1. VII Sem BE Biotechnology
under VTU, Belgaum
06BT74 Food Biotechnology
Unit 5
Synopsis of Common Foodborne
Bacteria, Molds and Yeasts
Dr Pratima Khandelwal, Biotechnology, NHCE, Nov 2011 1

2. Sl Bacterial groups Features % G + Occurrence Special
C feature
1 Acinetobacter Gram negative rods, strict 39- widely distributed
Family- aerobes, do not reduce 47 in soil, waters,
Moracellaceae nitrates, rod shaped foods (refrigerated
(young cultures) or fresh products,
coccoid (old cultures), meat products)
2 Aeromonas the gas producers; 57- Inhabitants of fish
aquatic, gram negative 65 intestines
rods, gas formers from
sugar fermentation,
3 Alcaligenes Mainly Gram negative, 58- In decomposing Genus is
rods, ferments sugars to 70 matter, rw milk, heteroge
produce alkali. Non- poultry products, neous
pigmented fecal matter
Dr Pratima Khandelwal, Biotechnology,
2
NHCE, Nov 2011

3. 4 Alteromonas Gram negative, 43-48 Marine/coastal Require sea
motile rods, strict water water for
aerobes inhabitants, growth
found on and in
all sea foods
5 Bacillus Gram positive 32-62 Foodborne Mostly
B. cereus spore forming gastroenteritis mesophiles,
B. anthracis rods, aerobes, thermophiles,
psychrotrophs
also exist
B. anthracis
B. cereus
Dr Pratima Khandelwal, Biotechnology,
3
NHCE, Nov 2011

4. 6 Campylobacter Gram negative, 30-35 Soil borne, Genus
(Formerly vibrios) spirally curved rods, vegetables, restructured to
C. jejuni sub sp micro-aerophilic- meat and Arcobacter and
anaerobic
jejuni poultry Helicobacter
7 Citrobacter Gram negative rods, 50-52 Enteric,
C freundii slow fermenting, vegetables,
Citrate as sole C fresh meats
source, associated
with warm blooded
animals
8 Clostridium Anaerobic, spore Widely Mesophiles,
C. perfringens for formers distributed thermophiles,
food poisoning psychrotrophs,
and botulism Imp for thermal
processing
Dr Pratima Khandelwal, Biotechnology,
4
NHCE, Nov 2011

5. C. perfringes
Dr Pratima Khandelwal, Biotechnology,
5
NHCE, Nov 2011

6. 9 Corynebacterium Gram positive, rods, 51-63 Spoilage of Mostly
vegetables, mesotrophs
meat
10 Enterobacter Gram negative, typical of Enteric Coliform
Enteriobacteriaceae for representative
growth requirements
11 Enterococcus Gram positive, ovoid Earlier in
cells, singly/pairs/short Streptococcus
chain
Dr Pratima Khandelwal, Biotechnology,
6
NHCE, Nov 2011

7. 12 Erwinia Gram negative rods 53-54 Associated Cause bacterial
with plants soft rot
13 Escherichia Gram negative enteric 48-52 GI tract of Fecal coliform,
E.coli rods, E.coli: 5 groups of warm Hemorrhagic
foodborne illness: blooded, colitis (0157:
Enteropathogenic (EPEC), waterborne H7), Travlers’
enterotoxigenic (ETEC), diarrhea
enteroinvasive (EIEC), (025:K98: NM)
enterohemorrhagic (EHEC),
Facultatively
enteropathogenic (FEEC)
14 Flavobacterium Gram negative rods, Associated Produce yellow
mesotrophs and with plants, to red pigments
psychrotrophs related to on agar
spoilage of
refrigerated
meats and
vegetables
Dr Pratima Khandelwal, Biotechnology,
7
NHCE, Nov 2011

8. E. coli
Dr Pratima Khandelwal, Biotechnology,
8
NHCE, Nov 2011

9. 15 Hafnia Gram negative rods, only 48-49 Enteric,
species: H alive, is spoilage of
motile, refrigerated
meats and
vegetables
16 Lactobacillus Gram positive, catalase Dairy 3 phylogenetic
negative rods, in long products, clusters:
chains, microaerophilic vegetables, Betabacterium,
to anaerobic refrigerated Streptobacteriu
stored and m,
vacuum Thermobacteri
packed meat um
Dr Pratima Khandelwal, Biotechnology,
9
NHCE, Nov 2011

10. LAB: Lactobacillus, Homofermentative (LA Production of dairy Bergey’s
Leuconostoc, only), EMP products, fermented Manual (IX
Pediococcus, and Heterofermentative meats, fisheries, pickled Edition)
(LA, ethanol, CO2), HMP/PP plant products
Streptococcus,
Carobacterium
(lactobacilli)
{Enterococcus,
Lactococcus,
Vagococcus}
streptococci
Lactococcus Gram positive, non-motile, Dairy products Earlier
L. lactis (sub sp catalase negative, spherical Streptococci
lactis, cremoris), to oval, homo- genera
fermentative
L.plantarum,
Dr Pratima Khandelwal, Biotechnology,
10
NHCE, Nov 2011

11. Leuconostoc Gram positive, catatase Spoilage of
negative cocci, hetero- wines, vac
fermentative packed foods
Listeria Gram positive non- <50
L. monocytogenes sporulating rods,
Micrococcus Gram positive, catalase 66-75 Widely Produce pink
positive cocci, mostly distributed I to red
mesotrophs, food prep pigments,
env
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011
11

12. 21 Proteus Gram negative rods, Enteric, often display
aerobic, motile, mostly isolated from pleomorphism
mesophiles vegetables,
meat
products
22 Pseudomonas Gram negative rods, 58-70 Fresh Some produce
products water soluble
(veg, meats, blue-green
poultry, sea pigments
foods), most
imp group
wrt spoilage
of
refrigerated
fresh foods
Dr Pratima Khandelwal, Biotechnology,
12
NHCE, Nov 2011

13. 23 Salmonella Gram negative, enteric, 50-53 Human I: S. typhi,
S. enteric sub sp- causes salmonellosis , pathogens, S.paratyphi A and
enteric, produces cytotoxin and commercially S.paratyphi C
Other subsp: enterotoxin, transfers prepared, II: host adapted
salmanae, easily through animal packed foods, serovars, human
arizone, feed and hides Eggs, poultry pathogens
indica, and meat most through food also
common food III: unadapted
vehicles serovars, mainly
foodborne
24 Serratia Gram negative rods, 53-59 Spoilage of Red pigments
S. liquefaciens: aerobic and proteolytic, refrigerated
most prevalent veg, meat
products
Dr Pratima Khandelwal, Biotechnology,
13
NHCE, Nov 2011

14. Salmonella (EM image)
Dr Pratima Khandelwal, Biotechnology,
14
NHCE, Nov 2011

15. 25 Shewanella Gram negative, 44-47 Aquatic/marine
S.putrefaciens straight/curved rods, habitats
motile and non-
pigmented
26 Shigella Gram negative, enteric, 49-53 Human Shigellosis
S dysenteriae Non-motile, produce enteropathogens
acid from sugars, , shell fish, F & V,
chicken, salads
Dr Pratima Khandelwal, Biotechnology,
15
NHCE, Nov 2011

16. 27 Staphylococcus Gram positive, catalase Foodborne
S aureus positive cocci, gastroenteritis
28 Vibrio Gram negative, 38-51 Seafoods, also Foodborne
V . parahaemolyticus straight/curved rods causes extra gastroenteritis,
V cholera intestinal other human
human illness
infections
Dr Pratima Khandelwal, Biotechnology,
16
NHCE, Nov 2011

17. 29 Yersinia 45.8- Foodborne Human plague
Y.pestis 46.8 gastroenterit agent
is, other
human
illness
Dr Pratima Khandelwal, Biotechnology,
17
NHCE, Nov 2011

18. Foodborne molds
Dr Pratima Khandelwal, Biotechnology,
18
NHCE, Nov 2011

19. Molds
• Mucoraceae (reproduction by zygospores):
– Mucor, Rhizopus
• Trichocomaceae (reproduction by ascospores):
– Byssochlamys, Eupenicillium, Euroticum
• Moniliaceae (reproduction by conidia):
– Alterneria, Aspergillus, Botrytis, Cladosporium, Fusarium,
Geotrichum, Helminthosporium, Monilia, Penicillium
Dr Pratima Khandelwal, Biotechnology,
19
NHCE, Nov 2011

20. Dr Pratima Khandelwal, Biotechnology,
Conidiospores, Arthrospores, Sporangiospres 20
NHCE, Nov 2011

21. Zygospores of Rhizopus
Dr Pratima Khandelwal, Biotechnology,
21
NHCE, Nov 2011

22. Common occurrence
Dr Pratima Khandelwal, Biotechnology,
22
NHCE, Nov 2011

23. Sl.no Gerena Features Occurrence and remarks
1 Alternaria Large brown Causes brown rots of fruits, stem end
conidia rot and black rot of citrus. A field
fungus, some produce mycotoxins
2 Aspergillus Produces chains of Causes Black rot of peaches, citrus fruits,
conidia and appear and figs is one of the fruit spoilage
yellow to green to conditions
black on a large Produced. Some species cause
number of foods spoilage of oils, such as palm, peanut,
and corn. The A. glaucus–A. restrictus are
storage fungi that invade seeds, soybeans,
and common beans. Several species
produce aflatoxins.
A.oryzae and A. soyae are involved in the
shogu fermentation and the former in
Spores koji. A. niger produces -
galactosidase, glucoamylase, invertase,
lipase, and pectinase: and A. oryzae
produces -amylase
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011 23

24. Sl.no Gerena Features Remarks
3 Botrytis Produce pigmented Cause gray mold rot of apples,
conidiospores, pears, citrus, grapes etc
mycelium is septate
4 Byssochlamys Produce clusters of Cause spoilage of high acid canned
asci (heat resistant) foods
5 Cladosporium Septate hypae with C. herbarum produces “black spot” on
dark budding and beef and frozen mutton. Some
highly branched spoil butter and margarine, and
conidia some cause restricted rot of stone
fruits and black rot of
grapes. They are field fungi that
grow on barley and wheat grains. C.
herbarum and C.
cladosporiodes are the two most prevalent
Dr Pratima Khandelwal, Biotechnology, on fruits and vegetables.
NHCE, Nov 2011
24

25. Sl.no Gerena Features Remarks
6 Colletotrichum Simple , elongated C.gloeosporioides is the species
Conidiophores are produced of concern in foods; it produces
anthracnose (brown /black spots)
on tropical fruits such as mangos
and papayas
7 Fusarium Extensive cottony mycelium Cause brown rot of citrus fruits
is produced with tinges of and pineapples and soft rot of
pink, red, purple, or brown. figs.
Produce macroconnidia As field fungi, some grow on
(septate fusiform to sickle- barley and wheat grains.
shaped)
8 Geotrichum Yeasts like fungi, reproduce G. candidum, the dairy mold
through vegetative hypae (imparts flavor and aroma to many
cheeses), machinery mold.
G.albidum involved in citrus and
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011 dairy cream spoilage
25

26. Sl.no Gerena Features Remarks
9 Mucor Produce Mucor miehei: lipase
sporangiophores, producer, mainly used in food
cottony colonies, fermentation (meat,
vegetables).
10 Penicillium Involved in the spoilage of
fruit juice concentrates.
Typical colors on foods are
blue to blue-green.
Blue and green mold rots of
citrus fruits and blue mold rot
of
apples, grapes, pears, and
stone fruits, are caused by
some species.
(P. roqueforti, produces Some species produce citrinin,
blue cheese) and other mycotoxins
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011 26

27. Sl.n Gerena Features Remarks
o
11 Rhizopus R. stolonifer is by far the Produce watery soft
most common species in rot of apples, pears,
foods. Sometimes stone fruits, grapes,
referred figs, and others.
to as “bread molds,” Some cause “black
spot” of beef and
frozen mutton.
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011 27

28. Sl.no Gerena Features Remarks
12 Trichothecium The only species,
(T. Roseum) pink in color and
causes pink rot
of fruits.
It also causes soft
rot of cucurbits and
is common on
barley, wheat, corn,
and pecans.
Some produce
mycotoxins.
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011 28

29. Foodborne yeasts
Dr Pratima Khandelwal, Biotechnology,
29
NHCE, Nov 2011

30. Sl.no Gerena Features Remarks
1 Brettanomyces B. intermedius is the They cause spoilage of
most prevalent, and it beer, wine, soft drinks,
B. bruxellensis is can grow at a pH as low and pickles
involved in some as 1.8.
sourdough
fermentations These asporogenous
yeasts form ogival
cells and terminal
budding.
Produce acetic acid from
glucose only under
aerobic
Conditions.
Dr Pratima Khandelwal, Biotechnology,
30
NHCE, Nov 2011

31. 2 Candida • Candida famata (Torulopsis
(Ascomycetous imperfect candida; T. famata)
species)
• Candida kefyr (Candida
pseudotropicalis, T. kefyr; Torula
+ Formerly Torulopsis
cremoris)
• Candida stellata (Torulopsis
stellata)
• Candida holmii (Torulopsis holmii)
Dr Pratima Khandelwal, Biotechnology,
31
NHCE, Nov 2011

32. Sl.no Gerena Features Remarks
3 Debaryomyces.: one of the two most
prevalent yeast
D. hansenii is the most genera in dairy
prevalent foodborne species.
products.
It can grow in 24%
NaCl and at an aw as
low as 0.65.
It forms slime, grows
in brines, cheeses, and
causes spoilage of
orange juice
concentrate and
yogurt.
Dr Pratima Khandelwal, Biotechnology,
32
NHCE, Nov 2011

33. Sl.no Gerena Features Remarks
4 Kluyveromyces Most prevalent yeasts in
dairy products (kumiss, for
lactase production, SCP)
Found on a wide variety of
fruits, and K. marxianus
causes cheese spoilage.
5 Rhodotorula R. glutinis and R. The genus contains many
mucilaginosa are psychrotrophic
the two most species/strains that are
prevalent species in found on fresh poultry,
foods (produce pink shrimp, fish, and beef.
to red pigments) Some grow on the surface
of butter
Dr Pratima Khandelwal, Biotechnology,
NHCE, Nov 2011 33

34. Sl.no Gerena Features Remarks
6 Saccharomyces Bakers’, brewers’,
wine, and champagne
yeasts are S.
cerevisiae. Found in
kefir grains, dry cured
salami.
S. cerevisiae rarely
causes spoilage.
7 Zygosaccharomyces Some are spoilers of Strong fermenters of
mayonnaise and sugars. Some
salad dressing, are involved in shoyu
especially and miso
fermentations
Z. bailii, which can
grow at a pH of 1.8.
Dr Pratima Khandelwal, Biotechnology,
34
NHCE, Nov 2011

35. References
• James M Jay. 2005. Modern Food Microbiology. CBS Publishers,
New Delhi. pp 13-37.
• Norman N Potter and Joseph H Hotchkiss. V Edition. Food Science,
CBS Publishers, New Delhi. pp 113-127
• Kalisdas Shetty. 2005. Food Biotechnology.CRC Press.
• Google Images
Dr Pratima Khandelwal, Biotechnology,
35
NHCE, Nov 2011