Browsing by Author "K N, Yogalakshmi"

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    Brevundimonas diminuta MYS6 associated Helianthus annuus L. for enhanced copper phytoremediation
    (Elsevier Ltd, 2020-08-31T00:00:00) Rathi, Manohari; K N, Yogalakshmi
    Natural occurring metal-tolerant microbial population have replaced conventional expensive metal remediation approach since the last few years. The present study focuses on investigating the potential of a copper-tolerant plant growth promoting rhizobacterial strain Brevundimonas diminuta MYS6 for Cu bioremediation, plant growth promotion and Cu uptake in Helianthus annuus L. Box-Behnken Design of response surface methodology optimized the influencing parameters such as pH, temperature and Cu concentration. At optimized conditions of pH (5), temperature (32.5 �C) and Cu concentration (250 mg/L), the rhizobacteria followed a sigmoid growth curve pattern with maximum Cu removal of 94.8% in the stationary phase of growth. Cu exposed Brevundimonas diminuta MYS6 produced increased EPS (18.6%), indicating their role in internal defence against Cu stress. The FTIR analysis suggested the role of carboxylic acids, alcohols and aliphatic amine groups in Cu bioremoval. Furthermore, the results of pot experiments conducted with Helianthus annuus L. var. CO4 and Brevundimonas diminuta MYS6 showed enhanced plant growth and Cu uptake. The rhizobacteria increased root and shoot length, fresh and dry plant biomass and leaf chlorophyll by 1.5, 1.7, 9.9, 15.8 and 2.1 fold. The plant biomass mediate enhanced Cu uptake in roots and shoots was found to be 2.98 and 4.1 folds higher when compared to non-inoculated treatment. Henceforth the results of the study evidence the rhizobacterial strain Brevundimonas diminuta MYS6 as an efficient bio-inoculant for copper remediation. � 2020 Elsevier Ltd
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    A critical review on limitations and enhancement strategies associated with biohydrogen production
    (Elsevier Ltd, 2021-02-15T00:00:00) Banu J, Rajesh; Usman T M, Mohamed; S, Kavitha; Kannah R, Yukesh; K N, Yogalakshmi; P, Sivashanmugam; Bhatnagar, Amit; Kumar, Gopalakrishnan
    The potential to operate energy efficient and less expensive production methods are important in biohydrogen production. Biological hydrogen production is often constrained by less productivity. However, to obtain industrial level implementation, greater productivity is essential. Researches on various bioreactors configurations and influencing factors were deeply investigated in this regard. The bioreactors operated in batch mode are appropriate for preliminary optimization whereas industrial level execution needs continuous mode. The main objective of this review is to recap the limitations and constraints associated with bioreactor operation and to list out the enhancement approaches that are currently investigated for improved biohydrogen generation. Recent approaches designed towards biohydrogen production enhancement such as substrate pre-treatments, inhibitors removal, bioaugmentation, immobilization, effluent recycling, buffering capacity maintenance, exploitation of by-products etc., are reviewed thoroughly. � 2021 Hydrogen Energy Publications LLC
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    Lignocellulosic biomass-based pyrolysis: A comprehensive review
    (Elsevier Ltd, 2021-08-06T00:00:00) K N, Yogalakshmi; T, Poornima Devi; P, Sivashanmugam; S, Kavitha; R, Yukesh Kannah; Varjani, Sunita; AdishKumar, S.; Kumar, Gopalakrishnan; J, Rajesh Banu
    The efficacious application of lignocellulosic biomass for the new valuable chemicals generation curbs the excessive dependency on fossil fuels. Among the various techniques available, pyrolysis has garnered much attention for conversion of lignocellulosic biomass (encompasses cellulose, hemicellulose and lignin components) into product of solid, liquid and gases by thermal decomposition in an efficient manner. Pyrolysis conversion mechanism can be outlined as formation of char, depolymerisation, fragmentation and other secondary reactions. This paper gives a deep insight about the pyrolytic behavior of the lignocellulosic components accompanied by its by-products. Also several parameters such as reaction environment, temperature, residence time and heating rate which has a great impact on the pyrolysis process are also elucidated in a detailed manner. In addition the environmental and economical facet of lignocellulosic biomass pyrolysis for commercialization at industrial scale is critically analyzed. This article also illustrates the prevailing challenges and inhibition in implementing lignocellulosic biomass based pyrolysis with possible solution. � 2021