Etiket Arşivleri: SOLID STATE FERMENTATION

Food Biotechnology ( N.INDRA )

  • FOOD BIOTECHNOLOGY

  • FERMENTATION,

  • BATCH AND CONTINUOUS FERMENTATION

  • SOLID STATE FERMENTATION

  • FERMENTOR DESIGN

  • PRESENTED BY

  • N.INDRA .

  • FERMENTATION

  • Fermentation is the oldest form of biotechnology, essentially consisting of transformation of the simple raw materials into value added amazing range of products by utilizing the growth of microorganism.

  • The basic purpose of micro organisms to break down the organic compounds is to get energy for their metabolic process.

  • Some fermented products

  • BATCH FERMENTATION

  • A batch fermentation is regarded as a closed system.

  • The sterile nutrient culture medium in the bioreactor is inoculated with micro organisms.

  • The incubation is carried out under optimal physiological conditions.

  • It may be necessary to add acid or alkali to maintain pH and antifoam agents to minimize foam under optimal conditions for growth.

  • Under optimal conditions for growth the following typical phases of growth, are observed in batch fermentation.

  • PHASES

  • Lag phase

  • Acceleration phase

  • Logarithmic (log) phase (exponential phase)

  • Deceleration phase

  • Stationary phase

  • Death phase

  • LAG PHASE

  • Initial period of culturing after inoculation is referred to as lag phase.

  • During the lag phase, the micro organisms adopt to the new environment avaliable nutrients, pH etc.,

  • There is no increase in the cell number, although the cellular weight may slightly increase.

  • PHASES GRAPH

  • Acceleration phase

  • It is a brief transient period during which cells start growing slowly.

  • This phase connects the lag phase and log phase.

  • Log phase

  • The most active growth of micro organisms and multiplication occur during log phase.

  • The cells undergo several doublings and the cell mass increase when the number of cell or biomass is plotted against time on a semi logarithmic graph, a straight line is obtained.

  • Growth rate of microbes in log phase is dependent on substrate (nutrient supply)

  • STATIONARY PHASE

  • The substrate in the growth medium gets depleted and the metabolic and products that are formed inhibit the growth, the cells enter the stationary phase.

  • The microbial growth may either slow down or completely stop.

  • The biomass may remain almost constant during this phase

  • Death phase

  • The cells die at an exponential rate.

  • In the commerical and industrial fermentation, the growth of the microbes is the end of the log phase or just before the death phase begins and the cells harvested.

  • CONTINUOUS FERMENTATION

  • It is an open system.

  • It involves the removal of culture medium continuously and replacement of this with a fresh sterile medium in a bioreactor.

  • Both addition and removal are done at the same rate so that the working volume remains constant.

  • Homogenously mixed Bioreactors

In this type, the culture solution is homogenously mixed

The bioreactors are of two types

  • Chemostat bioreactors

The concentration of any one of the substrate is adjusted to control the cell growth and maintain a steady state.

  • Turbidostat bioreactors

In this case, turbidity measurement is used to monitor the biomass concentration.

The rate of addition of nutrient solution can be appropriately adjusted to maintain a constant cell growth.

  • SOLID STATE FERMENTATION

  • Most fermentation technologies using microbes employ a fairly dilute medium where the substrate to be fermented is diluted in water and then inoculated with desired microbes.

  • Some fungai can grow in conditions without free water.

  • In this case the moisture required by the fungus exists than absorbed or complex form in the solid matrix , often ranging between 10% and 80% processes which exploit the growth of fungai in this type of system are designated solid state fermentation.

  • EXAMPLES FOR SOLID SUBSTRATE FERMENTATION

  • FERMENTOR DESIGN

  • WINE MAKING FERMENTOR

  • FERMENTOR DESIGN

  • A fermentor is a device in which the organisms are cultivated and motivated to form a desired product

  • Closed vessel or containment designed to give a right environment for optimal growth and metabolic activity of the organism

  • Fermenter: for microbes/ Bioreactor : for eukaryotic cells

  • Size variable ranging from 20-250 million litres or more.

  • Large scale production (10-100L to1000-million L capacity)

  • Regular monitoring for physical, chemical biological parameters is done through controlled systems of the fermentor, because these parameters influnces the growth of the microbes.

  • As per requirements and use of types of microorganisms there are different types of fermentors available.

  • The most common among these is stirred tank fermentor where impellers used to stirr the medium.

Helps to meet requirements of:

pH

temperature

aeration

agitation

drain or overflow

control systems

sensors

cooling to achieve maximum microbial yield

  • The increasing concentration of microbial cells will deplete the dissolved O2 concentration resulting in creation of anaerobic conditions.

  • The microbial growth will simultaneous decline in product production.

  • The forced aeration favours rapid growth of micro organisms.

  • A pH fitted with fermentor regularly monitors the pH and maintains at optimum by adding acid or alkali.

THANK YOU