Kumar Saurav

Kumar Saurav
The Czech Academy of Sciences | AVCR · Division of Autotrophic Microorganisms - Algatech

M.Phil., Ph.D.

About

95
Publications
18,028
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,072
Citations
Introduction
Kumar Saurav currently works at the Division of Autotrophic Microorganisms - Algatech, The Czech Academy of Sciences. Kumar does research in Biotechnology, Microbiology and Mycology. Past project was focused on 'AHL Quorum Sensing and Quenching molecules in marine sponges.' Currently, working on cyanobacterial secondary metabolites isolation....
Additional affiliations
May 2006 - December 2010
VIT University
Position
  • Research Assistant

Publications

Publications (95)
Cover Page
Research Topic Recent advancements in research allowed the development of the current practice of target-based drug discovery to find a broad spectrum of antimicrobial agents, however, it has failed to provide enough effective new antibiotics. The traditional antibiotic approach to treating bacterial infections is to find small molecules that eithe...
Article
Full-text available
Penicillium sp. S2014503 was isolated from a rotten whale bone sample. Constituent analysis and bioactivity evaluation of S2014503 were carried out to find more bioactive compounds from this fungus. Chemical structures of the purified compounds produced by S2014503 were determined by comprehensive analysis of NMR (nuclear magnetic resonance), MS (...
Preprint
Wounds are structural and functional disruptions of the skin that occur because of an accident. Chronic wounds are caused by a breakdown in the finely coordinated cascade of events that occurs during wound healing. Wound healing is a long process that split into at least three continuous and overlapping processes: an inflammatory response, a prolif...
Article
Full-text available
Marine microbial communities vary seasonally and spatially, but these two factors are rarely addressed together. In this study, the temporal and spatial patterns of the bacterial and archaeal community were studied along a coast-to-offshore transect in the Eastern Mediterranean Sea (EMS) over six cruises, in three seasons of 2 consecutive years. Am...
Article
Full-text available
Puwainaphycins (PUW) and minutissamides (MIN) are structurally homologous cyclic lipopeptides that exhibit high structural variability and possess antifungal and cytotoxic activities. While only a minor variation can be found in the amino acid composition of the peptide cycle, the fatty acid (FA) moiety varies largely. The effect of FA functionaliz...
Article
Full-text available
Low-molecular weight natural products display vast structural diversity and have played a key role in the development of novel therapeutics. Here we report the discovery of novel members of the aeruginosin family of natural products, which we named varlaxins. The chemical structures of varlaxins 1046A and 1022A were determined using a combination o...
Chapter
Biosurfactants are surface-active amphipathic biomolecules secreted by yeast, fungi, bacteria, cyanobacteria, and algae. Among bacterial Kingdom, Streptomyces is one of the well-known and reliable sources due to cosmopolitan distribution and higher yield. In addition, its tolerance even at extreme pH and temperature, further support the utilization...
Chapter
Secondary metabolites offer a wide variety of biologically active compounds with great potential in medicine, agriculture, or livestock. With the advance of computational techniques and genome sequencing availability, laborious screening of microbial products can be replaced by more efficient genome mining using extensive genome databases available...
Article
Scytophycins, including tolytoxin, represent a class of actin disrupting macrolides with strong antiproliferative effects on human cells. Despite intense research, little attention has been paid to scytophycin‐induced cell death or the structural features affecting its potency. We show that tolytoxin and its natural analog 7‐O‐methylscytophycin B,...
Article
Full-text available
Microbial cyclic lipopeptides are an important class of antifungal compounds with applications in pharmacology and biotechnology. However, the cytotoxicity of many cyclic lipopeptides limits their potential as antifungal drugs. Here we present a structure-activity relationship study on the puwainaphycin/minutissamide (PUW/MIN) family of cyclic lipo...
Article
Full-text available
The regulation of the production of oligopeptides is essential in understanding their ecological role in complex microbial communities, including harmful cyanobacterial blooms. The role of chemical communication between the cyanobacterium and the microbial community harbored as epibionts within its phycosphere is at an initial stage of research, an...
Cover Page
Full-text available
We are guest editing special issue "Microalgae Secondary Metabolites-Bioactivity Determination using Innovative Approach of Omics" in the open access journal Molecules (ISSN 1420-3049, http://www.mdpi.com/journal/molecules). Based on your expertise in this filed, we would like to invite you to contribute a paper to this special issue. An article pr...
Article
Full-text available
Cyanobacteria require iron for growth and often inhabit iron-limited habitats, yet only a few siderophores are known to be produced by them. We report that cyanobacterial genomes frequently encode PKS/NRPS biosynthetic pathways for synthesis of lipopeptides featuring β -hydroxyaspartate ( β -OH-Asp), a residue known to be involved in iron chelation...
Article
Full-text available
We report the draft genome sequence of Streptomyces sp. strain VITNK9, isolated from a soil sample collected in Vellore District (12.9165°N, 79.1325°E), Tamil Nadu, India, with an assembly size of 7,920,076 bp and 72.7% GC content.
Article
Full-text available
Xylitol is a white crystalline, amorphous sugar alcohol and low-calorie sweetener. Xylitol prevents demineralization of teeth and bones, otitis media infection, respiratory tract infections, inflammation and cancer progression. NADPH generated in xylitol metabolism aid in the treatment of glucose-6-phosphate deficiency-associated hemolytic anemia....
Article
Full-text available
Man-made shallow fishponds in the Czech Republic have been facing high eutrophication since the 1950s. Anthropogenic eutrophication and feeding of fish have strongly affected the physicochemical properties of water and its aquatic community composition, leading to harmful algal bloom formation. In our current study, we characterized the phytoplankt...
Cover Page
Full-text available
Cyanobacteria, Quorum sensing, Quorum sensing Inhibition, Antivirulence drug therapy, Toxins production and its detection Autoinducers detection, Antimicrobial activity, Biosynthesis of bioactive lead molecules, Host–microbe interaction mechanism, Dereplication strategy for metabolites.
Article
Full-text available
Heterocytous cyanobacteria are among the most prolific sources of bioactive secondary metabolites, including anabaenopeptins (APTs). A terrestrial filamentous Brasilonema sp. CT11 collected in Costa Rica bamboo forest as a black mat, was studied using a multidisciplinary approach: genome mining and HPLC-HRMS/MS coupled with bioinformatic analyses....
Preprint
Full-text available
Man-made shallow fishponds in the Czech Republic have been facing a high eutrophication since 1950s. Anthropogenic eutrophication and feeding of fish have strongly affected the physico-chemical properties of water and its aquatic community composition leading to harmful algal bloom formation. In our current study, we have characterised the phytopla...
Preprint
Full-text available
Heterocytous cyanobacteria are among the most prolific source of bioactive secondary metabolites, including anabaenopeptins (APTs). A terrestrial filamentous Brasilonema sp. CT11 collected in Costa Rica bamboo forest, as black mat was studied using a multidisciplinary approach: genome mining and HPLC-HRMS/MS coupled with bionformatic analyses. Here...
Preprint
Full-text available
Marine microbial communities vary seasonally and spatially, but these two factors are rarely addressed together. We studied temporal and spatial patterns of the microbial community structure and activity along a coast to offshore transect from the Israeli coast of the Eastern Mediterranean Sea (EMS) over six cruises, in three seasons of two consecu...
Article
Full-text available
Marine sponges, a well-documented prolific source of natural products, harbor highly diverse microbial communities. Their extracts were previously shown to contain quorum sensing (QS) signal molecules of the N-acyl homoserine lactone (AHL) type, known to orchestrate bacterial gene regulation. Some bacteria and eukaryotic organisms are known to prod...
Article
Full-text available
Streptomyces are among the most promising genera in terms of production ability to biosynthesize a variety of bioactive secondary metabolites with pharmaceutical interest. Coinciding with the increase in genomic sequencing of these bacteria, mining of their genomes for biosynthetic gene clusters (BGCs) has become a routine component of natural prod...
Preprint
Full-text available
Streptomyces, being one of the most promising genera due to its ability to synthesize a variety of bioactive secondary metabolites of pharmaceutical interest, here studied in relation to its genomic and metabolomic potential. Coinciding with the increase in sequenced data, mining of bacterial genomes for biosynthetic gene clusters (BGCs) has become...
Preprint
Full-text available
Marine sponges, a well documented prolific source of natural products, harbors numerous microbial communities believed to possess N-acyl homoserine lactones (AHLs) mediated Quorum sensing (QS) as one of the mechanisms of interaction. Bacteria and eukaryotic organisms are known to produce molecules that can interfere with QS signaling, thus affectin...
Article
Two polyketides neoenterocins A (1) and B (2), featuring a neighboring dicarbonyl motif and a furan-containing 5/6 ring system, were isolated from the enterocin producer Streptomyces sp. SCSIO 11863. Heterologous expression, gene disruptions, and isotope feeding experiments indicated that 1 and 2 were derived from the enterocin biosynthetic gene cl...
Article
The rapid emergence of resistance in pathogenic bacteria together with a steep decline in economic incentives has rendered a new wave in the drug development by the pharmaceutical industry and researchers. Since cyanobacteria are recognized as wide producers of pharmaceutically important compounds, we investigated thirty-four cyanobacterial extract...
Poster
Full-text available
Microalgae (Cyanobacteria and Eukaryots) grow in diverse environments that often determines production of various bioactive, high-value compounds with potential biotechnological use. Culturing conditions can affect production of these compounds. Firstly, we aimed to characterize three microalgae strains (filamentous Cylindrospermum sp. CCALA 988, a...
Article
Selenium (Se) is an indispensable microelement in our diet and health issues resulting from deficiencies are well documented. Se-containing food supplements are available on the market including Se-enriched Chlorella vulgaris (Se-Chlorella) which accumulates Se in the form of Se-amino acids (Se-AAs). Despite its popular uses, data about the bioacce...
Article
Herein, we deciphered the most important biosynthetic traits of a prominent group of bioactive lipopeptides. We reveal evidence for initiation of biosynthesis by two alternative starter units hardwired directly in the same gene cluster, eventually resulting in the production of a remarkable range of lipopeptide variants. We identified several unusu...
Article
Full-text available
Broad‐spectrum pesticides can have immediate toxic effects both on target pest species and on non‐target species. They may also have positive residual effects on mosquitoes after pesticide degradation, by altering the community structure, that is, by reducing abundances of mosquito competitors and predators, and via a trophic cascade, which may inc...
Article
The pederin family includes a number of bioactive compounds isolated from symbiotic organisms of diverse evolutionary origin. Pederin is linked to beetle-induced dermatitis in humans and pederin family members possess potent antitumor activity caused by selective inhibition of the eukaryotic ribosome. Their biosynthesis is accomplished by a polyket...
Article
Marine sponges form symbiotic relationships with complex microbial communities, yet little is known about the mechanisms by which these microbes regulate their behavior through gene expression. Many bacterial communities regulate gene expression using chemical signaling termed quorum sensing. While a few previous studies have shown presence of N-ac...
Article
Objective To isolate and identify secondary metabolites produced by two strains of Antarcticderived actinomycetes which inhabit in the intertidal zone of Antarctic ocean.Methods Strains were identified on the basis of morphology and 16 SrDNA sequence analysis.Organic extracts of the two strains fermentation broth were evaluated for lethal activity...
Article
Full-text available
There is an urgent need for novel strategies to fight drug resistance and multi-drug resistance. As an alternative to the classic antibiotic therapy, attenuation of the bacteria virulence affecting their Quorum sensing (QS) system is a promising approach. Quorum sensing (QS) is a genetic regulation system that allows bacteria to communicate with ea...
Article
Full-text available
Marine natural products with antibiotic activity have been a rich source of drug discovery; however, the emergence of antibiotic-resistant bacterial strains has turned attention towards the discovery of alternative innovative strategies to combat pathogens. In many pathogenic bacteria, the expression of virulence factors is under the regulation of...
Article
Sunlight can be directly harvested by photoheterotrophic bacteria to create a pH gradient across the membrane, which can then be utilized to produce ATP. Despite the potential importance of this trophic strategy, when and where such organisms are found in the seas and oceans is poorly described. Here, we describe the abundance and taxonomy of bacte...
Article
Eight new α-pyrones 1-8 and three known α-pyrones 9-11 were isolated from three marine-derived Nocardiopsis strains SCSIO 10419, SCSIO 04583, and SCSIO KS107. The structures of compounds 1-8 were elucidated by comprehensive spectral analyses. The absolute configurations of 4-deoxyphomapyrone C (1), 4-deoxy-11-hydroxyphomapyrone C (3), 4-deoxy-7R-hy...
Article
Full-text available
Owing to the extensive development of drug resistance in pathogens against the available antibiotic arsenal, antimicrobial resistance is now an emerging major threat to public healthcare. Anti-virulence drugs are a new type of therapeutic agent aiming at virulence factors rather than killing the pathogen, thus providing less selective pressure for...
Article
Full-text available
Gram-negative bacteria often use N-acyl homoserine lactones (AHLs) as quorum-sensing (QS) signal molecules. The present study aimed to identify and characterize the production of AHLs by Paracoccus sp. Ss63, which was isolated from the Mediterranean sponge Sarcotragus sp. High performance liquid chromatography – high resolution tandem mass spectrom...
Patent
Napyradiomycin derivatives (A) which are 4-dehydro-4a-dechloronapyradiomycin A1 of formula (I) and 3-chloro-6,8-dihydroxy-8- alpha -lapachone of formula (II) are new. An INDEPENDENT CLAIM is also included for preparation of (A).
Chapter
Over the past two decades, fungal infections have increased significantly and have been associated with increased morbidity and mortality. As advances in medical care have improved the survival of patients with severe and life-threatening illnesses, the more aggressive nature of such care has led to a rapid increase in the number of immunosuppresse...
Article
Full-text available
Sponges harbor a remarkable diversity of microbial symbionts where signal molecules can accumulate and enable cell-cell communication, such as quorum sensing (QS). Bacteria capable of QS were isolated from marine sponges, however an extremely small fraction of the sponge microbiome is amenable to cultivation. We took advantage of community genome a...
Article
Biomineralization-inspired preparation of nanopar-ticles by marine microorganisms is in the limelight of modern nanotechnology. In recent years, the use of marine microorganisms for the synthesis of nanoparticles has been gaining importance due to the simplicity and eco-friendliness of the approach. Here we describe the synthesis of silver nanopart...
Article
Full-text available
Biomineralization-inspired preparation of nanoparticles by marine microorganisms is in the limelight of modern nanotechnology. In recent years, the use of marine microorganisms for the synthesis of nanoparticles has been gaining importance due to the simplicity and eco-friendliness of the approach. Here we describe the synthesis of silver nanoparti...
Article
Full-text available
The criteria used for successful drug discovery involves high throughput screening for preclinical evaluation and its interaction with target enzymes. In silico approach resulting in the creation of drug like library and identification of essential reactions and pathways spreads across several parts of metabolism. The aim of the present study was t...
Article
Full-text available
Bioreduction of metal ions for the synthesis of stable nanoparticles in physiological environment has been a great challenge in the field of nanotechnology and its application. In the present study well-defined biofunctionalized gold nanoparticles (AuNPs) were developed following biomimetic approach for an enhanced anticancer activity. The fucoxant...
Article
Full-text available
Natural products remain either the source of the inspiration for a significant proportion of the new small molecule chemical entities introduced as drugs. Actinomycetes are the largest antibiotic producing genus in the microbial world discovered so far. The number of antimicrobial compounds reported from the different species of actinomycetes per y...
Article
Full-text available
The present study aims to isolate and identify actinobacteria associated with the soft coral Nephthea sp., and to isolate natural products from these actinobacteria under the guidance of PCR screening for polyketides synthase (PKS) genes. Eleven selective media were used to isolate actinobacteria associated with the soft coral Nephthea sp. collecte...