Carbon Sequestration using anaerobic microbial populations is being explored to discover new energy resources. The section is focused on identifying novel energy producing microorganisms from deep-sea sediments that are characterized by an environment that is devoid of sunlight, has low temperature and is carbon dioxide rich. The section is determining optimum culturing conditions, to mimic the natural microbial environment, as well develop new methodologies for the isolation and propagation of novel microbes that may lead to the discovery of new carbon fixation pathways. The sections bioanalytical techniques used to investigate microbial carbon sequestration includes a carbon analysis facility. A union to the stable and radiocarbon isotope analyses is the capability to measure carbon concentrations in a variety of matrices. The laboratory contains state-of-the-art instrumentation for analysis of dissolved and particulate organic and inorganic carbon pools, extraction of individual compounds, carbon gases, and mass spectroscopy for specific organic compounds.
CO2 Distillation System
GC-combustion interface to IRMS
Culturing the Unculturables
Culturing the unculturables for discovery of energy producing unique microorganisms from non-photosynthetic, cold, and carbon dioxide-rich environments. An increasing number of diverse metabolically intriguing microorganisms have been discovered from various environments by next generation sequencing analysis, however 99% of those microorganisms are still unculturable. The marine dark biosphere (MDB) is a unique environment due to the complete isolation from light sources, which makes MDB a great untapped resource for discovery of new microbial processes including new non-photosynthetic carbon fixation pathways, new anti-microbial molecules, new energy sources, and other beneficial traits. In our group, we are utilizing various culturing techniques (i.e., high throughput screening) to isolate and characterize the unculturables. Utilizing the analytical capabilities of our section we use a dual mass spectrometer system with a gas chromatograph, an ion trap mass spectrometer, an isotope ratio mass spectrometer, and a purge and trap system to provide simultaneous measurements of selected chemical species and stable carbon and nitrogen isotope values to design media compositions which mimic the native environments for microbial growth.
Identification of new Streptomyces sp. which has antimicrobial activity and potentially unique secondary metabolites. Plate on the left is the control, top right was incubated at 30°C and bottom right at 25°C.
Biopapers are thin polymer/hydrogel scaffold sheets which act as substrates for cell and biofactor printing. The patented NRL technique uses these biopapers as mechanically stable sheets to be used in a cell printing apparatus. Each polymer sheet can be addressed with different growth factors and then loaded into a cell printer for patterned cell seeding. After printing, the biopapers can be cultured to achieve the desired level of cell differentiation (e.g., vasculature formation) and/or tissue formation. They are strong enough that they can then be physically stacked into three dimensional structures. By printing multiple cell types in a defined pattern on each sheet, culturing, and then stacking the sheets, these biopapers can be used to enable heterogeneous tissue structures to be created in 3D including structures needed for prevascularization of tissue constructs and unique, high resolution, in vitro 3D cell culture models.
Biological-based inks, or bioinks, are biomaterials used for the fabrication of 3D bioprinted tissue engineering constructs (TECs) which support cells dispersed within them. Bioinks may consist of natural or synthetic materials and biomolecules which are able to generate precise 3D spatial features with high resolution when printed in order to closely mimic tissue in vivo. Bioinks are vital for not only the transportation of cells, but also for providing essential cues and guidance to the cells to promote morphogenesis, proliferation and differentiation. Bioinks must be biocompatible and maintain their shape and structural integrity through crosslinking in order to fabricate complex TECs. Tunability of the bioink in regards to composition and viscosity is essential due to the various bioprinting requirements and complex compositions of the targeted tissue. The development of novel bioinks for the use in laser-based 3D printing will advance the field of 3D bioprinting.
Biological Laser Printer
Biological laser printer, or BioLP, a non-contact, orifice-free bioprinter with the demonstrated ability to create micron-scale patterns of living mammalian cells and biomaterials. 3D cellular patterns can be routinely created with single-cell resolution and no deleterious effects to the printed cells. These technologies have direct application to tissue engineering by enabling the direct and controlled deposition of living mammalian cells in both 2D and 3D patterns with micron-scale resolution, opening the possibility to bio-fabricate tissue and cellular structures at the scale of nature. BioLP uses a thin laser absorption layer (usually nm-scale thickness of titanium or titania) to optimize the printing process. This improves the spot-to-spot reproducibility of the printer while protecting the bioink from potentially damaging UV laser light.
Bioreactor design is critical to appropriately link cell-laden 3D biopaper substrates to relevant tissue culture environments in vitro. Achieving this requires implementing computer aided design (CAD) with the desired geometry and features to create a prototype that optimally accommodates the biopaper while under perfusion. A stereolithography additive manufacturing process uses ultraviolet light to construct high-resolution polymeric 3D bioreactors with micro-scaled features from the digital CAD models. The product design complimented with biopaper scaffolds provide a scalable testbed containing in vitro complex, pre-vascularized 3D heterogeneous tissue models aimed to mimic native structures of interest. This research paradigm enables more comprehensive characterization and analysis to better understand biological processes relevant in tissue engineering and drug discovery.
Chronic wounds are a significant cause of patient morbidity and mortality in the United States. These wounds continue to be a burden on healthcare because of their complex composition in terms of bacterial infection. As such, it is important to develop strategies to examine the composition of chronic wounds in order to develop therapeutics. Accordingly, current research in the Section is focused on using microdissection and biological laser printing (BioLP) technologies in order to delineate the X-Y-Z spatial composition of wounds. Specifically, these strategies will allow for the understanding of the bacterial species and bacterial and host secreted proteins and metabolites that exist in human epidermal wound tissue.