Biocide Research Paper

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1. INTRODUCTION

Pesticides are certain substances that are meant for attracting, and then destroying, or extenuating any pest. They belong to a class of biocide. The most widespread use of pesticides is that they act as plant protection products (called as crop protection products) which has a function of protecting the plants from damaging factors such as plant diseases, weeds orinsects. On the basis of target pesticides are mainly classified into, fungicides, bactericides, herbicides, insecticides, rodenticides and insecticides. On the basis of chemical properties, pesticides can also be grouped into organophosphates (OP), carbamates, Coumadin, phenoxyl, organochlorines (OC), dithio-carbamates, carbamates, pyrethroids, triazine, and amide

Using a dropper or Pasteur pipette, placed 1 drop of 3 % Hydrogen-peroxide onto the organism on the microscope slide.

4. Did not mix and immediately covered it.

6. No bubble formation indicated the absence of catalase enzyme.

3.2.5.2 Sugar fermentation test

Principle

Many bacteria ferment various carbohydrates such as sucrose, lactose under anaerobic conditions. Sugar fermentation media containing phenol red as a pH indicator is used. When the bacterium is inoculated into the tube, the bacterium which ferments the sugar will result in the production of acid (Lactic acid, formic acid or acetic acid) that will detect the presence of gas. Sugar fermentation test showed by E. coli, Proteous vulgaris, Klebsiella pneumonia and Salmonella sp.etc.

Procedure

1. Used a single carbohydrate for each of medium batch medium prepared.

2. After inoculation paraffin liquid.

3. Kept one tube as un-inoculated or as a control.

4. Incubated at optimum temperature for 24 hours.

5. No colour change was taken as negative test (yellow to pink).

6. The inverted Durham tubes in the medium detected the presence or absence of gas.

3.2.5.3 Indole test

Examine the colour change, appearance of blue colour denotes alkalinisation.

3.2.5.7. Urease test

Principle

Urea is a waste nitrogenous material and excreted out by animals. Some bacteria can degrade the urea into ammonia and CO2. Due to production of ammonia, urease production can be easily demonstrated by the following reaction: Procedure:

1. Inoculate the urea broth medium with bacterial culture.

2. Incubate the culture at 37ᵒ C for 48 hours.

3. Phenol red indicator will turn to pink due to alkaline nature of the medium because of ammonia production. Otherwise the indicator will remain yellow at acidic range of pH. Then it shows no urease production by the bacteria.

3.2.5.8. Starch hydrolysis test

Principle

This test detects the amylase producing bacterial strains. The amylase enzyme produced by some bacteria degrades the starch present in media which was seen as a clear zone of lysis when it was treated with iodine solution.

Procedure

 Agar plates containing starch as carbon source were prepared.

 The plates were then streaked with bacterial strains with sterile loop in a laminar air flow and incubated overnight at 37oC.

 After incubation the plates were flooded with iodine solution.

 The plates were then observed for