Publications by authors named "Tal Luzzatto-Knaan"

The complex interactions between epiphytic bacteria and marine macroalgae are still poorly understood, with limited knowledge about their community structure, interactions, and functions. This study focuses on comparing epiphytic prokaryotes community structure between three seaweed phyla; Chlorophyta, Rhodophyta, and Heterokontophyta in an easternmost rocky intertidal site of the Mediterranean Sea. By taking a snapshot approach and simultaneously collecting seaweed samples from the same habitat, we minimize environmental variations that could affect epiphytic bacterial assembly, thereby emphasizing host specificity.

View Article and Find Full Text PDF

The shift from the terrestrial to the marine environment to discover natural products has given rise to novel bioactive compounds, some of which have been approved for human medicine. However, the ocean, which makes up nearly three-quarters of the Earth's surface, contains macro- and microorganisms whose natural products are yet to be explored. Among these underexplored marine organisms are macroalgae and their symbiotic microbes, such as Bacillota, a phylum of mostly Gram-positive bacteria previously known as Firmicutes.

View Article and Find Full Text PDF

Marine phytoplankton are responsible for about half of the photosynthesis on Earth. Many are mixotrophs, combining photosynthesis with heterotrophic assimilation of organic carbon, but the relative contribution of these two lifestyles is unclear. Here single-cell measurements reveal that Prochlorococcus at the base of the photic zone in the Eastern Mediterranean Sea obtain only ~20% of carbon required for growth by photosynthesis.

View Article and Find Full Text PDF

Gastrointestinal cancer refers to malignancy of the accessory organs of digestion, and it includes colorectal cancer (CRC) and pancreatic cancer (PC). Worldwide, CRC is the second most common cancer among women and the third most common among men. PC has a poor prognosis and high mortality, with 5-year relative survival of approximately 11.

View Article and Find Full Text PDF

The use of synthetic chemical products in agriculture is causing severe damage to the environment and human health, but agrochemicals are still widely used to protect our crops. To counteract this trend, we have been looking for alternative strategies to control plant diseases without causing harm to the environment or damage to our health. However, these alternatives are still far from completely replacing chemical products.

View Article and Find Full Text PDF

Metabolomics can be used to study complex mixtures of natural products, or secondary metabolites, for many different purposes. One productive application of metabolomics that has emerged in recent years is the guiding direction for isolating molecules with structural novelty through analysis of untargeted LC-MS/MS data. The metabolomics-driven investigation and bioassay-guided fractionation of a biomass assemblage from the South China Sea dominated by a marine filamentous cyanobacteria, cf.

View Article and Find Full Text PDF

Many microorganisms produce resting cells with very low metabolic activity that allow them to survive phases of prolonged nutrient or energy stress. In cyanobacteria and some eukaryotic phytoplankton, the production of resting stages is accompanied by a loss of photosynthetic pigments, a process termed chlorosis. Here, we show that a chlorosis-like process occurs under multiple stress conditions in axenic laboratory cultures of , the dominant phytoplankton linage in large regions of the oligotrophic ocean and a global key player in ocean biogeochemical cycles.

View Article and Find Full Text PDF
Article Synopsis
  • Ribosomally synthesized and post-translationally modified peptides (RiPPs) are significant natural products that include antibiotics and various bioactive compounds.
  • Current discovery methods for RiPPs are limited and ineffective at identifying unknown modifications in larger datasets.
  • MetaMiner is a new software tool that successfully identified 31 known and 7 unknown RiPPs from diverse microbial sources by analyzing millions of spectra from large genomic databases.
View Article and Find Full Text PDF

To visualize the personalized distributions of pathogens and chemical environments, including microbial metabolites, pharmaceuticals, and their metabolic products, within and between human lungs afflicted with cystic fibrosis (CF), we generated three-dimensional (3D) microbiome and metabolome maps of six explanted lungs from three cystic fibrosis patients. These 3D spatial maps revealed that the chemical environments differ between patients and within the lungs of each patient. Although the microbial ecosystems of the patients were defined by the dominant pathogen, their chemical diversity was not.

View Article and Find Full Text PDF

Background: Use of skin personal care products on a regular basis is nearly ubiquitous, but their effects on molecular and microbial diversity of the skin are unknown. We evaluated the impact of four beauty products (a facial lotion, a moisturizer, a foot powder, and a deodorant) on 11 volunteers over 9 weeks.

Results: Mass spectrometry and 16S rRNA inventories of the skin revealed decreases in chemical as well as in bacterial and archaeal diversity on halting deodorant use.

View Article and Find Full Text PDF

Microbes use metabolic exchange to sense and respond to their changing environment. Surfactins, produced by Bacillus subtilis, have been extensively studied for their role in biofilm formation, biosurfactant properties, and antimicrobial activity, affecting the surrounding microbial consortia. Using mass spectrometry, we reveal that Paenibacillus dendritiformis, originally isolated with B.

View Article and Find Full Text PDF

One of the goals of forensic science is to identify individuals and their lifestyle by analyzing the trace signatures left behind in built environments. Here, microbiome and metabolomic methods were used to see how its occupants used an office and to also gain insights into the lifestyle characteristics such as diet, medications, and personal care products of the occupants. 3D molecular cartography, a molecular visualization technology, was used in combination with mass spectrometry and microbial inventories to highlight human-environmental interactions.

View Article and Find Full Text PDF

Natural product screening programs have uncovered molecules from diverse natural sources with various biological activities and unique structures. However, much is yet underexplored and additional information is hidden in these exceptional collections. We applied untargeted mass spectrometry approaches to capture the chemical space and dispersal patterns of metabolites from an in-house library of marine cyanobacterial and algal collections.

View Article and Find Full Text PDF

Microbes are commonly studied as individual species, but they exist as mixed assemblages in nature. At present, we know very little about the spatial organization of the molecules, including natural products that are produced within these microbial networks. Lichens represent a particularly specialized type of symbiotic microbial assemblage in which the component microorganisms exist together.

View Article and Find Full Text PDF

Covering: up to 2016Humans are walking microbial ecosystems, each harboring a complex microbiome with the genetic potential to produce a vast array of natural products. Recent sequencing data suggest that our microbial inhabitants are critical for maintaining overall health. Shifts in microbial communities have been correlated to a number of diseases including infections, inflammation, cancer, and neurological disorders.

View Article and Find Full Text PDF

The cars we drive, the homes we live in, the restaurants we visit, and the laboratories and offices we work in are all a part of the modern human habitat. Remarkably, little is known about the diversity of chemicals present in these environments and to what degree molecules from our bodies influence the built environment that surrounds us and vice versa. We therefore set out to visualize the chemical diversity of five built human habitats together with their occupants, to provide a snapshot of the various molecules to which humans are exposed on a daily basis.

View Article and Find Full Text PDF

The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry (MS) techniques are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.

View Article and Find Full Text PDF

Since the time Van Leeuwenhoek was able to observe microbes through a microscope, an innovation that led to the birth of the field of microbiology, we have aimed to understand how microorganisms function, interact and communicate. The exciting progress in the development of analytical technologies and workflows has demonstrated that mass spectrometry is a very powerful technique for the interrogation of microbiology at the molecular level. In this review, we aim to highlight the available and emerging tools in mass spectrometry for microbial analysis by overviewing the methods and workflow advances for taxonomic identification, microbial interaction, dereplication and drug discovery.

View Article and Find Full Text PDF

The defence response of Zantedeschia aethiopica, a natural rhizomatous host of the soft rot bacterium Pectobacterium carotovorum, was studied following the activation of common induced resistance pathways—systemic acquired resistance and induced systemic resistance. Proteomic tools were used, together with in vitro quantification and in situ localization of selected oxidizing enzymes. In total, 527 proteins were analysed by label-free mass spectrometry (MS) and annotated against the National Center for Biotechnology Information (NCBI) nonredundant (nr) protein database of rice (Oryza sativa).

View Article and Find Full Text PDF

In geophyte plants, such as Zantedeschia, individual leaves are directly connected to a specialized underground storage organ (rhizome/tuber), raising a question regarding systemic resistance as a mechanism of defense. A systemic response requires a transfer of a signal through the storage organ which has been evolutionary adapted to store food, minerals and moisture for seasonal growth and development. We have characterized the nature of induced defense responses in Zantedeschia aethiopica, a rhizomatous (tuber-like) ornamental plant by the application of local elicitation using two well-known defense elicitors, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) and methyl jasmonate (MJ).

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionnli01dfei5tdv26lfeu6a53r3v6cuqul): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once