Rajib Bandopadhyay

Study of algal biomass harvesting using cationic guar gum from the natural plant source as flocculant

Microalgae are small in size with negatively charged surface. They are usually stable in suspension culture and hard to flocculate. The present work emphasizes on the synthesis of cationic guar gum (CGG) by the introduction of quaternary amine groups onto the backbone of guar gum (GG) from N-(3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHPTAC). The optimal dosage of the synthesized cationic guar gum is used to flocculate two different green algae viz. Chlorella sp. CB4 and Chlamydomonas sp. CRP7.

Physical molecular maps of wheat chromosomes.

In bread wheat, a set of 527 simple sequence repeats (SSRs) were tried on 164 deletion lines, leading to a successful mapping of 270 SSRs on 313 loci covering all 21 chromosomes. A maximum of 119 loci (38%) were located on B subgenome, and a minimum of 90 loci (29%) mapped on D subgenome. Similarly, homoeologous group 7 carried a maximum of 61 loci (19%), and group 4 carried a minimum of 22 loci (7%). Of the cited 270 SSRs, 39 had multiple loci, but only eight of these detected homoeologous loci. Linear order of loci in physical maps largely corresponded with those in the genetic maps. Apparently, distances between each of only 26 pairs of loci significantly differed from the corresponding distances on genetic maps. Some loci, which were genetically mapped close to the centromere, were physically located distally, while other loci that were mapped distally in the genetic maps were located in the proximal bins in the physical maps. This suggested that although the linear order of the loci was largely conserved, variation does exist between genetic and physical distances.

Study of algal biomass harvesting through cationic cassia gum, a natural plant based biopolymer

Green unicellular microalgae have a capacity to entrap CO2 to increase their biomass through photosynthesis and are important for the value added product. The presence of COOH and NH2 groups are responsible for imparting negative zeta value. The present work emphasizes on the synthesis of cationic cassia (CCAS) by the insertion of quaternary amine groups onto the backbone of cassia (CAS) from N-3-Chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) which was further characterized via FTIR, SEM, elemental analysis and intrinsic viscosity. The optimal dosage of the synthesized cationic cassia is used to flocculate two different green fresh water algae viz. Chlamydomonas sp. CRP7 and Chlorella sp. CB4 were evaluated. 80 and 35 mg L(-1) was optimized dose for dewatering of above algae, respectively.

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.

Now and next-generation sequencing techniques: future of sequence analysis using cloud computing.

Advances in the field of sequencing techniques have resulted in the greatly accelerated production of huge sequence datasets. This presents immediate challenges in database maintenance at datacenters. It provides additional computational challenges in data mining and sequence analysis. Together these represent a significant overburden on traditional stand-alone computer resources, and to reach effective conclusions quickly and efficiently, the virtualization of the resources and computation on a pay-as-you-go concept (together termed “cloud computing”) has recently appeared. The collective resources of the datacenter, including both hardware and software, can be available publicly, being then termed a public cloud, the resources being provided in a virtual mode to the clients who pay according to the resources they employ. Examples of public companies providing these resources include Amazon, Google, and Joyent. The computational workload is shifted to the provider, which also implements required hardware and software upgrades over time. A virtual environment is created in the cloud corresponding to the computational and data storage needs of the user via the internet. The task is then performed, the results transmitted to the user, and the environment finally deleted after all tasks are completed. In this discussion, we focus on the basics of cloud computing, and go on to analyze the prerequisites and overall working of clouds. Finally, the applications of cloud computing in biological systems, particularly in comparative genomics, genome informatics, and SNP detection are discussed with reference to traditional workflows.

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.

Phylogenetic analysis and biological characteristic tests of marine bacteria isolated from Southern Ocean (Indian sector) water

Fifty-seven bacteria were isolated from Southern Ocean (Indian sector) water samples which were collected from different latitude and longitude of the ocean. All the isolates were able to grow at 4°C, 20°C, 37°C and tolerable NaCl concentration up to 13.5% (w/v). 29 out of 57 isolates were identified using 16S rDNA amplification and the sequences were submitted to National Center for Biotechnology Information (NCBI). All the isolates were classified by using Ribosomal Database Project (RDP) and found that isolates belongs to Proteobacteria and Bacteriodes. The average G+C content was 56.4%. The isolates were screened for the presence of extracellular enzymes, viz. amylase, catalase, urease, esterase, lipase and protease. The disc diffusion method is used to screen antibiotic production by the isolates against four pathogenic bacteria, viz. Salmonella typhimurium (NCIM 2501), Staphylococcus aureus (NCIM 2122), Bacillus subtilis (NCIM 2193), and Pseudomonas aeruginosa (NCIM 2036). Nine out of 29 were found to be antibiotic producer.

In vitro organogenesis secondary metabolite production and heavy metal analysis in Swertia chirayita

An efficient protocol of plant regeneration through direct and indirect organogenesis in Swertia chirayita was developed. Explants cultured on Murashige and Skoog medium supplemented with 2,4-D (0.5 mg L−1) with combination of Kinetin (0.5 mg L−1) showed the highest frequency (84%) of callusing and 1.0mg L−1 6-benzyladenine (BA) in combination with (100 mg L−1) Adenine sulphate (Ads) + (0.1 mg L−1) Indole acetic acid (IAA) was excellent for maximum adventitious shoot (12.69 ± 1.30) formation in four week of culture. A maximum number of (7.14 ± 0.99) shoots were developed per leaf explants through direct organogenesis. The highest frequency of rooting (11.46 ± 1.56) was observed on MS medium augmented with IAA (1.0 mg L−1). Well-rooted shoots transferred to plastic pots containing a soilrite: sand mix and then moved to the greenhouse for further growth and development. Four major secondary metabolites were analyzed and quantified using high performance liquid chromatography. Amount of secondary metabolites was found significantly higher, in in vitro plantlets compared to in vivo plantlets and callus raised from S. chirayita. Higher heavy metal accumulation in in vitro as compared to in vivo plantlets correlates higher secondary metabolite production supporting that they play regulatory role in influencing the plant secondary metabolism.

Stage-specific reprogramming of gene expression characterizes Lr48-mediated adult plant leaf rust resistance in wheat

Wheat genotype CSP44 carrying a recessive gene Lr48 exhibits adult plant resistance (APR; incompatible reaction) but gives a compatible reaction (susceptibility) at the seedling stage against leaf rust. A comparative gene expression analysis involving cDNA-amplified fragment length polymorphism (cDNA-AFLP) and quantitative PCR (qPCR) was carried out for incompatible and compatible reactions in the genotype CSP44. cDNA-AFLP analysis was conducted using RNA samples that were isolated from flag leaves following inoculation with leaf rust race 77–5 (the most virulent race) and also after mock inoculation. As many as 298 of a total of 493 expressed transcript-derived fragments (TDFs) exhibited differential expression (262 upregulated and 36 downregulated). Of these 298 TDFs, 48 TDFs were eluted from gels, re-amplified, cloned, and sequenced. Forty two of these 48 TDFs had homology with known genes involved in the following biological processes: energy production, metabolism, transport, signaling, defense response, plant-pathogen interaction, transcriptional regulation, translation, and proteolysis. The functions of the remaining six TDFs could not be determined; apparently, these represented some novel genes. The qPCR analysis for 18 TDFs (with known and unknown functions, but showing major differences in expression) was conducted using RNA isolated from the seedlings as well as from the adult plants. The expression of at least 11 TDFs was induced and that of 4 other TDFs attenuated or remained near normal in adult plants following leaf rust inoculations. The remaining three TDFs had non-specific/developmental stage-specific expression. Functional annotation of TDFs that were upregulated suggest that the APR was supported by transient recruitment and reprogramming of processes like perception and recognition of pathogen effector by receptors, followed by CDPK and MAPK signaling, transport, metabolism, and energy release.