Fisrt accident with Antony van Leeuwenhoek (1632–1723) in micribiology

                  Antony van Leeuwenhoek (1632–1723)

 Antonie van Leeuwenhoek is considered a father of microbiology as he observed and experimented with microscopic organisms in 1676, using simple microscopes of his own design. Scientific microbiology developed in the 19th century through the work of Louis Pasteur and in medical microbiology Robert Koch

   

Leeuwenhoek was a master at grinding lenses for his microscopes. Working in Delft, Holland, in the mid-1600s, he is
considered the greatest early microscopist.
Leeuwenhoek was a manic observer, who tried to look at
everything with his microscopes.
Those little animals were everywhere! He told the Royal
Society of finding swarms of those subvisible things in
his mouth—of all places: “Although I am now fifty years
old,” he wrote, “I have uncommonly well-preserved teeth,
because it is my custom every morning to rub my teeth
very hard with salt, and after cleaning my teeth with a
quill, to rub them vigorously with a cloth. . . .”
From his teeth he scraped a bit of white stuff, mixed
it with pure rainwater, stuck it in a little tube onto the
needle of his microscope, closed the door of his study—
As he brought the tube into focus, there was an
unbelievable tiny creature, leaping about in the water of
the tube. . . . There was a second kind that swam
forward a little way, then whirled about suddenly, then
tumbled over itself in pretty somersaults. . . . There was
a menagerie in his mouth! There were creatures shaped
like flexible rods that went to and fro . . . there were
spirals that whirled through the water like violently
animated corkscrews. . . .—Paul de KruifMicrobe Hunters (1926

Definition of climate and climate zone with History

Definition of climate and climate zone

Climate is the long term pattern of weathers in a locality

Climate is the long term pattern of weathers in a locality, region or over the globe the term climate and weather have different meaning weather is the short term properties such as temperature, pressure, moisture of atmospheric condition  for a specific place and time weather differ both two most important factore determining an areas climate are air temprature and precipitation spatially and temporally

Definition-2

Climate means the usual condition of the temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological elements in an area of the Earth's surface for a long time Climate means the usual condition of the temperature, humidity, atmospheric pressure, wind, rainfall, and other meteorological elements in an area of the Earth's surface for a long time

Global climate is influenced by many interacting systems, including the atmosphere, oceans, land and ice, which together we call the climate system. ... Climate change refers to a large-scale, long-term shift in the planet's weather patterns and average temperatures

Type of climates

The 4 climates The Climate of the Philippines is either tropical rainforest, tropical savanna or tropical monsoon, or humid subtropical (in higher-altitude areas) characterized by relatively high temperature, oppressive humidity and plenty of rainfall. 2 There are two seasons in the country, the wet season and the dry 

History

The concept of a geographical zone was first hypothesized by the ancient Greek scholar Parmenides^[1] and lastingly modified by Aristotle.^[2] Both philosophers theorized the Earth divided into three types of climatic zones based on their distance from the equator.

Like Parmeneides, thinking that the area near the equator was too hot for habitation, Aristotle dubbed the region around the equator (from 23.5° N to 23.5° S) the "Torrid Zone." Both philosophers reasoned the region from the Arctic Circle to the pole to be permanently frozen. This region, thought uninhabitable, was called the "Frigid Zone." The only area believed to be habitable was the northern "Temperate Zone" (the southern one not having been discovered), lying between the "Frigid Zones" and the "Torrid Zone". However, humans have inhabited almost all climates on Earth, including inside the Arctic Circle.

As knowledge of the Earth's geography improved, a second "Temperate Zone" was discovered south of the equator, and a second "Frigid Zone" was discovered around the Antarctic. Although Aristotle's map was oversimplified, the general idea was correct. Today, the most commonly used climate map is the Köppen climate classification, developed by Russian climatologist of German descent and amateur botanist Wladimir Köppen (1846–1940), which divides the world into five major climate regions, based on average annual precipitation, average monthly precipitation, and average monthly temperature.

1. Climate zone
2. Definition
3. Climate Zone: are divisions of the Earth's climates into general climate zones according to average temperatures and average rainfall. The three major climate zones on the Earth are the polar, temperate, and tropical zones. Temperatures in these three climate zones are determined mainly by the location, or latitude, of the zone.
4. ·         polar- has the coldest with temperatures almost always below freezing. 
5. ·         temperate- contains most of the Earth’s land masses with more moderate temperatures and rainfall year-round. 
6. ·         tropical zones- has the warmest average temperatures and gets the most rain.
7. Climate zone is represented by geographical zone
8. 
   
9. Tropical- 0-20 c latitude
10. Sub tropical> 20-40c latitude
11. Temperate >  40-60c latitude
12. Arctic and Antarctic> 60-80 latitude
13. The five main latitude regions of the Earth's surface comprise geographical zones, divided by the major circles of latitude. The differences between them relate to climate They are as follows:
14. 1. The North frigid zone, between the Arctic Circle 66.5° N and the North Pole 90° N. Covers 4.12% of Earth's surface.
15. 2.  
16. 3. The North temperate zone, between the Tropic of Cancer 23.5° N and the Arctic Circle 66.5° N. Covers 25.99% of Earth's surface.
17. 4. The Torrid zone, between the Tropic of Cancer 23.5° N and the Tropic of Capricorn 23.5° S. Covers 39.78% of Earth's surface.
18. 5. The South temperate zone, between the Tropic of Capricorn 23.5° S and the Antarctic Circle 66.5° S. Covers 25.99% of Earth's surface.
19. 6.  
20. 7. The South frigid zone, from Antarctic Circle 66.5° S and the South Pole 90° S. Covers 4.12% of Earth's surface.
21. 
22. Earth's climatic zones
23.   Ice cap
24.   Tundra
25.   Boreal
26.   Warm temperate
27.   Subtropical
28.   Tropical
29. On the basis of latitudinal extent, the globe is divided into three broad heat zones.
31. ·         1Torrid zone
32. ·         2Temperate zones
33. ·         3Frigid zones
34. ·         4History
35. ·         5See also
36. ·         6References
37. Torrid zonE
38. The Torrid is also known as the Tropics. The zone is bounded on the north by the Tropic  of Cancer and on the south by the Tropic of Capricorn; these latitudes mark the northern and southern extremes in which the sun seasonally passes directly overhead. This happens annually, but in the region between, the sun passes overhead twice a year.
39. In the  Northern Hemisphere,  in the sun's apparent northward migration after the March equinox, it passes overhead once, then after the June solstice, at which time it reaches the Tropic of Cancer, it passes over again on its apparent southward journey. After the September equinox the sun passes into the Southern Hemisphere. It then passes similarly over the southern tropical regions until it reaches the Tropic of Capricorn at the December solstice, and back again as it returns northwards to the Equator.
40. Temperate zone
41. In the two temperate zones, consisting of the tepid latitudes, the Sun is never directly overhead, and the climate is mild, generally ranging from warm to cool. The four annual seasons, spring, summer, autumn and winter, occur in these areas. The North Temperate Zone includes Europe, Northern Asia, and North and Central America. The South Temperate Zone includes Southern Australasia, southern South America, and Southern Africa.
42. Frigid zonE
43. The two frigid zones, or polar regions, experience the midnight sun and the polar night for part of the year - at the edge of the zone there is one day at the winter solstice when the Sun is invisible, and one day at the summer solstice when the sun remains above the horizon for 24 hours. In the center of the zone (the pole) the day is one year long with six months of daylight and six months of night. The frigid zones are the coldest regions of Earth and are generally covered in ice and snow. It receives slanting rays of the sun as this region lies farthest from the equator. Summer season in this region lasts for about 2 to 3 months and there is almost 24 hour sunlight during summer.it Ray's are always slanting and provides less heat.
44. 
    

Fresh Meats and Poultry Microbiology

Fresh Meats and Poultry Microbiology

Fresh Meats and Poultry Microbiology

It is generally agreed that the internal tissues
of healthy slaughter animals are free of bacteria
at the time of slaughter, assuming that the animals are not in a state of exhaustion. When one
examines fresh meat and poultry at the retail
level, varying numbers and types of microorganisms are found. The following are the primary
sources and routes of microorganisms to fresh
meats with particular emphasis on red meats

• The stick knife. After being stunned and
hoisted up by the hind legs, animals such as
steers are exsanguinated by slitting the jugular vein with what is referred to as a "stick
knife." If the knife is not sterile, organisms
are swept into the bloodstream, where they
may be deposited throughout the carcass.
• Animal hide. Organisms from the hide are
among those that enter the carcass via the
stick knife. Others from the hide may be
deposited onto the dehaired carcass or onto
freshly cut surfaces

• Gastrointestinal tract. By way of punctures,
intestinal contents along with the usual
heavy load of microorganisms may be deposited onto the surface of freshly dressed
carcasses. Especially important in this regard is the paunch or rumen of ruminant

THE BIOTA OF MEATS AND
POULTRY
The major genera of bacteria, yeasts, and
molds that are found in these products before
spoilage are listed inTables 4-1 and 4-2. In general, the biota is reflective of the slaughtering
and processing environments as noted above,
with gram-negative bacteria being predominant.
Among gram positives, the enterococci are the
biota most often found along with lactobacilli.
Because of their ubiquity in meat-processing
environments, a rather large number of mold
genera may be expected, including Penicillium,
Mucor, and Cladosporium. The most ubiquitous
yeasts found in meats and poultry are members of the genera Candida and Rhodotorula

Genus	Gram Reaction	Fresh Meats	Fresh Livers
Acinetobacter	XX
Aeromonas	XX
Alcaligenes
Arcobacter
Bacillus

Genera of Fungi Most Often Found
on Meats and Poultry
Fresh and

Refrigerated

Genus	Meats	Poultry
Molds
Alternaria	X	X
Aspergillus	X	X
Aureobasidium	X
Cladosporium	XX	X
Eurotium	X
Fusarium	X
Geotrichum	XX	X
Monascus	X
Monilia	X
Mucor	XX	X
Neurospora	X
Penicillium	X	X
Rhizopus	XX	X
Sporotrichum	XX
Thamnidium

INCIDENCE/PREVALENCE OF
MICROORGANISMS IN FRESH
RED MEATS

The incidence and prevalence of microorganisms in some red meats are presented in
The aerobic plate counts (APCs) of
the fresh ground beef in this table are considerably

trending-down of bacteria in fresh ground beef
or of laboratory methodology is unclear. For
many decades, comminuted meats have been
shown to contain higher numbers of microorganisms than noncomminuted meats such as steaks,
and there are several reasons for this:

• Commercial ground meats consisting of
trimmings from various cuts that are handled
excessively generally contain high levels of
microbial contamination. Ground meats that
are produced from large cuts tend to have
lower microbial numbers.

• Ground meat provides a greater surface area,
which itself accounts in part for the increased flora. It should be recalled that as
particle size is reduced, the total surface area
increases with a consequent increase in surface energy.

• This greater surface area of ground meat
favors the growth of aerobic bacteria, the
usual low-temperature spoilage flora.

• In some commercial establishments, the
meat grinders, cutting knives, and storage
utensils are rarely cleaned as often and as
thoroughly as is necessary to prevent the
successive buildup of microbial numbers.
This may be illustrated by data obtained
from a study of the bacteriology of several
areas in the meat department of a large grocery store. The blade of the meat saw and
the cutting block were swabbed immediately
after they were cleaned on three different
occasions with the following mean results:
the saw blade had a total log10 per square
inch count of 5.28, with 2.3 coliforms, 3.64
enterococci, 1.60 staphylococci, and 3.69
micrococci; the cutting block had a mean
log per square inch count of 5.69, with 2.04
coliforms, 3.77 enterococci, <1.00 staphylococci, and 3.79 micrococci. These are
among the sources of the high total bacterial count to comminuted meats.

• One heavily contaminated piece of meat is
sufficient to contaminate others, as well as
the entire lot, as they pass through the
grinder. This heavily contaminated portion

 

Mechanically Deboned Meat, Poultry,
and Fish

When meat animals are slaughtered for human consumption, meat from the carcasses is
removed by meat cutters. However, the most economical way to salvage the small bits and pieces
of lean meat left on carcass bones is by mechanical means (mechanical deboning). Mechanically
deboned meat (MDM) is removed from bones
by machines. The production of MDM began in
the 1970s, preceded by chicken meat in the late
1950s and fish in the late 1940s.3336 During the
deboning process, small quantities of bone powder become part of the finished product, and the
1978 U.S. Department of Agriculture (USDA)
regulation limits the amount of bone (based on
calcium content) to no more than 0.75% (the
calcium content of meat is 0.01%). MDM must
contain a minimum of 14% protein and no more
than 30% fat. The most significant parametrical
difference between MDM and conventionally
processed meat relative to microbial growth is
the higher pH of the former, typically 6.0-7.0.3334
The increased pH is due to the incorporation of
marrow in MDM.
Although most studies on the microbiology
of MDM have shown these products to be not
unlike those produced by conventional methods,
some have found higher counts. The microbiological quality of deboned poultry was compared
to other raw poultry products, and although the
counts were comparable, MPN coliform counts
of the commercial MDM products ranged from
460 to >l,100/g. Six of 54 samples contained
salmonellae, four contained C. perfringens, but
none contained S. aureus.