New Biocalcifying Marine Bacterial Strains Isolated from Calcareous Deposits and Immediate Surroundings

Marine bacterial biomineralisation by CaCO3 precipitation provides natural limestone structures, like beachrocks and stromatolites. Calcareous deposits can also be abiotically formed in seawater at the surface of steel grids under cathodic polarisation. In this work, we showed that this mineral-rich alkaline environment harbours bacteria belonging to different genera able to induce CaCO3 precipitation. We previously isolated 14 biocalcifying marine bacteria from electrochemically formed calcareous deposits and their immediate environment. By microscopy and µ-Raman spectroscopy, these bacterial strains were shown to produce calcite-type CaCO3. Identification by 16S rDNA sequencing provided between 98.5 and 100% identity with genera Pseudoalteromonas, Pseudidiomarina, Epibacterium, Virgibacillus, Planococcus, and Bhargavaea. All 14 strains produced carbonic anhydrase, and six were urease positive. Both proteins are major enzymes involved in the biocalcification process. However, this does not preclude that one or more other metabolisms could also be involved in the process. In the presence of urea, Virgibacillus halodenitrificans CD6 exhibited the most efficient precipitation of CaCO3. However, the urease pathway has the disadvantage of producing ammonia, a toxic molecule. We showed herein that different marine bacteria could induce CaCO3 precipitation without urea. These bacteria could then be used for eco-friendly applications, e.g., the formation of bio-cements to strengthen dikes and delay coastal erosion.

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Metabolite fingerprinting of novel Streptomyces UK-238 from the Himalayan forest

Current Pharmaceutical Analysis ◽

10.2174/1573412916666200206160836 ◽

2020 ◽

Vol 16 ◽

Author(s):

Nidhi Srivastava ◽

Indira P. Sarethy

Keyword(s):

Ethyl Acetate ◽

16S Rdna ◽

Retention Index ◽

Ethyl Acetate Extract ◽

Similarity Index ◽

Antimicrobial Drug ◽

16S Rdna Sequencing ◽

Metabolite Fingerprinting ◽

Streptomyces Sp ◽

Rdna Sequencing

Aims: Characterization of antimicrobial metabolites of novel Streptomyces sp. UK-238. Background: Novel antimicrobial drug discovery is urgently needed due to emerging multi antimicrobial drug resistance among pathogens. Since many years, natural products have provided the basic skeletons for many therapeutic compounds including antibiotics. Bioprospection of un/under explored habitats and focussing on selective isolation of actinobacteria as major reservoir of bio and chemodiversity has yielded good results. Objective: The main objectives of the study were the identification of UK-238 by 16S rDNA sequencing and antimicrobial metabolite fingerprinting of culture extracts. Method: In the present study, a promising isolate, UK-238, has been screened for antimicrobial activity and metabolite fingerprinting from the Himalayan Thano Reserve forest. It was identified by 16S rDNA sequencing. Ethyl acetate extract was partially purified by column chromatography. The pooled active fractions were fingerprinted by GC-MS and compounds were tentatively identified by collated data analysis based on Similarity Index, observed Retention Index from Databases and calculated Retention Index. Results: UK-238 was identified as Streptomyces sp. with 98.4% similarity to S. niveiscabiei. It exhibited broad-spectrum antibacterial and antifungal activity. GC-MS analysis of active fractions of ethyl acetate extract showed the presence of eighteen novel antimicrobial compounds belonging to four major categories- alcohols, alkaloid, esters and peptide. Conclusion: The study confirms that bioprospection of underexplored habitats can elaborate novel bio and chemodiversity.

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2-Way k-Means as a Model for Microbiome Samples

Journal of Healthcare Engineering ◽

10.1155/2017/5284145 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Weston J. Jackson ◽

Ipsita Agarwal ◽

Itsik Pe’er

Keyword(s):

Unsupervised Learning ◽

16S Rdna ◽

Mixture Model ◽

Vaginal Microbiome ◽

16S Rdna Sequencing ◽

Sequencing Data ◽

Cluster Assignment ◽

Rdna Sequencing

Motivation. Microbiome sequencing allows defining clusters of samples with shared composition. However, this paradigm poorly accounts for samples whose composition is a mixture of cluster-characterizing ones and which therefore lie in between them in the cluster space. This paper addresses unsupervised learning of 2-way clusters. It defines a mixture model that allows 2-way cluster assignment and describes a variant of generalized k-means for learning such a model. We demonstrate applicability to microbial 16S rDNA sequencing data from the Human Vaginal Microbiome Project.

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Evaluation of MALDI-TOF mass spectrometry and MALDI BioTyper in comparison to 16S rDNA sequencing for the identification of bacteria isolated from Arctic sea water

PLoS ONE ◽

10.1371/journal.pone.0181860 ◽

2017 ◽

Vol 12 (7) ◽

pp. e0181860 ◽

Cited By ~ 19

Author(s):

Anna Maria Timperio ◽

Susanna Gorrasi ◽

Lello Zolla ◽

Massimiliano Fenice

Keyword(s):

Mass Spectrometry ◽

16S Rdna ◽

Sea Water ◽

16S Rdna Sequencing ◽

Maldi Tof Mass Spectrometry ◽

Maldi Tof ◽

Rdna Sequencing ◽

Arctic Sea ◽

Maldi Biotyper ◽

Identification Of Bacteria

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Analysis of the bacterial floral structure and diversity of Xuanwei ham by 16S rDNA sequencing

Journal of Food Safety ◽

10.1111/jfs.12800 ◽

2020 ◽

Vol 40 (4) ◽

Author(s):

Luying Shan ◽

Yinjiao Li ◽

Shi Zheng ◽

Yuanmiao Wei ◽

Ying Shang

Keyword(s):

16S Rdna ◽

16S Rdna Sequencing ◽

Floral Structure ◽

Rdna Sequencing

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ISOLATION, PURIFICATION, AND CHARACTERIZATION OF LIPASE FROM BACILLUS SP. FROM KITCHEN GREASE

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2018.v11i6.24955 ◽

2018 ◽

Vol 11 (6) ◽

pp. 224

Author(s):

Jaiganesh R ◽

Jaganathan Mk

Keyword(s):

16S Rdna ◽

Solvent Tolerance ◽

16S Rdna Sequencing ◽

Bacillus Sp ◽

Purification And Characterization ◽

Lipase Enzyme ◽

Sequencing Method ◽

Rdna Sequencing ◽

Solvent Tolerant

Objective: The objective of this work was to isolation, purification and characterization of solvent tolerant lipase from Bacillus sp. The objective of this work was to isolation, purification and characterization of solvent tolerant lipase from Bacillus sp. from kitchen grease for a variety of applications including organic synthetic reactions and preparation of enantiomerically pure pharmaceuticals.Methods: Lipase producing isolates were screened from kitchen grease on a selective medium rhodamine B olive oil agar, and tributyrin agar was used to screen the lipase and esterase producing an organism, respectively. The isolate identified using 16S rDNA sequencing method and enzyme activity was quantitatively assayed. Lipase production was characterized in different conditions.Results: The isolate showed highest lipase activity was which later was identified as Bacillus sp. using 16S rDNA sequencing method. The lipase was purified using ammonium sulfate precipitation. The isolate showed excellent tolerance to methanol, ethanol, acetonitrile, and moderate tolerance to butanol. The increased biomass concentration, maximum production, and activity were achieved at 37°C in 24 h incubation, then gradual reduction in production was observed. The maximum activity of lipase enzyme was obtained at pH between 6 and 9.Conclusion: The isolate produce solvent tolerance lipase enzyme and it can be a promising candidate of solvent tolerance lipase enzyme for variety of industrial applications.

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