Biology

1205 Zitate
0 Likes
0Verified
71Authors

Timeline

First Quote Added

April 10, 2026

Latest Quote Added

April 10, 2026

All Quotes

"I dreamed of you for the first time the other night. You were swaddled in a blanket and floating. Your hair was dark brown before it curled and turned blonde, just like your father's. I brought my head down to my clavicle and nuzzled you, melting a little. I told you, or did you tell me that it wasn't time yet? We are waiting for you, wondering who you will be. I've made a habit of Googling strange changes in my body in the off chance they might be connected to your existence. Too much saliva, bleeding gums, muscle pains in the lower abdomen. Every time, no matter how seemingly random, all of these symptoms are correct, connected to the making of you. I'm reminded my body is marching onward without any help from me. There is a quietness that comes with pregnancy, a humbling. I'm listening for you. I'm full of wonder. Mornings and nights, my stomach grows. It's getting colder, an election is coming. I feel you flutter underneath my belly button. I want you to see the world's potential. You feel like the world's potential. I'm driving through Manhattan, looking out the backseat window of my friend's car, studying pedestrians as they move through the city. A man crosses the street in glasses, another jogs in place, his eyes focused ahead of him. I stare at these strangers. Will that be you? I wonder. I'm in the shower, rearranging all the names I'm thinking of for you in my head. I peer down at my belly and say one of them aloud to see if it fits. Water steadily beats against my back. In that moment I can't feel it myself or the space around me. Just you. Hello, I think, is that you? My chest swells and my eyes sting with the thought that one day soon, so very soon, your presence will be real. I close my eyes and try to imagine you moving through the pixelated darkness of my mind's eye. I cannot wait to see who you will be."

- Pregnancy

• 0 likes• themes• sexuality• women• gender• biology•
"Undesirable acid-forming bacteria... capable of forming substances that impart to milk an offensive odor and a disagreeable taste not infrequently appear instead of the desirable group. Instead of producing from the sugar of milk large quantities of lactic acid, these types generate other acids, such as acetic and formic, which impart a sharp taste to the milk. Besides the acids the bacteria of this group form gases from the sugar of the milk. Some produce small amounts of gas; others so much that the curd will be spongy and will float on the surface of the whey. The fermentation caused by them is often called a "gassy fermentation" and is dreaded by butter and cheese makers since the gas is indicative of bad flavors... Gas may also be produced in other types of fermentations... This class of bacteria enters the milk with the dust, dirt, and manure, in which materials they are especially abundant. No spores are formed; hence they are easily killed by heating the milk. They grow both in the presence and in the absence of free oxygen. High temperatures favor their growth, most rapid development taking place at 100° to 103° F. ...The normal souring of milk is due to a mixture of these two groups [Bacillus lactis acidi and the undesirable acid-forms] of bacteria. The relative proportions existing between the two in any sample of milk is dependent on a number of factors, most important of which is the degree of cleanliness..."

- Fermentation in food processing

• 0 likes• food-and-drink• biology•
"The present status of surgery depends, primarily, upon the efforts of chemists, especially those interested in wine and beer production, to determine why milk turns sour, grape juice becomes wine, wine vinegar, and vinegar "a foul, insipid fluid," without the addition of any chemical reagent. The difficulty in explaining this change was due to the fact that no chemical formula could be evolved which fully represented the equation. It was easy to write a formula that expressed in definite terms the change that had resulted in a given case, but it was impossible to explain what had set the process in motion. Why was it that milk would change from sweet to sour, showing that the milk sugar it contained had become lactic acid, while a solution of pure milk sugar in pure water absolutely refused to undergo the same process? It became evident that there was something else inherent to the fermenting process that set it in motion. ... The problem was gradually clearing up as far back as Von Helmont... who first showed that the gas eliminated during fermentation was different from the air and identical with that formed by the combustion of charcoal and the calcination of limestone. ... Stahl... was the first to discover that vinous fermentation and putrefaction belong to the same class of phenomena... Leuwenhoek... in 1680 found, with the imperfect microscopes in use at that time, that yeast consisted of minute globular or ovoid particles... It took until 1836 for Schwann and Caignard-Latour, acting independently of one another, to prove that Leuwenhoek's globules were membranous bags, exhibiting the characteristics of vegetable cells and increasing and multiplying rapidly in the same way when brought under proper conditions. It had already been recognized that the yeast increased in vinous fermentation, and therefore it was natural that they should conclude that yeast was a plant, and that as it grew it in some unexplained way set up the chemical change. ... Schroeder and Von Dusch (1854) published the fact that a cotton plug prevented the something in the air that set fermentation and putrefaction in motion from coming in contact with the solutions or solids that otherwise would become proper media for the setting up of the processes. In 1860, and the next few succeeding years, Pasteur settled the whole question by his masterly review of the field, and his own remarkable series of experiments. Following this came Lister's appreciation of the results of these experiments in their application to surgery..."

- Fermentation in food processing

• 0 likes• food-and-drink• biology•
"If a number of flasks be charged with a clear nutrient solution, of a kind favourable to the growth of yeast and containing a fermentable sugar, and each of them be inoculated with a trace of a pure culture of different yeasts, such as are used in brewing, distillery work, vinification, &c., the cultures being then kept at room temperature for a couple of days, it will be found that cell reproduction and fermentation—manifested by the appearance of turbidity and gas bubbles—will occur in all. It will thereafter soon be possible to separate the flasks into two groups, according to the appearance presented. In the one group the yeast crop developed from the sowing will remain almost entirely within the liquid throughout the entire period of fermentation, and mostly at the bottom even from the start. Yeasts of this kind are termed bottom yeasts, and excite bottom-fermentation, the yeast crop being sedimental. In the other group the fermentation is very brisk and attended with the formation of large quantities of froth (head); and in the earlier stages a larger or smaller number of the new cells are raised to the surface by the ascending bubbles of gas, and remain there—provided the vessel be high enough to prevent frothing over—until fermentation is terminated and the froth breaks up, whereupon they sink down to the bottom of the liquid and increase the sedimental deposit. This kind of fermentation is termed top-fermentation, and the yeasts producing it are called top-fermentation yeasts. Typical examples of bottom-fermentation yeasts are afforded by the Munich lager-beer yeasts."

- Fermentation in food processing

• 0 likes• food-and-drink• biology•
"Searching investigations into the chemical activity of the different species of acetic acid bacteria would be not only opportune in the interests of science, but also highly important to the practice of the vinegar industry. In this business the employment of selected pure culture ferments is not yet regarded as a fundamental rule, everything being still left to the mercy of chance. ...there are two different methods of making vinegar. In one of them wine forms the raw material, this method being known as the Orleans process... There (as elsewhere) the work is still performed in the same manner as it was centuries ago as follows:—A number of oaken casks, each of a capacity of some 55 gallons, are arranged in rows in a chamber maintained at a constant temperature of 18° to 22° C [64° to 71° F]. In the upper part of the front end (head) of each cask a circular aperture (a few cm in width) is provided, through which the cask can be filled or emptied, and which is generally kept closed, whilst near it is a very small hole (vent) always left open for the admission of air. In normal work each cask is about half full. Before setting a new cask in work, it is scalded out several times with steam or hot water, in order to extract the sap from the wood, and is then "soured" by impregnating it with good, boiling-hot vinegar. About 1 hl. (22 gallons) of good, clear vinegar and 2 l. (0.44 gallons) of wine are then placed in the cask, another 3 l. of wine being added at the end of eight days, 4 to 5 l. more after the lapse of another week, and so on until the cask contains 180-200 l. (40 to 44 gallons). Then, for the first time, vinegar is drawn from the cask, and in such quantity that about 22 gallons are left behind in the vessel. From that time the cask "mother" is in continuous use, 10 litres (2.2 gallons) of vinegar being withdrawn every week and replaced by an equal quantity of wine. The "mother" casks may remain in work during six or eight years without interruption, but at the end of this period they will contain such a considerable accumulation of deposited yeast, tarter and , as to necessitate their being emptied and cleansed. A skin, known as vinegar flowers or mother of vinegar, and composed of acetic acid bacteria, develops on the surface of the liquid, and the manner and luxuriance of its growth enables the operator to judge the progress of the fermentation. However, at the outset the growth proceeds very slowly, since the wine employed mostly contains but very few of these bacteria. Consequently an opportunity is afforded for the development of rapid-growing injurious organisms, chiefly certain budding fungi, which consume the acetic acid. The aerobic "vinegar eels" also make their appearance."

- Fermentation in food processing

• 0 likes• food-and-drink• biology•