Isolation of multiple drug resistant and heavy metal resistant Stenotrophomonas maltophila strain BN1, a plant growth promoting rhizobacteria, from mangrove associate Ipomoea pes-caprae of Indian Sundarbans.
31 Dec 2016-Journal of Pure and Applied Microbiology (Journal of Pure and Applied Microbiology)-Vol. 10, Iss: 4, pp 3131-3139
TL;DR: Dual expressions of antibiotics and heavymetal resistance along with the plant growth promoting properties would make the isolate Stenotrophomonas maltophila strain BN1 ideal candidate strain for bioremediation of heavy metal contaminated sites effected with salinity.
Abstract: During the screening of heavy metal resistant plant growth promoting rhizobacteria of the mangrove associate species Ipomoea pes-caprae of Indian Sundarbans, one multiple heavy metal resistant bacterium was isolated. The strain was identified as Stenotrophomonas maltophila strain BN1at 16S rDNA level. The strain was found to be resistant to 11 different antibiotics including ampicillin, streptomycin, cefuroxime, netillin, penicillin, gentamycin, nitrofurantoin, chloramphenicol, amikacin, amoxyclav, imipenem and could tolerate multiple heavy metals. The scanning electron micrography revealed small rod shaped bacteria and the cell surface forms microspheres. This bacterium was not only positive for various plant growth promoting features like IAA, siderophore and ammonia production but also showed phosphate solubilization and protease production ability. Therefore, dual expressions of antibiotics and heavymetal resistance along with the plant growth promoting properties would make the isolate Stenotrophomonas maltophila strain BN1 ideal candidate strain for bioremediation of heavy metal contaminated sites effected with salinity.
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TL;DR: The antibacterial activity of Suaeda maritima against a wide spectrum of Gram-negative and Gram-positive isolates and multiple antibiotic resistant strains suggested that it may be a potential antibacterial agent to control antibiotic resistant infections.
Abstract: In this study, antimicrobial property of Suaeda maritima, a mangrove associate species collected from lower Gangetic delta complex was evaluated. The antibacterial activity of the extract against a wide spectrum of Gram-negative and Gram-positive isolates and multiple antibiotic resistant strains suggested that it may be a potential antibacterial agent to control antibiotic resistant infections. Among the different solvent fractions examined, n-hexane extract of the shoot of S. maritima L (Dumort) was found to possess highest antibacterial activity against four Gram-positive (Bacillus subtilis, Staphylococcus haemolyticus, Staphylococcus aureus, Enterococcus faecalis) and six Gram-negative (Escherichia coli, Citrobacter sp., Klebsiella pneumoniae, KPC producing K. Pneumonia, Pseudomonas sp. and Stenotrophomonas maltophila) bacteria. Fungicidal activity was noted against Saccharomyces cerevisiae. Minimum inhibitory concentration and minimum bactericidal concentration values were determined in disc diffusion and macrodilution assays. The inhibition zones ranged between 13-20 mm. GC-MS analysis of the n-hexane fraction showed the presence of various fatty acid esters and essential oils. In addition, scytalone known for its antioxidant property, campesterol and ethanone were detected. Antioxidant activity was found having an IC50 value of 52.53 mg/ml.
20 citations
Cites background from "Isolation of multiple drug resistan..."
...maltophila whose MDR power has been the research topic for a decade[34,35]....
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01 Jan 2019
TL;DR: To comprehend the microbial diversity of an ecosystem in the light of this new genomic era, recently performed deep sequencing studies of the Sundarbans have been included in the last part of this chapter.
Abstract: This chapter provides a conspectus of the microbial diversity and biotechnological potential of mangrove-derived microbes with special reference to the world’s largest tidal mangrove forest, the Sundarbans. In the first part, we have described the importance of microbial community in mangrove and discussed various methodologies that have been exploited to assess the microbial diversity of this unique ecosystem. In the next part, we have provided a brief description of the microbial isolates reported from the Sundarbans in respect to their beneficial promises and subsequent role in conservation of this world heritage site. Culture-dependent studies were observed not to be adequate to completely report the actual microbial diversity and their spatiotemporal interplay. Thus to comprehend the microbial diversity of an ecosystem in the light of this new genomic era, recently performed deep sequencing studies of the Sundarbans have been included in the last part of this chapter.
18 citations
01 Jan 2019
TL;DR: In this paper, the authors focused mainly on diversity, distribution, and function of microbes in Indian mangrove ecosystem and discussed both culture-dependent and culture-independent studies on understanding the diversity and function.
Abstract: Mangrove forests are excellent examples of extremely productive ecosystems, present on earth. Located along the coastal zones, they provide nutrients that help to nourish the coastal waters, as well as serve as barriers that protect the coastal zones. In the last century, mangrove ecosystems became increasingly threatened due to changes in land usage pattern, different biotic pressure, natural calamities, and finally anthropogenic influences. It is therefore indispensable to monitor and assess mangrove ecosystems at a regular interval. India has a long coastline of which an area of about 4921 km2 is covered with mangroves, making this country the fourth largest concerning the area covered with mangrove ecotype. Microbes are important components of mangrove ecosystems where they play an integral part in maintaining the biogeochemistry of such ecologically important regions. In Indian mangroves, a considerable effort has been made to understand flora and fauna biodiversity. However, knowledge about the microbial diversity and function within Indian mangrove ecosystem is comparatively less. The present chapter focuses mainly on diversity, distribution, and function of microbes in Indian mangrove ecosystem. Both culture-dependent and culture-independent studies on understanding the diversity and function of microorganisms in Indian mangroves have been discussed.
4 citations
References
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TL;DR: The neighbor-joining method and Sattath and Tversky's method are shown to be generally better than the other methods for reconstructing phylogenetic trees from evolutionary distance data.
Abstract: A new method called the neighbor-joining method is proposed for reconstructing phylogenetic trees from evolutionary distance data. The principle of this method is to find pairs of operational taxonomic units (OTUs [= neighbors]) that minimize the total branch length at each stage of clustering of OTUs starting with a starlike tree. The branch lengths as well as the topology of a parsimonious tree can quickly be obtained by using this method. Using computer simulation, we studied the efficiency of this method in obtaining the correct unrooted tree in comparison with that of five other tree-making methods: the unweighted pair group method of analysis, Farris's method, Sattath and Tversky's method, Li's method, and Tateno et al.'s modified Farris method. The new, neighbor-joining method and Sattath and Tversky's method are shown to be generally better than the other methods.
57,055 citations
"Isolation of multiple drug resistan..." refers methods in this paper
...The evolutionary history was inferred using the Neighbor-Joining method (Saitou and Nei 1987)....
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TL;DR: Version 4 of MEGA software expands on the existing facilities for editing DNA sequence data from autosequencers, mining Web-databases, performing automatic and manual sequence alignment, analyzing sequence alignments to estimate evolutionary distances, inferring phylogenetic trees, and testing evolutionary hypotheses.
Abstract: We announce the release of the fourth version of MEGA software, which expands on the existing facilities for editing DNA sequence data from autosequencers, mining Web-databases, performing automatic and manual sequence alignment, analyzing sequence alignments to estimate evolutionary distances, inferring phylogenetic trees, and testing evolutionary hypotheses. Version 4 includes a unique facility to generate captions, written in figure legend format, in order to provide natural language descriptions of the models and methods used in the analyses. This facility aims to promote a better understanding of the underlying assumptions used in analyses, and of the results generated. Another new feature is the Maximum Composite Likelihood (MCL) method for estimating evolutionary distances between all pairs of sequences simultaneously, with and without incorporating rate variation among sites and substitution pattern heterogeneities among lineages. This MCL method also can be used to estimate transition/transversion bias and nucleotide substitution pattern without knowledge of the phylogenetic tree. This new version is a native 32-bit Windows application with multi-threading and multi-user supports, and it is also available to run in a Linux desktop environment (via the Wine compatibility layer) and on Intel-based Macintosh computers under the Parallels program. The current version of MEGA is available free of charge at (http://www.megasoftware.net).
29,021 citations
"Isolation of multiple drug resistan..." refers methods in this paper
...The phylogenetic tree was constructed using MEGA7 (Tamura et al. 2007)....
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...A phylogenetic tree was constructed by multiple alignment and neighbor joining method using MEGA7 (Fig....
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TL;DR: Some examples were worked out using reported globin sequences to show that synonymous substitutions occur at much higher rates than amino acid-altering substitutions in evolution.
Abstract: Some simple formulae were obtained which enable us to estimate evolutionary distances in terms of the number of nucleotide substitutions (and, also, the evolutionary rates when the divergence times are known). In comparing a pair of nucleotide sequences, we distinguish two types of differences; if homologous sites are occupied by different nucleotide bases but both are purines or both pyrimidines, the difference is called type I (or “transition” type), while, if one of the two is a purine and the other is a pyrimidine, the difference is called type II (or “transversion” type). Letting P and Q be respectively the fractions of nucleotide sites showing type I and type II differences between two sequences compared, then the evolutionary distance per site is K = — (1/2) ln {(1 — 2P — Q) }. The evolutionary rate per year is then given by k = K/(2T), where T is the time since the divergence of the two sequences. If only the third codon positions are compared, the synonymous component of the evolutionary base substitutions per site is estimated by K'S = — (1/2) ln (1 — 2P — Q). Also, formulae for standard errors were obtained. Some examples were worked out using reported globin sequences to show that synonymous substitutions occur at much higher rates than amino acid-altering substitutions in evolution.
26,016 citations
"Isolation of multiple drug resistan..." refers methods in this paper
...The evolutionary distances were computed using the Kimura 2- parameter method (Kimura 1980) and are in the units of the number of base substitutions per site....
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TL;DR: Recommendations of the National Committee for Clinical Laboratory Standards continue to be based on this publication; the “Kirby-Bauer” method is, among the many disk methods used in other countries, still the one that has been researched most thoroughly and updated continuously.
Abstract: In the words of the authors, the paper by A. W. Bauer et al., from the University of Washington in Seattle, on a standardized single-disk method for antibiotic susceptibility testing “. . . consolidate(s) and update(s) previous descriptions of the method and provide(s) a concise outline for its performance and interpretation.” Clinical microbiologists were relieved that finally a disk diffusion method had been standardized, could be used with ease, and provided reliable results as compared with minimum inhibitory concentration tests. The pivotal role of Hans Ericsson’s theoretical and practical studies (H. Ericsson and G. Svartz-Malmberg, Antibiot. Chemother. 6:41–74, 1959), as well as earlier reports by some of the authors of the publications cited, must be mentioned as a matter of fairness. Most of the recommendations given are still valid today even though some of the antimicrobial agents are obsolete, new ones have been added, some zone sizes had to be modified, and new media were designed for Haemophilus influenzae and Neisseria gonorrhoeae. Recommendations of the National Committee for Clinical Laboratory Standards continue to be based on this publication; the “Kirby-Bauer” method is, among the many disk methods used in other countries, still the one that has been researched most thoroughly and updated continuously. ALEXANDER VON GRAEVENITZ
16,916 citations
"Isolation of multiple drug resistan..." refers methods in this paper
...Antibiotics resistance assay The antibiotics susceptibility testing of the strain was done in Mueller Hinton agar by agar disc diffusion technique (Bauer et al. 1966)....
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TL;DR: During a study of the inactivation of IAA in aqueous solutions, it was frequently necessary to assay at one time many samples where the IAA concentrations were low, or where the degree of significance of small differences in concentrations between experimental unite required evaluation, so it was desirable to re-examine the ferric chloride-sulphuric acid procedure.
Abstract: The wide use of the auxin, indoleacetic acid, in physiological and biochemical experiments has promoted interest in methods for its colorimetrie estimation. Mitchell and Brunstetteb (1) have proposed both the nitrite and the ferric chloride-sulphuric acid tests for the quantitative estimation of indoleacetic acid (IAA) in aqueous solutions, basing their suggested procedures upon a study of optimal reaction conditions for these two reagents. According to them, the nitrite method is sensitive to 10 /tig. IAA/ml. and develops a red color that is stable after two hours. In several attempts to duplicate their nitrite method using solutions of IAA varying from 20 to 45 /tg./ml., we could not obtain a stable red color with IAA at the two hours proposed, or at any other time. A faint pink develops almost immediately which rapidly fades to orange or yellow, depending on IAA concentrations, within i hour. If the concentration of nitrite is reduced, the red color becomes sufficiently persistent to be read. Indole likewise gives a strong, relatively stable, red color in this test (cf. table II)?a reaction which is sometimes used as a qualitative test for indole (Nitroso-Indole reaction). Tang and Bonner (2) have modified the ferric chloride-sulphuric acid method for IAA, combining the iron and sulphuric acid as a single reagent to yield improved sensitivity. However, the color produced is also unstable, rapidly developing and then fading. We have found, as have these workers, that the fading color can be practically dealt with by adopting a standard time between addition of reagent and reading of absorbancy or transmittance. Both of the methods discussed above possess disadvantages, lacking either specificity, sensitivity, or stability of color complex formed. During a study of the inactivation of IAA in aqueous solutions, it was frequently necessary to assay at one time many samples where the IAA concentrations were low, or where the degree of significance of small differences in concentrations between experimental unite required evaluation. Hence, we considered it desirable 'to re-examine the ferric chloride-sulphuric acid procedure. Several alterations have been made which produce a more stable color, of increased specificity, which changes in density more rapidly with variation in IAA concentration. 1. The procedure of Tang and Bonner can be improved somewhat by reading at 15 minutes after addition of reagent (instead of 30 minutes as they suggest), since the transient color reaches a maximum at the former time. Maximum absorption was found to occur at 530 ???.
1,988 citations