Aparna Banerjee

Use of dextran nanoparticle: A paradigm shift in bacterial exopolysaccharide based biomedical applications

This review is a concise compilation of all the major researches on dextran nanoparticle based biomedical applications. Dextran is a highly biocompatible and biodegradable neutral bacterial exopolysaccharide with simple repeating glucose subunits. Its simple yet unique biopolymeric nature made it highly suitable as nanomedicine, nanodrug carrier, and cell imaging system or nanobiosensor. Most importantly, it is extremely water soluble and shows no post drug delivery cellular toxicity. Complete metabolism of dextran is possible inside body thus possibility of renal failure is minimum. Dextran based nanoparticles have superior aqueous solubility, high cargo capacity and intrinsic viscosity, and short storage period. The main focus area of this review is- past and present of major biomedical applications of dextran based nanomaterials thus showing a paradigm shift in bacterial exopolysaccharide based nanobiotechnology.

Cu(II) complex of a new isoindole derivative: structure, catecholase like activity, antimicrobial properties and bio-molecular interactions

An isoindole based Cu(II) complex, [Cu(PICPH)Cl2], was synthesized in situ by reacting copper(II) chloride with a pyridine derived ligand, PICPH. The complex was characterized by spectroscopic techniques while its structure was confirmed by single crystal X-ray diffraction analysis. The complex has a trigonal bipyramid geometry containing both five- and seven-member chelate rings. It shows catecholase-like activity. Interaction of the complex with a bio-relevant antipyrine derivative (ANNAP) was studied using fluorescence spectroscopy. DFT studies unfold the energetics associated with PICPH, [Cu(PICPH)Cl2] and the adduct between [Cu(PICPH)Cl2] and ANNAP. Antimicrobial activities of the compounds were also studied.

Preparations and Applications of Polysaccharide Based Green Synthesized Metal Nanoparticles: A State-of-the-Art

Green chemistry is the torch bearing field of sustainable research where without use of any toxic chemicals, environment-friendly metal nanoparticles are produced. Advantages of green nanoparticle synthesis over chemical-based synthesis are its nearly zero toxicity with wider applications. As the multidrug resistant species begin to emerge, green synthesized nanoparticles have been arisen as a potent alternative of antimicrobials along with various other applications in diverse fields. The main hindrances behind green synthesis are choice of material and its availability. Because of cheaper cost, wide availability, enhanced effectivity and fewer side effects, polysaccharides have successfully replaced the position of chemical reducing agents in nanoparticle synthesis. Our present review focuses on preparation and applications of polysaccharide based metal nanoparticles; a state-of-the-art research with special emphasis on green synthesized silver nanoparticles as a potent source of emerging antimicrobial.

Structural and Functional Properties, Biosynthesis, and Patenting Trends of Bacterial Succinoglycan: A Review

The exopolysaccharide succinoglycan is produced mainly by a large number of soil microbes of Agrobacterium, Rhizobium or Pseudomonas genera etc. Structural properties of succinoglycan are unique in terms of its thermal stability and superior viscosifying property. Unlike the other highly commercialized bacterial exopolysaccharides like dextran or xanthan, mass scale application of succinoglycan has not been that much broadly explored yet. Bacterial succinoglycan is found suitable as a viscosifying and emulsifying agent in food industry, in gravel packing or fluid-loss control agent etc. In this present review, the key aspects of succinoglycan study, in particular, developments in structural characterizations, exo/exs operon system involved in biosynthesis pathway, commercial applications in food and other industries and patenting trends have been discussed.

Degradation of Synthetic Azo Dyes of Textile Industry: a Sustainable Approach Using Microbial Enzymes

By releasing of azo dye through textile effluent, textile industry is the main cause of water pollution resulting into acute effect on environment and human health. Development of any eco-friendly and cost-effective method that may address the drawbacks to physical or chemical methods of dye removal is the recent global priority. Physical or chemical methods for textile wastewater pretreatment are of high cost, extremely energy consuming, and environmentally low efficient and generate toxic sludge. Thus, the use of microbial technique for textile dye degradation will be eco-friendly and is probably a lucrative alternative to physico-chemical processes. Microbial enzymes, viz. laccase and azoreductase, are cost-efficient, easy to harvest, easily downstream processable, and effortlessly mobilizable. Recent research trends on nanoparticle-microbial enzyme conjugates are also highly efficient to remove the azo dye from textile waste within a few minutes. But unfortunately, due to some gap between academia and industry, these methods remain only limited up to laboratory and its industrialization is still a challenge. The present review is an illustrated compilation of the use of microbial enzymes in removal of textile dyes.

Draft Genome Sequence of the Nonpathogenic, Thermotolerant, and Exopolysaccharide-Producing Bacillus anthracis Strain PFAB2 from Panifala Hot Water Spring in West Bengal, India

ABSTRACT Bacillus anthracis is the causative agent of fatal anthrax in both animals and humans. It is prevalently pathogenic. Here, we present a Bacillus anthracis PFAB2 strain from a relatively unexplored Panifala hot water spring in West Bengal, India. It is nonpathogenic, exopolysaccharide producing, and thermotolerant in nature.

Draft Genome Report of Bacillus altitudinis SORB11, Isolated from the Indian Sector of the Southern Ocean

ABSTRACT Here, we present the draft genome sequence of Bacillus altitudinis SORB11, which is tolerant to UV radiation. The strain was isolated from the Indian sector of the Southern Ocean at a depth of 3.8 km. The genome sequence information reported here for B. altitudinis SORB11 gives the basis of its UV resistance mechanism and provides data for further comparative studies with other bacteria resistant to UV radiation.

Transgenic Research in Vegetable Crops With Special Reference to Brinjal

Abstract A developing country such as India is continuously struggling with food production to fulfill the requirements of the growing population, and most of the people living in rural areas are suffering from malnutrition. Major crops and vegetables grown on existing cultivable lands have contributed to the increase in food supply. Insects, pests, fungi, and microbes have a major effect on brinjal or eggplant ( Solanum melongena ), the major vegetable crop in India, which contains vitamins and minerals (especially iron). In addition to its importance as a vegetable, the eggplant has been used extensively in traditional medicine since ancient times. The fruit and shoot borer ( Leucinodes orbonalis ) causes heavy losses to the yield of brinjal production. Indiscriminant use of synthetic chemical insecticides to cure diseases not only contaminates water and food sources, but also poisons nontarget beneficial insects, and develops resistance in insect pests. Bt -brinjal has been developed to combat brinjal loss and to minimize the uses of chemical pesticides, but the controversy regarding its commercialization has adverse effects in India. Biosafety issues are the main concern in this regard based on experimental data on human health and environmental hazards. Bt -brinjal is the one of the best solutions to this emerging problem and can be dealt with in different ways by transplastomic mechanisms.

In silico studies on bacterial xylanase enzyme: Structural and functional insight

Xylans are the second most abundant form of hemicelluloses and are the second most abundant polysaccharide in nature after cellulose. To degrade xylan, microbes produce mainly xylanase enzyme. Wide range of microorganisms like fungi, bacteria, yeast, marine algae etc. are capable of producing xylanase. Main source of xylanase is fungi but industrial production of bacterial xylanase is low cost, easy downstream process and high production rate. To understand primary, secondary and tertiary structure of xylanase, in silico composition of amino acids, basic physiological characteristics; viz., pI, molecular weight, instability index, GRAVY, molar extinction coefficient, secondary structure, presence of functional domain and motifs, phylogenetic tree, salt bridge compositions are determined. In silico study of xylanase focused on 36 different bacterial sources are performed by retrieving FASTA and PDB sequences using RCSB PDB. FASTA and PDB files are proceed further in ExPASy-ProtParam, RAMPAGE, QMEAN, MEME, PSIPRED, InterProScan, MOTIF scan, ERRAT, Peptide cutter, ESBRI and MEGA 7. The instability index range (16.90–38.78) clearly indicates that the protein is highly stable. α-helix mean value (27.11%) infers the protein is dominated by α-helix region. The aliphatic index (39.80–90.68) gives information that the protein is highly thermostable, prevalence by alanine amino acid in aliphatic side chain. No transmembrane domain was found in the protein which confirms the enzyme is extracellular in nature. Ancestor chart analysis confirmed that it is a part of carbohydrate metabolic process and more specifically a member of glycoside hydrolase super family.