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The production, characterization and bioactivities of exopolysaccharides (EPSs) from a thermophilic bacterium Geobacillus sp. strain WSUCF1 were investigated. Using glucose as a carbon source 525.7 mg/L of exoproduct were produced in a 40-L bioreactor at 60 °C. Two purified EPSs were obtained: EPS-1 was a glucomannan containing mannose and glucose in a molar ratio of 1:0.21, while EPS-2 was composed of mannan only. The molecular weights of both EPSs were estimated to be approximately 1000 kDa, their FTIR and NMR spectra indicated the presence of α-type glycosidic bonds in a linear structure, and XRD analysis indicated a low degree of crystallinity of 0.11 (EPS-1) and 0.27 (EPS-2). EPS-1 and EPS-2 demonstrated high degradation temperatures of 319 °C and 314 °C, respectively, and non-cytotoxicity to HEK-293 cells at 2 and 3 mg/mL, respectively. In addition, both showed antioxidant activities. EPSs from strain WSUCF1 may expand the applications of microorganisms isolated from extreme environments and provide a valuable resource for exploitation in biomedical fields such as drug delivery carriers.

A lignocellulolytic and thermophilic bacterium Geobacillus sp. WSUCF1 was investigated for its production of biopolymers (exopolysaccharides, EPSs) using agricultural waste corn stover. The maximum...

Although cyanobacteria are a common group of microorganisms well-suited to utilization in photobioreactors (PBRs), studies of cyanobacteria fouling and its prevention are scarce. Using a cyanobacterium

Adsorption of conditioning films on a solid surface is the first step in the development of biofilms. With the goal of understanding the preliminary adhesion mechanisms of cyanobacteria on photobioreactor (PBR) materials to prevent biofouling, the physical changes occurring on PBR materials were investigated during the initial adhesion and biofilm formation by

Carbon nanofibers (CNFs) and halloysite nanotubes (HNTs) were incorporated in syntactic foams containing a 90% by volume homogeneous mixture of (20/80 wt%) glass/thermoplastic microballoons to enhance the mechanical and impact response properties. Tensile, compressive, and impact tests were employed to comparatively characterize the effect of nano-additive reinforcement on mechanical response properties. Compressive strength and modulus enhancements as large as 39% and 18%, respectively, were achieved with a 0.125 wt% addition of CNF and increases of 61% and 7%, respectively, were achieved with a 0.125 wt% addition of HNT. Tensile strength and modulus enhancements as large as 107% and 68%, respectively, were achieved with a 0.125 wt% addition of CNF and increases of 104% and 70%, respectively, were achieved with a 0.125 wt% addition of HNT. Impact analysis data were used to show that measured peak force increased and build-up time to peak force decreased with increasing CNF or HNT weight percentage due to stiffening of the matrix. The smallest increase observed in peak force was 20% for a 0.125 wt% addition of CNF and 17% for a 0.125 wt% addition of HNT.

The aim of this study was to investigate the effect of atmospheric pressure cold plasma on the microbial substrate utilization and biomass yield in a thermophilic strain. Geobacillus sp. strain WSUCF1, a thermophile capable of producing cellulolytic enzymes with higher activity was used for this investigation. Treatment with cold plasma for 4 min increased the rates of glucose utilization by 74% and biomass yield by 60% when compared with the control. WSUCF1 treated with plasma also displayed enhanced biofilm formation. This study for the first time, reports the use of cold plasma for enhancing the substrate utilization and biofilm formation in a thermophile.

Mechanically flexible electrospun carbon and glass nanofiber mats (i.e., ECNF-mats and EGNF-mats) were prepared by electrospinning followed by thermal treatments; subsequently, a technique was applied to fabricate two types of multi-scale thermoplastic composites, involving infiltration of molten cyclic butylene terephthalate (CBT) followed by in-situ polymerization under compression. For the first composite type, eight conventional carbon fabrics were interleaved with seven ECNF-mats. For the second composite type, eight conventional glass fabrics were interleaved with seven EGNF-mats. Compared to the values acquired from the corresponding control samples without nanofiber mats, the interlaminar shear strength, flexural strength, flexural modulus, and work of fracture acquired from the hybrid multi-scale composite containing ECNF-mats were increased by 32%, 25%, 19%, and 33%, respectively; while the values acquired from the hybrid multi-scale composite containing EGNF-mats were increased by 66%, 43%, 17%, and 64%, respectively. Furthermore, the enhancements of out-of-plane properties were not at the expense of in-plane tensile strength or modulus. The study indicated that the employed fabrication technique could be adopted as an efficient approach to produce polybutylene terephthalate (PBT) thermoplastic composites through in-situ polymerization of CBT oligomer; and the ECNF-mats and EGNF-mats could be utilized as innovative reinforcement fillers for enhancing the performance of structural thermoplastic composites.

Numerous microorganisms inhabiting harsh niches produce exopolysaccharides as a significant strategy to survive in extreme conditions. The exopolysaccharides synthesized by extremophiles possess distinctive characteristics due to the varied harsh environments which stimulate the microorganisms to produce these biopolymers. Despite many bioprocesses have been designed to yield exopolysaccharides, the production of exopolysaccharides by extremophiles is inefficient compared with mesophilic and neutrophilic exopolysaccharide producers. Meanwhile, the industrial development of novel extremophilic exopolysaccharides remains constrained due to the lack of exploration. In this review, we summarize the structure and properties of various exopolysaccharides produced by extremophiles, and also discuss potential metabolic and genetic engineering strategies for enhanced yield and modified structure of extremophilic exopolysaccharides. Special focus is given to the applications of extremophilic exopolysaccharides in the areas of biomedicine, food industry, and biomaterials via nano-techniques, casting and electrospinning.

Methanotrophs have been studied during the last several decades for their capability to assimilate methane, providing new opportunities to realize the concept of a methane-based bio-industry. The biosynthetic process using an inexpensive greenhouse gas (GHG), methane, as a feedstock can bring a sustainable solution for various industries with large, environmental footprints. Methanotrophs are valuable microbial cell factories for bioproducts using methane as the sole carbon and energy sources. Currently, due to the increasing physiological and phylogenetic diversity of methanotrophy, the research has been extended to biopolymers produced by methanotrophs from methane, which hold promise as outstanding alternatives to replace conventional petroleum-derived polymers. In this chapter, an overview of the most recent advances for biopolymer production from methane is provided. Several methanotrophs recently discovered are discussed for their potential in biopolymer synthesis. The state of the art in understanding the mechanisms from methane assimilation to biopolymer production is presented, and several potential designs and engineering strategies for the improvement of methane utilization and biopolymer yields are proposed. Finally, recent progress is discussed concerning biopolymers synthesized as the primary bioproducts by methanotrophs in bioreactors.

Cellulose in its natural form is produced by plants, amoebae, sea animals, fungi, and bacteria. Nanocellulose, with at least one dimension less than 100 nm, has attracted interest due to its unique characteristics such as high surface area to volume ratio, high tensile modulus and strength, low coefficient of thermal expansion, and chemically active surface. In this chapter, we will focus on production methods for bacterial nanocellulose, nanocellulose from plants, and various microscopic and analytical techniques for their characterization. Imaging techniques to characterize the structure of nanocellulose include Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Confocal Laser Scanning Microscopy (CLSM), and Atomic Force Microscopy (AFM). In addition, Analytical techniques for measurement of cellulose crystallinity, including X-Ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR), and Raman spectroscopy, are discussed. The chapter also describes the thermal analysis of bacterial cellulose using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). These techniques can be used to study the structures and properties of nanocellulose and help to identify appropriate applications.

The mimicking of evolution on a laboratory timescale to enhance biocatalyst specificity, substrate utilization activity, and/or product formation, is an effective and well-established approach that does not involve genetic engineering or regulatory details of the microorganism. The present work employed an evolutionary adaptive approach to improve the lignocellulose deconstruction capabilities of the strain by inducing the expression of laccase, a multicopper oxidase, in Geobacillus sp. strain WSUCF1. This bacterium is highly efficient in depolymerizing unprocessed lignocellulose, needing no preprocessing/pretreatment of the biomasses. However, it natively produces low levels of laccase. After 15 rounds of serially adapting this thermophilic strain in the presence of unprocessed corn stover as the selective pressure, we recorded a 20-fold increase in catalytic laccase activity, at 9.23 &plusmn, 0.6 U/mL, in an adapted yet stable strain of Geobacillus sp. WSUCF1, compared with the initial laccase production (0.46 &plusmn, 0.04 U/mL) obtained with the unadapted strain grown on unprocessed corn stover before optimization. Chemical composition analysis demonstrated that lignin removal by the adapted strain was 22 wt.% compared with 6 wt.% removal by the unadapted strain. These results signify a favorable prospect for fast, cost competitive bulk production of this thermostable enzyme. Also, this work has practical importance, as this fast adaptation of the Geobacillus sp. strain WSUCF1 suggests the possibility of growing industrial quantities of Geobacillus sp. strain WSUCF1 cells as biocatalysts on reasonably inexpensive carbon sources for commercial use. This work is the first application of the adaptive laboratory evolution approach for developing the desired phenotype of enhanced ligninolytic capability in any microbial strain.

Syntactic foams comprising glass or thermoplastic microballoons have gained considerable attention in recent years due to mechanical and thermal properties that are advantageous for naval and aerospace applications. This work reports a method for producing syntactic foams with unusually high-volume fraction microballoon loadings (>0.74) and its utilization for the creation of “hybrid” epoxy resin-based syntactic foams comprising various mixtures of glass and thermoplastic microballoons. Microstructural analyses using X-ray micro-computed tomography provided non-destructive quantitative characterization of microballoon packing, confirming the high loading levels suggested by density measurements. By systematically varying the glass/thermoplastic microballoon ratio, it was shown that a range of mechanical properties can be engineered into these lightweight materials. The peak impact force of these syntactic foams can be significantly reduced (∼30% reduction) through combining glass and thermoplastic microballoons in a ratio where the thermoplastic microballoons are the dominant fraction but not the sole microballoon component.

The aim of the present work was to use a thermophilic consortium for H2 production using lignocellulosic biomass in a single pot. The thermophilic consortium, growing at 60 °C utilized both glucose and xylose, making it an ideal source of microbes capable of utilizing and fermenting both hexose and pentose sugars. The optimization of pH, temperature, and substrate concentration increased the H2 production from 1.07 mmol H2/g of prairie cordgrass (PCG) to 2.2 mmol H2/g PCG by using the thermophilic consortium. A sequential cultivation of a thermostable lignocellulolytic enzyme producing strain Geobacillus sp. strain WSUCF1 (aerobic) with the thermophilic consortium (anaerobic) further increased H2 production with PCG 3-fold (3.74 mmol H2/g PCG). A single pot sequential culturing of aerobic and anaerobic microbes can be sustainable and advantageous for industrial scale production of biofuels.

The aim of this work was to study biologically reduced graphene oxide (RGO) for engineering the surface architecture of the bioelectrodes to improve the performance of Bioelectrochemical System (BES). Gluconobacter roseus mediates the reduction of graphene oxide (GO). The RGO modified bioelectrodes produced a current density of 1 mA/cm2 and 0.69 mA/cm2 with ethanol and glucose as substrates, respectively. The current density of RGO modified electrodes was nearly 10-times higher than the controls. This study, for the first time, reports a new strategy to improve the yield as well as efficiency of the BES by wrapping and wiring the electroactive microorganisms to the electrode surfaces using RGO. This innovative wrapping approach will decrease the loss of electrons in the microbe-electrolyte interfaces as well as increase the electron transfer rates at the microorganism-electrode interfaces.

Lattice structural composites are of great interest to various industries where lightweight multifunctionality is important, especially aerospace. However, strong coupling among the composition, microstructure, porous topology, and fabrication of such materials impedes conventional trial-and-error experimental development. In this work, a discontinuous carbon fiber reinforced polymer matrix composite was adopted for structural design. A reliable and robust design approach for developing lightweight multifunctional lattice structural composites was proposed, inspired by biomimetics and based on topology optimization. Three-dimensional periodic lattice blocks were initially designed, inspired by the cuttlefish bone microstructure. The topologies of the three-dimensional periodic blocks were further optimized by computer modeling, and the mechanical properties of the topology optimized lightweight lattice structures were characterized by computer modeling. The lattice structures with optimal performance were identified.

Two different endoxylanase genes of deep biosphere bacteria were cloned and overexpressed in E. coli . Overexpression resulted in 11- and 8-fold improvement in endoxylanase activity of XylSG7 and XylSG13 proteins, respectively. Purified XylSG7 and XylSG13 showed an optimal catalytic temperature of 60 °C and 65 °C, respectively, with a half-life of 20 h under similar operational conditions (60 °C, pH 7.0). The K M value for XylSG7 was 0.2371 mg mL −1 compared to 0.4768 mg mL −1 exhibited by XylSG13 with beechwood xylan. Evaluation of surface characteristics of endoxylanases through Surface Plasmon Resonance highlights a novel approach to characterization of binding prior to covalent immobilization. For improved hydrolysis of corn stover (CS), two enzymatic cocktails were prepared by mixing immobilized XylSG7 and XylSG13 with Cellic® C-Tec2, separately. Application of purified immobilized endoxylanases for CS hydrolysis is a pioneering effort in bioethanol production. Both immobilized endoxylanase were successfully reused up to 4 hydrolysis cycles with a fresh supplement of Cellic® C-Tec2 each time. Kluyveromyces marxianus yeast was selected for its thermotolerant properties, weak glucose repression and ability to metabolize the hemicellulolytic hydrolyzate. A novel high-temperature-high-pressure (HTHP) technique was deployed for maximal utilization of sugars, and enhanced recovery of the produced ethanol, during fermentation. Intermittent use of HTHP simultaneously with the fermentation reaction resulted in 18.2% improved ethanol production over the conventional fermentation process. Simultaneous recovery of ethanol prompted the complete utilization of reducing sugars, compared to a residual concentration of 11.2 g/L observed with a conventional process. These findings are the first to be reported on the application of the HTHP technique for improved ethanol production, and on a highly thermostable endoxylanase showing the lowest K M value to date.

Cellular composites are of significant interest to the materials research community as they often possess multifunctional physical properties. To meet the application requirements, various design and fabrication methods are adopted to produce highly porous composites. In this work, the one-step and two-step approaches for efficient design and prediction of cellular structure's performance were presented for developing ultra-lightweight and high-strength cellular composites reinforced by discontinuous fibers. The topology designs of a 2D honeycomb hexagon model, a 2D cuttlefish model, and a 3D octahedron model, inspired by biomimetics, were presented. Computer modeling based on finite element analysis was conducted on the periodic representative volume elements identified from the cellular structural models to characterize the designed cellular composites' performance and properties. Additive manufacturing technique (3D printing) was used for prototyping the design, and experimental tests were carried out for validating the design methodology.

Syntactic foams comprising glass microballoons have gained considerable attention over the past several years due to mechanical and thermal properties that are advantageous for use as a core material in naval and aerospace applications. Recent advancements in the production of thermoplastic microballoon syntactic foams have allowed for an increase in microballoon volume fraction (up to 0.9 volume fraction), with correspondingly lower densities but reduced mechanical properties. In this work, carbon nanofibers and halloysite nanotubes were incorporated in thermoplastic microballoon-based syntactic foam to enhance the mechanical properties and the relative effects of these two nanoscale reinforcements were compared. X-ray micro-computed tomography was employed to analyze the microstructure of the materials produced, and scanning electron microscopy was used to assess the dispersion of nano-additives within the resin. Compressive strength and modulus enhancements as large as 180% and 250% respectively were achieved with a 0.25 wt% addition of carbon nanofiber and increases of 165% and 244% respectively were achieved with a 0.5 wt% addition of halloysite nanotube. Tensile strength and modulus enhancements as large as 110% and 165% respectively were achieved with a 0.125 wt% addition of carbon nanofiber and increases of 133% and 173% respectively were achieved with a 0.125 wt% addition of halloysite nanotube.

Flexoelectricity is a gradient electromechanical coupling effect that exists in all dielectrics and is important for the understanding of a variety of gradient-induced physical phenomena and the design of new electromechanical devices. At present, the flexoelectric effect in polymer materials has not been well studied. In this work, thick rectangular poly(vinylidene fluoride) (PVDF)-based polymer samples were fabricated and the flexoelectric coefficient was measured. Our results show that the flexoelectric coefficient of the PVDF, which is on the order of several nC/m, is more than twice higher than that of P(VDF-CTFE) and P(VDF-HFP) polymers. All these materials exhibited a non-polar α phase, but the copolymers showed much smaller crystallinity values than the PVDF homopolymer. The difference in the flexoelectric response in these polymers is believed to be related to the crystallinity of the polymers.

Glass microballoon syntactic foams consisting of 60–70 vol% hollow glass microballoons and epoxy resin matrix have gained considerable attention in recent years due to their unique combination of mechanical properties and low density, with applications in the naval and aerospace industries. An important limitation of these materials is the volume fraction ceiling (∼0.74) and subsequent density limit (0.36 g/cm3). Utilizing thermoplastic microballoons, syntactic foams were produced with densities as low as 0.067 g/cm3, achieved by developing a method that produces epoxy/microballoon compositions comprising an unusually high volume fraction of microballoons (0.75–0.95). The resulting morphology features microballoons which, having expanded in a restricted volume, are deformed into irregular shapes that efficiently pack together and are encapsulated by a thin coating of epoxy. The compressive yield strength, tensile strength and initial modulus of these highly loaded syntactic foams exhibit a non-linear decrease with increasing microballoon volume fraction to values typical of highly porous polymers, but display a high degree of recovery, or rebound, from large compressive strain compared with glass microballoon syntactic foams.

Investigations on microbial electrocatalysis as a strategy for enhancing the rates of substrate utilization leading to enhanced yield of biomass and enhanced biofilm formation are reported. A thermophilic Geobacillus sp. strain WSUCF1 (60 °C), a potential lignocellulose degrading microorganism was used as the electrocatalyst. Glucose, cellulose, and corn stover were used as the feedstocks. The results of this investigation showed that applying the oxidation potential of −0.383 mV (vs PRE) increased the glucose utilization and COD removal by 25.5% and 29.7% respectively. The bioelectrocatalysis strategy also increased the biomass yield by 81.2, 42.1, and 49.5% in the case of systems fed with glucose, cellulose, and corn stover, respectively, when compared with the systems without applied oxidation potential. This is the first work reporting the effects of applied oxidation potential on increasing the rates of degradation of lignocellulosic biomass and enhanced biofilm formation.

In the past few years, surface drillings have expanded our perspective of the Earth’s deep biosphere from the terrestrial and oceanic realms to include deep dark subterranean and subseafloor environments. Conditions in the deep biosphere approach the limits for life, but scientific expeditions undertaken for deep subsurface life suggest that these biospheres are hosting a large fraction of microorganisms; living in water, occupying pore space, or colonizing mineral and rock surfaces. Microbes in the deep biosphere are phylogenetically different from most cultured taxa and represent novel microbial assemblages with novel metabolic capabilities. Thus, investigating these subsurface terrains, which are the deepest and potentially the largest accessible ecosystem on Earth, provides a unique opportunity for obtaining direct insights into the deep microscopic world. The insights obtained from deep biosphere expeditions are also likely to facilitate and inform exobiological exploration. This chapter describes current understanding of the subsurface depth and environmental limits of our planet’s life processes and factors that potentially define diversity/distribution of life in the deep terrestrial crustal system. The chapter also highlights the microbiological studies from the selected deep terrestrial biospheres such as hydrothermal vents, oil reservoirs, caves, and subsurface mines.

Electroactive biofilms play a crucial role as bioelectrocatalysts in any Microbial Electrochemical Technology (MET). They help in accelerating the oxidation/reduction reactions and facilitate the direct or mediated electron transfer reactions at electrode–electrolyte interfaces. Approaches such as engineering new MET configurations, substrate type, electrolyte, and electrocatalyst have been investigated to improve the yield of microbial electrocatalysis. However, electroactive biofilms are the key players in microbial electrochemical systems. Hence, biofilm engineering will be a promising strategy to enhance the rates of microbial electrocatalysis, thereby improving the performance of MET. Herein, the basic concepts of electroactive biofilm formation, as well as different strategies for engineering biofilms on electrodes for improving the rates of microbial electrocatalysis, are discussed. This chapter will also address new electrode materials, electrode functionalization techniques, biochemical and genome editing approaches, system biology strategies, and genome to phenome approaches for biofilm engineering and enhanced performance of MET.

Firmicutes is almost a ubiquitous phylum. Several genera of this group, for instance, Geobacillus, are recognized for decomposing plant organic matter and for producing thermostable ligninolytic enzymes. Amplicon sequencing was used in this study to determine the prevalence and genetic diversity of the Firmicutes in two distinctly related environmental samples&mdash, South Dakota Landfill Compost (SDLC, 60 &deg, C), and Sanford Underground Research Facility sediments (SURF, 45 &deg, C). Although distinct microbial community compositions were observed, there was a dominance of Firmicutes in both the SDLC and SURF samples, followed by Proteobacteria. The abundant classes of bacteria in the SDLC site, within the phylum Firmicutes, were Bacilli (83.2%), and Clostridia (2.9%). In comparison, the sample from the SURF mine was dominated by the Clostridia (45.8%) and then Bacilli (20.1%). Within the class Bacilli, the SDLC sample had more diversity (a total of 11 genera with more than 1% operational taxonomic unit, OTU). On the other hand, SURF samples had just three genera, about 1% of the total population: Bacilli, Paenibacillus, and Solibacillus. With specific regard to Geobacillus, it was found to be present at a level of 0.07% and 2.5% in SURF and SDLC, respectively. Subsequently, culture isolations of endospore-forming Firmicutes members from these samples led to the isolation of a total of 117 isolates. According to colony morphologies, and identification based upon 16S rRNA and gyrB gene sequence analysis, we obtained 58 taxonomically distinct strains. Depending on the similarity indexes, a gyrB sequence comparison appeared more useful than 16S rRNA sequence analysis for inferring intra- and some intergeneric relationships between the isolates.

The utilization of lignocellulosic feedstocks is the most promising, sustainable, and eco-friendly approach towards the production of polyhydroxyalkanoate since it entirely avoids the consumption of food crops. The use of these renewable and inexpensive feedstocks can make the production of polyhydroxyalkanoates affordable and facilitate the competitive commercialization of these carbon-neutral bio-based polyesters and their copolymers. Nevertheless, lignocellulosic biomass currently needs pretreatment to realize high sugar yields for the microbes to synthesize the polyhydroxyalkanoates. Steam pretreatment with dilute acids, followed by cellulase enzyme pretreatment, is a relatively practical approach to decompose these rigid biomasses into sugar monomers. However, the cost of commercial cellulase preparations continues to obstruct the large-scale economic conversion of lignocellulosic materials. Development of an eco-friendly consolidated bioprocessing system employing thermophiles for the single-step conversion of lignocellulose to polyhydroxyalkanoate, which excludes pretreatment and enzyme addition steps, and could be operative at low capital investment, would be an important breakthrough for the bioplastic industry. The scope of the present review is to highlight the significant and valuable research and development activities made in recent years to biosynthesize polyhydroxyalkanoates utilizing low-cost lignocellulosic biomass as the potential raw material. The future opportunity for the economical production of polyhydroxyalkanoate through unprocessed lignocellulosic biomass using thermophiles is also discussed.

Thermophiles are promising options to use as electrocatalysts for bioelectrochemical applications including microbial electrolysis. They possess several interesting characteristics such as ability to catalyze a broad range of substrates at better rates and over a broad range of operating conditions, and better electrocatalysis/electrogenic activity over mesophiles. However, a very limited number of investigations have been carried out to explore the microbial reactions/pathways and the molecular mechanisms that contribute to better electrocatalysis/electrolysis in thermophiles. Here, we review the electroactive characteristics of thermophiles, their electron transfer mechanisms, and molecular insights behind the choice of thermophiles for bioelectrochemical/electrolytic processes.

Successful and efficient extraction of high quality, high molecular weight genomic DNA from the environmental samples is an essential primary step to understand the genetic, metabolic and evolutionary characteristics of the microbial communities. Deep mine biofilm samples that contain high amounts of mucoid exopolysaccharide often pose difficulties to obtaining refined community DNA. To circumvent this hindrance, we report our “MINES” method which we developed for optimal biofilm DNA recovery suitable for all types of high-resolution downstream applications. The method is also suitable for samples collected from landfill compost, kitchen digest (KD), and for Gram-positive Geobacillus sp. strain WSUCF1 and Gram-negative E. coli DH5α strains. In one form of the method, use of a gentle preprocessing technique to loosen the mucoid layer, combined with a multi-lytic polyzyme treatment to maximize yields from all cell types in the biofilm sample, yielded >1 μg of high molecular weight DNA (16–20 kb) per gram of the biofilm sample, with an A260/280 and A260/230 ratio of about 2. Furthermore, amplification of 16S rRNA genes as well as restriction digestion with BamHI and HindIII suggest that the newly developed method can minimize any inhibitory effects of contaminants. Results indicate that it is an appropriate methodology for the extraction of total genomic DNA for functional metagenomic studies and may be applicable to other environmental samples from which DNA extraction is challenging. Importance Our present knowledge of microorganisms and their enzymes from deep mine subsurfaces is based largely on laboratory studies of pure microbial cultures. These methods tend only to hit nearly 1% of the entire microbial community. In this regard, metagenomics, has emerged as a strategic approach to explore unculturable microbes through the sequencing and analysis of DNA extracted from the environmental samples. This research paper discusses our “MINES” method for genomic DNA extraction from deep biosphere biofilm samples.

This chapter will introduce the basic concepts of bioelectrocatalysis and the advantages of extremophiles for bioelectrochemical systems. The chapter will discuss electrogenic activity and electron transfer characteristics of extremophiles and their applications in microbial fuel cells, microbial electrolytic cells, microbial desalination cells, and microbial electrosynthesis. The use of extremophilic bioprocesses for production of bioenergy and value-added products from lignocellulosic biomass will also be discussed.

This chapter will provide basic information about consolidated bioprocessing (CBP), including native and recombinant strategies and their application in biofuel production. It will address the integrated CBP process to produce biopolymers (e.g., polyhydroxyalkanoates, extracellular polysaccharides), organic compounds (e.g., 1,3-propanediol), and biogas (methane). The chapter will also discuss the production of biofuels by integrating the CBP process with fuel cells and other bioelectrochemical systems. A detailed discussion will be provided on the thermophilic anaerobic digestion (TAD) process to produce methane from agricultural biomass using thermophilic microorganisms as well as biological oxidation of methane to methanol using methanotrophic bacteria. The chapter will conclude with presenting different approaches in modeling CBP processes for existing applications.

Human waste simulants were for the first time converted into biohydrogen by a newly developed anaerobic microbial consortium via thermophilic consolidated bioprocessing. Four different BioH2-producing consortia (denoted as C1, C2, C3 and C4) were isolated, and developed using human waste simulants as substrate. The thermophilic consortium C3, which contained Thermoanaerobacterium, Caloribacterium, and Caldanaerobius species as the main constituents, showed the highest BioH2 production (3.999 mmol/g) from human waste simulants under optimized conditions (pH 7.0 and 60 °C). The consortium C3 also produced significant amounts of BioH2 (5.732 mmol/g and 2.186 mmol/g) using wastewater and activated sludge, respectively. The developed consortium in this study is a promising candidate for H2 production in space applications as in situ resource utilization.

Sustaining the extra-terrestrial presence of humans in the solar system will require the ability to provide structural, thermal insulation composites (STICs) that have thermal insulation properties in the range of 10–50 mW/m K and mechanical properties at least capable of supporting an anticipated lunar habitat internal pressure of 100 kPa. A technique has been developed which permits the introduction of micro- and nano-scale channels in polymers, in controlled configurations that will allow for optimization of both thermal insulation and mechanical properties. In this approach, conductive heat transfer mechanisms are being limited by the introduction of crisscrossed channel obstacles into an epoxy matrix, which creates a tortuous pathway and inhibits thermal conduction. By varying the volume fraction of micro-channels, control over final density and effective thermal conductivity can be achieved. The micro-channeled materials were created via sacrificial removal of poly(lactic acid) (PLA) fiber networks embedded in a high-temperature epoxy matrix, using either selective thermal degradation or solvation of the thermoplastic fiber. These processes allowed for acceptable rigidity and strength to be retained by the epoxy matrix. Furthermore, it is expected that as channel diameter decreases from micro-scale to nano-scale, gas diffusion will be constrained by the Knudsen effect, since the gas molecules will increasingly collide with the channel wall, and less frequently with each other, as channel diameter becomes comparable to, or smaller than, the molecules׳ mean free path. This effect, which may limit convective heat transfer through the channels, may be augmented by an even higher degree of tortuosity (or pathlength) imposed by the tightly packed nano-channels. In this report, the thermal conductivities of micro-channeled specimens were compared over a range of channel fractions to provide insight into the mechanisms controlling and limiting heat transfer in these systems.