Accessory food substances or vitamins, Biology

Assignment Help:

Q. Accessory Food Substances or Vitamins ?

Bacteria also vary in their need for vitamins or accessory growth factors. Some microorganisms are unable to synthesize some or all of the vitamins needed for their growth. For example, Staphylococcus aureus synthesizes part while Pseudomonas or Escherichia coli all of the factors needed. The lactics and many pathogens must have all of the vitamins furnished.

Microorganisms may require B vitamins in low quantities and most of the natural foods have an abundant quantity of these. Gram positive bacteria are the least synthetic and must, therefore, be supplied with one or more of these compounds before they will grow. Gram-negative bacteria and molds are able to synthesize most of their requirements. Consequently, these two groups of organisms may be found growing on foods low in B vitamins. Fruits tend to be lower in B vitamins than meats. Thus, the usual spoilage of fruits is by molds rather than bacteria since fruits also have a low pH and positive Eh, which favour mold growth.

Egg white contains biotin but also contains avidin, which ties it up, making it unavailable to microorganisms and thus eliminate spoilage of eggs through biotin requiring organisms. The processing of foods often reduces the vitamin content. For example, thiamine, pantothenic acid, folic acid and ascorbic acid (in air) are heat-labile. Drying causes a loss in vitamins such as thiamine and ascorbic acid. Even storage of foods for long periods, especially if the storage temperature is elevated, may result in a decrease in the level of some of these growth factors.


Related Discussions:- Accessory food substances or vitamins

Reparative regeneration, Reparative Regeneration This type of regener...

Reparative Regeneration This type of regeneration, as the name suggests, involves repair of a wound or replacement of a body part removed intentionally or because of injury.

Explain food effects on drug excretion, Explain Food Effects on Drug Excret...

Explain Food Effects on Drug Excretion? Food and nutrients can alter the re-absorption of drugs from the renal tubes. Urinary acidity affects drug re-absorption from the renal

General preventive measures for animals, GENERAL PREVENTIVE MEASURES - ...

GENERAL PREVENTIVE MEASURES - 1.      Infected animal should be immediately isolated and looked after. 2.      The premises should be disinfected whenever there is an outbre

What is a provirus, It is the DNA representing, the genome of virus that ha...

It is the DNA representing, the genome of virus that has been included into the DNA of the host.

Does the fish heart pump venous or arterial blood, Does the fish heart pump...

Does the fish heart pump venous or arterial blood? The venous blood coming from the tissues enters the atrium and passes to the ventricle that then pumps the blood towards the

Cell with a euploid number of chromosomes, A cell with a euploid number of ...

A cell with a euploid number of chromosomes contains: A.one half of a complete set of chromosomes B.several complete sets of chromosomes C.the correct number of chromosomes D.two c

How is the smoothing tendency of cornea functioned, How is the smoothing te...

How is the smoothing tendency of cornea functioned? Smoothing tendency: In health and in disease condition the epitheliurm has a strong tendency to smoothen the underlyin

What are the allele frequencies, You observe the following numbers of indiv...

You observe the following numbers of individuals of each genotype in a population: AA 700 Aa 200 aa 100 a.) what are the observed genotype frequencies in this populaiton?

What is linkage, Question Write a short note on the following: 1 D...

Question Write a short note on the following: 1 Dihybrid cross 2 Supplementary interaction 3 Maternal effect 4 Hardy Weinberg Equilibrium 5 What is Linkage? Ex

Coa to succinate in the citric acid cycle, Name the high-energy complex gen...

Name the high-energy complex generated during the conversion of succinyl CoA to succinate in the citric acid cycle GTP  or  ATP is  the high-energy  complex generated during th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd