Students design and conduct experiments to determine what environmental factors favor decomposition by soil microbes. They use chunks of carrots for the materials to be decomposed, and their experiments are carried out in plastic bags filled with dirt. Every few days students remove the carrots from the dirt and weigh them. Depending on the experimental conditions, after a few weeks most of the carrots will have decomposed completely.

This video segment adapted from A Science Odyssey tells the story of researcher Sir Alexander Fleming, whose luck and scientific reasoning led to the groundbreaking discovery of penicillin.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Microbial interactions play a crucial role in the functioning and biogeochemical cycling of Earth's ecosystem. But these connections are highly dynamic and poorly understood. A clear picture of how microbes interact over time could help gain insight into processes that influence nutrient cycling, productivity, and the overall health of marine ecosystems. Researchers investigated microbial dynamics in the Mediterranean Sea on a monthly basis over 10 years. To pinpoint persistent, seasonal, and temporary microbial associations, the researchers identified a temporal network capturing the interactomes of each sample. This network followed an annual cycle that collapsed and reassembled with changes in water temperature. And microbial associations were more repeatable in colder versus warmer months. However, only 16 associations could be validated in the literature, underlining a serious knowledge gap in marine microbial ecological interactions..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Dimethyl sulfide (DMS) is a gas produced by bacteria and algae that gives the ocean its distinctive scent. It also plays an important role in cloud formation, leading scientists to think its production may be instrumental in regulating climate change. But sea ice melt in the polar oceans under global warming has led to a reduction in DMS production, which may further intensify climate warming. To gain a better understanding of how bacteria contribute to DMS production, scientists recently investigated the distribution of bacterial genes involved in DMS cycling in seawater samples collected from around the world. They found evidence that intense DMS cycling facilitated predominantly by Alphaproteobacteria and Gammaproteobacteria occurs in the Arctic and Antarctic oceans, with high involvement of the enzymes DMSP demethylase, DMSP lyases, and trimethylamine monooxygenase..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This lab will reinforce the experimental design process while also learning about nanomaterials such as colloidal silver.  

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Nitrogen is vital to aquatic ecosystems. But too much nitrogen, which can build up from fertilizer use or wastewater discharge, can be deadly. A recent study examined how two groups of nitrogen-removing bacteria interact in the hopes of discovering a synergy that can help remediate over-nitrified lakes. The two groups consisted of anammox bacteria, which feed on ammonium and release nitrogen gas and denitrifying bacteria, which do the same but feed on nitrates instead. Researchers locked the bacteria in bioreactors and monitored their activity for over a year as they fed on sediments from a nitrogen-rich lake. Findings revealed high nitrogen removal efficiencies of up to 86% for ammonium and 95% for nitrites with denitrifying and anammox bacteria showing signs of cooperation. For example, certain denitrifiers may provide amino acids and vitamins that support anammox bacteria..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Staphylococcus aureus is a common commensal that can cause an array of serious human diseases, from mild skin infection to life-threatening disease. S. aureus can rapidly adapt to selective pressures such as antibiotics, and this ability is enhanced by biofilm formation on implanted medical devices. With antibiotic resistance on the rise, there is a growing need to find non-antibiotic alternatives to treat serious infections. One such alternative is bacteriophage therapy, which introduces viruses that selectively infect and kill bacteria. A recent study sought to better understand the impact of bacteriophage therapy on the host microbiome. In a follow-up to a case study of a patient with an implanted cardiac device who was treated with bacteriophage therapy combined with antibiotics for a persistent S. aureus infection, researchers used high-throughput sequencing to evaluate patient microbial samples from the gut, saliva, and skin..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"All living things need phosphorus to survive. However, its low availability in soil is often a limiting factor for plant and microbial growth. Microorganisms in the plant root-soil interface (rhizosphere) can convert non-labile phosphorus into bioavailable forms. One way microbes do this is the mineralization of organic phosphorus compounds like phytate. Rising atmospheric CO₂ levels may accelerate mineralization, but the molecular mechanisms are not yet understood. Recent research confirmed that elevated CO₂ (eCO₂) increased the mineralization of phytate in the rhizosphere of wheat. Tracing the carbon flow showed that plants grown under eCO₂ increased the release of bioavailable carbon belowground, which corresponded to increased microbial growth and altered community composition. The bacterial community under eCO₂ favored groups of bacteria capable of degrading aromatic phosphorus compounds and the mycorrhizal fungi benefited from the increased supply of phosphorus and carbon..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"The symbiotic microbial community that many animals have floating freely in their gut is critical to their health and well-being. But some insects, like cereal weevils, take this a step further and host bacteria inside their own cells. These endosymbiotic bacteria reside in massive, specialized cells organized in an organ called the bacteriome. Previous studies have suggested that the cereal weevil bacteriome participates in immune responses. But how, or if, the bacteriome protects its resident bacteria from that immune activity remains unclear. To answer this, researchers activated the cereal weevil innate immune system with pathogen protein fragments and examined the gene expression changes in the bacteriome and its residents. Rather than differentiate between pathogens and symbionts, the cereal weevils protected their endosymbionts with physical separation..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"The characteristics of the world around us vary from one location to the next. This is also true of aquatic environments, where bottom-dwelling microorganisms must cope with variation in temperature, salinity, dissolved oxygen, and nutrients. Unfortunately, little is known about how these microbial communities and their functional genes respond to environmental changes. A team of researchers at Stockholm University recently set out to do just that by collecting samples of sediment at 59 sites spanning 1,145 km across the Baltic Sea. They characterized the environmental attributes and microbial community at each site using genetic sequencing and other laboratory techniques. The researchers found that salinity and dissolved oxygen content had the greatest effects on the microbes making up each community with the communities in oxygen-deficient “dead” zones being particularly dissimilar to those with higher dissolved oxygen content..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Researchers at the RIKEN Center for Sustainable Resource Science have developed a new genetic pathway that can be used to co-opt E. coli bacteria to produce maleate, one of the most important industrial chemicals in use today. A chief component in the coatings of substances like nylon and galvanized steel and an important stabilizing agent in pharmaceuticals, maleate is typically produced through harsh treatments of crude oil. But by using genetically engineered microorganisms to produce maleate, the researchers have developed a much more sustainable approach. Maleate is the end product of a complex chemical reaction. Bacteria don’t normally come equipped with machinery to power this reaction, so the researchers had to design a ground-up approach before they could start harvesting maleate. This required careful analysis of the intermediates needed for maleate synthesis and the identification of genes that could help E. coli make each of these molecules..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Genetic and molecular differences in individual bacterial strains of the gut microbiome may affect health outcomes, including aging, in humans. However, the details and effects of host-microbe co-evolution remain unclear. To obtain insights, a recent study investigated Bifidobacterium longum, a key long-term member of the human gut microbiome that has also been linked to aging. Population genomics analyses of 418 human gut strains revealed three geographic populations of B. longum, with differences in cell wall synthesis genes and carbohydrate metabolism genes. B. longum was actively transmitted between individuals, families, and regions, but a single clone tended to colonize each host. B. longum relative abundance declined with host age, while certain genotype features, such as a sequence variant in the B. longum arginine biosynthesis pathway, were positively related to age. In mice, B..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Drinking water is essential for life, but drinking water distribution systems can contain hidden ecosystems. Complex microbial communities reside in water and the systems used for water storage and distribution. To manage these microbes and keep drinking water safe, water treatment plants often use disinfectants like chlorine. Unfortunately, disinfectants may affect the safety of drinking water by potentially boosting the formation of harmful disinfection byproducts. A recent study assessed the effect of disinfection treatment on microbial communities in drinking water. Using metagenomics, researchers compared the microbiomes of disinfected and non-disinfected drinking water distribution systems. The results suggested that disinfected drinking water contains a less diverse microbiome than non-disinfected water, and disinfection may select for microorganisms that can feed off of decaying microbes..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

In this class, students engage in independent research projects to probe various aspects of the physiology of the bacterium Pseudomonas aeruginosa PA14, an opportunistic pathogen isolated from the lungs of cystic fibrosis patients. Students use molecular genetics to examine survival in stationary phase, antibiotic resistance, phase variation, toxin production, and secondary metabolite production.
Projects aim to discover the molecular basis for these processes using both classical and cutting-edge techniques. These include plasmid manipulation, genetic complementation, mutagenesis, PCR, DNA sequencing, enzyme assays, and gene expression studies. Instruction and practice in written and oral communication are also emphasized.
WARNING NOTICE
The experiments described in these materials are potentially hazardous and require a high level of safety training, special facilities and equipment, and supervision by appropriate individuals. You bear the sole responsibility, liability, and risk for the implementation of such safety procedures and measures. MIT shall have no responsibility, liability, or risk for the content or implementation of any of the material presented.
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This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"The blood-feeding kissing bugs are the vector for Trypansoma cruzi, the parasite that causes Chagas disease in humans. One factor believed to alter parasite transmission is the kissing bug’s microbiome, which is a fundamental component of natural gut environment where T.cruzi develops. To explore this complex environment, researchers set out to identify the factors that shape the kissing bug's microbiome. They investigated the microbiome composition of 5 species of kissing bugs from two U.S. states across all life stages. They analysed 170 T. cruzi negative kissing bugs sampled from the nests of white-throated woodrats. The primary factors determining microbiome structure were developmental stage, species identity, and environment. Later developmental stages correlated with lower microbial diversity. In fact, adult microbiomes were frequently dominated by a single taxon of bacteria..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Managing wastewater is a major logistical puzzle that impacts the environment, the climate, and public health. While metropolitan wastewater typically undergoes complex processing and sanitation, rural livestock wastewater is often simply composted for fertilizer, but composting can release harmful contaminants like ammonia, CO₂, and methane. One way to still capture the nutrients with fewer harmful byproducts is by cultivating microalgae, which actually absorb CO₂ via photosynthesis rather than producing it. But how do microalgae impact pathogens? A recent pilot study using raw piggery wastewater found that microalgae cultivation dramatically reduced the pathogen load while also triggering a dramatic shift in the overall bacterial community composition. Further investigation using the most abundant pathogen, Oligella, found that the microalgae weren’t impacting Oligella directly. Rather, microalgae cultivation reduced Oligella abundance through a network of other bacterial species..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Ruminants’ ability to break down human-inedible plant fibers stems from the microbes in their rumen. This process is primarily driven by microbes that can ferment plant fibers into volatile fatty acids (VFAs), followed by the rumen epithelial layer absorbing and partially metabolizing these VFAs. Recently, researchers examined how microbes and epithelial cells interact and contribute to VFA metabolism in lactating dairy cows. Metagenomic binning allowed researchers to categorize and examine the metabolic capacity of even uncultivated microbes and identify bacterial genomes with both cellulose/xylan/pectin degradation capabilities and associations with VFA biosynthesis. They then used gene expression data to construct a single-cell map of the rumen epithelial cell subtypes. Searching gene expression profiles for VFA transporters highlighted key epithelial cell subtypes. Leveraging this data highlighted interactions where microbes potentially influenced the gene expression of host epithelial cells..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This lesson describes the major components and functions of the immune system and the role of engineers in keeping the body healthy (e.g., vaccinations and antibiotics, among other things). This lesson also discusses how an astronaut's immune system is suppressed during spaceflight due to stress and other environmental factors.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Microorganisms exist in nearly every part of our planet, including areas that can barely support life. The McMurdo Dry Valleys of Antarctica were considered lifeless until microbial communities were found inside porous rocks. Little is known about the evolution, diversity, and genetics of these exclusive cryptoendolithic life-forms. Recently, researchers used sequencing technology to generate microbial metagenomes from Antarctic rocks. They obtained 497 bacterial genomes from 269 previously uncharacterized candidate species. “Candidatus Jiangella antarctica” may be adapted to severe conditions, as it was found in all samples and contained additional genes. Most of the new species diverged from their known relatives 1.2 billion to 410 million years ago, long before the origin of modern Antarctica, and the Antarctic bacteria are functionally distinct from their closest known relatives, suggesting that groups of cold-adapted bacteria arrived when Antarctica became cold, spread, and diversified..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"As global warming persists, it’s becoming clear that even the smallest forms of life need protection, including in the cold deserts of Antarctica. But scientists know very little about the microbes that make their home in Antarctic soil, leaving the picture of biodiversity and ecological change in this region incomplete. Now, researchers from Australia are filling in the blanks. They’ve conducted the first-ever microbial biodiversity report for two Antarctic regions: the extremely dry Vestfold Hills and the Windmill Islands. Bacterial communities in both areas were dominated by microbes of the metabolically and physiologically diverse phylum Actinobacteria, but the Vestfold Hills showed a higher prevalence of members of the Bacteriodetes phylum, likely due to the saltier soils found in this region. Overall, the observed diversity of community members suggests that microbes have found a way to share their environment equitably..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.