1.15k likes | 3.35k Views
Mode of Fermentation; Batch, Fed Batch and Continuous. Sri Kumalaningsih. Outline. Overview Batch fermentation Fed batch fermentation Continuous fermentation. Outline. Overview Batch fermentation Fed Batch culture Continuous culture Growth kinetics. Batch fermentation.
E N D
Mode of Fermentation; Batch, Fed Batch and Continuous Sri Kumalaningsih
Outline Overview Batch fermentation Fed batch fermentation Continuous fermentation
Outline Overview Batch fermentation Fed Batch culture Continuous culture Growth kinetics
Batch fermentation • Most fermentations are batch processes • Nutrients and the inoculum are added to the sterile fermenter and left to get on with it! • Anti-foaming agent may be added. • Once the desired amount of product is present in the fermenter the contents are drained off and the product is extracted. • After emptying, the tank is cleaned & prepared for a new batch.
Product examples • Food grade ethanol (cosmetics and pharmacy) • Wine • Kimchi • Saurkraut • Astaxantin
Outline Overview Batch fermentation Fed Batch culture Continuous culture Growth kinetics
INDUSTRIAL APPLICATION OF FED-BATCH • Penicillin Glucose, phenyl acetic acid, ammonia source • Cephalosporin Glucose, methionine • Streptomycin Glucose, ammonia source Glutamic acid Urea, ethanol, (acetic acid) • Amylase Carbon source • Bakers Yeast Glucose • Citric acid Glucose, ammonia
Continuous fermentation • Some products are made by a continuous culture system. • Sterile medium is added to the fermentation with a balancing withdrawal of broth for product extraction.
ADVANTAGES / DISADVANTAGES OF CC Advantages • Uniformity of operation • Process demands are constant i.e. continuous cycle of sterilisation,fermentation, harvesting, extraction • Once in steady-state demands re process control are constant i.e. oxygen demand Disadvantages >> high cost • Susceptibility to contamination • Duration of run is longer increased chance of contamination • Strain degeneration arising from large number of generations
Set up for Continuous culture Fresh medium from reservoir Sterile air Flow-rate regulator Stirrer Culture Overflow Effluent
APPLICATION OF CONTINUOUS CULTURE INDUSTRY; • Waste-treatment • Single-cell protein • Continuous beer production • Continuous amino acids, organic acids production • Continuous ethanol • Continuous bakers yeast
TYPES OF CONTINUOUS CULTURE Method of control; Chemostat - regulated by control of concentration of limiting nutrient Turbidostat - regulated by biomass using optical density (photoelectric cell) Biostat - regulated by systems monitoring biomass other than optical density (e.g CO2 production)
The development of growth in a chemostat Steady State Growth rate equals loss of cell biomass Cell Number Nutrient limitation causes decrease in m Population density increases mmax Inoculation Time in Hours
MODIFICATIONS OF BASIC CHEMOSTAT • MULTI-STAGE Different environments or growth rates in the various reactors (e.g. 1st biomass, 2nd product) • SINGLE STAGE WITH CELL RECYCLE Application in activated sludge waste-treatment Relationship between D and different when recycle used. EFFECT OF FEEDBACK; 1. Increase biomass conc. in fermenter - lower in effluent 2. Decrease residual substrate 3. Maximise rate of product formation 4. Drift is increased - useful when substrate is dilute
Chemostats in series F1 SR X1 S1 V1 FO2 SR2 X2 S2 V2 F2
Growth Kinetics Involved by: • Binary fision • Growth Curve • Spesific growth rate • Substrate utilization • Monod Equation
(2) Growth Curve • Lag phase • Log phase • Stationary phase • Death phase
The steps of growth 5 4 6 3 2 1
The steps of growth (1) (1) Fase permulaan Karakteristik: Terjadi adaptasi oleh mikroba yang diinokulasikan Mikroba memproduksi berbagai macam enzim dan zat antara yang berguna bagi pertumbuhan Sel-sel mikroba mulai membesar Akan tetapi belum terjadi pembelahan 1
The steps of growth (2) (2) Fase pertumbuhan yang dipercepat Karakteristik: Bakteri mulai membelah diri Akan tetapi waktu generasinya masih panjang Fase permulaan dan pertumbuhan yang dipercepat biasa disebut dengan lag-phase 2
The steps of growth (3) (3) Fase pertumbuhan logaritma Karakteristik: Pada fase ini kecepatan pembelahan paling tinggi Waktu generasinya pendek dan konstan Metabolisme terjadi paling pesat Keadaan terus berlangsung sampai salah satu nutrien habis Atau terjadi penimbunan racun akibat metabolisme yang menyebabkan terhambatnya pertumbuhan 3
The steps of growth (4) (4) Fase pertumbuhan yang mulai terhambat Karakteristik: Kecepatan pembelahan berkurang Sel yang mati bertambah banyak Terjadi karena makin berkurangnya nutrien dan bertambahnya racun Terdapat perubahan kondisi fermantasi (misal perubahan pH, kenaikan suhu) 4
The steps of growth (5) (5) Fase stasioner yang maksimum Karakteristik: Terjadi penurunan kadar nutrien dan penimbunan zat racun Kecepatan pembelahan berkurang Jumlah bakteri yang mati semakin meningkat Jumlah bakteri yang dihasilkan sama dengan jumlah bakteri yang mati sehingga jumlah bakteri konstan 5
The steps of growth (6) (6) Fase kematian yang dipercepat dan kematian logaritma Karakteristik: Disebut juga dengan fase menurun Kematian terus meningkat Kecepatan pembelahan menjadi nol Setelah sampai pada fase kematian logaritma kecepatan kematian mencapai maksimal dan jumlah sel menurun dengan cepat 6
ln X X e d f c Slope = b a Waktu Waktu 3. Specific growth rate
2. Specific growth rate (laju pertumbuhan spesifik padasetiapwaktupertumbuhandapatditentukansebagaiberikut : Keterangan : F = lajualir V = volume kultur = lajukematianspesifik Akumulasisel = pertumbuhan – pengeluaran – sel yang mati UntukKulturFed Batch UntukKulturCurah (Batch) dx/dt=0 μ = D di mana D = F V
4. Substrate Utilization LajuPenggunaanSubstrat AkumulasiSubstrat = substratmasuk – substrat yang dikonsumsiuntukpertumbuhan– substrat yang dikonsumsiuntuksistesisproduk– substrat yang dikonsumsiuntukperawatan–substratkeluar
F = Lajualir (l/jam) • V = Volume kultur (l) • S0 = [substrat yang masuk] (g/l) • Yx/s = koefisienrendemenbiomassa • Yp/s = koefisienrendemenproduk • = lajupertumbuhanspesifik qp = lajupembentukanprodukspesifik m = koefisienpemeliharaan 4. Substrat Utilization Rate LajuPenggunaanSubstrat
4. Specific Utilization Rate UntukKulturCurah/batch: Lajupenggunaansubstratspesifik (qs) UntukKultur fed batch:
Terima Kasih Thank you