1               Giriş                                                                                                                          1

1.1                   Önleyici gıda hijyeni                                                                                              1

1.1.1                                                   Gıda mikrobiyolojisinin görevi ve önemi                                                               1

1.1.2                                                   Gıda mikrobiyolojisi analitiğinden beklenenler                                                    5

1.1.3                                                   Bakteri sistematiği                                                                                                    6

1.1.4                                                Fizyolojik özelliklerine göre bakterilerin sınıflandırılması                                    7

1.1.5                                                   Mikroorganizmaların gru plan d iril m asında sıcaklık                                                      8

1.1.6                                                   Gıda kalitesinin değerlendirilmesinde mikroorganizmalar          .                        9

1.2                   Mikroorganizmalarla çalışırken dikkat edilecek hususlar                        11

1.2.1                 Tehlike potansiyelleri ve bulaşma risklerine göre
mikroorganizmaların ve hastalık etmenlerinin sınıflandırılması                         11

1.2.1.1                                               Bakterilerin sınıflandırılması                                                          12

1.2.1.2                    Fımgusların sınıflandırılması                                                         13

 

1.2.2                                                   "İyi mikrobiyolojik uygulama tekniğinin" temel kuralları                                  13

1.2.3                                                   Bakteri ve funguslarla çalışan laboratuarlarda aranan özellikler                      14

2                Teknikler - Yöntemler - Besiyerleri - Analiz Yöntemleri                                      17

2.1                Laboratuar donanımı                                                                                              17

2.1.1              Mikrobiyoloji laboratuarı için donanım                                                                 17

2.1.1.1                     Alet-ekipman ve teknik yardımcı maddeler                                17

2.1.1.2                     Cam ve plastik malzemeler                                                            20

2.1.1.3            Örnek almak için gerekli malzemeler                                             20

Besiyerleri                                                                                                                21

Besiyerlerinin hazırlanması                                                                                   22

2.2.1.1                     Besiyerleri için kullanılan suyun kalitesi                                    23

2.2.1.2                     Kuru besiyerinin eritilmesi                                                           23

2.2.1.3                     pH'nın ayarlanması                                                                        24

2.2.1.4                     Besiyerlerinin sterilizasyonu                                                       24

2.2.1.5                     Besiyerlerinin pctri kaplarına dökülmesi                                    24

2.2.1.6                     Bcsiyerinin kurutulması ve ön inkubasyona tabi
tutuiması                                                                                         25

 

2.2.2                         Tüpte besiyeri haz ırkım a                                                                                     25

2.2.3                         Kullanıma hazır besiyerlerinin saklanması                                                         26

2.3                    Sterilizasyon yöntemleri                                                                                        26

2.3.1                         Nemli sıcaklık ile sterilizasyon                                                                              26
2.3.1.1           Tindalizasyon                                                                                         28

2.3.2                          Kuru sıcaklıkta sterilizasyon                                                                                   29

2.3.3                          Akkor hale getirilerek ve alevde sterilizasyon                                                        29

2.3.4                          Filtrasyon ile sterilizasyon                                                                                                29

2.3.5                          Besiyerlerindc ve laboratuar malzemelerinde sterilizasyonun
kontrolü                                                                                                                      30

2.4                    Analiz aşamaları                                                                                                        30

2.4.1                           Örnek alma                                                                                                                30
2.4.1.1           Ürüne özgü örnek: alma teknikleri ve Örnek hazırlama    31

2.4.2                           Gıda örneğinin seyreltilmesi (dilüsyon hazırlanması)                                           32

2.4.3                           Örnek miktarı ile dilüsyon sıvısı arasındaki ilişki                                                33

2.4.4                           Dilüsyon .serisi                                                                                                              34

 

2.4.4.1                       Deney tüplerinde dilüsyon serisi                                                    34

2.4.4.2                       Şişelerde dilüsyon serisi                                                                 34

2.4.5                  Ekim yöntemleri                                                                                                            35

2.4.5.1                       Dökme plaka yöntemi                                                                      36

2.4.5.2             Yayma plaka yöntemi                                                                      38

2.4.5.3                       Petri damlatma yöntemi                                                                  38

2.4.5.4             Pctri film yöntemi                                                                           40

 

2.4.6                           İnkübe edilmiş pctri kaplarının değerlendirilmesi                                                  41

2.4.7                           Mikroorganizma sayısı ve ortalama değer hesaplanması                                        41

 

2.4.7.1                       Mikroorganizma sayısının hesaplanması                                         41

2.4.7.2                       Ortalama değer hesaplanması                                                           41

2.4.7.3                       Basit aritmetik ortalama                                                                          43

2.4.7.4             Ağırlıklı aritmetik ortalama                                                           43

2.4.8                 Ön zenginleştirme kültürü                                                                                     44

2.5                    Mikroorganizma içeriğini saplamak için daldırma yöntemi                               45

2.5.1              Lam daldırma yöntemi                                                                                               45

2.5.1.1                     Kullanım alanı                                                                                46

2.5.1.2                     Deneyin yapılışı                                                                             46

2.5.1.3                     Değerlendirme                                                                                47
2.5.1.4          Dikkat edilecek noktalar                                                                    48

Mikroorganizmaların kültürel olmayan ve indirckt kültürel

sayımı                                                                                                                     48

Direkt epİfloresans filtre tekniği (DEFT)                                                            49

Limulııs test yöntemi (LAL)                                                                                  49

İmpedans yöntemi                                                                                                 50

Adenozİntrİfosfat (ATP) Ölçümü                                                                        50

Gaz değişimlerinin ölçülmesi             .                                                                   51

Ekim yöntemi                                                                                                        52

Mikroorganizmaların izolasyonu ve saflaştırılması                                           52

2.7.1.1              Çizim yöntemi                                                                                 52

Mikroorganizmaların inokulasyon yöntemleri                                                   53

2.7.2. i           İnokulumun alınması                                                                       53

2.7.2.2              İnokulasyonun yapılması                                                            54

Mikroorganizmaların saklanması                                                                      54

Anaerobik kültür                                                                                                    55

2.1 AA           Anaerobik kavanoz                                                                         55

2.7.4.2          Anaerobik poşet                                                                                57

2.1 A3          Kapağa dökme yöntemi (Marino petrisi)                                      57