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96-473: The first discovery of valuable mineral deposits at Iron Mountain was by Thomas Jefferson Harrison, Robert Lyon, and Stephan Alozo Meek in 1852. It became known as Pumptown later to be known as Buckeye all three partners sold their claims to Quartz Hill Gold mining company, based in Cook County Illinois , Shasta historical society During its high point over two hundred stamp mills were under production,

192-510: A hydrogel , which is a complex polymer that contains many times its dry weight in water. Biofilms are not just bacterial slime layers but biological systems; the bacteria organize themselves into a coordinated functional community. Biofilms can attach to a surface such as a tooth or rock, and may include a single species or a diverse group of microorganisms. Subpopulations of cells within the biofilm differentiate to perform various activities for motility, matrix production, and sporulation, supporting

288-402: A microbiome or be a portion of it. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium. Biofilms can form on the teeth of most animals as dental plaque , where they may cause tooth decay and gum disease . Microbes form a biofilm in response to

384-583: A biofilm depends highly on the different species present. The EPS matrix consists of exopolysaccharides , proteins and nucleic acids. A large proportion of the EPS is more or less strongly hydrated, however, hydrophobic EPS also occur; one example is cellulose which is produced by a range of microorganisms. This matrix encases the cells within it and facilitates communication among them through biochemical signals as well as gene exchange. The EPS matrix also traps extracellular enzymes and keeps them in close proximity to

480-452: A biofilm depends on competence stimulating peptide (CSP). CSP also functions as a quorum-sensing peptide. It not only induces biofilm formation, but also increases virulence in pneumonia and meningitis. It has been proposed that competence development and biofilm formation is an adaptation of S. pneumoniae to survive the defenses of the host. In particular, the host's polymorphonuclear leukocytes produce an oxidative burst to defend against

576-578: A biofilm exopolysaccharide released immotile aggregates at high initial velocities, enabling the bacteria to recolonize fresh surfaces and cause infections in the hosts efficiently. Hence, biofilm dispersal is more complex than previously thought, where bacterial populations adopting distinct behavior after biofilm departure may be the key to survival of bacterial species and dissemination of diseases. Biofilms are usually found on solid substrates submerged in or exposed to an aqueous solution , although they can form as floating mats on liquid surfaces and also on

672-446: A biofilm is thought to make it harder to treat the infected lungs of people with cystic fibrosis. Early detection of biofilms in wounds is crucial to successful chronic wound management. Although many techniques have developed to identify planktonic bacteria in viable wounds, few have been able to quickly and accurately identify bacterial biofilms. Future studies are needed to find means of identifying and monitoring biofilm colonization at

768-575: A biofilm was recorded after spine surgery. It was found that in the absence of clinical presentation of infection, impregnated bacteria could form a biofilm around an implant, and this biofilm can remain undetected via contemporary diagnostic methods, including swabbing. Implant biofilm is frequently present in "aseptic" pseudarthrosis cases. Furthermore, it has been noted that bacterial biofilms may impair cutaneous wound healing and reduce topical antibacterial efficiency in healing or treating infected skin wounds. The diversity of P. aeruginosa cells within

864-523: A calcified state which is more difficult to remove. Removal techniques can also include antimicrobials . Dental plaque is an oral biofilm that adheres to the teeth and consists of many species of both bacteria and fungi (such as Streptococcus mutans and Candida albicans ), embedded in salivary polymers and microbial extracellular products. The accumulation of microorganisms subjects the teeth and gingival tissues to high concentrations of bacterial metabolites which results in dental disease. Biofilm on

960-503: A commonly used biofilm model organism since it is involved in different types of biofilm-associated chronic infections. Examples of such infections include chronic wounds, chronic otitis media, chronic prostatitis and chronic lung infections in cystic fibrosis (CF) patients. About 80% of CF patients have chronic lung infection, caused mainly by P. aeruginosa growing in a non-surface attached biofilms surround by PMN . The infection remains present despite aggressive antibiotic therapy and

1056-591: A comprehensive assessment of the site and establishing the necessary groundwork for a successful drilling operation. Here's a breakdown of the key aspects involved: Before drilling can begin, a thorough site assessment is conducted to determine the optimal drilling locations. This assessment involves evaluating factors such as the type of material to be drilled, subsurface conditions, potential obstacles (e.g., underground utilities), and structural integrity. This information helps identify suitable areas for drilling that minimize risks and ensure accurate results. Depending on

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1152-537: A form of sexual interaction, favored under conditions of high cell density and/or stress where there is maximal opportunity for interaction between the competent cell and the DNA released from nearby donor cells. This system is optimally expressed when S. mutans cells reside in an actively growing biofilm. Biofilm grown S. mutans cells are genetically transformed at a rate 10- to 600-fold higher than S. mutans growing as free-floating planktonic cells suspended in liquid. When

1248-515: A gold mine in the Witwatersrand, the orebody can be massive similar to the Olympic Dam mine , South Australia, or Cadia-Ridgeway Mine , New South Wales . The width or size of the orebody is determined by the grade as well as the distribution of the ore. The dip of the orebody also has an influence on the mining method for example a narrow horizontal vein orebody will be mined by room and pillar or

1344-407: A highly purified effluent. Slow sand filters are used in water purification for treating raw water to produce a potable product. They work through the formation of a biofilm called the hypogeal layer or Schmutzdecke in the top few millimetres of the fine sand layer. The Schmutzdecke is formed in the first 10–20 days of operation and consists of bacteria , fungi, protozoa , rotifera and

1440-416: A longwall method whereas a vertical narrow vein orebody will be mined by an open stoping or cut and fill method. Further consideration is needed for the strength of the ore as well as the surrounding rock. An orebody hosted in strong self-supporting rock may be mined by an open stoping method and an orebody hosted in poor rock may need to be mined by a cut and fill method where the void is continuously filled as

1536-443: A number of different factors, which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics . A cell that switches to the biofilm mode of growth undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated . A biofilm may also be considered

1632-400: A range of aquatic insect larvae. As an epigeal biofilm ages, more algae tend to develop and larger aquatic organisms may be present including some bryozoa , snails and annelid worms. The surface biofilm is the layer that provides the effective purification in potable water treatment, the underlying sand providing the support medium for this biological treatment layer. As water passes through

1728-412: A reel. In shallower mines the ore is then dumped into a truck to be hauled to the surface. In deeper mines, the ore is dumped down an ore pass (a vertical or near vertical excavation) where it falls to a collection level. On the collection level, it may receive primary crushing by a jaw or cone crusher, or by a rockbreaker . The ore is then moved by conveyor belts , trucks or occasionally trains to

1824-400: A self-produced matrix of extracellular polymeric substances (EPSs) adhere to each other and/or to a surface. A biofilm is a syntrophic community of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within

1920-419: A surface. The first colonist bacteria of a biofilm may adhere to the surface initially by the weak van der Waals forces and hydrophobic effects. If the colonists are not immediately separated from the surface, they can anchor themselves more permanently using cell adhesion structures such as pili . A unique group of Archaea that inhabit anoxic groundwater have similar structures called hami . Each hamus

2016-419: A timeline for the core drilling project is essential for effective project management. This includes setting deadlines, scheduling equipment and personnel, and coordinating with other stakeholders involved in the project. Logistics, such as transportation of equipment and materials to the site, are also planned during this stage. Declines are often started from the side of the high wall of an open cut mine when

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2112-488: Is a common cause of death in CF patients due to constant inflammatory damage to the lungs. In patients with CF, one therapy for treating early biofilm development is to employ DNase to structurally weaken the biofilm. Biofilm formation of P. aeruginosa , along with other bacteria, is found in 90% of chronic wound infections, which leads to poor healing and high cost of treatment estimated at more than US$ 25 billion every year in

2208-563: Is a long tube with three hook attachments that are used to attach to each other or to a surface, enabling a community to develop. Hyperthermophilic archaeon Pyrobaculum calidifontis produce bundling pili which are homologous to the bacterial TasA filaments, a major component of the extracellular matrix in bacterial biofilms, which contribute to biofilm stability. TasA homologs are encoded by many other archaea, suggesting mechanistic similarities and evolutionary connection between bacterial and archaeal biofilms. Hydrophobicity can also affect

2304-470: Is easier for other marine organisms such as barnacles to attach. Such fouling can reduce maximum vessel speed by up to 20%, prolonging voyages and consuming fuel. Time in dry dock for refitting and repainting reduces the productivity of shipping assets, and the useful life of ships is also reduced due to corrosion and mechanical removal (scraping) of marine organisms from ships' hulls. Stromatolites are layered accretionary structures formed in shallow water by

2400-443: Is further broken down into two methods, long hole and short hole. Short hole mining is similar to development mining, except that it occurs in ore. There are several different methods of long hole mining. Typically, long hole mining requires two excavations within the ore at different elevations below surface, (15 m – 30 m apart). Holes are drilled between the two excavations and loaded with explosives. The holes are blasted and

2496-473: Is hard to eradicate due to the complexity of its aggregation structure, and it has a significant contribution to developing aggressive medical complications, increase in hospitalization rate, and cost of treatment. The development of E. coli biofilm is a common leading cause of urinary tract infections (UTI) in hospitals through its contribution to developing medical device-associated infections . Catheter-associated urinary tract infections (CAUTI) represent

2592-795: Is highly different from that of planktonic and biofilm cells. Hence, the dispersal process is a unique stage during the transition from biofilm to planktonic lifestyle in bacteria. Dispersed cells are found to be highly virulent against macrophages and Caenorhabditis elegans , but highly sensitive towards iron stress, as compared with planktonic cells. Furthermore, Pseudomonas aeruginosa biofilms undergo distinct spatiotemporal dynamics during biofilm dispersal or disassembly, with contrasting consequences in recolonization and disease dissemination. Biofilm dispersal induced bacteria to activate dispersal genes to actively depart from biofilms as single cells at consistent velocities but could not recolonize fresh surfaces. In contrast, biofilm disassembly by degradation of

2688-409: Is known as development, and is the stage in which the biofilm is established and may only change in shape and size. The development of a biofilm may allow for an aggregate cell colony (or colonies) to be increasingly tolerant or resistant to antibiotics . Cell-cell communication or quorum sensing has been shown to be involved in the formation of biofilm in several bacterial species. Biofilms are

2784-481: Is much faster in responding to pathogen induced infection, and may be able to deflect pathogens before they are able to establish themselves. Plants increase the production of lignin, reinforcing cell walls and making it difficult for pathogens to penetrate into the cell, while also cutting off nutrients to already infected cells, effectively halting the invasion. They produce antimicrobial compounds such as phytoalexins, chitinases, and proteinase inhibitors, which prevent

2880-404: Is often facilitated within bacterial and archaeal biofilms and can leads to a more stable biofilm structure. Extracellular DNA is a major structural component of many different microbial biofilms. Enzymatic degradation of extracellular DNA can weaken the biofilm structure and release microbial cells from the surface. However, biofilms are not always less susceptible to antibiotics. For instance,

2976-407: Is removed ("mucked out" or "bogged") from the stope using center articulated vehicles . These vehicles are referred to as "boggers" or LHD (Load, Haul, Dump machines) . These pieces of equipment may operate using diesel engines or electric motors , and resemble a low-profile front end loader . Electrically powered LHD utilize trailing cables which are flexible and can be extended or retracted on

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3072-417: Is required in order to maintain the stability of the openings that are excavated. This support comes in two forms; local support and area support. Area ground support is used to prevent major ground failure. Holes are drilled into the back (ceiling) and walls and a long steel rod (or rock bolt ) is installed to hold the ground together. There are three categories of rock bolt, differentiated by how they engage

3168-677: Is the most acidic water naturally found on Earth; some samples collected in 1990 and 1991 have been measured to have a pH value of -3.6. Water temperatures as high as 47 °C have been measured underground. The drainage water endangers fish, including winter-run Chinook salmon , a federally listed endangered species that spawns in the Sacramento River. Salmon kills have been noted since 1899. The mine opening contains huge stalactite - stalagmite structures that span from floor to ceiling and are composed of rhomboclase and other iron sulfate minerals. The bacteria and archaea living in

3264-445: Is uneconomical, the open stope is filled with backfill, which can be a cement and rock mixture, a cement and sand mixture or a cement and tailings mixture. This method is popular as the refilled stopes provide support for the adjacent stopes, allowing total extraction of economic resources. The mining method selected is determined by the size, shape, orientation and type of orebody to be mined. The orebody can be narrow vein such as

3360-539: The DNA of the five dominant species at once, assembling the genomes afterwards. Four new species were identified in this way in 2004. In 2005, the proteins produced by these bacteria were identified; of the 2033 found proteins 572 were unique to this biofilm. In 2006, Baker identified three novel archaea, the Archaeal Richmond Mine Acidophilic Nanoorganisms . The bacteria obtain carbon from

3456-616: The United States . In order to minimize the P. aeruginosa infection , host epithelial cells secrete antimicrobial peptides , such as lactoferrin , to prevent the formation of the biofilms. Streptococcus pneumoniae is the main cause of community-acquired pneumonia and meningitis in children and the elderly, and of sepsis in HIV-infected persons. When S. pneumoniae grows in biofilms, genes are specifically expressed that respond to oxidative stress and induce competence. Formation of

3552-504: The shaft to be hoisted to the surface in buckets or skips and emptied into bins beneath the surface headframe for transport to the mill. In some cases the underground primary crusher feeds an inclined conveyor belt which delivers ore via an incline shaft direct to the surface. The ore is fed down ore passes, with mining equipment accessing the ore body via a decline from the surface. Biofilm Aggregate of microorganisms in which cells that are frequently embedded within

3648-528: The Keswick Reservoir formed by a dam across the Sacramento River . Historic mining activity at the site has fractured the mountain, exposing minerals in the mountain to surface water, rain water, and oxygen. When pyrite is exposed to moisture and oxygen, sulfuric acid forms. This sulfuric acid runs through the mountain and leaches out copper, cadmium, zinc, and other heavy metals. This acid flows out of

3744-645: The ability of bacteria to form biofilms. Bacteria with increased hydrophobicity have reduced repulsion between the substratum and the bacterium. Some bacteria species are not able to attach to a surface on their own successfully due to their limited motility but are instead able to anchor themselves to the matrix or directly to other, earlier bacteria colonists. Non-motile bacteria cannot recognize surfaces or aggregate together as easily as motile bacteria. During surface colonization bacteria cells are able to communicate using quorum sensing (QS) products such as N-acyl homoserine lactone (AHL). Once colonization has begun,

3840-664: The air's carbon dioxide and nitrogen from the air's N 2 gas. They are aerobes and obtain energy by using oxygen to oxidize ferrous iron dissolved from the iron sulfide rock; in the process they produce sulfuric acid which releases more metals from the rock. The bacteria belong to the group of acidophilic ferrous iron oxidizers . Underground mining (hard rock) Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals , usually those containing metals , such as ore containing gold , silver , iron , copper , zinc , nickel , tin , and lead . It also involves

3936-566: The aquatic invertebrates upon which many fish feed. Biofilms are found on the surface of and inside plants. They can either contribute to crop disease or, as in the case of nitrogen-fixing rhizobia on root nodules , exist symbiotically with the plant . Examples of crop diseases related to biofilms include citrus canker, Pierce's disease of grapes, and bacterial spot of plants such as peppers and tomatoes. Percolating filters in sewage treatment works are highly effective removers of pollutants from settled sewage liquor. They work by trickling

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4032-544: The bacteria species in the biofilm on the respective patient's tissue. In other words, the cultures were negative though the bacteria were present. New staining techniques are being developed to differentiate bacterial cells growing in living animals, e.g. from tissues with allergy-inflammations. Research has shown that sub-therapeutic levels of β-lactam antibiotics induce biofilm formation in Staphylococcus aureus . This sub-therapeutic level of antibiotic may result from

4128-516: The bedside to permit timely initiation of treatment. It has been shown that biofilms are present on the removed tissue of 80% of patients undergoing surgery for chronic sinusitis . The patients with biofilms were shown to have been denuded of cilia and goblet cells , unlike the controls without biofilms who had normal cilia and goblet cell morphology. Biofilms were also found on samples from two of 10 healthy controls mentioned. The species of bacteria from intraoperative cultures did not correspond to

4224-444: The behavioral step of reducing the supply of fermentable carbohydrates (i.e. sugar intake) and frequent removal of the biofilm (i.e., toothbrushing ). A peptide pheromone quorum sensing signaling system in S. mutans includes the competence stimulating peptide (CSP) that controls genetic competence. Genetic competence is the ability of a cell to take up DNA released by another cell. Competence can lead to genetic transformation,

4320-676: The biofilm form of Pseudomonas aeruginosa has no greater resistance to antimicrobials than do stationary-phase planktonic cells, although when the biofilm is compared to logarithmic-phase planktonic cells, the biofilm does have greater resistance to antimicrobials. This resistance to antibiotics in both stationary-phase cells and biofilms may be due to the presence of persister cells . Biofilms are ubiquitous in organic life. Nearly every species of microorganism have mechanisms by which they can adhere to surfaces and to each other. Biofilms will form on virtually every non-shedding surface in non-sterile aqueous or humid environments. Biofilms can grow in

4416-527: The biofilm grows by a combination of cell division and recruitment. Polysaccharide matrices typically enclose bacterial biofilms. The matrix exopolysaccharides can trap QS autoinducers within the biofilm to prevent predator detection and ensure bacterial survival. In addition to the polysaccharides, these matrices may also contain material from the surrounding environment, including but not limited to minerals, soil particles, and blood components, such as erythrocytes and fibrin. The final stage of biofilm formation

4512-452: The biofilm helps plants build stronger resistance to pathogens. Plants that have been colonized by PGPR forming a biofilm have gained systemic resistances and are primed for defense against pathogens. This means that the genes necessary for the production of proteins that work towards defending the plant against pathogens have been expressed, and the plant has a "stockpile" of compounds to release to fight off pathogens. A primed defense system

4608-408: The biofilm matrix may be useful as anti-biofilm agents. Evidence has shown that a fatty acid messenger, cis -2-decenoic acid , is capable of inducing dispersion and inhibiting growth of biofilm colonies. Secreted by Pseudomonas aeruginosa , this compound induces cyclo heteromorphic cells in several species of bacteria and the yeast Candida albicans . Nitric oxide has also been shown to trigger

4704-487: The biofilm produce the EPS components, which are typically a polymeric combination of extracellular polysaccharides , proteins , lipids and DNA . Because they have a three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes". Biofilms may form on living (biotic) or non-living (abiotic) surfaces and can be common in natural, industrial, and hospital settings. They may constitute

4800-433: The biofilm, containing S. mutans and related oral streptococci, is subjected to acid stress, the competence regulon is induced, leading to resistance to being killed by acid. As pointed out by Michod et al., transformation in bacterial pathogens likely provides for effective and efficient recombinational repair of DNA damages. It appears that S. mutans can survive the frequent acid stress in oral biofilms, in part, through

4896-450: The biofilms developed in the gut. This is especially important because the appendix holds a mass amount of these bacterial biofilms. This discovery helps to distinguish the possible function of the appendix and the idea that the appendix can help reinoculate the gut with good gut flora. However, modified or disrupted states of biofilms in the gut have been connected to diseases such as inflammatory bowel disease and colorectal cancer . In

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4992-477: The cells. Thus, the matrix represents an external digestion system and allows for stable synergistic microconsortia of different species. Some biofilms have been found to contain water channels that help distribute nutrients and signalling molecules. This matrix is strong enough that under certain conditions, biofilms can become fossilized ( stromatolites ). Bacteria living in a biofilm usually have significantly different properties from free-floating bacteria of

5088-598: The companies liabilities including the cleanup. The mine is located at 40°40′20″N 122°31′40″W  /  40.67222°N 122.52778°W  / 40.67222; -122.52778 in the Klamath Mountains of Shasta County , about 9 miles northwest of Redding . The mine area is drained by several creeks which ultimately enter the Spring Creek Reservoir , formed by the Spring Creek Dam , and finally

5184-484: The conditions at that time were too harsh for their survival. They can be found very early in Earth's fossil records (about 3.25 billion years ago) as both Archaea and Bacteria, and commonly protect prokaryotic cells by providing them with homeostasis, encouraging the development of complex interactions between the cells in the biofilm. The formation of a biofilm begins with the attachment of free-floating microorganisms to

5280-406: The dental biofilm is driven by certain (cariogenic) microbiological populations beginning to dominate when the environment favors them. The shift to an acidogenic , aciduric, and cariogenic microbiological population develops and is maintained by frequent consumption of fermentable dietary carbohydrate . The resulting activity shift in the biofilm (and resulting acid production within the biofilm, at

5376-708: The diffusion of quorum sensing molecules into the environment and prevented the detection of C. elegans . Many different bacteria form biofilms, including gram-positive (e.g. Bacillus spp, Listeria monocytogenes , Staphylococcus spp, and lactic acid bacteria , including Lactobacillus plantarum and Lactococcus lactis ) and gram-negative species (e.g. Escherichia coli , or Pseudomonas aeruginosa ). Cyanobacteria also form biofilms in aquatic environments. Biofilms are formed by bacteria that colonize plants, e.g. Pseudomonas putida , Pseudomonas fluorescens , and related pseudomonads which are common plant-associated bacteria found on leaves, roots, and in

5472-408: The dispersal of biofilms of several bacteria species at sub-toxic concentrations. Nitric oxide has potential as a treatment for patients that have chronic infections caused by biofilms. It was generally assumed that cells dispersed from biofilms immediately go into the planktonic growth phase. However, studies have shown that the physiology of dispersed cells from Pseudomonas aeruginosa biofilms

5568-409: The growth of pathogens. These functions of disease suppression and pathogen resistance ultimately lead to an increase in agricultural production and a decrease in the use of chemical pesticides, herbicides, and fungicides because there is a reduced amount of crop loss due to disease. Induced systemic resistance and pathogen-induced systemic acquired resistance are both potential functions of biofilms in

5664-502: The host rock. They are: Local ground support is used to prevent smaller rocks from falling from the back and ribs. Not all excavations require local ground support. Using this method, mining is planned to extract rock from the stopes without filling the voids; this allows the wall rocks to cave in to the extracted stope after all the ore has been removed. The stope is then sealed to prevent access. Where large bulk ore bodies are to be mined at great depth, or where leaving pillars of ore

5760-535: The human environment, biofilms can grow in showers very easily since they provide a moist and warm environment for them to thrive. Mold biofilms on ceilings may form due to roof leaks. They can form inside water and sewage pipes and cause clogging and corrosion . On floors and counters, they can make sanitation difficult in food preparation areas. In soil, they can cause bioclogging . In cooling- or heating-water systems, they are known to reduce heat transfer. Biofilms in marine engineering systems, such as pipelines of

5856-452: The hypogeal layer, particles of foreign matter are trapped in the mucilaginous matrix and soluble organic material is adsorbed . The contaminants are metabolised by the bacteria, fungi and protozoa. The water produced from an exemplary slow sand filter is of excellent quality with 90–99% bacterial cell count reduction. Plant-beneficial microbes can be categorized as plant growth-promoting rhizobacteria . These plant growth-promoters colonize

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5952-408: The inhibition of efflux pump activity and interactions with extracellular and intracellular nucleic acids. Escherichia coli biofilms are responsible for many intestinal infectious diseases. The Extraintestinal group of E. coli (ExPEC) is the dominant bacterial group that attacks the urinary system , which leads to urinary tract infections . The biofilm formation of these pathogenic E. coli

6048-452: The invading bacteria, and this response can kill bacteria by damaging their DNA. Competent S. pneumoniae in a biofilm have the survival advantage that they can more easily take up transforming DNA from nearby cells in the biofilm to use for recombinational repair of oxidative damages in their DNA. Competent S. pneumoniae can also secrete an enzyme (murein hydrolase) that destroys non-competent cells (fratricide) causing DNA to be released into

6144-407: The level into the ore. There are two principal phases of underground mining: development mining and production mining. Development mining is composed of excavation almost entirely in (non-valuable) waste rock in order to gain access to the orebody. There are six steps in development mining: remove previously blasted material (muck out round), scaling (removing any unstable slabs of rock hanging from

6240-423: The liquid over a bed of hard material which is designed to have a very large surface area. A complex biofilm develops on the surface of the medium which absorbs, adsorbs and metabolises the pollutants. The biofilm grows rapidly and when it becomes too thick to retain its grip on the media it washes off and is replaced by newly grown film. The washed off ("sloughed" off) film is settled out of the liquid stream to leave

6336-453: The location and regulations governing the site, it may be necessary to obtain permits and permissions before commencing drilling activities. This involves understanding and complying with local regulations, environmental guidelines, and any specific requirements for drilling in certain areas. Safety is paramount in any drilling operation. During the planning stage, safety protocols and measures are established to protect personnel, equipment, and

6432-859: The main progenitors of biofilms are diatoms , which colonise both fresh and marine environments worldwide. For other species in disease-associated biofilms and biofilms arising from eukaryotes , see below. Biofilms have been found to be involved in a wide variety of microbial infections in the body, by one estimate 80% of all infections. Infectious processes in which biofilms have been implicated include common problems such as bacterial vaginosis , urinary tract infections , catheter infections, middle-ear infections , formation of dental plaque , gingivitis , coating contact lenses , and less common but more lethal processes such as endocarditis , infections in cystic fibrosis , and infections of permanent indwelling devices such as joint prostheses , heart valves , and intervertebral disc. The first visual evidence of

6528-426: The mine such as Leptospirillum (bacteria) and Ferroplasma (archaea) are of interest because they can survive in this extreme environment, and because their metabolism contributes to the pollution. They form a pink biofilm several millimeters thick that floats on the surface of the hot water with a pH of 0.8. Since the bacteria cannot be isolated and cultured, scientists have performed community sequencing of

6624-401: The most extreme environments: from, for example, the extremely hot, briny waters of hot springs ranging from very acidic to very alkaline, to frozen glaciers . Biofilms can be found on rocks and pebbles at the bottoms of most streams or rivers and often form on the surfaces of stagnant pools of water. Biofilms are important components of food chains in rivers and streams and are grazed by

6720-404: The offshore oil and gas industry, can lead to substantial corrosion problems. Corrosion is mainly due to abiotic factors; however, at least 20% of corrosion is caused by microorganisms that are attached to the metal subsurface (i.e., microbially influenced corrosion ). Bacterial adhesion to boat hulls serves as the foundation for biofouling of seagoing vessels. Once a film of bacteria forms, it

6816-481: The ore body is of a payable grade sufficient to support an underground mining operation, but the strip ratio has become too great to support open cast extraction methods. They are also often built and maintained as an emergency safety access from the underground workings and a means of moving large equipment to the workings. Levels are excavated horizontally off the decline or shaft to access the ore body. Stopes are then excavated perpendicular (or near perpendicular) to

6912-410: The ore is removed from the bottom excavation. One of the most important aspects of underground hard rock mining is ventilation . Ventilation is the primary method of clearing hazardous gases and/or dust which are created from drilling and blasting activity (e.g., silica dust, NOx), diesel equipment (e.g., diesel particulate, carbon monoxide), or to protect against gases that are naturally emanating from

7008-410: The ore is removed. Orebodies that do not cave readily are sometimes preconditioned by hydraulic fracturing , blasting, or by a combination of both. Hydraulic fracturing has been applied to preconditioning strong roof rock over coal longwall panels, and to inducing caving in both coal and hard rock mines. In mines which use rubber-tired equipment for coarse ore removal, the ore (or "muck")

7104-408: The overall success of the biofilm. The biofilm bacteria can share nutrients and are sheltered from harmful factors in the environment, such as desiccation, antibiotics, and a host body's immune system. A biofilm usually begins to form when a free-swimming, planktonic bacterium attaches to a surface. Biofilms are thought to have arisen during primitive Earth as a defense mechanism for prokaryotes, as

7200-477: The product of a microbial developmental process. The process is summarized by five major stages of biofilm development, as shown in the diagram below: Dispersal of cells from the biofilm colony is an essential stage of the biofilm life cycle. Dispersal enables biofilms to spread and colonize new surfaces. Enzymes that degrade the biofilm extracellular matrix , such as dispersin B and deoxyribonuclease , may contribute to biofilm dispersal. Enzymes that degrade

7296-475: The recombinational repair provided by competence and transformation. Predator-prey interactions Predator - prey interactions between biofilms and bacterivores, such as the soil-dwelling nematode Caenorhabditis elegans , had been extensively studied. Via the production of sticky matrix and formation of aggregates, Yersinia pestis biofilms can prevent feeding by obstructing the mouth of C. elegans . Moreover, Pseudomonas aeruginosa biofilms can impede

7392-466: The release of harmful quantities of heavy metals into the Sacramento River . Approximately 70,000 people use surface water within 3 miles as their source of drinking water. The low pH level and the heavy metal contamination from the mine have caused the virtual elimination of aquatic life in sections of Slickrock Creek, Boulder Creek, and Spring Creek. The drainage water from the Iron Mountain Mine

7488-812: The rhizosphere often result in pathogen or plant induced systemic resistances. Molecular properties on the surface of the bacterium cause an immune response in the plant host. These microbe associated molecules interact with receptors on the surface of plant cells, and activate a biochemical response that is thought to include several different genes at a number of loci. Several other signaling molecules have been linked to both induced systemic responses and pathogen-induced systemic responses, such as jasmonic acid and ethylene. Cell envelope components such as bacterial flagella and lipopolysaccharides, which are recognized by plant cells as components of pathogens. Certain iron metabolites produced by Pseudomonas have also been shown to create an induced systemic response. This function of

7584-459: The rhizosphere, and should be taken into consideration when applied to new age agricultural practices because of their effect on disease suppression without the use of dangerous chemicals. Studies in 2003 discovered that the immune system supports biofilm development in the large intestine. This was supported mainly with the fact that the two most abundantly produced molecules by the immune system also support biofilm production and are associated with

7680-643: The rock (e.g., radon gas). Ventilation is also used to manage underground temperatures for the workers. In deep, hot mines ventilation is used to cool the workplace; however, in very cold locations the air is heated to just above freezing before it enters the mine. Ventilation raises are typically used to transfer ventilation from surface to the workplaces, and can be modified for use as emergency escape routes. The primary sources of heat in underground hard rock mines are virgin rock temperature, machinery, auto compression, and fissure water. Other small contributing factors are human body heat and blasting. Some means of support

7776-499: The roof and sidewalls to protect workers and equipment from damage), installing support or/and reinforcement using shotcrete etceteras, drill face rock, load explosives, and blast explosives. To start the mining, the first step is to make the path to go down. The path is defined as 'Decline' as describe above. Before the start of a decline, all pre-planning of the power facility, drilling arrangement, de-watering, ventilation and, muck withdrawal facilities are required. Production mining

7872-769: The roots of plants, and provide a wide range of beneficial functions for their host including nitrogen fixation, pathogen suppression, anti-fungal properties, and the breakdown of organic materials. One of these functions is the defense against pathogenic, soil-borne bacteria and fungi by way of induced systemic resistance (ISR) or induced systemic responses triggered by pathogenic microbes (pathogen-induced systemic acquired resistance). Plant exudates act as chemical signals for host specific bacteria to colonize. Rhizobacteria colonization steps include attractions, recognition, adherence, colonization, and growth. Bacteria that have been shown to be beneficial and form biofilms include Bacillus , Pseudomonas , and Azospirillum . Biofilms in

7968-417: The same species, as the dense and protected environment of the film allows them to cooperate and interact in various ways. One benefit of this environment is increased resistance to detergents and antibiotics , as the dense extracellular matrix and the outer layer of cells protect the interior of the community. In some cases antibiotic resistance can be increased up to 5,000 times. Lateral gene transfer

8064-409: The same techniques used to excavate ores of gems , such as diamonds and rubies . Soft-rock mining refers to the excavation of softer minerals, such as salt , coal , and oil sands . Accessing underground ore can be achieved via a decline (ramp), inclined vertical shaft or adit . Planning and preparation are crucial initial steps in the core drilling process. This stage involves conducting

8160-597: The seeps and portals of the mine. Much of the acidic mine drainage ultimately is channeled into the Spring Creek Reservoir by creeks surrounding the mine. The Bureau of Reclamation periodically releases the stored acid mine drainage into Keswick Reservoir. Planned releases are timed to coincide with the presence of diluting releases of water from Shasta Dam . On occasion, uncontrolled spills and excessive waste releases have occurred when Spring Creek Reservoir reached capacity. Without sufficient dilution, this results in

8256-547: The site was mined by the Mountain Copper Company, Ltd., both underground using open stope mining techniques and at the surface in the form of open pit and sidehill mining. As a result, the mountain fractured and mineral deposits were exposed to oxygen, water, and certain bacteria, resulting in acidic mine drainage. Though mining operations were discontinued in 1963, underground mine workings, waste rock dumps, piles of mine tailings, and an open mine pit still remain at

8352-468: The site. The mine was designated a Superfund site in 1983 and a water treatment plant was built in 1994. In 2000, the government reached a settlement with Aventis CropScience (now part of Bayer ), for the long-term funding of the cleanup efforts. Aventis, formerly known as Rhône-Poulenc , acquired Stauffer Chemical in 1987. Stauffer had purchased Mountain Copper Company in 1968 and in doing so took on

8448-420: The slithering motility of C. elegans , termed as 'quagmire phenotype', resulting in trapping of C. elegans within the biofilms and preventing the exploration of nematodes to feed on susceptible biofilms. This significantly reduced the ability of predator to feed and reproduce, thereby promoting the survival of biofilms. Pseudomonas aeruginosa biofilms can also mask their chemical signatures, where they reduced

8544-434: The soil, and the majority of their natural isolates form biofilms. Several nitrogen-fixing symbionts of legumes such as Rhizobium leguminosarum and Sinorhizobium meliloti form biofilms on legume roots and other inert surfaces. Along with bacteria, biofilms are also generated by archaea and by a range of eukaryotic organisms, including fungi e.g. Cryptococcus laurentii and microalgae . Among microalgae, one of

8640-484: The surface of leaves, particularly in high humidity climates. Given sufficient resources for growth, a biofilm will quickly grow to be macroscopic (visible to the naked eye). Biofilms can contain many different types of microorganism, e.g. bacteria, archaea , protozoa , fungi and algae ; each group performs specialized metabolic functions. However, some organisms will form single-species films under certain conditions. The social structure (cooperation/competition) within

8736-484: The surface of teeth is frequently subject to oxidative stress and acid stress. Dietary carbohydrates can cause a dramatic decrease in pH in oral biofilms to values of 4 and below (acid stress). A pH of 4 at body temperature of 37 °C causes depurination of DNA, leaving apurinic (AP) sites in DNA, especially loss of guanine. Dental plaque biofilm can result in dental caries if it is allowed to develop over time. An ecologic shift away from balanced populations within

8832-595: The surrounding environment. This includes assessing potential hazards, developing emergency response plans, and ensuring the availability of necessary safety equipment. Planning also involves determining the equipment and resources required for the core drilling operation. This includes selecting the appropriate drilling rig, drill bits, and accessories based on factors such as the material being drilled, desired core diameter, and drilling depth. Adequate resources such as water supply, drilling mud, and coolants are also considered to ensure smooth drilling operations. Establishing

8928-508: The surrounding medium for potential use by the competent cells. The insect antimicrobial peptide cecropin A can destroy planktonic and sessile biofilm-forming uropathogenic E. coli cells, either alone or when combined with the antibiotic nalidixic acid , synergistically clearing infection in vivo (in the insect host Galleria mellonella ) without off-target cytotoxicity. The multi-target mechanism of action involves outer membrane permeabilization followed by biofilm disruption triggered by

9024-408: The tooth surface) is associated with an imbalance of demineralization over remineralization, leading to net mineral loss within dental hard tissues ( enamel and then dentin ), the symptom being a carious lesion , or cavity. By preventing the dental plaque biofilm from maturing or by returning it back to a non-cariogenic state, dental caries can be prevented and arrested. This can be achieved through

9120-449: The trapping, binding and cementation of sedimentary grains by microbial biofilms, especially of cyanobacteria . Stromatolites include some of the most ancient records of life on Earth, and are still forming today. Within the human body, biofilms are present on the teeth as dental plaque , where they may cause tooth decay and gum disease . These biofilms can either be in an uncalcified state that can be removed by dental instruments, or

9216-733: The use of antibiotics as growth promoters in agriculture, or during the normal course of antibiotic therapy. The biofilm formation induced by low-level methicillin was inhibited by DNase, suggesting that the sub-therapeutic levels of antibiotic also induce extracellular DNA release. Moreover, from an evolutionary point of view, the creation of the tragedy of the commons in pathogenic microbes may provide advanced therapeutic ways for chronic infections caused by biofilms via genetically engineered invasive cheaters who can invade wild-types 'cooperators' of pathogenic bacteria until cooperator populations go to extinction or overall population 'cooperators and cheaters ' go to extinction. P. aeruginosa represents

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