Question and answer
explain the conditions needed for the growth of microorganisms
This varies depending on the type of bacteria. For example, warmblooded animal pathogenic bacteria require a temperature of around 98oF, a correct entry site, and for the host to be susceptible to that type of bacteria. [ Thermo-phillic bacteria require extremely hot temperature to grow. Viruses require a healthy host cell in order to get its DNA/RNA replicated. Parasites require the host body
to be healthy enough to sustain itself and the parasite. ]
Expert answered|Fanboy|Points 1000|
Question
Asked 4/17/2012 7:19:28 AM
Updated 5/10/2013 4:11:49 PM
1 Answer/Comment
Get an answer
New answers
Rating
0
Most micro-organisms require food, warmth, moisture, oxygen, time and a certain pH level in order to grow and multiply.

Moulds
•Most moulds are saprophytic i.e. they feed on dead organic matter. They grow on many foods especially fruit, bread, jam and cheese.
•Most moulds are mesophiles i.e. they thrive at temperatures between 20 and 45 degrees Celsius. Freezing (-18 degrees Celsius) inactivates mould growth. Temperatures below 15 degrees Celsius including fridge temperatures (1 to 4 degrees Celsius) retard mould growth. Cooking temperatures above 75 degrees Celsius destroy moulds.
•Moulds grow best in humid moist conditions, on foods with water present in liquid form. Frozen foods are unsuitable.
•Moulds are aerobic i.e. they require oxygen. As a result they grow on the surface of solid foods e.g. jam, and throughout open structure foods e.g. bread.
•Moulds favour slightly acidic conditions of pH 4 to pH 6. Extremely acidic or alkaline conditions inhibit mould growth.
•Moulds need time in order to multiply.

Yeast
•Yeast feeds on carbohydrates.
•Yeast thrives at temperatures between 25 to 30 degrees Celsius. Low temperatures inactivate yeast, while high temperatures of about 60 degrees Celsius kill yeast.
•Yeast needs moisture in order to grow.
•Yeast is a facultative organism i.e. it can live with or without oxygen.
•Yeast grows best in an acidic environment.
•Yeast needs time to grow.

Bacteria
•Some bacteria are saprophytic, and some are parasitic. Saprophytic bacteria i.e. those that feed on dead organic matter, include those bacteria which are present in soil and food and cause decomposition. Parasitic bacteria i.e. those that feed on living matter, cause diseases in humans, plants and animals.
•Bacteria have a very wide temperature range. Some are psychrophiles i.e. they thrive at low temperatures of -5 to 20 degrees Celsius, e.g. some clostridia bacteria.
Added 5/10/2013 4:11:49 PM
Comments

There are no comments.

Add an answer or comment
Log in or sign up first.
Questions asked by the same visitor
identify common sources of infection
Weegy: he sources of infection are numerous, and for each type of infection a specific source becomes more significant than the others in the delivery of the infectious agent to the host, which is man in our discussion. [ The sources of infection can be divided into two main groups. These are exogenous and endogenous sources (3). A source of infection is endogenous when the infectious agent comes from the patient’s own body, usually from his own normal flora. Endogenous sources of infections become important when the person’s own immunity against his normal flora becomes compromised such as in cases of contamination during surgery, malnutrition, impairment of blood supply and debilitating diseases such as AIDS, diabetes or any other accompanying infection. Examples are the genera of staphylococci and streptococci which are normally found in the body, but can become pathogenic in certain circumstances (2). The exogenous sources of infection introduce organisms from any where outside to inside the body, which is the case most of the time. In addition to being exogenous, most of the time infections are transmitted from person to person or from animal to man (4). To be more specific, exogenous sources of infections can be either human, animal, or environmental in origin. Humans can be a source of infection in three cases, either when they are clinically infected (symptomatic infection), when they are asymptomatically infected or when they are carriers (5). ] (More)
Question
Expert Answered
Asked 4/17/2012 7:50:02 AM
0 Answers/Comments
17,584,815 questions answered
Popular Conversations
A list of potential sources of information for a paper is a(n) ...
Weegy: A list of potential sources of information for a paper in annotated bibliography. User: An index to ...
9/29/2014 2:50:04 PM| 4 Answers
You've settled on an idea for an essay to write. What should you do ...
Weegy: D.) Conduct interviews, do some research, ask questions, and make a plan. User: To make sure your reader ...
9/29/2014 5:55:28 PM| 4 Answers
What is the square root of 6000?
9/29/2014 2:39:45 PM| 3 Answers
Because the subject of a composition is like a crystal with many ...
Weegy: Because the subject of a composition is like a crystal with many facets, you should A. offer your reader ideas ...
9/29/2014 7:06:34 PM| 3 Answers
In the Roman Republic, ____________ did not have power in the ...
Weegy: In the Roman Republic,non-citizens did not have power in the government.
9/29/2014 5:48:03 AM| 2 Answers
-2(4x + 1)= -8x + 2
9/29/2014 7:08:45 AM| 2 Answers
Weegy Stuff
S
R
L
1
1
P
C
1
P
1
1
L
P
C
P
C
1
P
C
L
P
C
1
P
C
P
C
P
C
L
Points 3211 [Total 27609]| Ratings 8| Comments 3131| Invitations 0|Online
S
L
1
L
P
C
1
Points 2919 [Total 9450]| Ratings 12| Comments 2799| Invitations 0|Offline
S
L
C
P
C
1
L
L
P
C
1
Points 2715 [Total 18654]| Ratings 18| Comments 2535| Invitations 0|Offline
S
L
P
C
L
P
C
P
C
L
P
C
P
C
P
C
Points 2659 [Total 19831]| Ratings 12| Comments 2539| Invitations 0|Offline
S
L
1
1
1
1
L
1
L
Points 2548 [Total 12328]| Ratings 0| Comments 2548| Invitations 0|Offline
S
1
L
1
L
P
P
L
Points 917 [Total 12163]| Ratings 0| Comments 917| Invitations 0|Offline
S
L
P
C
P
C
1
L
P
C
L
P
C
P
C
P
C
P
C
Points 864 [Total 19395]| Ratings 2| Comments 844| Invitations 0|Offline
S
L
Points 729 [Total 1398]| Ratings 0| Comments 729| Invitations 0|Offline
S
1
L
L
Points 632 [Total 5755]| Ratings 4| Comments 592| Invitations 0|Offline
S
P
C
L
P
L
1
Points 173 [Total 6230]| Ratings 2| Comments 153| Invitations 0|Offline
Home | Contact | Blog | About | Terms | Privacy | Social | ©2014 Purple Inc.