Pico Ag, 5731 Lexington Drive, Parrish, FL 34219 800 995-9203, 336 306-0193, Email: donwilshe@biobased.us Emails can go to spam, Please call me, We are available 7 days week EST 10AM to 10PM! High-Brix 18-20 Crops eliminate Grasshopper, Cereal Leaf Beetle, Army Worms, etc, etc! This is a story about neighbor and his grasshoppers and a new farmer A, Kansas is in the heart of alfalfa-growing country. Farmer A, been interested in nutrient-dense agriculture for several years when he came across, a company that promotes Reams' biological approach to farming. "Everything I'd been thinking about [in relation to growing nutrient dense crops] made sense when I talked to them," Farmer A reports. Thus, things began to fall into place for the farmer A's growing program after he began implementing the Reams program. The farmer A's been growing high-Brix crops of alfalfa, wheat, timothy and Bermuda grasses for dairy cattle and horses ever since. Few years ago, when the farmer A moved to his current farm, his next-door neighbor told him he'd regret it. The farm and soil were in bad shape. But things didn't quite work out as his neighbor predicted. The farmer A recalls an incident in the summer of 2000 when his neighbor's conventionally-grown alfalfa crops were wiped out by grasshoppers. His neighbor used conventional fertilizers and sprayed both Pesticides and Herbicides lower Brix Levels So Ag Supply can sell more Pesticides you understand) for your crops. The farmer A sprayed nothing on his crops, he just used Reams methods and fertilizers to grow high-Brix crops. One day his neighbor stood on the border of his alfalfa crops and his own. Neighbor then took three steps into his own field and was immediately swarmed by grasshoppers. Neighbor stepped back into his farm field and the grasshoppers hopped off him. Neighbor stepped back into his own field and was immediately covered with the grasshopper once again. Neighbor repeated this five times with the farmer A and several others witnessing. Each time the same thing happened. Neighbor was covered with grasshoppers when Neighbor stepped into his own field, but they hopped off him when Neighbor stepped back into the farmer A's field. Both fields contained the same variety of alfalfa. The major difference was the higher fertility of the farmer A soil. His alfalfa crops were on average 12-14 Brix (his highest Brixed at 19) while his neighbor's crop was on average 3-4 Brix or 400% lower. It was the farmer A's best year for growing alfalfa, and his Neighbor's worst. So this leads to a few storys that support our methods of farming contrary to about anyone giving you farming advice. IRRI Bangladesh Rice Farmers Found Out: When Pesticides Weren't Used They Got No Pests! This makes perfect Sense! Here is the deal if you dont want pests dont make your plants sick, make sense?? You do this when you use Organic Chemistry based pesticides as plants only like to grow using physical chemsitry or dirt!!! The more organic chemistry the more your lower plant health (Brix Levels) and plants are not able to defend themselves as there health is lower and lower with persistent use! These pesticides and herbicides can chelate or immobilize the nurtients by up to 80%. So why would you want to waste 80% of the money you spent on fertilizers of all kinds. Story to come! Story to come! The Effects of pH on Microbial GrowthLearning Objectives
Survival at the Low pH of the StomachPeptic ulcers (or stomach ulcers ) are painful sores on the stomach lining. Until the 1980s, they were believed to be caused by spicy foods, stress, or a combination of both. Patients were typically advised to eat bland foods, take anti-acid medications, and avoid stress. These remedies were not particularly effective, and the condition often recurred. This all changed dramatically when the real cause of most peptic ulcers was discovered to be a slim, corkscrew-shaped bacterium, Helicobacter pylori . This organism was identified and isolated by Barry Marshall and Robin Warren, whose discovery earned them the Nobel Prize in Medicine in 2005. The ability of H. pylori to survive the low pH of the stomach would seem to suggest that it is an extreme acidophile. As it turns out, this is not the case. In fact, H. pylori is a neutrophile. So, how does it survive in the stomach? Remarkably, H. pylori creates a microenvironment in which the pH is nearly neutral. It achieves this by producing large amounts of the enzyme urease, which breaks down urea to form NH4+ and CO2. The ammonium ion raises the pH of the immediate environment. This metabolic capability of H. pylori is the basis of an accurate, noninvasive test for infection. The patient is given a solution of urea containing radioactively labeled carbon atoms. If H. pylori is present in the stomach, it will rapidly break down the urea, producing radioactive CO2 that can be detected in the patient’s breath. Because peptic ulcers may lead to gastric cancer, patients who are determined to have H. pylori infections are treated with antibiotics.Temperature and Microbial GrowthLearning Objectives
Clinical Focus: Nataliya, ResolutionThis example concludes Nataliya’s story that started in How Microbes Grow and Oxygen Requirements for Microbial Growth. The presence of Listeria in Nataliya’s blood suggests that her symptoms are due to listeriosis , an infection caused by L. monocytogenes. Listeriosis is a serious infection with a 20% mortality rate and is a particular risk to Nataliya’s fetus. A sample from the amniotic fluid cultured for the presence of Listeria gave negative results. Because the absence of organisms does not rule out the possibility of infection, a molecular test based on the nucleic acid amplification of the 16S ribosomal RNA of Listeria was performed to confirm that no bacteria crossed the placenta. Fortunately, the results from the molecular test were also negative. Nataliya was admitted to the hospital for treatment and recovery. She received a high dose of two antibiotics intravenously for 2 weeks. The preferred drugs for the treatment of listeriosis are ampicillin or penicillin G with an aminoglycoside antibiotic. Resistance to common antibiotics is still rare in Listeria and antibiotic treatment is usually successful. She was released to home care after a week and fully recovered from her infection. L. monocytogenes is a gram-positive short rod found in soil, water, and food. It is classified as a psychrophile and is halotolerant. Its ability to multiply at refrigeration temperatures (4–10 °C) and its tolerance for high concentrations of salt (up to 10% sodium chloride [NaCl]) make it a frequent source of food poisoning. Because Listeria can infect animals, it often contaminates food such as meat, fish, or dairy products. Contamination of commercial foods can often be traced to persistent biofilms that form on manufacturing equipment that is not sufficiently cleaned. Listeria infection is relatively common among pregnant women because the elevated levels of progesterone downregulate the immune system, making them more vulnerable to infection. The pathogen can cross the placenta and infect the fetus, often resulting in miscarriage, stillbirth, or fatal neonatal infection. Pregnant women are thus advised to avoid consumption of soft cheeses, refrigerated cold cuts, smoked seafood, and unpasteurized dairy products. Because Listeria bacteria can easily be confused with diphtheroids, another common group of gram-positive rods, it is important to alert the laboratory when listeriosis is suspected. The organisms retrieved from arctic lakes such as Lake Whillans are considered extreme psychrophiles (cold loving). Psychrophiles are microorganisms that can grow at 0 °C and below, have an optimum growth temperature close to 15 °C, and usually do not survive at temperatures above 20 °C. They are found in permanently cold environments such as the deep waters of the oceans. Because they are active at low temperature, psychrophiles and psychrotrophs are important decomposers in cold climates. Figure 1. A black smoker at the bottom of the ocean belches hot, chemical-rich water, and heats the surrounding waters. Sea vents provide an extreme environment that is nonetheless teeming with macroscopic life (the red tubeworms) supported by an abundant microbial ecosystem. (credit: NOAA) Organisms that grow at optimum temperatures of 50 °C to a maximum of 80 °C are called thermophiles (“heat loving”). They do not multiply at room temperature. Thermophiles are widely distributed in hot springs, geothermal soils, and manmade environments such as garden compost piles where the microbes break down kitchen scraps and vegetal material. Examples of thermophiles include Thermus aquaticus and Geobacillus spp. Higher up on the extreme temperature scale we find the hyperthermophiles , which are characterized by growth ranges from 80 °C to a maximum of 110 °C, with some extreme examples that survive temperatures above 121 °C, the average temperature of an autoclave. The hydrothermal vents at the bottom of the ocean are a prime example of extreme environments, with temperatures reaching an estimated 340 °C (Figure 1). Microbes isolated from the vents achieve optimal growth at temperatures higher than 100 °C. Noteworthy examples are Pyrobolus and Pyrodictium , archaea that grow at 105 °C and survive autoclaving. Figure 2 shows the typical skewed curves of temperature-dependent growth for the categories of microorganisms we have discussed. Figure 2. The graph shows growth rate of bacteria as a function of temperature. Notice that the curves are skewed toward the optimum temperature. The skewing of the growth curve is thought to reflect the rapid denaturation of proteins as the temperature rises past the optimum for growth of the microorganism. Life in extreme environments raises fascinating questions about the adaptation of macromolecules and metabolic processes. Very low temperatures affect cells in many ways. Membranes lose their fluidity and are damaged by ice crystal formation. Chemical reactions and diffusion slow considerably. Proteins become too rigid to catalyze reactions and may undergo denaturation. At the opposite end of the temperature spectrum, heat denatures proteins and nucleic acids. Increased fluidity impairs metabolic processes in membranes. Some of the practical applications of the destructive effects of heat on microbes are sterilization by steam, pasteurization, and incineration of inoculating loops. Proteins in psychrophiles are, in general, rich in hydrophobic residues, display an increase in flexibility, and have a lower number of secondary stabilizing bonds when compared with homologous proteins from mesophiles. Antifreeze proteins and solutes that decrease the freezing temperature of the cytoplasm are common. The lipids in the membranes tend to be unsaturated to increase fluidity. Growth rates are much slower than those encountered at moderate temperatures. Under appropriate conditions, mesophiles and even thermophiles can survive freezing. Liquid cultures of bacteria are mixed with sterile glycerol solutions and frozen to −80 °C for long-term storage as stocks. Cultures can withstand freeze drying (lyophilization) and then be stored as powders in sealed ampules to be reconstituted with broth when needed. Macromolecules in thermophiles and hyperthermophiles show some notable structural differences from what is observed in the mesophiles. The ratio of saturated to polyunsaturated lipids increases to limit the fluidity of the cell membranes. Their DNA sequences show a higher proportion of guanine–cytosine nitrogenous bases, which are held together by three hydrogen bonds in contrast to adenine and thymine, which are connected in the double helix by two hydrogen bonds. Additional secondary ionic and covalent bonds, as well as the replacement of key amino acids to stabilize folding, contribute to the resistance of proteins to denaturation. The so-called thermoenzymes purified from thermophiles have important practical applications. For example, amplification of nucleic acids in the polymerase chain reaction (PCR) depends on the thermal stability of Taq polymerase , an enzyme isolated from T. aquaticus. Degradation enzymes from thermophiles are added as ingredients in hot-water detergents, increasing their effectiveness.Other Environmental Conditions that Affect GrowthLearning Objectives
Osmotic and Barometric PressureFigure 1. Photograph taken from space of the Great Salt Lake in Utah. The purple color is caused by high density of the alga Dunaliella and the archaean Halobacterium spp. (credit: NASA) Most natural environments tend to have lower solute concentrations than the cytoplasm of most microorganisms. Rigid cell walls protect the cells from bursting in a dilute environment. Not much protection is available against high osmotic pressure . In this case, water, following its concentration gradient, flows out of the cell. This results in plasmolysis (the shrinking of the protoplasm away from the intact cell wall) and cell death. This fact explains why brines and layering meat and fish in salt are time-honored methods of preserving food. Microorganisms called halophiles (“salt loving”) actually require high salt concentrations for growth. These organisms are found in marine environments where salt concentrations hover at 3.5%. Extreme halophilic microorganisms, such as the red alga Dunaliella salina and the archaeal species Halobacterium in Figure 1, grow in hypersaline lakes such as the Great Salt Lake, which is 3.5–8 times saltier than the ocean, and the Dead Sea, which is 10 times saltier than the ocean. Dunaliella spp. counters the tremendous osmotic pressure of the environment with a high cytoplasmic concentration of glycerol and by actively pumping out salt ions. Halobacterium spp. accumulates large concentrations of K+ and other ions in its cytoplasm. Its proteins are designed for high salt concentrations and lose activity at salt concentrations below 1–2 M. Although most halotolerant organisms, for example Halomonas spp. in salt marshes, do not need high concentrations of salt for growth, they will survive and divide in the presence of high salt. Not surprisingly, the staphylococci, micrococci, and corynebacteria that colonize our skin tolerate salt in their environment. Halotolerant pathogens are an important cause of food-borne illnesses because they survive and multiply in salty food. For example, the halotolerant bacteria S. aureus, Bacillus cereus, and V. cholerae produce dangerous enterotoxins and are major causes of food poisoning. Microorganisms depend on available water to grow. Available moisture is measured as water activity (a w ) , which is the ratio of the vapor pressure of the medium of interest to the vapor pressure of pure distilled water; therefore, the aw of water is equal to 1.0. Bacteria require high aw (0.97–0.99), whereas fungi can tolerate drier environments; for example, the range of aw for growth of Aspergillus spp. is 0.8–0.75. Decreasing the water content of foods by drying, as in jerky, or through freeze-drying or by increasing osmotic pressure, as in brine and jams, are common methods of preventing spoilage. Microorganisms that require high atmospheric pressure for growth are called barophiles . The bacteria that live at the bottom of the ocean must be able to withstand great pressures. Because it is difficult to retrieve intact specimens and reproduce such growth conditions in the laboratory, the characteristics of these microorganisms are largely unknown.LightPhotoautotrophs, such as cyanobacteria or green sulfur bacteria , and photoheterotrophs, such as purple nonsulfur bacteria , depend on sufficient light intensity at the wavelengths absorbed by their pigments to grow and multiply. Energy from light is captured by pigments and converted into chemical energy that drives carbon fixation and other metabolic processes. The portion of the electromagnetic spectrum that is absorbed by these organisms is defined as photosynthetically active radiation (PAR). It lies within the visible light spectrum ranging from 400 to 700 nanometers (nm) and extends in the near infrared for some photosynthetic bacteria. A number of accessory pigments, such as fucoxanthin in brown algae and phycobilins in cyanobacteria, widen the useful range of wavelengths for photosynthesis and compensate for the low light levels available at greater depths of water. Other microorganisms, such as the archaea of the class Halobacteria , use light energy to drive their proton and sodium pumps. The light is absorbed by a pigment protein complex called bacteriorhodopsin, which is similar to the eye pigment rhodopsin. Photosynthetic bacteria are present not only in aquatic environments but also in soil and in symbiosis with fungi in lichens. The peculiar watermelon snow is caused by a microalga Chlamydomonas nivalis , a green alga rich in a secondary red carotenoid pigment (astaxanthin) which gives the pink hue to the snow where the alga grows.Media Used for Bacterial GrowthLearning Objectives
Nutritional RequirementsThe number of available media to grow bacteria is considerable. Some media are considered general all-purpose media and support growth of a large variety of organisms. A prime example of an all-purpose medium is tryptic soy broth (TSB) . Specialized media are used in the identification of bacteria and are supplemented with dyes, pH indicators, or antibiotics. One type, enriched media , contains growth factors, vitamins, and other essential nutrients to promote the growth of fastidious organisms , organisms that cannot make certain nutrients and require them to be added to the medium. When the complete chemical composition of a medium is known, it is called a chemically defined medium . For example, in EZ medium , all individual chemical components are identified and the exact amounts of each is known. In complex media , which contain extracts and digests of yeasts, meat, or plants, the precise chemical composition of the medium is not known. Amounts of individual components are undetermined and variable. Nutrient broth, tryptic soy broth, and brain heart infusion , are all examples of complex media. Figure 1. On this MacConkey agar plate, the lactose-fermenter E. coli colonies are bright pink. Serratia marcescens, which does not ferment lactose, forms a cream-colored streak on the tan medium. (credit: American Society for Microbiology) Media that inhibit the growth of unwanted microorganisms and support the growth of the organism of interest by supplying nutrients and reducing competition are called selective media . An example of a selective medium is MacConkey agar . It contains bile salts and crystal violet, which interfere with the growth of many gram-positive bacteria and favor the growth of gram-negative bacteria , particularly the Enterobacteriaceae . These species are commonly named enterics, reside in the intestine, and are adapted to the presence of bile salts. The enrichment cultures foster the preferential growth of a desired microorganism that represents a fraction of the organisms present in an inoculum. For example, if we want to isolate bacteria that break down crude oil, hydrocarbonoclastic bacteria , sequential subculturing in a medium that supplies carbon only in the form of crude oil will enrich the cultures with oil-eating bacteria. The differential media make it easy to distinguish colonies of different bacteria by a change in the color of the colonies or the color of the medium. Color changes are the result of end products created by interaction of bacterial enzymes with differential substrates in the medium or, in the case of hemolytic reactions, the lysis of red blood cells in the medium. In Figure 1, the differential fermentation of lactose can be observed on MacConkey agar. The lactose fermenters produce acid, which turns the medium and the colonies of strong fermenters hot pink. The medium is supplemented with the pH indicator neutral red, which turns to hot pink at low pH. Selective and differential media can be combined and play an important role in the identification of bacteria by biochemical methods.Time
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