Harish Chandra

Removal of chromium (VI) through biosorption by the Pseudomonas spp. isolated from tannery effluent

Heavy metal contamination of the rivers is a world wide environmental problem and its removal is a great challenge. Kanpur and Unnao two closely located districts of Uttar Pradesh India are known for their leather industries. The tanneries release their treated effluent in the near by water ways containing Cr metal that eventually merges with the river Ganges. Untreated tannery effluent contains 2.673 ± 0.32 to 3.268 ± 0.73 mg l–1 Cr. Microbes were isolated, keeping the natural selection in the view, from the tannery effluent since microbes present in the effluent exposed to the various types of stresses and metal stress is one of them. Investigations include the exposure of higher concentrations of Cr(VI) 1.0 to 4.0 mg l–1 to the bacteria (presumably the Pseudomonas spp.) predominant on the agar plate. The short termed study (72 h) of biosorption showed significant reduction of metal in the media especially in the higher concentrations with a value from 1.0 ± 0.02, 2.0 ± 0.01, 3.0 ± 0, and 4.0 ± 0.09 at zero h to 0.873 ± 0.55, 1.840 ± 1.31, 2.780 ± 0.03 and 3.502 ± 0.68 at 72 h respectively. The biosorption of metal show in the present study that the naturally occurring microbes have enough potential to mitigate the excessive contamination of their surroundings and can be used to reduce the metal concentrations in aqueous solutions in a specific time frame. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Plant–microbe interaction in aquatic system and their role in the management of water quality: a review

Microbial assemblage as biofilm around the aquatic plant forms a firm association that largely depends upon the mutual supplies of nutrients, e.g., microbes interact with plants in an aquatic system most likely for organic carbon and oxygen, whereas plants receive defensive immunity and mineral exchange. Apart from the mutual benefits, plant–microbe interactions also influence the water quality especially at rhizosphere providing inherent ability to the aquatic system for the mitigation of pollution from the water column. The review presents and in-depth information along with certain research advancements made in the field of ecological and bio/chemical aspects of plant–microbe interactions and the underlying potential to improve water quality.

Antimicrobial Resistance and the Alternative Resources with Special Emphasis on Plant-Based Antimicrobials—A Review

Indiscriminate and irrational use of antibiotics has created an unprecedented challenge for human civilization due to microbe’s development of antimicrobial resistance. It is difficult to treat bacterial infection due to bacteria’s ability to develop resistance against antimicrobial agents. Antimicrobial agents are categorized according to their mechanism of action, i.e., interference with cell wall synthesis, DNA and RNA synthesis, lysis of the bacterial membrane, inhibition of protein synthesis, inhibition of metabolic pathways, etc. Bacteria may become resistant by antibiotic inactivation, target modification, efflux pump and plasmidic efflux. Currently, the clinically available treatment is not effective against the antibiotic resistance developed by some bacterial species. However, plant-based antimicrobials have immense potential to combat bacterial, fungal, protozoal and viral diseases without any known side effects. Such plant metabolites include quinines, alkaloids, lectins, polypeptides, flavones, flavonoids, flavonols, coumarin, terpenoids, essential oils and tannins. The present review focuses on antibiotic resistance, the resistance mechanism in bacteria against antibiotics and the role of plant-active secondary metabolites against microorganisms, which might be useful as an alternative and effective strategy to break the resistance among microbes.

Advances in microbial bioremediation and the factors influencing the process

Irrational and rapid global human societal development has culminated to a condition of environmental deterioration. Accidental leakage and deliberate use of organic and inorganic chemicals have contaminated the environment up to the level of ecosystem. Advancements have been made in the field of research on bioremediation of the hazardous contaminants especially in last three decades. Microbial bioremediation has been the most understood biotechnological process of environmental restoration. Bacteria and fungi because of their inherent ability to adapt and grow in extreme environments have been employed for either removal or degradation of the chemical contaminants. Researchers all over the world are getting breakthroughs in finding new bacterial strains having plasmid linked degradation/reduction ability. Molecular biology and genetic engineering helped in crafting the microbes for the desired results on environment. Despite having favorable conditions, microbial remediation largely depends on environmental factors and on the basic biological characters of microbes, especially bacteria being Gram-positive or Gram-negative. Metagenomic studies revealed the importance of microbial ecology as microbes work well in community, i.e., consortia. This review along with several other studies suggests the need of precision during microbial community identification, substrate specificity and the designing of microbes.

Antimicrobial resistance (AMR) and plant-derived antimicrobials (PDAms) as an alternative drug line to control infections

Abstract Infectious diseases caused by antimicrobial-resistant microbes (ARMs) and the treatment are the serious problems in the field of medical science today world over. The development of alternative drug line to treat such infectious diseases is urgently required. Researches on ARMs revealed the presence of membrane proteins responsible for effusing the antibiotics from the bacterial cells. Such proteins have successfully been treated by plant-derived antimicrobials (PDAms) synergistically along with the commercially available antibiotics. Such synergistic action usually inhibits the efflux pump. The enhanced activity of plant-derived antimicrobials is being researched and is considered as the future treatment strategy to cure the incurable infections. The present paper reviews the advancement made in the researches on antimicrobial resistance along with the discovery and the development of more active PDAms.

Response of C3 and C4 Plant Systems Exposed to Heavy Metals for Phytoextraction at Elevated Atmospheric CO2 and at Elevated Temperature

Jatin Srivastava1, Harish Chandra 2, Anant R. Nautiyal3 and Swinder J. S. Kalra4 1Department of Applied Sciences, Global Group of Institutions Raebareli Road Lucknow UP 2Department of Biotechnology, G. B. Pant Engineering College Ghurdauri, Pauri Garhwal, Uttrakhand 3High Altitude Plant Physiology Research Centre H. N. B. Garhwal University, Srinagar Garhwal, Uttrakhand 4Department of Chemistry, Dayanand Anglo Vedic College, Civil-Lines, Kanpur UP India

Green synthesis of zinc oxide nanoparticles using leaf extract of Hedera nepalensis K. Koch and its biological activity

Green synthesis of metal oxide nanoparticles using plant extract is now getting popular these days because of its simplicity, economical and eco-friendly approach. The green synthesis method is now the preferred method as compared to physical and chemical method of nanoparticle synthesis. The present investigation was carried out by taking leaf extract of H. nepalensis for the synthesis of zinc oxide nanoparticles from zinc acetate dehydrate. The synthesized nanoparticles was characterised by using UV-Visible spectroscopy XRD, SEM, and EDX which proved that the synthesized ZnO NPs are in the range of nanoparticles. The wavelength specific UV-Vis absorption peaks for ZnO NPs were recorded at 372 nm which confirmed the presence of zinc oxide in nano scale. Synthesized nanoparticles were tested for their antimicrobial activity against uro-pathogens and some standard strain of pathogenic bacteria. The synthesized ZnO NPs are active against K. pneumoniae, E. coli, Bacillus subtilis, Staphylococcus aureus, B. cereus, Serratia marcescens and no activity has been recorded against Proteus spp. and S. typhi. The synthesized ZnO NPs was also tested for their antioxidant potential and found to have significant antioxidant properties.