Microbial Analysis of Soil Essay

Abstraction: dirt samples were collected biweekly from country near Dahisar River. A river in suburb of Mumbai. research lab analysis started from July 2010 to September 2010. Entire bacterial and fungous count were estimated by standard spread home base isolation. Isolated bacteriums were capable to colony word picture and were estimated by their morphological and biochemical characters. As being a monsoon the happening of fluctuation of different species were high. The micro-organisms isolated from the dirt were of staphylococci strain and were gram positive. aerophilic. cocci shaped bacteriums. The fungous species were besides identified. of which Aspergillus and Penicillium were dominant. followed by mucur. as sub dominant. This undertaking aims to happen out the H2O and dirt quality of River and as it is fluxing through an industrial country. to happen out if it is acquiring affected by the Industrial pollutants.


Dirt is the part on the earth’s crust where geology and biological science meet. the land surface that provides a place to works animate being and microbic life ( Pelczar et al. . 1993 ) . Soil teems with microscopic life ( bacteriums. Fungi. algae. Protozoa and viruses ) every bit good as macroscopic life such as angleworms. roundworms. touchs. and insects. and besides the root systems of workss. The Numberss and sorts of micro- beings present in dirt depend on many environmental factors: sum and type of foods available. available wet. grade of aeration. pH. temperature etc ( Prescott et al. . 1999 ) . Soil bacterium and fungi drama polar functions in assorted biochemical rhythms and are responsible for the recycling of organic compounds ( Wall and Virginia. 1999 ) . Soil micro-organism besides influence above- land ecosystems by lending to works nutrition. works wellness. dirt construction and dirt birthrate ( O’Donnell et al. . 2001 ) . Dirt is by and large a favourable home ground for the proliferation of micro-organisms. with micro settlements. developing around dirt atoms.

Numbers of micro being.

In dirt home grounds usually are much higher than those in fresh H2O or Marine home grounds ( Atals and Bartha. 1998 ) . Bacterias make up the most abundant group of micro- beings in the dirt ( 3. 0 ten 106 – 5. 0 ten 108 ) per gm of dirt. followed by the actinomycetes ( 1. 0 ten 106 – 2. 0 ten 107 ) . Fungi ( 5. 0 ten 103 – 9. 0 ten 106 ) . barm ( I. 0 ten 103 – 1. 0 ten 106 ) . algae and Protozoa ( 1. 0 ten 103- 5. 0 ten 105 ) and roundworms ( 50 – 200 ) counts per gm of dirt are broad differences in the comparative proportions of single bacteriums genera found in peculiar dirts ( Atals and Bartha. 1998 ) .

Soil Fungi may happen as nonparasitic beings or in mycorrhizal association with works roots. Fungus kingdoms are found chiefly in the top 10 centimeter of the dirt and are seldom found below 30 centimeter. They are most abundant in well-aerated and acidic dirts ( Domsch et al. . 1980 ) . Most fungi in dirt are timeserving ( zymogenous ) . They grow and carry out active metamorphosis when conditions are favourable which implies equal wet. equal aeration and comparatively high concentrations of utilizable substrates ( Postage. 1994 ; Miyanoto et Al. . 2002 ) . In this research we isolate culturable heterotrophic bacteriums and fungi from different top dirt samples MATERIALS AND METHODS

Lab analysis
Preparation of stuffs

The stuffs needed for this experiment include ; glass wares ( conelike flasks. bijou bottles. pipettes. petri-dishes ) and they were washed with detergents. These glass wares were rinsed exhaustively with clean distilled portable H2O and left to aerate dry before sterilising them in the sterilizer at 15?C for 1 hr. Besides. the research lab cabinets on which the work would be carried out was swabbed with cotton wool soaked in methylated spirit to sterilise it before any microbiological analysis was carried out to avoid the growing and isolation of other beings non present in the samples. After sterilisation. the home bases were allowed to chill to approximately 45 grades before they were used.

Microbiological rating

Ten ( 10 ) gm of the dirt sample for microbiological rating was weighed into 9ml of unfertile H2O. Preparation of consecutive dilution goes therefore: 1ml of the original stocks solution was poured into 9ml unfertile distilled H2O and assorted exhaustively to give 10-2 of the original sample and this was done for each sample and the bottles labeled harmonizing to day of the month of aggregation

Isolation and Enumeration of Micro-organisms.

1gram of the samples was homogenized in 9mls of distilled H2O to obtain a ratio of 1:9 and the 2nd diluted of each sample was plated utilizing the pour home base technique. Sterile liquefied alimentary agar ( NA ) . murphy dextrose agar ( PDA ) . macconky’s agar. ( MA ) manitol salt agar ( MSA ) and deoxycholate astrate agar ( DCA ) were used { the murphy dextroglucose agar ( PDA ) was acidified ) . These agars were so added and left to solidify undisturbed. These home bases were incubated 37oC for 24hours ( incubation was aerophilic ) and the process was repeated utilizing 10-2 eventually the figure of settlements per home bases were counted and recorded. The acidified PDA was incubated at 25C for 3-7 yearss for microbic growing.

Entire Bacterial counts ( Cfu/g )

The entire bacterium count for each sample was determined with the pour home base techniques utilizing alimentary agar. The home bases were incubated between 24hours at 370C and all settlements looking on the terminal of the incubation period were counted utilizing digital limitless settlement counter and the counts were expressed in settlement organizing unit per gm { CFU/g } of the sample. Colonies of bacteriums developing on the home bases were observed. stray and reisolated on a fresh media until pure civilization was obtained.

Preparation of Pure Culture

It is necessary to insulate beings in pure civilization before analyzing and placing them because a pure civilization originates from one cell. Features settlements from the original civilization on the home bases were picked with a unfertile wire cringle ( utilizing surface streaking method ) and this cringle was used to do run of the settlement on the surface of freshly prepared unfertile agar home bases of NA. MA & A ; MSA. These run will infinite out the inoculums and distinct settlement of a peculiar coinage of being and so incubated at 35-37oC for 24hours to heighten microbic growing. Distinct settlements were re-inoculated on another fresh agar home bases in order to obtain a pure civilization. The isolates were picked with unfertile cringle and streaked into prepared agar angles. labeled and incubated for growing after which they were kept in the icebox for future usage and designation.

Designation of Isolates

These stray bacteriums were identified utilizing both morphological civilization features ( i. e. the colour. form. lift. capacity. consistence. border ) and biochemical trial ( i. e. citrate. oxidase. indole. sugar agitation. trial etc. ) and the bacteriums were identified based on the consequences obtained from the above mentioned biochemical word picture consequences and the processs include.

Grams Staining Techniques

A bead of distilled H2O was placed on a clean glass slide. The vaccinating wire cringle was sterilized by flaring until it was ruddy hot ( this is to forestall the invasion of unwanted micro- beings that might be populating the wire cringle ) in the bluish fire of a Bunsen burner. The cringle was allowed to chill and the little part of each settlement of micro-organisms to be gram stained was picked and smeared in the bead of H2O ( distilled ) on the glass slide and so distribute into a thin vilification along the slide. The vilification was air dried and passed through the bluish fire. The vilification was stained with 1 % crystal violet and left for 1minutes ( 60secs ) and so washed with running distilled H2O it was so stained once more with Lugols I for another 60secs and besides washed with running distilled H2O.

The slide was decolorized quickly with 75 % intoxicant in order to show the being from holding the colour of the primary reagent and it was washed instantly with distilled H2O. The slide eventually was flooded with a counter discoloration saffranine ( a secondary discoloration ) for 60secons and besides washed off with distilled H2O and let to air dry. The slide was covered with a screen slide and observed under the microscope utilizing oil submergence x 100 nonsubjective lens with submergence oil. The gram reaction of the stray agreement and the form of the cell were observed and recorded. Gram positive ( +ve ) bacterial were characterized by a violet colour ( i. e. the primary discoloration ) while the gm negative ( -ve ) bacteriums were characterized by ruddy colour ( i. e. the secondary discoloration ) . This process is really used to determine the constituent of each beings cell wall.


Motility was determined by hanging bead techniques. Using cringle. a small portion of the settlement of the beings were grown in peptone H2O for 18hours and so placed in the lubricating oil free slide and covered with a Vaseline edge screen faux pas and so observed under x100 nonsubjective lens. A motile being is so seen traveling in the bead of liquid.

Designation Of Mold Isolates

Mold isolated was identified utilizing cultural and morphological features and harmonizing to ( Fawole and Oso. 2001 ) . microscopic observation was carried out utilizing lacto phenol blue discoloration.

Procedure for Mold Staining

A bead of lacto phenol blue discoloration was dropped on a clean lubricating oil free sterilized glass slide and after this a unfertile vaccinating wire cringle was used to pick the mycelium unto the glass slide from the mold civilization. The mycelium was spread equally on the slide. Teasing was carried out to divide the mycelium in order to acquire a homogeneous mixture and the mixture was so covered with cover faux pass gently and so allowed to remain for some seconds before detecting under x40 under the microscope. The microscope scrutiny of actively turning cast was on the footing of constructions bearing spores. presence or absence of septate.


Catalase Test

Catalase trial demonstrates the presence of catalase enzyme by aerophilic micro-organisms. Catalase is an enzyme that catalysis the release of O from H peroxide ( H2O2 ) . To prove for catalase. a bead of 3 % H peroxide solution was added to a slide and the being to be tested for catalase production is brought in contact with the H peroxide. The production of gas bubbles nevertheless indicates a positive reaction and this shows that catalase enzyme is produced. ( Fawole & A ; Oso. 2001 )

Oxidase trial

This was carried out by puting a clean filter paper on the working bench or petri dishes and 2-3 beads of newly prepared oxidase reagent was added to the isolate utilizing a unfertile vaccinating wire cringle. After this. a few measure of oxidase reagent was added and a violet colour was observed within 10-15minutes which indicated that the being is oxidase positive and harmonizing to Olutiola et Al. 1991. a positive reaction is dependent on the presence of cytochrome. This trial is besides utile for the separation of Neisseria in assorted civilization and in distinguishing Pseudomonas from enteral bacteriums.

Indole trial

Olutiola et Al. 1991. describes the trial as one which is of import in the distinction of settlements and it depends on the production of indole from tryptophan by the being. An inoculating cringle was used to inoculate the being into a trial tubing incorporating decarboxylase medium becomes violet. An uninoculated trial tubing serves as a control ( i. e. remained xanthous )

Sugar agitation trial

The ability of the isolates to use certain sugar as energy beginning was tested. If the being does ferment a peculiar sugar. acid will be produced and gas may be produced or non. Acid production is indicated by colour alteration of the medium from ruddy to yellow and acid presence could besides be noticeable with a pH. index in the medium while the production of gas is indicated by a nothingness produced in a Durham tubing. The agitation medium was prepared by 0. 1g of Na chloride and 0. 1g of fermentable sugar ( glucose ) in 10ml of distilled H2O.

An sum of 9ml of the medium was pipette into a trial tubing incorporating Durham’s tubings in replicates. 5ml of phenol ruddy index was instantly discharged into the trial tubing. The trial tubing incorporating medium were sterilized in an sterilizer at 121 O for 15minutes. After sterilisation. each isolate were incubated in glucose Medium. An uninoculated trial tubing was besides incubated for glucose to function as a control. The trial was besides carried out utilizing maltose. lactose. galactose. manitol. saccharose. fructose and mannose. ( Olutiolaet al. . 1991 )


The copiousness of bacteriums and Fungis in this survey were typical of environment with high species profusion and functional diverseness. Despite the fact that it is possible that a figure of bacteriums and Fungis may be missed in this survey. the isolates could be readily assigned dominant ( e. g. Bacillus sp. Aspergillus sp ) or transient/succession functions in the isolation of organisms signifier different seasons. which form the footing of this survey. In add-ons to the deductions of the finding of the figure of micro-organisms during dirt sampling. one should see the qualitative facet of the saving of of import species and groups of micro-organisms and of the alterations in these biochemical features ensuing from the fluctuations in these counts.

Although the consequences of this survey would non be considered to be thorough. as it was done within the bounds of installations available in the research lab. an penetration into the population kineticss and distribution of culturable aerophilic bacteriums and fungi diverseness has been elucidated. This is without bias to the possible influence which a significant proportion of bacteriums and Fungis that are non culturable in vitro could hold on the overall image of event. It would necessitate more modern engineering ( nuclei acid investigations ) to obtain such elaborate overview of microbic diverseness. This should be a topic of extension of this probe in future.


Through this undertaking. if accent is made on public wellness. the observation and findings show dramatic predomination of Salmonella typhi. And E. coli. E. coli being an enterobacter cause dysentery and S. typhi poses a great hazard of enteric fever. Health inspector and municipal governments should look into this affair for farther probe and if possible betterment


Research workers are thankful to the Principal & A ; Management of S. V. K. M’s Mithibai College for changeless encouragement & A ; support. And caput of section of fauna Prof. V. V. Dalvie for supplying me chances and Prof. Radhika D’souza. under whose counsel the undertaking was successfully completed


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