Sanjeev Ghadi | Goa University (original) (raw)
Papers by Sanjeev Ghadi
Journal of Molecular Structure, 2022
Current Science, 2017
Grewia nervosa belonging to the Malvaceae family is abundantly found in the Western Ghats of Indi... more Grewia nervosa belonging to the Malvaceae family is abundantly found in the Western Ghats of India. Though G. nervosa is considered to have therapeutic potential, this has not been scientifically corroborated. However, the plant has been scientifically proven to demonstrate insecticidal, larvicidal and free radical scavenging activities.
Enzymatic Technologies for Marine Polysaccharides, 2019
Microbial Pathogenesis, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Virus Research, 2018
Highlights A lytic ϕMC1 specific to Microbulbifer strain CMC-5-a multiple polysaccharide degrad... more Highlights A lytic ϕMC1 specific to Microbulbifer strain CMC-5-a multiple polysaccharide degrading bacteria was isolated from Anjuna beach, Goa, India. Effect of temperature, pH, organic solvents, divalent cations, host range study and growth kinetics of ϕMC1 were tested. TEM analysis indicated tailless icosahedral phages of 60 nm. Genomic study of ϕMC1 revealed DNA size to be of 48.5 kb.
Current Science, 2018
Viruses are known to be highly abundant and, therefore, ecologically significant entities of all ... more Viruses are known to be highly abundant and, therefore, ecologically significant entities of all aquatic ecosystems. However, very few studies from marine and freshwater ecosystems in India have dealt with enumeration, isolation or characterization of their virus (virioplankton) populations. In the present study, we have estimated total virioplankton populations from several kinds of aquatic niches, viz. rice fields, lakes and estuaries, using flow cytometry. Rice field floodwaters displayed the highest virioplankton count of 1.21 × 10 7 particles per ml. As cyanophages form the second most abundant class of virioplankton (after bacteriophages), we also isolated four cyanophages from the same aquatic niches.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, 2019
Microbulbifer strain CMC-5 reportedly degrades multiple polysaccharides including agar. In presen... more Microbulbifer strain CMC-5 reportedly degrades multiple polysaccharides including agar. In present study, the agarase from the culture supernatant of Microbulbifer strain CMC-5 pregrown in artificial sea water-based medium containing agar was tenfold concentrated by ultrafiltration. The bacteriological agar-derived oligosaccharides obtained by agarase treatment were observed to depict reducing power, lipid peroxidation inhibition and hydroxyl radical scavenging activities. The oligosaccharides produced from agar by agarase treatment for 6 h demonstrated higher antioxidative activities as compared to agar oligosaccharides produced by 12-h agarase treatment. Further, the agar oligosaccharides demonstrated concentration-dependent augmentation of antioxidative activities. Since agar is a recognized safe food additive, the agarderived oligosaccharides can be blended with food to augment its antioxidative property. Additionally, the agarase from strain CMC-5 in conjunction with Onozuka R-10 degraded Gracilaria corticata thalli to produce single cell detritus that can be used as aquaculture feed material reducing the dependency on artificial feeds.
Bioorganic & Medicinal Chemistry, 2018
A synthetic flavone derivative 2-(benzo[d][1,3]dioxol-5-yl)-4H-chromen-4-one (BDC) was synthesize... more A synthetic flavone derivative 2-(benzo[d][1,3]dioxol-5-yl)-4H-chromen-4-one (BDC) was synthesized by the one pot reaction method and assessed for α-glucosidase inhibitory activity. The BDC demonstrated dose dependent inhibition of α-glucosidase activity. A maximum inhibition (99.3 ± 0.26%) of α-glucosidase was observed at 27.6 µM. The maximum α-glucosidase inhibitory activity depicted by BDC 27.6 µM concentration was 22.4 fold over the maximum inhibition observed with acarbose (97.72 ± 0.59% at 669.57 µM), a standard commercial anti-diabetic drug. In contrast to acarbose that depicted competitive type inhibition, kinetic studies of α-glucosidase inhibition by BDC demonstrated non-competitive inhibition with Km of 0.71 mM-1 and a Vmax of 0.028 mmol/min. In silico studies suggest allosteric interaction of BDC with α-glucosidase at a minimum binding energy (ΔG) of -8.64 kcal/mol and Ki of 465.3 nM, whereas, acarbose interacted at the active site of α-glucosidase with ΔG of -9.23 kcal/mol and Ki of 172 nM. Thus BDC significantly inhibited α-glucosidase in comparison to acarbose. Moreover, BDC has been endorsed for drug likeness by evaluating it as per Lipinski rule of five. Thus, BDC can be a lead compound for the management of type-2 diabetes mellitus.
Biotechnology reports (Amsterdam, Netherlands), 2018
strain CMC-5 produces agarase, alginate lyase, xylanase, carboxymethyl cellulase and carrageenase... more strain CMC-5 produces agarase, alginate lyase, xylanase, carboxymethyl cellulase and carrageenase. The extracellular production of the above carbohydrases was investigated by growingstrain CMC-5 in a sea water based medium containing homologous/heterologous polysaccharides as a single substrate or as a combination of mixed assorted substrate. Presence of singular homologous polysaccharides in the growth medium induces respective carbohydrase at high levels. Any two polysaccharides in various combinations produced high level of homologous carbohydrase and low level of other heterologous carbohydrase. All five carbohydrases were consistently produced by strain CMC-5, when carboxymethyl cellulose was included as one of the substrate in dual substrate combination, or in presence of mix blends of all five polysaccharides. Interestingly, thalli ofsp. that contain agar and cellulose predominantly in their cell wall induces only agarase expression in strain CMC-5.
Chemistry & biodiversity, Jan 16, 2017
Grewia nervosa is herbal plant used as traditional medicine for different purposes. Bioassay-guid... more Grewia nervosa is herbal plant used as traditional medicine for different purposes. Bioassay-guided chemical fractionation of G. nervosa roots resulted in an identification of two known and one new compound, named Microgrewiapine A, Homomicrogrewiapine and N-methyl-microcosamine respectively. Their structures were determined using combination of LC-HRMS, (1) H NMR and IR spectra analyses followed by comparison with those reported in the literature. The problematic separation of these alkaloids on traditional column chromatography (Silica gel, Octadecyl silane (ODS), Sephadex) was resolved by using HPLC method. Structurally identical compounds from the piperidine family have been characterized by using HRMS analysis in combination with NMR data of crude sample. The major constituent i.e. N-methyl-microcosamine in n-butanol fraction of methanol root extract (MRE) was found to possess the dose dependent α-glucosidase inhibition activity with an IC50 value of 53.40 μM. Furthermore, N-Me...
Medicinal Chemistry Research, 2015
Pristine and 2 % silver-doped indium oxide (In 2 O 3) nanoparticles, synthesized by solution comb... more Pristine and 2 % silver-doped indium oxide (In 2 O 3) nanoparticles, synthesized by solution combustion method, yielded spherical nanoparticles in the range of 20-30 nm. The nanoparticles were stabilized in cubic bixbyite structure as revealed from X-ray diffraction study. In order to evaluate the potential of these nanoparticles to modulate enzyme activity, a-amylase and a-glucosidase were used as model enzymes. Pristine and 2 % silverdoped In 2 O 3 nanoparticles demonstrated dose-dependent inhibition of a-amylase and a-glucosidase activities. Pristine In 2 O 3 nanoparticles demonstrated 26.4 % (300 lg/mL) and 65.3 % (300 lg/mL) inhibition against a-amylase and aglucosidase, respectively. In contrast, silver-doped In 2 O 3 nanoparticles depicted 94.1 % (300 lg/mL) and 99.6 % (0.18 lg/mL) inhibition against a-amylase and a-glucosidase, respectively. In comparison with acarbose, a standard anti-diabetic drug that depicted absolute inhibition of aglucosidase activity at 300 lg/mL, 2 % silver-doped In 2 O 3 nanoparticles completely inhibited a-glucosidase at a very low concentration (0.18 lg/mL). In view of our results, the activity of a-amylase and a-glucosidase, which are targets for treatment of type 2 diabetes, can be modulated using silver-doped In 2 O 3 nanoparticles in the concentration-dependent manner. Therefore, silver-doped In 2 O 3 has a potential to be used as a prospective starch blocker.
Current Science, 2016
Pila globosa, an edible variety of apple snail is a common inhabitant of lentic ecosystem and fee... more Pila globosa, an edible variety of apple snail is a common inhabitant of lentic ecosystem and feeds on plant detritus. The tissue extract of gastrointestinal tract from Pila globosa demonstrated the presence of carboxymethyl cellulase, xylanase, alginate lyase and pectinase activity. Culture-dependent method was used to isolate carboxymethyl cellulose (CMC) degrading bacteria from the gastrointestinal tract of apple snail. Morphologically identical colonies were obtained on M9 gelrite plates containing CMC as carbon source. One such bacterial isolate was purified by streaking and designated as strain PG-1. Bacterial strain PG-1 degraded CMC, pectin, starch and alginate. The 16S rDNA sequence of strain PG1 was 99% identical to Klebsiella oxytoca. Phylogenetic analysis using maximum likelihood revealed the clustering of strain PG1 with the clade belonging to Klebsiella oxytoca type strain.
Marine Biotechnology, 2017
Microbulbifer mangrovi strain DD-13 T is a noveltype species isolated from the mangroves of Goa, ... more Microbulbifer mangrovi strain DD-13 T is a noveltype species isolated from the mangroves of Goa, India. The draft genome sequence of strain DD-13 comprised 4,528,106 bp with G+C content of 57.15%. Out of 3479 open reading frames, functions for 3488 protein coding sequences were predicted on the basis of similarity with the cluster of orthologous groups. In addition to protein coding sequences, 34 tRNA genes and 3 rRNA genes were detected. Analysis of nucleotide sequence of predicted gene using a Carbohydrate-Active Enzymes (CAZymes) Analysis Toolkit indicates that strain DD-13 encodes a large set of CAZymes including 255 glycoside hydrolases, 76 carbohydrate esterases, 17 polysaccharide lyases, and 113 carbohydrate-binding modules (CBMs). Many genes from strain DD-13 were annotated as carbohydrases specific for degradation of agar, alginate, carrageenan, chitin, xylan, pullulan, cellulose, starch, β-glucan, pectin, etc. Some of polysaccharide-degrading genes were highly modular and were appended at least with one CBM indicating the versatility of strain DD-13 to degrade complex polysaccharides. The cell growth of strain DD-13 was validated using pure polysaccharides such as agarose or alginate as carbon source as well as by using red and brown seaweed powder as substrate. The homologous carbohydrase produced by strain DD-13 during growth degraded the polysaccharide, ensuring the production of metabolizable reducing sugars. Additionally, several other polysaccharides such as carrageenan, xylan, pullulan, pectin, starch, and carboxymethyl cellulose were also corroborated as growth substrate for strain DD-13 and were associated with concomitant production of homologous carbohydrase.
Marine Pollution and Microbial Remediation, 2016
Complex polysaccharides (CPs) such as agar, alginates, carrageenan, etc., are largely present as ... more Complex polysaccharides (CPs) such as agar, alginates, carrageenan, etc., are largely present as component of cell wall of seaweeds, promoting structural integrity and shielding the host from pathogens or predators. Marine bacteria-degrading CPs are ubiquitous and have been isolated from diverse sources such as costal water, sediments, and deep sea, as well as from the surface of seaweeds and crustaceans. Polysaccharide-degrading enzymes (carbohydrases) such as agarase, alginate lyase, and carrageenase are produced by CP-degrading bacteria that aid in depolymerizing agar, alginate, and carrageenan, respectively. The resultant oligosaccharides are subsequently degraded to various intermediates that are further channelized to energy conversion pathways. Several of these carbohydrases have been purified, and study of their biochemical properties such as molecular weight, substrate specificity, pH, and temperature range for optimal activity indicates a vast diversity. Recently, several multiple CP-degrading bacteria (epiphytic/free form) have been isolated. Saccharophagus degradans and Microbulbifer species are the dominant groups of multiple polysaccharide-degrading bacteria and play a significant role in recycling of carbon from CPs. In natural marine ecosystem, the cell wall of seaweeds comprises an array of CPs in mixed proportion. The production of diverse carbohydrases by CP-degrading bacteria enables it to decompose seaweeds into single cell detritus as well as generate reducing sugars from degraded polysaccharides. Thus, CP-degrading bacteria are potential candidates for eco-friendly degradation of algal waste.
ChemInform, 2014
Graphite Catalyzed Solvent Free Synthesis of Dihydropyrimidin-2(1H)-ones/ thiones and Their Antid... more Graphite Catalyzed Solvent Free Synthesis of Dihydropyrimidin-2(1H)-ones/ thiones and Their Antidiabetic Activity.-The title compounds (IV) are obtained by a solvent-free three-component condensation reaction between various aromatic aldehydes, ethyl acetoacetate, and urea/thiourea. Compound (IVf) shows the highest inhibition of -amylase.-(DHUMASKAR,
International Journal of Systematic and Evolutionary Microbiology, 2012
A rod-shaped, Gram-negative, non-motile, aerobic and non-endospore forming bacterium, designated ... more A rod-shaped, Gram-negative, non-motile, aerobic and non-endospore forming bacterium, designated strain DD-13T, was isolated from the mangrove ecosystem of Goa, India. Strain DD-13T degraded polysaccharides such as agar, alginate, chitin, cellulose, laminarin, pectin, pullulan, starch, carrageenan, xylan and β-glucan. The optimum pH and temperature for growth was 7 and 36 °C, respectively. The strain grew optimally in the presence of 3 % NaCl (w/v). The DNA G+C content was 61.4 mol%. The predominant fatty acid of strain DD-13T was iso-C15 : 0. Ubiquinone-8 was detected as the major respiratory lipoquinone. Phylogenetic studies based on 16S rRNA gene sequence analysis demonstrated that strain DD-13T formed a coherent cluster with species of the genus Microbulbifer . Strain DD-13T exhibited 16S rRNA gene sequence similarity levels of 98.9–97.1 % with Microbulbifer hydrolyticus IRE-31T, Microbulbifer salipaludis JCM 11542T, Microbulbifer agarilyticus JAMB A3T, Microbulbifer celer KCTC ...
Advances in Biological Science Research, 2019
Abstract Complex polysaccharides, such as agar, alginate, carrageenan, chitin, xylan, etc., are a... more Abstract Complex polysaccharides, such as agar, alginate, carrageenan, chitin, xylan, etc., are abundantly present in marine algae and crustaceans. Degradation of these polysaccharides is attributed to microbial agarase, alginate lyase, carrageenase, chitinase, and xylanase, respectively. Conventional dye-based plate assay for the screening/detection of microbes secreting these polysaccharide-degrading enzymes has many limitations as only individually produced extracellular enzymes could be identified. However, genome sequencing and annotation would provide holistic identification of polysaccharide-degrading genes in organisms. As the genome annotation would give the sequence of the genes, the identified genes encoding polysaccharide-degrading enzymes would be characterized on genomic level. Using the genome sequencing strategy, polysaccharide-degrading genes are identified and characterized from many marine bacteria, including Saccharophagus degradans 2-40T, Microbulbifer mangrovi DD-13T, Microbulbifer elongatus HZ11, etc. These bacterial genomes harbor an array of genes specific for multiple polysaccharide degradation. Furthermore, genome sequencing and functional annotation enable a comprehensive classification of polysaccharide-degrading genes into appropriate carbohydrate-active enzymes (CAZymes), families facilitating a holistic understanding of their ecological role, and exploiting them for creating novel technologies.
Biotechnology and Bioprocess Engineering, Jan 1, 2011
Journal of Molecular Structure, 2022
Current Science, 2017
Grewia nervosa belonging to the Malvaceae family is abundantly found in the Western Ghats of Indi... more Grewia nervosa belonging to the Malvaceae family is abundantly found in the Western Ghats of India. Though G. nervosa is considered to have therapeutic potential, this has not been scientifically corroborated. However, the plant has been scientifically proven to demonstrate insecticidal, larvicidal and free radical scavenging activities.
Enzymatic Technologies for Marine Polysaccharides, 2019
Microbial Pathogenesis, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Virus Research, 2018
Highlights A lytic ϕMC1 specific to Microbulbifer strain CMC-5-a multiple polysaccharide degrad... more Highlights A lytic ϕMC1 specific to Microbulbifer strain CMC-5-a multiple polysaccharide degrading bacteria was isolated from Anjuna beach, Goa, India. Effect of temperature, pH, organic solvents, divalent cations, host range study and growth kinetics of ϕMC1 were tested. TEM analysis indicated tailless icosahedral phages of 60 nm. Genomic study of ϕMC1 revealed DNA size to be of 48.5 kb.
Current Science, 2018
Viruses are known to be highly abundant and, therefore, ecologically significant entities of all ... more Viruses are known to be highly abundant and, therefore, ecologically significant entities of all aquatic ecosystems. However, very few studies from marine and freshwater ecosystems in India have dealt with enumeration, isolation or characterization of their virus (virioplankton) populations. In the present study, we have estimated total virioplankton populations from several kinds of aquatic niches, viz. rice fields, lakes and estuaries, using flow cytometry. Rice field floodwaters displayed the highest virioplankton count of 1.21 × 10 7 particles per ml. As cyanophages form the second most abundant class of virioplankton (after bacteriophages), we also isolated four cyanophages from the same aquatic niches.
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences, 2019
Microbulbifer strain CMC-5 reportedly degrades multiple polysaccharides including agar. In presen... more Microbulbifer strain CMC-5 reportedly degrades multiple polysaccharides including agar. In present study, the agarase from the culture supernatant of Microbulbifer strain CMC-5 pregrown in artificial sea water-based medium containing agar was tenfold concentrated by ultrafiltration. The bacteriological agar-derived oligosaccharides obtained by agarase treatment were observed to depict reducing power, lipid peroxidation inhibition and hydroxyl radical scavenging activities. The oligosaccharides produced from agar by agarase treatment for 6 h demonstrated higher antioxidative activities as compared to agar oligosaccharides produced by 12-h agarase treatment. Further, the agar oligosaccharides demonstrated concentration-dependent augmentation of antioxidative activities. Since agar is a recognized safe food additive, the agarderived oligosaccharides can be blended with food to augment its antioxidative property. Additionally, the agarase from strain CMC-5 in conjunction with Onozuka R-10 degraded Gracilaria corticata thalli to produce single cell detritus that can be used as aquaculture feed material reducing the dependency on artificial feeds.
Bioorganic & Medicinal Chemistry, 2018
A synthetic flavone derivative 2-(benzo[d][1,3]dioxol-5-yl)-4H-chromen-4-one (BDC) was synthesize... more A synthetic flavone derivative 2-(benzo[d][1,3]dioxol-5-yl)-4H-chromen-4-one (BDC) was synthesized by the one pot reaction method and assessed for α-glucosidase inhibitory activity. The BDC demonstrated dose dependent inhibition of α-glucosidase activity. A maximum inhibition (99.3 ± 0.26%) of α-glucosidase was observed at 27.6 µM. The maximum α-glucosidase inhibitory activity depicted by BDC 27.6 µM concentration was 22.4 fold over the maximum inhibition observed with acarbose (97.72 ± 0.59% at 669.57 µM), a standard commercial anti-diabetic drug. In contrast to acarbose that depicted competitive type inhibition, kinetic studies of α-glucosidase inhibition by BDC demonstrated non-competitive inhibition with Km of 0.71 mM-1 and a Vmax of 0.028 mmol/min. In silico studies suggest allosteric interaction of BDC with α-glucosidase at a minimum binding energy (ΔG) of -8.64 kcal/mol and Ki of 465.3 nM, whereas, acarbose interacted at the active site of α-glucosidase with ΔG of -9.23 kcal/mol and Ki of 172 nM. Thus BDC significantly inhibited α-glucosidase in comparison to acarbose. Moreover, BDC has been endorsed for drug likeness by evaluating it as per Lipinski rule of five. Thus, BDC can be a lead compound for the management of type-2 diabetes mellitus.
Biotechnology reports (Amsterdam, Netherlands), 2018
strain CMC-5 produces agarase, alginate lyase, xylanase, carboxymethyl cellulase and carrageenase... more strain CMC-5 produces agarase, alginate lyase, xylanase, carboxymethyl cellulase and carrageenase. The extracellular production of the above carbohydrases was investigated by growingstrain CMC-5 in a sea water based medium containing homologous/heterologous polysaccharides as a single substrate or as a combination of mixed assorted substrate. Presence of singular homologous polysaccharides in the growth medium induces respective carbohydrase at high levels. Any two polysaccharides in various combinations produced high level of homologous carbohydrase and low level of other heterologous carbohydrase. All five carbohydrases were consistently produced by strain CMC-5, when carboxymethyl cellulose was included as one of the substrate in dual substrate combination, or in presence of mix blends of all five polysaccharides. Interestingly, thalli ofsp. that contain agar and cellulose predominantly in their cell wall induces only agarase expression in strain CMC-5.
Chemistry & biodiversity, Jan 16, 2017
Grewia nervosa is herbal plant used as traditional medicine for different purposes. Bioassay-guid... more Grewia nervosa is herbal plant used as traditional medicine for different purposes. Bioassay-guided chemical fractionation of G. nervosa roots resulted in an identification of two known and one new compound, named Microgrewiapine A, Homomicrogrewiapine and N-methyl-microcosamine respectively. Their structures were determined using combination of LC-HRMS, (1) H NMR and IR spectra analyses followed by comparison with those reported in the literature. The problematic separation of these alkaloids on traditional column chromatography (Silica gel, Octadecyl silane (ODS), Sephadex) was resolved by using HPLC method. Structurally identical compounds from the piperidine family have been characterized by using HRMS analysis in combination with NMR data of crude sample. The major constituent i.e. N-methyl-microcosamine in n-butanol fraction of methanol root extract (MRE) was found to possess the dose dependent α-glucosidase inhibition activity with an IC50 value of 53.40 μM. Furthermore, N-Me...
Medicinal Chemistry Research, 2015
Pristine and 2 % silver-doped indium oxide (In 2 O 3) nanoparticles, synthesized by solution comb... more Pristine and 2 % silver-doped indium oxide (In 2 O 3) nanoparticles, synthesized by solution combustion method, yielded spherical nanoparticles in the range of 20-30 nm. The nanoparticles were stabilized in cubic bixbyite structure as revealed from X-ray diffraction study. In order to evaluate the potential of these nanoparticles to modulate enzyme activity, a-amylase and a-glucosidase were used as model enzymes. Pristine and 2 % silverdoped In 2 O 3 nanoparticles demonstrated dose-dependent inhibition of a-amylase and a-glucosidase activities. Pristine In 2 O 3 nanoparticles demonstrated 26.4 % (300 lg/mL) and 65.3 % (300 lg/mL) inhibition against a-amylase and aglucosidase, respectively. In contrast, silver-doped In 2 O 3 nanoparticles depicted 94.1 % (300 lg/mL) and 99.6 % (0.18 lg/mL) inhibition against a-amylase and a-glucosidase, respectively. In comparison with acarbose, a standard anti-diabetic drug that depicted absolute inhibition of aglucosidase activity at 300 lg/mL, 2 % silver-doped In 2 O 3 nanoparticles completely inhibited a-glucosidase at a very low concentration (0.18 lg/mL). In view of our results, the activity of a-amylase and a-glucosidase, which are targets for treatment of type 2 diabetes, can be modulated using silver-doped In 2 O 3 nanoparticles in the concentration-dependent manner. Therefore, silver-doped In 2 O 3 has a potential to be used as a prospective starch blocker.
Current Science, 2016
Pila globosa, an edible variety of apple snail is a common inhabitant of lentic ecosystem and fee... more Pila globosa, an edible variety of apple snail is a common inhabitant of lentic ecosystem and feeds on plant detritus. The tissue extract of gastrointestinal tract from Pila globosa demonstrated the presence of carboxymethyl cellulase, xylanase, alginate lyase and pectinase activity. Culture-dependent method was used to isolate carboxymethyl cellulose (CMC) degrading bacteria from the gastrointestinal tract of apple snail. Morphologically identical colonies were obtained on M9 gelrite plates containing CMC as carbon source. One such bacterial isolate was purified by streaking and designated as strain PG-1. Bacterial strain PG-1 degraded CMC, pectin, starch and alginate. The 16S rDNA sequence of strain PG1 was 99% identical to Klebsiella oxytoca. Phylogenetic analysis using maximum likelihood revealed the clustering of strain PG1 with the clade belonging to Klebsiella oxytoca type strain.
Marine Biotechnology, 2017
Microbulbifer mangrovi strain DD-13 T is a noveltype species isolated from the mangroves of Goa, ... more Microbulbifer mangrovi strain DD-13 T is a noveltype species isolated from the mangroves of Goa, India. The draft genome sequence of strain DD-13 comprised 4,528,106 bp with G+C content of 57.15%. Out of 3479 open reading frames, functions for 3488 protein coding sequences were predicted on the basis of similarity with the cluster of orthologous groups. In addition to protein coding sequences, 34 tRNA genes and 3 rRNA genes were detected. Analysis of nucleotide sequence of predicted gene using a Carbohydrate-Active Enzymes (CAZymes) Analysis Toolkit indicates that strain DD-13 encodes a large set of CAZymes including 255 glycoside hydrolases, 76 carbohydrate esterases, 17 polysaccharide lyases, and 113 carbohydrate-binding modules (CBMs). Many genes from strain DD-13 were annotated as carbohydrases specific for degradation of agar, alginate, carrageenan, chitin, xylan, pullulan, cellulose, starch, β-glucan, pectin, etc. Some of polysaccharide-degrading genes were highly modular and were appended at least with one CBM indicating the versatility of strain DD-13 to degrade complex polysaccharides. The cell growth of strain DD-13 was validated using pure polysaccharides such as agarose or alginate as carbon source as well as by using red and brown seaweed powder as substrate. The homologous carbohydrase produced by strain DD-13 during growth degraded the polysaccharide, ensuring the production of metabolizable reducing sugars. Additionally, several other polysaccharides such as carrageenan, xylan, pullulan, pectin, starch, and carboxymethyl cellulose were also corroborated as growth substrate for strain DD-13 and were associated with concomitant production of homologous carbohydrase.
Marine Pollution and Microbial Remediation, 2016
Complex polysaccharides (CPs) such as agar, alginates, carrageenan, etc., are largely present as ... more Complex polysaccharides (CPs) such as agar, alginates, carrageenan, etc., are largely present as component of cell wall of seaweeds, promoting structural integrity and shielding the host from pathogens or predators. Marine bacteria-degrading CPs are ubiquitous and have been isolated from diverse sources such as costal water, sediments, and deep sea, as well as from the surface of seaweeds and crustaceans. Polysaccharide-degrading enzymes (carbohydrases) such as agarase, alginate lyase, and carrageenase are produced by CP-degrading bacteria that aid in depolymerizing agar, alginate, and carrageenan, respectively. The resultant oligosaccharides are subsequently degraded to various intermediates that are further channelized to energy conversion pathways. Several of these carbohydrases have been purified, and study of their biochemical properties such as molecular weight, substrate specificity, pH, and temperature range for optimal activity indicates a vast diversity. Recently, several multiple CP-degrading bacteria (epiphytic/free form) have been isolated. Saccharophagus degradans and Microbulbifer species are the dominant groups of multiple polysaccharide-degrading bacteria and play a significant role in recycling of carbon from CPs. In natural marine ecosystem, the cell wall of seaweeds comprises an array of CPs in mixed proportion. The production of diverse carbohydrases by CP-degrading bacteria enables it to decompose seaweeds into single cell detritus as well as generate reducing sugars from degraded polysaccharides. Thus, CP-degrading bacteria are potential candidates for eco-friendly degradation of algal waste.
ChemInform, 2014
Graphite Catalyzed Solvent Free Synthesis of Dihydropyrimidin-2(1H)-ones/ thiones and Their Antid... more Graphite Catalyzed Solvent Free Synthesis of Dihydropyrimidin-2(1H)-ones/ thiones and Their Antidiabetic Activity.-The title compounds (IV) are obtained by a solvent-free three-component condensation reaction between various aromatic aldehydes, ethyl acetoacetate, and urea/thiourea. Compound (IVf) shows the highest inhibition of -amylase.-(DHUMASKAR,
International Journal of Systematic and Evolutionary Microbiology, 2012
A rod-shaped, Gram-negative, non-motile, aerobic and non-endospore forming bacterium, designated ... more A rod-shaped, Gram-negative, non-motile, aerobic and non-endospore forming bacterium, designated strain DD-13T, was isolated from the mangrove ecosystem of Goa, India. Strain DD-13T degraded polysaccharides such as agar, alginate, chitin, cellulose, laminarin, pectin, pullulan, starch, carrageenan, xylan and β-glucan. The optimum pH and temperature for growth was 7 and 36 °C, respectively. The strain grew optimally in the presence of 3 % NaCl (w/v). The DNA G+C content was 61.4 mol%. The predominant fatty acid of strain DD-13T was iso-C15 : 0. Ubiquinone-8 was detected as the major respiratory lipoquinone. Phylogenetic studies based on 16S rRNA gene sequence analysis demonstrated that strain DD-13T formed a coherent cluster with species of the genus Microbulbifer . Strain DD-13T exhibited 16S rRNA gene sequence similarity levels of 98.9–97.1 % with Microbulbifer hydrolyticus IRE-31T, Microbulbifer salipaludis JCM 11542T, Microbulbifer agarilyticus JAMB A3T, Microbulbifer celer KCTC ...
Advances in Biological Science Research, 2019
Abstract Complex polysaccharides, such as agar, alginate, carrageenan, chitin, xylan, etc., are a... more Abstract Complex polysaccharides, such as agar, alginate, carrageenan, chitin, xylan, etc., are abundantly present in marine algae and crustaceans. Degradation of these polysaccharides is attributed to microbial agarase, alginate lyase, carrageenase, chitinase, and xylanase, respectively. Conventional dye-based plate assay for the screening/detection of microbes secreting these polysaccharide-degrading enzymes has many limitations as only individually produced extracellular enzymes could be identified. However, genome sequencing and annotation would provide holistic identification of polysaccharide-degrading genes in organisms. As the genome annotation would give the sequence of the genes, the identified genes encoding polysaccharide-degrading enzymes would be characterized on genomic level. Using the genome sequencing strategy, polysaccharide-degrading genes are identified and characterized from many marine bacteria, including Saccharophagus degradans 2-40T, Microbulbifer mangrovi DD-13T, Microbulbifer elongatus HZ11, etc. These bacterial genomes harbor an array of genes specific for multiple polysaccharide degradation. Furthermore, genome sequencing and functional annotation enable a comprehensive classification of polysaccharide-degrading genes into appropriate carbohydrate-active enzymes (CAZymes), families facilitating a holistic understanding of their ecological role, and exploiting them for creating novel technologies.
Biotechnology and Bioprocess Engineering, Jan 1, 2011