Characterization of Halophilic Isolates Producing Bioactive Metabolites Against Pathogens (original) (raw)
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Metabolism, Physiology And Biotechnological Applications of Halobacteria
Journal of Health, Medicine and Nursing, 2015
Halophiles ( lat . “salt-loving”) is the taxonomic group of extreme aerobic microorganisms that live in conditions of high salinity – in the seas, salt lakes, saline soils etc. These microorganisms are known to reddish patina on products, preserved with using large quantities of salt (NaCl). Halophiles were isolated for the first time at the beginning of the XX century from the marine flora estuary mud, but their systematic study was started only at the end of the second decade of the XX century. The internal environment of the human body is not suitable for existence of halobacteria, since none of them are known to have pathogenic forms. Halobacteria have great practical potential for using in molecular bioelectronics and bio-nanotechnology due to their unique ability to convert the energy of sunlight into electrochemical energy of protons H + due to the presence in their cells a special photo transforming retinal containing integral protein – bacteriorhodopsin, the mechanism of ac...
Isolation, Characterization of Halotolerant bacteria and its biotechnological potentials
2013
1 Abstract— Marine microbes represent a potential source for commercially important bioactive compounds and their bioremediation capabilities are also remarkable. Hence for the present study the bacterial strains were isolated from salt enriched soils which were collected from the natu- ral saline habitats from Bhitarkanika coastal region of Orissa, India. The phenotypic characters of the isolates conclusively proved that isolates S1-4 belongs to Bacillus spp. and S5 belongs to Micrococcus luteus and S6 could not be identified, it would be a new isolate, which changed their shape to spherical forms when grown in NaCl which is a halotolerant character. The bacteria isolates (S 1-4) produced gummy (except S1) colonies of different shape, size margin and elevation. Bacterias were motile except S5, aerobic, gram +ve except S6, spherical and elliptical spores forming rods and cocci of (2.26 - 4.25) x (0.70-0.85) µm size range and catalase (+)ve. However, the organisms differed in some ph...
Int.J.Curr.Microbiol.App.Sci , 2015
Dead Sea is a hypersaline terminal desert lake with 34.8% salinity and is one of the extreme habitats for the sustenance of life on earth. Present ionic composition of the lake is 2M Mg 2+ , 0.5M Ca 2+ , 1.5M Na + , 0.2M K + , 6.5M Cl-and 0.1 M Br-, which is inhibitory to most of life forms. Dead Sea harbours numerous halophilic microorganisms such as algae, bacteria, archaea and fungi; which can withstand the extreme conditions of the lake. During the years of heavy rainfall such as 1980 and 1992, upper water layer of the Dead Sea becomes diluted and leads to development of algal blooms which is followed by bloom of red halophilic Archaea. Metagenomic studies revealed the significant difference between microbial community during the algal bloom and resident community during the interbloom period. Halophilic archaea and bacteria isolated from the lake include the members of the genera Haloferax, Haloarcula, Halobaculum, Halorubrum, Halomonas, Chromohalobacter and Salibacillus. The halophilic microorganisms are utilized for various biotechnological applications and present study focuses on the isolation and screening of halophilic microorganisms from the Dead Sea for biotechnologically important properties such as extracellular protease production, Polyhydroxy alkanoates (PHA) production, halocin production and bio emulsifier production. Highest extracellular protease activity of 12.45 U/ml and highest PHA concentration of 27.5 % of cell dry weight was obtained. Isolates showing halocin production were also tested against the human pathogens such as S. aureus and P. aeruginosa; while this is one of the few reports, describing the bioemulsifier production from the halophiles.
Potential of halotolerant and halophilic microorganisms for biotechnology
Extremophiles, 2001
Halotolerant or halophilic microorganisms, able to live in saline environments, offer a multitude of actual or potential applications in various fields of biotechnology. The technical applications of bacteriorhodopsin comprise holography, spatial light modulators, optical computing, and optical memories. Compatible solutes are useful as stabilizers of biomolecules and whole cells, salt antagonists, or stress-protective agents. Biopolymers, such as biosurfactants and exopolysaccharides, are of interest for microbially enhanced oil recovery. Other useful biosubstances are enzymes, such as new isomerases and hydrolases, that are active and stable at high salt contents. Halotolerant microorganisms play an essential role in food biotechnology for the production of fermented food and food supplements. The degradation or transformation of a range of organic pollutants and the production of alternative energy are other fields of applications of these groups of extremophiles. Key words Halotolerant/halophilic • Biotechnology • Bacteriorhodopsin • Compatible solutes • Biopolymers • Halofermentation • Waste treatment (biodegradation) Bacteriorhodopsin Certain extremely halophilic Archaea contain membranebound retinal pigments, bacteriorhodopsin (BR) and halor
Nature and bioprospecting of haloalkaliphilics: a review
The haloalkaliphilics are an important subset of extremophiles that grow in salt [upto 33% (wt/vol) NaCl] and alkaline pH (> 9). They are found in hypersaline environments especially in the brines in arid, coastal and deep sea locations, and in alkaline environments, such as soda soils, lakes and deserts. Some authors have described haloalkaliphilic bacteria as moderate halophilic bacteria, but the molecular and classical studies revealed that they belong to moderately to extremely halophilic bacteria and archaea. Organic solutes, such as glycine, betaine and other amino acid derivatives, sugars such as, sucrose and trehalose, and sugar alcohols present in the haloalkaliphilics help for their osmoadaptation, and also serve as stabilizers. Haloalkalphilics secrete exoenzymes like proteases, amylases, xylanases, cellulases and peroxidases which have potential industrial applications. They also produce bacteriorhodopsin, compatible solutes, pigments, biopolymers, secondary metabolites like biosurfactants, polyhydroxyalkanoate (PHA) and exopolysaccharides and antimicrobial/anticancer compounds. They have unique metabolic pathways which can be used to treat industrial pollutants, heavy metals and waste water.
Molecules, 2017
Though intensive research has been channeled towards the biotechnological applications of halophiles and other extremophilic microbes, these studies have not been, by any means, exhaustive. Saline environments still offer a vast diversity of microbes with potential to produce an array of natural products which can only be unlocked by concerted research efforts. In this study, a combination of culture and molecular approaches were employed to characterize halophilic bacteria from saltpan water samples and profile their potential biotechnological applications. Physicochemical analysis of the water samples showed that pH was alkaline (pH 8.8), with a salinity of 12.8%. 16S rRNA gene targeted amplicon analysis produced 10 bacterial phyla constituting of Bacteroidetes (30.57%), Proteobacteria (15.27%), Actinobacteria (9.05%), Planctomycetes (5.52%) and Cyanobacteria (3.18%). Eighteen strains were identified using sequencing analysis of the culturable bacterial strains. From these, the strains SP7 and SP9 were positive for cellulase production while the strains SP4, SP8 and SP22 were positive for lipase production. Quantitative enzyme assays showed moderate extracellular cellulase activity (1.95 U/mL) and lipase activity (3.71 U/mL) by the isolate SP9 and SP4 respectively. Further, of the six isolates, the isolate SP9 exhibited exploitable potential in the bioremediation of hydrocarbon pollution as demonstrated by its fairly high activity against benzanthracene (70% DCPIP reduction). Elucidation of the isolates secondary metabolites showed the production of the molecules 2,3-butanediol, hexahydro-3-(2-methylpropyl)pyrrole[1,2a]pyrazine-1,4-dione, aziridine, dimethylamine and ethyl acetate (GC-MS) and oxypurinol and 5-hydroxydecanoic acid (LC-MS), particularly by the isolate Salinivibrio sp. SP9. Overall, the study showed that the isolated halophiles can produce secondary metabolites with potential industrial and pharmaceutical application.
Halophiles – Taxonomy, Diversity, Physiology and Applications
Microorganisms in Environmental Management, 2011
Halophiles are salt-loving organisms inhabiting environments with the capacity to balance the osmotic pressure of the environment and resist the denaturing effects of salts such as salt induced co-aggregation of proteins. They are diverse group of organisms that thrive extreme saline environments. Depending upon their requirement for salt concentration, they are classifi ed as halotolerant, moderately halophile and extreme halophile.
Halophilic bacteria grow over a wide range of salt concentrations. In this study we aimed to isolate and screen out the halophilic bacteria and to determine their activity for production of the bioactive compounds. A total of 50 water, sediments and soil samples were collected from Maharlu salt lake in southern region of Fars-Iran and subjected for isolation of the bioactive compound producing Halophilic bacteria. The results obtained indicated that out of all isolates, three strains could produce the bioactive compounds. The isolates were molecular (16SrRNA) identified as Bacillus licheniformis, Bacillus subtilis and Bacterium Culaeen. Furthermore, structural analysis of the bioactive compounds was carried out in order to achieve maximum information concerning to them. The results obtained illustrated the existence of glycoprotein in all the bioactive compounds. Although, Staphylococcus aureus, Aspergillusniger and Mucor…. were sensitive to all the bioactive compounds, Pseudomonas aeruginosa, Escherichia coli and Bacillus cereus were resistant to them. In addition, the bioactive compound producing isolated strains by Bacillus licheniformis and Bacillus subtilis showed antifungal activity against Aspergillusniger and mucor sp. In total, our finding illustrated that the maharlu salt lake might be considered a source of halophilic bacteria with potent activity for production of the bioactive compounds. In addition, isolation and characterization of these compounds culminate in the achievement of the new drugs.