Biotechnology Lecture Notes

Solid State Fermentation Technology: Examples, Advantages and Disadvantages


Solid State Fermentation (SSF)
(Solid State Fermentation: Technology, Advantages and Disadvantages)

What is Solid State Fermentation (SSF)?

In Solid State Fermentation, also called Solid Substrate Fermentation or SSF, the fermentation substrate or media will be in the solid state. Here the microorganisms are grown on a solid substratum in the absence or near absence of free water. The moisture content of the substratum in SSF is usually maintained below 15%. The solid state fermentation is most commonly carried out for the production of fermented food products such as bread, fermented fish, meat, yogurt, cheese and pickles. The microbial fermentation increases the nutrient content and flavor of food products. It also increases the digestibility of foods. The cultivation of edible mushrooms on a suitable substratum is also a solid state fermentation process.

Pleurotus djamor

Mushroom Cultivation (wikipedia)

Substrates / Media in Solid State Fermentation


The substrates commonly used in SSF are usually very complex, heterogeneous and are insoluble in water. These substrates include cereals grains, wheat bran, lingo-cellulosic materials such as wood shavings, sawdust, molasses etc. In most of the cases, the substrate or the raw materials were undergone through a pre-treatment such as soaking, boiling in water, mechanical pre-treatment or chemical treatment. These pre-treatments increase the bioavailability of nutrients for the microbes to act on them.

Instrumentation and Growth Kinetics in Solid State Fermentation

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Molecular Biology Tutorials

Philadelphia Chromosome and Oncogenic BCR ABL Gene Translocation in CML

Philadelphia Translocation

Philadelphia Chromosome (PH)
(Philadelphia Translocation, PH and Chronic Myeloid Leukemia – CML)

Translocation is a Structural Aberration of Chromosome

Translocation is a type of structural aberration of the chromosome where a segment of chromosome gets translocated to another chromosome. There may be two types of translocation based on the nature of the exchange. They are:

(1). Homologous Translocation

(2). Heterologous Translocation

In homologous translocation, the exchange of chromosomal segments occurs between the homologous chromosomes. In heterologous translocation, the chromosomal segments are exchanged between non-homologous chromosomes. The heterologous translocation in most of the cases will be a reciprocal translocation (exchange of segments between chromosomes).

Translocation causes ‘Position Effect’

The translocation of chromosomes leads to a phenomenon in molecular genetics called the ‘Position Effect’. The position effect is the change in the expression pattern of a gene due to its current position in the chromosome. For example, a normally active gene may be converted to an inactive gene when it is translocated into a new position or vice versa.

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Biostatistics Study Materials

Graphical Representation of Data (Frequency Polygon, Frequency Curve, Ogive and Pie Diagram)

Graphs for Data Representation

Graphical Representation of Data: Part 2
(Data Representation Methods: Frequency Polygon, Frequency Curve, Ogive and Pie Chart)

This post is the continuation of the Previous Post (Graphical Representation of Data Part 1).

(3). Frequency Polygon

Ø  The Frequency Polygon is a curve representing a frequency distribution.

Ø  In frequency polygon, the mid values of each class are first obtained.

Ø  In a graph paper, the frequency of each class is plotted against the mid-value of class (on the X axis).

Ø  Then these points are then joined by a straight line.

Ø  This straight line is extended in both directions to meet on the X axis.

Ø  The first point is joined to the lower limit of the first class and the last point is joined to the upper limit of last class. Thus, the frequency polygon is a closed graph.

Ø  The graph now obtained is called Frequency polygon.

Example: Construct a Frequency Polygon using the following data


data for frequency polygon

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Biostatistics Study Materials

Graphical Representation of Data (Line Graph, Bar Diagram & Histogram)

Data Representation

Graphical Representation of Data: Part 1
(Diagrammatic Data Representation: Line Chart, Bar Diagrams and Histogram)

Graphical Representation of Data / Variables

Ø  The data presentation in statistics may be Numerical or Graphical.

Ø  If the data is presented in the numerical form, it will not attract the attention of the audience.

Ø  In order to attract the attention of the audience, Graphical Representation method is usually adopted.

Ø  Graphical Representation: It is the representation or presentation of data as Diagrams and Graphs.

Ø  The statistical graphs were first invented by William Playfair in 1786.

Ø  In graphical data representation, the Frequency Distribution Table is represented in a Graph.

Advantages of Graphical Representation of Data

Ø  Data are presented pictorially.

Ø  Give better insight and understanding of the data.

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Biostatistics Study Materials

Frequency Distribution Table: Definition with Examples + PPT

What is Frequency Distribution?

Frequency Table / Frequency Distribution
(Definition, Construction and Significance of Frequency Distribution)

In the previous post, we have discussed the concept of Tables and Tabulation of Variables in Statistics. Here we will discuss the concept of Statistical Tables better known as Frequency Distributions of Frequency Tables.

Statistical Tables

Ø  There are different types of tables in statistics.

Ø  The most common type of table in the statistics is ‘Frequency Table’ or ‘Frequency Distribution’.

Ø  Frequency Distribution definition: “The frequencies of occurrence of data values are presented in tabular form in the ascending order of magnitude”.

Ø  It is a statistical table that shows the frequency of various outcomes in a sample.

Ø  The frequency table shows the total for each category or group of data.

Example: A raw data and its frequency distribution is given below

Example of Frequency table

Ø  A frequency table composed of TWO components:

(1).   Class

(2).   Frequency

Class and Frequency

Ø  When a population is divided into small groups on the basis of some attributes or characteristics, each such group is considered as a class.

Ø  In each class, the number of individual value of that particular feature is one or many.

Ø  Such occurrence of individuals in a class is called frequency.

Thus a Frequency Table is “the arrangement of distribution of individuals of a class which displays the frequency of the individuals according to a characteristic.”

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