Microbial colonization and persistence in deep fractured shales is guided by metabolic exchanges and viral predation

Background Microbial colonization of subsurface shales following hydraulic fracturing offers the opportunity to study coupled biotic and abiotic factors that impact microbial persistence in engineered deep subsurface ecosystems. Shale formations underly much of the continental USA and display geographically distinct gradients in temperature and salinity. Complementing studies performed in eastern USA shales that contain brine-like fluids, here we coupled metagenomic and metabolomic approaches to develop the first genome-level insights into ecosystem colonization and microbial community interactions in a lower-salinity, but high-temperature western USA shale formation. Results We collected materials used during the hydraulic fracturing process (i.e., chemicals, drill muds) paired with temporal sampling of water produced from three different hydraulically fractured wells in the STACK (Sooner Trend Anadarko Basin, Canadian and Kingfisher) shale play in OK, USA. Relative to other shale formations, our metagenomic and metabolomic analyses revealed an expanded taxonomic and metabolic diversity of microorganisms that colonize and persist in fractured shales. Importantly, temporal sampling across all three hydraulic fracturing wells traced the degradation of complex polymers from the hydraulic fracturing process to the production and consumption of organic acids that support sulfate- and thiosulfate-reducing bacteria. Furthermore, we identified 5587 viral genomes and linked many of these to the dominant, colonizing microorganisms, demonstrating the key role that viral predation plays in community dynamics within this closed, engineered system. Lastly, top-side audit sampling of different source materials enabled genome-resolved source tracking, revealing the likely sources of many key colonizing and persisting taxa in these ecosystems. Conclusions These findings highlight the importance of resource utilization and resistance to viral predation as key traits that enable specific microbial taxa to persist across fractured shale ecosystems. We also demonstrate the importance of materials used in the hydraulic fracturing process as both a source of persisting shale microorganisms and organic substrates that likely aid in sustaining the microbial community. Moreover, we showed that different physicochemical conditions (i.e., salinity, temperature) can influence the composition and functional potential of persisting microbial communities in shale ecosystems. Together, these results expand our knowledge of microbial life in deep subsurface shales and have important ramifications for management and treatment of microbial biomass in hydraulically fractured wells.

Diet Rather than Genetic Status Shapes the Gut Microbiota in Two Congeneric Snakes

Background: Various external and internal factors affect the gut microbiota of animals. The colonization and proliferation of gut microbes have been studied in a diverse array of animal taxa but remain poorly known in snakes. Here, we used the 16S rRNA gene sequencing technology on the Roach 454 platform to analyze the gut microbiota composition using fecal samples collected from three snake groups [gravid females, newly hatched (preprandial) hatchlings and postprandial hatchlings] of two congeneric colubrid snake species (Elaphe carinata and E. taeniura) that are sympatric across a wide range in mainland China. We tested two hypotheses. First, the gut microbiota should not differ between the two species at hatching if the maternal or genetic contribution has no role in affecting post-hatching gut microbial colonization. Second, differences in the gut microbiota between newly hatched (preprandial) and postprandial hatchlings should not exist in both species if the dietary contribution has no role in affecting post-hatching gut microbial colonization.Results: The top three dominant phyla were Firmicutes, Bacteroidetes, and Proteobacteria in both species. None of the measured alpha diversity indexes differed among the three snake groups or between the two species. The relative abundance of the gut microbiota differed among the three snake groups and between the two species, and so did the relative abundances of the functions associated with the metabolism, cellular processes and environmental information processing. Evidence from gravid females and hatchlings showed that the gut microbiota composition was similar between the two species. The metabolism held the overwhelming predominance of functional categories at the top level in both species.Conclusion: Only the relative abundance of the gut microbiota differed between the two species, and the gut microbiota composition changed rapidly in postprandial hatchlings and differed among the three snakes groups in both species. From these findings, we may conclude that the dietary rather than the maternal or genetic contribution affects gut microbial colonization in snakes.

Recent progress in Tannic Acid-driven antimicrobial/antifouling surface coating strategies

Medical devices and surgical implants are a necessary part of tissue engineering and regenerative medicines. However, the biofouling and microbial colonization on the implant surface continues to be a major...

Effect of light-converting coatings on the growth of Sarepta mustard (Brassica juncea L.) plants colonized by associative microorganisms

The effect of colonization by beneficial associative microorganisms Pseudomonas putida KT 2442 and Rhodococcus erythropolis X5 on the growth of Sarepta mustard (Brassica juncea L.) under a covering light-converting material containing organic photoluminophore, in vitro and in vivo, was investigated. The combined use of microbial colonization and photoluminophore coating led to stimulation of plant growth much stronger (2.4 times more) than separately only photoluminophoric coating (1.3 times) or colonization (2.1 times). These data indicate that when covering materials with photoluminophores are used in agrobiotechnologies, luminescent red light (610-730 nm) induces an increase in biochemical processes not only in plants, but also in microorganisms that supply plants with growth regulators and other useful metabolites. The data obtained are relevant for further study of the photobiological mechanisms of interactions between the plant-microorganism system in agrobiotechnologies.

The Role of Dietary Fats in the Development and Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a significant cause of mortality and morbidity in preterm infants. The pathogenesis of NEC is not completely understood; however, intestinal immaturity and excessive immunoreactivity of intestinal mucosa to intraluminal microbes and nutrients appear to have critical roles. Dietary fats are not only the main source of energy for preterm infants, but also exert potent effects on intestinal development, intestinal microbial colonization, immune function, and inflammatory response. Preterm infants have a relatively low capacity to digest and absorb triglyceride fat. Fat may thereby accumulate in the ileum and contribute to the development of NEC by inducing oxidative stress and inflammation. Some fat components, such as long-chain polyunsaturated fatty acids (LC-PUFAs), also exert immunomodulatory roles during the early postnatal period when the immune system is rapidly developing. LC-PUFAs may have the ability to modulate the inflammatory process of NEC, particularly when the balance between n3 and n6 LC-PUFAs derivatives is maintained. Supplementation with n3 LC-PUFAs alone may have limited effect on NEC prevention. In this review, we describe how various fatty acids play different roles in the pathogenesis of NEC in preterm infants.

The Role of Adequate Nutrition on Early Stages of Child Development. New Aspects of Goat Milk-Based Infant Formulas Implementation

The early stages of child development are characterized by various processes of maturation such as brain growth and development. The digestive and immune systems are developing as well at the same time. The intestinal microbiota plays significant role in the development of all organs and systems. Various disorders of microbial colonization of digestive system can negatively affect food programming processes. Nutrition type (breastfeeding or artificial) also has its own noticeable effect on early development. Breastfeeding is the “gold standard” in children’s nutrition. Modern approaches on creation of adapted formulas based on goat’s milk allow to develop its optimal composition (protein fraction for easy digestion, -palmitate, oligosaccharides, and natural nucleotides) that has positive effect on the child’s development.

Early Influences of Microbiota on White Matter Development in Germ-Free Piglets

Abnormalities in the prefrontal cortex (PFC), as well as the underlying white matter (WM) tracts, lie at the intersection of many neurodevelopmental disorders. The influence of microorganisms on brain development has recently been brought into the clinical and research spotlight as alterations in commensal microbiota are implicated in such disorders, including autism spectrum disorders, schizophrenia, depression, and anxiety via the gut-brain axis. In addition, gut dysbiosis is common in preterm birth patients who often display diffuse WM injury and delayed WM maturation in critical tracts including those within the PFC and corpus callosum. Microbial colonization of the gut aligns with ongoing postnatal processes of oligodendrogenesis and the peak of brain myelination in humans; however, the influence of microbiota on gyral WM development remains elusive. Here, we develop and validate a neonatal germ-free swine model to address these issues, as piglets share key similarities in WM volume, developmental trajectories, and distribution to humans. We find significant region-specific reductions, and sexually dimorphic trends, in WM volume, oligodendrogenesis, and mature oligodendrocyte numbers in germ-free piglets during a key postnatal epoch of myelination. Our findings indicate that microbiota plays a critical role in promoting WM development during early life when the brain is vulnerable to environmental insults that can result in an array of disabilities manifesting later in life.

From Intrauterine to Extrauterine Life—The Role of Endogenous and Exogenous Factors in the Regulation of the Intestinal Microbiota Community and Gut Maturation in Early Life

Differentiation of the digestive tube and formation of the gut unit as a whole, are regulated by environmental factors through epigenetic modifications which enhance cellular plasticity. The critical period of DNA imprinting lasts from conception until approximately the 1,000th day of human life. During pregnancy, besides agents that may directly promote epigenetic programming (e.g., folate, zinc, and choline supplementation), some factors (e.g., antibiotic use, dietary components) can affect the composition of the mother's microbiota, in turn affecting the fetal microbiome which interacts with the offspring's intestinal epithelial cells. According to available literature that confirms intrauterine microbial colonization, the impact of the microbiome and its metabolites on the genome seems to be key in fetal development, including functional gut maturation and the general health status of the offspring, as well as later on in life. Although the origin of the fetal microbiome is still not well-understood, the bacteria may originate from both the vagina, as the baby is born, as well as from the maternal oral cavity/gut, through the bloodstream. Moreover, the composition of the fetal gut microbiota varies depending on gestational age, which in turn possibly affects the regulation of the immune system at the barrier between mother and fetus, leading to differences in the ability of microorganisms to access and survive in the fetal environment. One of the most important local functions of the gut microbiota during the prenatal period is their exposure to foreign antigens which in turn contributes to immune system and tissue development, including fetal intestinal Innate Lymphoid Cells (ILCs). Additional factors that determine further infant microbiome development include whether the infant is born premature or at term, the method of delivery, maternal antibiotic use, and the composition of the mother's milk, among others. However, the latest findings highlight the fact that a more diverse infant gut microbiome at birth facilitates the proliferation of stem cells by microbial metabolites and accelerates infant development. This phenomenon confirms the unique role of microbiome. This review emphasizes the crucial perinatal and postnatal factors that may influence fetal and neonatal microbiota, and in turn gut maturation.

Successional Stages in Infant Gut Microbiota Maturation

After birth, microbial colonization of the infant intestinal tract is important for health later in life. However, this initial process is highly dynamic and influenced by many factors.