (AD) was investigated in this study. Furthermore, the UV-visible spectra examination of the synthesized nanoparticles revealed a high peak at 432 nm. Using a transmission electron microscope, the average particle size of IONPs observed was 30-80 nm, with irregular, ultra-small, semi-spherical shapes that were slightly aggregated and well-distributed. IONPs had a polydisparity index (PDI) of 219 nm and a zeta potential of -27.0 mV. A set of six bio-digesters were fabricated and tested to see how varying concentrations of IONPs (9, 12, 15, 18, and 21 mg/L) influenced biogas, methane output, and effluent chemical composition from AD at mesophilic temperatures (35 ± 2 °C). With 18 mg/L IONPs, the maximum specific biogas and methane production were 136.74 L/g of volatile solids (VS) and 64.5%, respectively, compared to the control (p < 0.05), which provided only 107.09 L/g and 51.4%, respectively. Biogas and methane production increased by 27.6% and 25.4%, respectively using 18 mg/L IONPs as compared to control. In all treatments, the pH of the effluent was increased, while total volatile fatty acids, total solids, volatile solids, organic carbon content, and dehydrogenase activity decreased. Total solid degradation was highest (43.1%) in cattle manure + 18 mg/L IONPs (T5). According to the results, the IONPs enhanced the yield of biogas and methane when compared with controls.

Methane utilizing plant growth-promoting microbial diversity analysis of flooded paddy ecosystem of India.

Methane utilizing bacteria (MUB) are known to inhabit the flooded paddy ecosystem where they play an important role in regulating net methane (CH4) emission. We hypothesize that efficient MUB having plant growth-promoting (PGP) attributes can be used for developing novel bio-inoculant for flooded paddy ecosystem which might not only reduce methane emission but also assist in improving the plant growth parameters. Hence, soil and plant samples were collected from the phyllosphere, rhizosphere, and non-rhizosphere of five rice-growing regions of India at the tillering stage and investigated for efficient methane-oxidizing and PGP bacteria. Based on the monooxygenase activity and percent methane utilization on NMS medium with methane as the sole C source, 123 isolates were identified and grouped phylogenetically into 13 bacteria and 2 yeast genera. Among different regions, a significantly higher number of isolates were obtained from lowland flooded paddy ecosystems of Aduthurai (33.33%) followed by Ernakulum (20.33%) and Brahmaputra valley (19.51%) as compared to upland irrigated regions of Gaya (17.07%) and Varanasi (8.94%). Among sub-samples, a significantly higher number of isolates were found inhabiting the phyllosphere (58.54%) followed by non-rhizosphere (25.20%) and rhizosphere (15.45%). Significantly higher utilization of methane and PGP attributes were observed in 30 isolates belonging to genera Hyphomicrobium, Burkholderia, Methylobacterium, Paenibacillus, Pseudomonas, Rahnella, and Meyerozyma. M. oryzae MNL7 showed significantly better growth with 74.33% of CH4 utilization at the rate of 302.9 ± 5.58 and exhibited half-maximal growth rate, Ks of 1.92 ± 0.092 mg CH4 L-1. Besides the ability to utilize CH4, P. polymyxa MaAL70 possessed PGP attributes such as solubilization of P, K, and Zn, fixation of atmospheric N and production of indole acetic acid (IAA). Both these promising isolates can be explored in the future for developing novel biofertilizers for flooded paddies.

Inoculation of plant growth promoting-methane utilizing bacteria in different N-fertilizer regime influences methane emission and crop growth of flooded paddy.

Methane (CH4) emission in rice fields is greatly influenced by the type and quantity of nitrogenous fertilizer used. The net methane emission from paddy fields is also influenced by the activity of methane utilizing bacteria, which inhabit the flooded paddy ecosystem. Efficient methane utilizing and plant growth promoting bacteria Methylobacterium oryzae MNL7 and Paenibacillus polymyxa MaAL70, respectively were co-inoculated along with different nitrogenous fertilizer combinations in flooded paddy to assess their impact on cumulative methane emission and crop growth promotion. Co-inoculation significantly influenced the plant growth parameters of paddy, resulting in an increase in grain yield by 14.04, 11.08, and 12.38% in treatments receiving Urea, Di-ammonium Phosphate (DAP) + Urea, or farm yard manure (FYM), over their respective un-inoculated plots. Significant improvement in the rice grain nutrient quality in term of crude protein, Fe and Zn content was observed as a result of bacterial co-inoculation in FYM fertilized plots as compared to Urea and DAP+ Urea fertilized plots. Significantly higher cumulative methane emission of 63.39 kg ha-1 was observed in uninoculated plots fertilized with FYM treatment as compared to Urea (33.83 kg ha-1) and DAP+Urea (31.66 kg ha-1) treatments. Bacterial co-inoculation significantly reduced the cumulative methane emission by 12.03, 11.47 and 6.92% in Urea, DAP+Urea, and FYM fertilized plots over their respective uninoculated treatments. Among the different fertilizer treatments, bacterial co-inoculation with urea application performed significantly better in reducing cumulative methane emission. These findings suggest that methane utilizing bacteria which also possess plant growth promoting trait can be explored for developing a novel biofertilizer for flooded paddies, as they can aid in managing both the overall methane emission and enhancing crop yield.

Initial Development of an Air-Jet Dry Powder Inhaler for Rapid Delivery of Pharmaceutical Aerosols to Infants.

Background: Positive-pressure dry powder inhalers (DPIs) have recently been developed that in combination with highly dispersible spray-dried powder formulations can achieve high efficiency aerosolization with low actuation air-volumes (AAVs). The objective of this study was to initially develop the positive-pressure air-jet DPI platform for high efficiency aerosol delivery to newborn infants by using the nose-to-lung route. Methods: Aerosolization performance metrics of six air-jet DPIs were first assessed at AAVs that were consistent with full-term (30 mL) and preterm (10 mL) neonates. Designs of the air-jet DPIs varied based on geometry of the inlet and outlet flow passages and shape of the aerosolization chamber. Aerosolization metrics evaluated at the device outlet were emitted dose (ED) and mass median aerodynamic diameter (MMAD). Designs with the best aerosolization performance were connected to a smoothly expanding nasal interface and full-term infant (3550 g) nose-throat (NT) model with tracheal filter. Results: The three best performing devices had characteristics of a cylindrical and horizontal aerosolization chamber with a flush or protruding outlet orifice. Including multiple air inlets resulted in meeting the aerosolization targets of >80% ED (based on loaded dose) and MMAD <1.8 µm. Reducing the AAV by a factor of threefold from 30 to 10 mL had little effect on aerosol formation. The three leading devices all delivered ∼50% of the loaded dose through a full-term NT in vitro model by using an AAV of 30 mL. Conclusion: With careful selection of design attributes, the air-jet DPI platform is capable of high-efficiency aerosolization of a 10 mg powder mass by using AAVs that are consistent with infant inhalation. The associated infant air-jet DPI system, which forms a seal at the nostril(s) and delivers both the aerosol and a complete inhalation, is capable of rapid and efficient aerosol administration to infant lungs, based on initial testing in a full-term in vitro NT model.

Use of computational fluid dynamics deposition modeling in respiratory drug delivery.

INTRODUCTION: Respiratory drug delivery is a surprisingly complex process with a number of physical and biological challenges. Computational fluid dynamics (CFD) is a scientific simulation technique that is capable of providing spatially and temporally resolved predictions of many aspects related to respiratory drug delivery from initial aerosol formation through respiratory cellular drug absorption. AREAS COVERED: This review article focuses on CFD-based deposition modeling applied to pharmaceutical aerosols. Areas covered include the development of new complete-airway CFD deposition models and the application of these models to develop a next-generation of respiratory drug delivery strategies. EXPERT OPINION: Complete-airway deposition modeling is a valuable research tool that can improve our understanding of pharmaceutical aerosol delivery and is already supporting medical hypotheses, such as the expected under-treatment of the small airways in asthma. These complete-airway models are also being used to advance next-generation aerosol delivery strategies, like controlled condensational growth. We envision future applications of CFD deposition modeling to reduce the need for human subject testing in developing new devices and formulations, to help establish bioequivalence for the accelerated approval of generic inhalers, and to provide valuable new insights related to drug dissolution and clearance leading to microdosimetry maps of drug absorption.