Tag Archives: Pamela A Silver

Nano and a Unified Microbiome Initiative (UMI)

A Jan. 6, 2015 news item on Nanowerk features a proposal by US scientists for a Unified Microbiome Initiative (UMI),

In October [2015], an interdisciplinary group of scientists proposed forming a Unified Microbiome Initiative (UMI) to explore the world of microorganisms that are central to life on Earth and yet largely remain a mystery.

An article in the journal ACS Nano (“Tools for the Microbiome: Nano and Beyond”) describes the tools scientists will need to understand how microbes interact with each other and with us.

A Jan. 6, 2016 American Chemical Society (ACS) news release, which originated the news item, expands on the theme,

Microbes live just about everywhere: in the oceans, in the soil, in the atmosphere, in forests and in and on our bodies. Research has demonstrated that their influence ranges widely and profoundly, from affecting human health to the climate. But scientists don’t have the necessary tools to characterize communities of microbes, called microbiomes, and how they function. Rob Knight, Jeff F. Miller, Paul S. Weiss and colleagues detail what these technological needs are.

The researchers are seeking the development of advanced tools in bioinformatics, high-resolution imaging, and the sequencing of microbial macromolecules and metabolites. They say that such technology would enable scientists to gain a deeper understanding of microbiomes. Armed with new knowledge, they could then tackle related medical and other challenges with greater agility than what is possible today.

Here’s a link to and a citation for the paper,

Tools for the Microbiome: Nano and Beyond by Julie S. Biteen, Paul C. Blainey, Zoe G. Cardon, Miyoung Chun, George M. Church, Pieter C. Dorrestein, Scott E. Fraser, Jack A. Gilbert, Janet K. Jansson, Rob Knight, Jeff F. Miller, Aydogan Ozcan, Kimberly A. Prather, Stephen R. Quake, Edward G. Ruby, Pamela A. Silver, Sharif Taha, Ger van den Engh, Paul S. Weiss, Gerard C. L. Wong, Aaron T. Wright, and Thomas D. Young. ACS Nano, Article ASAP DOI: 10.1021/acsnano.5b07826 Publication Date (Web): December 22, 2015

Copyright © 2015 American Chemical Society

This is an open access paper.

I sped through very quickly and found a couple of references to ‘nano’,

Ocean Microbiomes and Nanobiomes

Life in the oceans is supported by a community of extremely small organisms that can be called a “nanobiome.” These nanoplankton particles, many of which measure less than 0.001× the volume of a white blood cell, harvest solar and chemical energy and channel essential elements into the food chain. A deep network of larger life forms (humans included) depends on these tiny microbes for its energy and chemical building blocks.

The importance of the oceanic nanobiome has only recently begun to be fully appreciated. Two dominant forms, Synechococcus and Prochlorococcus, were not discovered until the 1980s and 1990s.(32-34) Prochloroccus has now been demonstrated to be so abundant that it may account for as much as 10% of the world’s living organic carbon. The organism divides on a diel cycle while maintaining constant numbers, suggesting that about 5% of the world’s biomass flows through this species on a daily basis.(35-37)

Metagenomic studies show that many other less abundant life forms must exist but elude direct observation because they can neither be isolated nor grown in culture.

The small sizes of these organisms (and their genomes) indicate that they are highly specialized and optimized. Metagenome data indicate a large metabolic heterogeneity within the nanobiome. Rather than combining all life functions into a single organism, the nanobiome works as a network of specialists that can only exist as a community, therein explaining their resistance to being cultured. The detailed composition of the network is the result of interactions between the organisms themselves and the local physical and chemical environment. There is thus far little insight into how these networks are formed and how they maintain steady-state conditions in the turbulent natural ocean environment.

Rather than combining all life functions into a single organism, the nanobiome works as a network of specialists that can only exist as a community

The serendipitous discovery of Prochlorococcus happened by applying flow cytometry (developed as a medical technique for counting blood cells) to seawater.(34) With these medical instruments, the faint signals from nanoplankton can only be seen with great difficulty against noisy backgrounds. Currently, a small team is adapting flow cytometric technology to improve the capabilities for analyzing individual nanoplankton particles. The latest generation of flow cytometers enables researchers to count and to make quantitative observations of most of the small life forms (including some viruses) that comprise the nanobiome. To our knowledge, there are only two well-equipped mobile flow cytometry laboratories that are regularly taken to sea for real-time observations of the nanobiome. The laboratories include equipment for (meta)genome analysis and equipment to correlate the observations with the local physical parameters and (nutrient) chemistry in the ocean. Ultimately, integration of these measurements will be essential for understanding the complexity of the oceanic microbiome.

The ocean is tremendously undersampled. Ship time is costly and limited. Ultimately, inexpensive, automated, mobile biome observatories will require methods that integrate microbiome and nanobiome measurements, with (meta-) genomics analyses, with local geophysical and geochemical parameters.(38-42) To appreciate how the individual components of the ocean biome are related and work together, a more complete picture must be established.

The marine environment consists of stratified zones, each with a unique, characteristic biome.(43) The sunlit waters near the surface are mixed by wind action. Deeper waters may be mixed only occasionally by passing storms. The dark deepest layers are stabilized by temperature/salinity density gradients. Organic material from the photosynthetically active surface descends into the deep zone, where it decomposes into nutrients that are mixed with compounds that are released by volcanic and seismic action. These nutrients diffuse upward to replenish the depleted surface waters. The biome is stratified accordingly, sometimes with sudden transitions on small scales. Photo-autotrophs dominate near the surface. Chemo-heterotrophs populate the deep. The makeup of the microbial assemblages is dictated by the local nutrient and oxygen concentrations. The spatiotemporal interplay of these systems is highly relevant to such issues as the carbon budget of the planet but remains little understood.

And then, there was this,

Nanoscience and Nanotechnology Opportunities

The great advantage of nanoscience and nanotechnology in studying microbiomes is that the nanoscale is the scale of function in biology. It is this convergence of scales at which we can “see” and at which we can fabricate that heralds the contributions that can be made by developing new nanoscale analysis tools.(159-168) Microbiomes operate from the nanoscale up to much larger scales, even kilometers, so crossing these scales will pose significant challenges to the field, in terms of measurement, stimulation/response, informatics, and ultimately understanding.

Some progress has been made in creating model systems(143-145, 169-173) that can be used to develop tools and methods. In these cases, the tools can be brought to bear on more complex and real systems. Just as nanoscience began with the ability to image atoms and progressed to the ability to manipulate structures both directly and through guided interactions,(162, 163, 174-176) it has now become possible to control structure, materials, and chemical functionality from the submolecular to the centimeter scales simultaneously. Whereas substrates and surface functionalization have often been tailored to be resistant to bioadhesion, deliberate placement of chemical patterns can also be used for the growth and patterning of systems, such as biofilms, to be put into contact with nanoscale probes.(177-180) Such methods in combination with the tools of other fields (vide infra) will provide the means to probe and to understand microbiomes.

Key tools for the microbiome will need to be miniaturized and made parallel. These developments will leverage decades of work in nanotechnology in the areas of nanofabrication,(181) imaging systems,(182, 183) lab-on-a-chip systems,(184) control of biological interfaces,(185) and more. Commercialized and commoditized tools, such as smart phone cameras, can also be adapted for use (vide infra). By guiding the development and parallelization of these tools, increasingly complex microbiomes will be opened for study.(167)

Imaging and sensing, in general, have been enjoying a Renaissance over the past decades, and there are various powerful measurement techniques that are currently available, making the Microbiome Initiative timely and exciting from the broad perspective of advanced analysis techniques. Recent advances in various -omics technologies, electron microscopy, optical microscopy/nanoscopy and spectroscopy, cytometry, mass spectroscopy, atomic force microscopy, nuclear imaging, and other techniques, create unique opportunities for researchers to investigate a wide range of questions related to microbiome interactions, function, and diversity. We anticipate that some of these advanced imaging, spectroscopy, and sensing techniques, coupled with big data analytics, will be used to create multimodal and integrated smart systems that can shed light onto some of the most important needs in microbiome research, including (1) analyzing microbial interactions specifically and sensitively at the relevant spatial and temporal scales; (2) determining and analyzing the diversity covered by the microbial genome, transcriptome, proteome, and metabolome; (3) managing and manipulating microbiomes to probe their function, evaluating the impact of interventions and ultimately harnessing their activities; and (4) helping us identify and track microbial dark matter (referring to 99% of micro-organisms that cannot be cultured).

In this broad quest for creating next-generation imaging and sensing instrumentation to address the needs and challenges of microbiome-related research activities comprehensively, there are important issues that need to be considered, as discussed below.

The piece is extensive and quite interesting, if you have the time.

Safety mechanisms needed before synthetic biology moves from the labs into the real world

A Sept. 17, 2015 news item on Nanotechnology Now makes note of an article where experts review the state of the synthetic biology field and discuss the need for safety as synthetic biology is poised to move from the laboratory into the real world,

Targeted cancer treatments, toxicity sensors and living factories: synthetic biology has the potential to revolutionize science and medicine. But before the technology is ready for real-world applications, more attention needs to be paid to its safety and stability, say experts in a review article published in Current Opinion in Chemical Biology.

Synthetic biology involves engineering microbes like bacteria to program them to behave in certain ways. For example, bacteria can be engineered to glow when they detect certain molecules, and can be turned into tiny factories to produce chemicals.

Synthetic biology has now reached a stage where it’s ready to move out of the lab and into the real world, to be used in patients and in the field. According to Professor Pamela Silver, one of the authors of the article from Harvard Medical School in the US, this move means researchers should increase focus on the safety of engineered microbes in biological systems like the human body.

A Sept. 16, 2015 Elsevier press release, which originated the news item, expands on the theme,

“Historically, molecular biologists engineered microbes as industrial organisms to produce different molecules,” said Professor Silver. “The more we discovered about microbes, the easier it was to program them. We’ve now reached a very exciting phase in synthetic biology where we’re ready to apply what we’ve developed in the real world, and this is where safety is vital.”

Microbes have an impact on health; the way they interact with animals is being ever more revealed by microbiome research – studies on all the microbes that live in the body – and this is making them easier and faster to engineer. Scientists are now able to synthesize whole genomes, making it technically possible to build a microbe from scratch.

“Ultimately, this is the future – this will be the way we program microbes and other cell types,” said Dr. Silver. “Microbes have small genomes, so they’re not too complex to build from scratch. That gives us huge opportunities to design them to do specific jobs, and we can also program in safety mechanisms.”

One of the big safety issues associated with engineering microbial genomes is the transfer of their genes to wild microbes. Microbes are able to transfer segments of their DNA during reproduction, which leads to genetic evolution. One key challenge associated with synthetic biology is preventing this transfer between the engineered genome and wild microbial genomes.

There are already several levels of safety infrastructure in place to ensure no unethical research is done, and the kinds of organisms that are allowed in laboratories. The focus now, according to Dr. Silver, is on technology to ensure safety. When scientists build synthetic microbes, they can program in mechanisms called kill switches that cause the microbes to self-destruct if their environment changes in certain ways.

Microbial sensors and drug delivery systems can be shown to work in the lab, but researchers are not yet sure how they will function in a human body or a large-scale bioreactor. Engineered organisms have huge potential, but they will only be useful if proven to be reliable, predictable, and cost effective. Today, engineered bacteria are already in clinical trials for cancer, and this is just the beginning, says Dr. Silver.

“The rate at which this field is moving forward is incredible. I don’t know what happened – maybe it’s the media coverage, maybe the charisma – but we’re on the verge of something very exciting. Once we’ve figured out how to make genomes more quickly and easily, synthetic biology will change the way we work as researchers, and even the way we treat diseases.”

Lucy Goodchild van Hilten has written a Sept. 16, 2015 article for Elsevier abut this paper,

In January, the UK government announced a funding injection of £40 million to boost synthetic biology research, adding three new Synthetic Biology Research Centres (SBRCs) in Manchester, Edinburgh and Warwick. The additional funding takes the UK’s total public spending on synthetic biology to £200 million – an investment that hints at the commercial potential of synthetic biology.

In fact, according to the authors of a new review published in Current Opinion in Chemical Biology, synthetic biology has the potential to revolutionize science and medicine. …

Here’s a link to and a citation for the paper,

Synthetic biology expands chemical control of microorganisms by Tyler J Ford, Pamela A Silver. Current Opinion in Chemical Biology Volume 28, October 2015, Pages 20–28  doi:10.1016/j.cbpa.2015.05.012

I believe this paper is open access until January 16, 2016.

As the paper has a nice introductory description of synthetic biology, I thought I’d include it here, as well as, the conclusion which is not as safety-oriented as I expected,

Synthetic biology allows scientists to re-program interactions between genes, proteins, and small molecules. One of the goals of synthetic biology is to produce organisms that predictably carry out desired functions and thereby perform as well-controlled so-called biological devices. Together, synthetic and chemical biology can provide increased control over biological systems by changing the ways these systems respond to and produce chemical stimuli. Sensors, which detect small molecules and direct later cellular function, provide the basis for chemical control over biological systems. The techniques of synthetic biology and metabolic engineering can link sensors to metabolic processes and proteins with many different activities. In this review we stratify the activities affected by sensors to three different levels: sensor-reporters that provide a simple read-out of small molecule levels, sensor-effectors that alter the behavior of single organisms in response to small molecules, and sensor effectors that coordinate the activities of multiple organisms in response to small molecules …

Conclusion

We have come to the point in synthetic biology where there are many lab-scale or proof-of-concept examples of chemically controlled systems useful to sense small molecules, treat disease, and produce commercially useful compounds. These systems have great potential, but more attention needs to be paid to their stability, efficacy, and safety. Being that the sensor-effectors discussed above function in living, evolving organisms, it is unclear how well they will retain function when distributed in a patient or in a large-scale bioreactor. Future efforts should focus on developing these sensor-effectors for real-world application. Engineered organisms will only be useful if we can prove that their functions are reliable, predictable, and cost effective.