xii ◾ Contents
Viable-but-Nonculturable ...............................................................................................109
Definition and Terminologies ................................................................................109
Proponent Views ....................................................................................................109
Opponent Views .................................................................................................... 111
Current Views ........................................................................................................ 111
Physiological Properties of VBNC Cells ................................................................112
Importance of VBNC Microorganisms in Food ....................................................112
Conclusion ......................................................................................................................112
References .......................................................................................................................114
SeCtion iii BeneFiCiAL USeS oF MiCRooRGAniSMS in FooD
11 Microorganisms Used in Food Fermentation ........................................................... 119
Introduction ................................................................................................................... 119
Microbiology of Fermented Foods .................................................................................. 119
Lactic Starter Cultures ................................................................................................... 120
Lactococcus .............................................................................................................121
Streptococcus .......................................................................................................... 122
Leuconostoc ............................................................................................................ 122
Pediococcus ............................................................................................................ 122
Lactobacillus .......................................................................................................... 123
Oenococcus ............................................................................................................ 124
Other Starter Cultures ................................................................................................... 124
Bifidobacterium ..................................................................................................... 124
Propionibacterium ..................................................................................................125
Brevibacterium .......................................................................................................125
Acetobacter .............................................................................................................125
Yeasts and Molds ............................................................................................................125
Yeasts .................................................................................................................... 126
Molds ................................................................................................................... 126
Conclusion ..................................................................................................................... 127
References ...................................................................................................................... 127
12 Biochemistry of Some Beneficial Traits ....................................................................129
Introduction ...................................................................................................................129
Mechanisms of Transport of Nutrients ...........................................................................129
Transport and Metabolism of Carbohydrates ................................................................. 130
PEP-PTS System for Lactose Transport in Lactococcus lactis ..................................131
Permease System for Lactose in Lactobacillus acidophilus .......................................131
Carbohydrates Available Inside the Cells for Metabolism ......................................131
Homolactic Fermentation of Carbohydrates ..........................................................131
Heterolactic Fermentation of Carbohydrates .........................................................133
Metabolism of Pentoses ........................................................................................ 134
Hexose Fermentation by Bifidobacterium ...............................................................135
Diacetyl Production from Citrate ..........................................................................135
Propionic Acid Production by Propionibacterium .................................................. 136
Transport and Metabolism of Proteinaceous Compounds and Amino Acids ................. 136
Viable-but-Nonculturable ...............................................................................................109
Definition and Terminologies ................................................................................109
Proponent Views ....................................................................................................109
Opponent Views .................................................................................................... 111
Current Views ........................................................................................................ 111
Physiological Properties of VBNC Cells ................................................................112
Importance of VBNC Microorganisms in Food ....................................................112
Conclusion ......................................................................................................................112
References .......................................................................................................................114
SeCtion iii BeneFiCiAL USeS oF MiCRooRGAniSMS in FooD
11 Microorganisms Used in Food Fermentation ........................................................... 119
Introduction ................................................................................................................... 119
Microbiology of Fermented Foods .................................................................................. 119
Lactic Starter Cultures ................................................................................................... 120
Lactococcus .............................................................................................................121
Streptococcus .......................................................................................................... 122
Leuconostoc ............................................................................................................ 122
Pediococcus ............................................................................................................ 122
Lactobacillus .......................................................................................................... 123
Oenococcus ............................................................................................................ 124
Other Starter Cultures ................................................................................................... 124
Bifidobacterium ..................................................................................................... 124
Propionibacterium ..................................................................................................125
Brevibacterium .......................................................................................................125
Acetobacter .............................................................................................................125
Yeasts and Molds ............................................................................................................125
Yeasts .................................................................................................................... 126
Molds ................................................................................................................... 126
Conclusion ..................................................................................................................... 127
References ...................................................................................................................... 127
12 Biochemistry of Some Beneficial Traits ....................................................................129
Introduction ...................................................................................................................129
Mechanisms of Transport of Nutrients ...........................................................................129
Transport and Metabolism of Carbohydrates ................................................................. 130
PEP-PTS System for Lactose Transport in Lactococcus lactis ..................................131
Permease System for Lactose in Lactobacillus acidophilus .......................................131
Carbohydrates Available Inside the Cells for Metabolism ......................................131
Homolactic Fermentation of Carbohydrates ..........................................................131
Heterolactic Fermentation of Carbohydrates .........................................................133
Metabolism of Pentoses ........................................................................................ 134
Hexose Fermentation by Bifidobacterium ...............................................................135
Diacetyl Production from Citrate ..........................................................................135
Propionic Acid Production by Propionibacterium .................................................. 136
Transport and Metabolism of Proteinaceous Compounds and Amino Acids ................. 136