Microbiology of Fluid
Milk
Compiled by: - Mr.
Abhay Pandey
Q: The
production of clean, wholesome milk free from pathogens, maintenance of this
condition from farm to the consumers is called:
A.Milk
hygiene
Q:The safe
foods should not contain
A.Pathogens
Q:The
microorganism responsible for the spread of mastitis among herd is
A.
Streptococcus agalactiae
Q:The
predominant genera present in the interior of udder
A.Micrococci
Q:The most
common spores found in milk are of
A.Clostridium and Bacillus
Q:The microbial
counts of air in sheds should not exceed
A.200
cfu/l
Q:Health of
a milk yielding animal will be maintained by checking
A.Routine vaccination,Infectious
diseases and Mastitis in all teats
Q:The milker
should never be allowed for milking the animal if he is suffering with
A.Stomach
upset
Q:Ropiness
in milk and milk products is generally caused by:
A.Alcaligenes
viscosus
Q:Lactic
acid bacteria are classified as:
A.Heterotrophic
chemoorganotrophs
Q:Microorganism
that can survive to varying extent of pasteurization temperature is
A.Thermoduric
Q:Fruity
flavour in dairy products is due the contamination of:
A.Pseudomonas
fragi
Q:Lipolytic
mold found in milk or its products is
A.Geotrichum
candidum
Q:According
to ShermanÂ’s classification streptococci are classified into __ groups
A.Four
Q:The
significant features of Streptococcus dysgalactiae is _____
A.
CAMP test is negative, Belongs to Lancefield C and Causes bovine mastitis
Q:Lactococcus
lactis spp lactis does not
A.Gas
from citrate
Q:Lactococcus
lactis spp lactis biovar diacetylactis produces ____ from
citrate
A.Diacetyl
Q:Homofermentative
bacilli having therapeutic properties is
A.L.
acidophilus
Q:A bacilli L.
bulgaricus along with a cocci is used for the production of yogurt
A.Lactobacillus
bulgaricus
Q: ________
is a flavour producer in the presence of lactic acid.
A.Leuconostoc
Q:Life-threatening
nosocomial infections in humans, especially in the hospital environment are
caused by
A.E.
faecalis
Q:Water
soluble fluorescent greenish-brown pigment known as ‘Pyoverdin’ is produced by:
A.Pseudomonas
fluorescens
Q:_______ is
an opportunistic pathogen that causes mastitis in dairy animals and human
infection.
A.Pseudomonas
aeruginosa
Q:________
is a pseudolactic acid bacteria
A. E.
coli
Q:A natural
inhabitant of intestine is:
A. E.
coli
Q:Typhoid is
caused by _______________
A.S.
Typhi
Q:A
bacterial species named from Greek meaning the ‘golden grape-cluster berry’
A.Staphylococcus
aureus
Q:The genus
having a pathogen known to cause serious diseases in mammals, i.e.
tuberculosis, is:
A.Mycobacterium
Q:An
organism that produce yellow to deep orange red carotenoid pigments and used
for preparation of surface ripened Limburger type chesses, is:
Brevibacterium
linens
Q:The strain
used in cheese making to create CO2 bubbles that become ‘eyes’, round holes in
the cheese is:
A.Propionibacterium
freudenreichii subsp. Shermanii
Q:Produces
‘sweet curdling’ by coagulating milk at lower acidity
A.Bacillus
cereus
Q:Late
blowing condition in cheeses is caused by ______________
A.Clostridium
tyrobutyricum
Q:The main
target of milk sterilization
A.Bacillus
stearothermophilus
Q:Used in
the detection of antibiotics in milk
A.Bacillus
stearothermophilus
Q:A
Gram-positive anaerobic spore former
A.Clostridium
Q:The mould
generally used for the preparation of blue veined cheeses is_____
A.Pencillium
roqueforti
Q:Bacteriophages
are the
A.Viruses
that infect bacteria
Q:Aflatoxins
are produced by the species of
A.Aspergillus
spp
Q:All
viruses contains
A. DNA
or RNA and a protein coat
Q:Psychrotrophs
are capable of growing:
A.At
7°C or below
Q:The two
predominant psychrotrophic pathogens found in milk products are: A.Listeria
monocytogenes and Yersinia enterocolitica
Q:The most
frequently reported psychrotroph in raw milk.
A.Pseudomonas,
Q:The
suggested standards of psychrotrophs for satisfactory raw milk are:
A.
Less than 104 cfu per ml -
Q:SPC of
very good quality raw milk
A.Less
than 2,00,000
Q:The DMC of
good quality raw milk
A.Less
than 5,00,000
Q:Thermoduric
count of good quality milk
A.Less
than 10,000
Q:Q-fever is
caused by
A.Coxiella
burnetii
Q:It is
unlikely that _____ ever live in the udder of an animal.
A.Psychrophile
Q:The main
cause of spoilage of refrigerated raw milk samples is the production and
secretion of _________ and various other thermo-resistant enzymes.
A.Hydrolytic
Q:The
maximum hygienic parameter for fecal coliforms is
A.2035
Q:At
low-temperature storages only ___________ will grow that produces heat
resistant enzymes that causes off flavour
A.Psychrotolerant
Q:A decrease
in temperature from _________ increases the keeping time of milk approximately
the same number of days as did cooling from 35-5º C
A.5-0°C
Q:The test
provides a rapid indication of the quality of liquid milk products and, at the
same time, supplies a permanent record of the quality.
A.DMC
Q:The test
is insensitive if the bacterial load is very less
A.DMC
Q:
__________ count is taken at low temperature.
A.Thermoduric
Q:Metabolic
reactions caused by bacteria are difficult to measure in _____ quality products
A.High
Q:The
electrical impedance in a culture medium remains fairly constant until a
threshold of _____ cells per milliliter is reached, when major changes in
impedance start to occur
A.10^6
– 10^7
Q:The
oxidation-reduction potential of good quality milk while testing
A.+
0.3 volts.
Q:The number
of microbes at the time of decolorizing of methylene blue will be nearly
A.100
– 120 millions
Q:The dye
reduction tests are of little value as an index of the bacterial content of
A.Refrigerated
milk
Q:The
Lovibond comparator is used in
A.RRT
Q:The
bacteria which reduces resazurin more quickly than methylene blue
A.Lactococcus
lactis ssp lactis
Q:The method
which is useful for a rapid estimation of the total bacterial population (both
live and dead cells) of a milk sample is:
A.DMC
Q:The
indirect method for tracing the sources of contamination of milk is:
A.DMC
Q:In DMC,
the milk smear is prepared on ___ square centimetre area.
A. One
Q:In DMC,
the milk smear is stained with a special stain called
A.Newman's
stain
Q:Milk for
making smear in DMC test is taken with the help of a sterile
A.Breed’s
pipette
Q:The test
useful in the estimation of number of viable microorganisms in the given sample
of milk
A.SPC
Q:The SPC of
very good quality raw milk.
A.Not
exceeding 2,00,000
Q:The
purpose of making serial dilutions in this test is aimed to reduce the bacterial
number to ____ level while adding to Petri dish
A.30
to 300
Q:The SPC of
pasteurized milk
A.30,000
Q:The
quantity of the previously melted and cooled sterilized standard plate count
agar to each Petri dish is
A.12
to15 ml
Q:Coliforms
are Gram's negative, oxidase negative, non-spore forming rods that can grow
aerobically or facultative in presence of
A.Bile
salts
Q:Coliforms
are able to ferment______ with the production of acid and gas within 48 h. at
37°C.
A.Lactose
Q:Presence
of coliforms in milk or milk products indicates, possible contamination with
A.Faeces
Q:Raw milk
is graded/ accepted as criterion of satisfactory quality, based on the absence
of coliforms in
A.1:
100 dilution
Q:In
addition to the presence of faecal coliforms, the faecal streptococci and Clostridium
perfringens are likely to exist in the gut of all warm-blooded animals, and
their presence in milk will also indicate the source of faecal contamination.
Hence, this coliform test is called as:
A. Presumptive
coliform test
Q:Micro-organisms
capable of growing at refrigeration temperature (7-10°C) are:
A.Psychrotroph
Q:The media
used for the isolation and identification of the proteolytic micro-organisms of
milk is:
A.Milk
agar
Q:The plates
for psychrotrophic count are incubated in a refrigerator at 7-10°C for
A.10
days
Q:The Plates
for estimating thermophilic microorganisms are incubated at ___ for 24 to 48 h
and colonies are counted.
A.45° C
Q:Proteolytic
psychrotrophic colonies identification can be enhanced by flooding the plates
with a solution of
A.1%
Hydrochloric acid
Q:The media
used for the enumeration of yeast and moulds from milk is
A.Potato
Dextrose agar
Q:The pH of
the medium used for enumeration of yeast and mould should be
A.Acidic
Q:The most
important source of contamination of milk with yeasts and moulds is
A.Air
Q:An
important mould in dairy industry is:
A.Penicillium
roqueforti
Q:The main
goals of all living forms are
A.Self
perpetuation
Q:An
interaction between two or more species, where species derive a mutual benefit
A.Mutualism
Q:The
relationship between two species which interact but do not affect each other
A.Neutralism
Q:Production
of antibiotic or inhibitory substances by one organism that affect the growth
or survival of another organism can be called
A.Antagonism
Q:The
relationship between microorganisms in which one organism benefits from the
association but the other organism is not affected, denotes
A.Commensalisms
Q:Micro-organisms
that are able to survive the acidity already produced and in turn produce more
acidity are:
A.Lactobacilli
Q:Micro-organism,
which may establish itself on the surface of the coagulated milk and oxidize
lactic acid to H2O and CO2:
A.Geotricum
candidum
Q:When
lactose is exhausted the micro-organisms that develop and decompose the casein
are:
A.Proteolytic
and spore formers
Q:The pH of
uncared milk after prolonged storage is:
A.8 to
10
Q:The
production of gas mainly CO2 and acid by certain micro-organisms in dairy
products is responsible for a defect called:
A.Frothiness
Q:Micro-organism
that ferment lactose of milk or cream into gas and acid and cause early gas
production:
A.Escherichia
coli,
Q:The
organism which ferment lactose of milk or cream into gas and acid and cause
late gas production:
A.Clostridiuym
butyricum
Q:The
lactose fermenting yeast is:
A.Candida
pseudotrophicalis
Q:Ropy
fermentation is brought about by the growth of ____ bacteria leading to change
in consistency of the produce that forms threads of viscous masses when poured:
A.Alcaligenes
viscosus
Q:The milk
obtained from animals suffering from the udder infection is called:
A.Mastitic
milk
Q:Natural
inhabitant of udder and mastitis causing micro-organism is:
A.Streptococcus
agalactiae
Q:Summer
mastitis is caused by:
A.Corynebacterium
pyogenes
Q:Environmental
mastitis is caused by:
A.Streptococcus
uberis
Q:In case of
milk obtained from infected udder, the oxygen liberated with catalase on adding
hydrogen peroxide will exceed:
A.2.5
ml
Q:CAMP test
is very specific for the detection of mastitis caused by:
A.Streptococcus
agalactiae
Q:In milk
obtained from healthy udder the leucocytes count will be less than:
A.1.0
lakh/ ml
Q:Very long
chains of micro-organisms in a smear of mastitic milk is indicative of:
A.Streptococcus
agalactiae
Q:Rusty
brown colour colonies in Hotis test is indicative of
A.Staphylococcus
aureus
Q:Botulism
poisoning is the severest of all the food poisonings, as it affects the _______
and is often extremely fatal:
A.Nervous
system
Q:Unhygienic
practices appear to be chiefly responsible for the eruption of outbreak:
A.Cholera
Q:The
“infantile diarrhea or Travellers’ diarrhea” characterized by watery diarrhea
leading to dehydration & shock is caused by:
A.Invasive
EEC
Q:The common
food poisoning caused by canned foods is due to:
A.
Clostridium perfringens
Q:Alatoxins
are mycotoxins produced by:
A.Aepergillus
flavus
Q:Milk borne
tuberculosis is directly or indirectly related to consumption of raw milk from
infected dairy herds and the causative microorganism is
A.Mycobacterium
tuberculosis
Q:Corynebacterium
diphtheriae is a causative microorganism mainly parasitic to man and is
usually found in ________ of the infected or healthy carriers
A.Respiratory
tract
Q:Most heat
resistant pathogenic microorganism which can be used as indicator worganism for
pasteurization
A.Coxiella
burnetti
Q:Infectious
hepatitis is caused by
A.Virus
Q1:Like many
other diarrheal diseases, poliomyelitis occurs commonly i______ ,
A.Summer
Q:Specific
naturally occurring anti microbial substances in milk
A.
Immunoglobulins
Q:Non-specific
naturally occurring anti microbial substances in milk
A.Lactoferrin
Q:The chief
immunoglobulin of milk and confers passive immunity
A.Ig A
Q:Invading
of pathogens by leucocytes for the protection of udder from mastitis
A.Phagocytosis
Q:The milk
contains bifidus factor responsible for the dominance of a bacterium Bifidobacterium
bifidus in infants
A.Human
Milk
Q:Most
pathogenic bacteria are classified as _____________ for their growth
temperature requirements
A.Mesophiles
Q:Bacteria
require nitrogen for the synthesis of _______ :
A.Proteins
Q:Through
metabolism, pathogens often produce acids that interfere with their own growth,
hence, ________ are added to media to control pH changes
A.Buffers
Q:A
microorganism that can grow at 4°C and 25°C both but grows best at 20°C would
be classified as ______ :
A.Psychrotroph
Reference:-
1.
ICAR E-course
2.
NDRI class notes
3.
Previous
year question papers
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