Agricultural soil sample Essay


Microbes have developed many different schemes to populate most, if non all of the different environments present on Earth. They are found in the dirts of the Earth in great copiousness, runing from 4.8×109 cells in the wood dirt, to 1.

8×1010 in grazing land dirt ( Wiley et al. 2008 ) . In the dirt different microbic communities are found on the surface of the dirt and throughout its deepness ( Wiley et al. 2009 ) . There is such a big diverseness that less than 1 % of all dirt bugs have been cultured ( Wiley et al. 2009 ) . The variableness of bugs found in different dirts depends on the foods found in the dirt, and the decomposition rates and litter accretion ( Wiley et al.

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2009 ) . The temperate part dirts are normally rich in resources, as there decomposition rates are slower than that of the primary production rates, and in temperate cone-bearing dirts, the inordinate accretion of organic affair causes the dirt to endure and the deficiency of decomposition consequences in organic acids being produced and solubilize aluminium and other dirt constituents ensuing in a faded zone ( Wiley et al. 2009 ) . In temperate cone-bearing soils the most outstanding manner to keep alimentary cycling is by fire, normally in the signifier of controlled Burnss ( Wiley et al. 2009 ) . With this information in head this survey set out to insulate and place a bacteria from the wood dirt through a assortment of different trials.


1 gm of forest dirt was added to 99 milliliter of distilled H2O. Further dilution of this sample was done up to 10-7.

From the original dilution a run home base was made utilizing an vaccinating cringle and sterile technique, which includes sterilising the inoculating cringle in 70 % ethyl alcohol, and go throughing it through the fire of a Bunsen burner. Sub-culturing was done from this original home base by fixing a new run home base with the stray bacterial settlement. The original settlement was besides examined under microscope to find the characteristics of the single bacteria. Additionally gram staining was done on the settlement from the original run home base. Further trials were done from the sub-cultured run home base that included starch hydrolysis prepared on a amylum agar home base, H2S and motility that were done in SIM deeps, ammonification done in a peptone stock, nitrification done in ammonium sulphate and nitrite stocks, denitrification done in a nitrate stock, catalase done by adding H peroxide to the settlement on a 2nd run home base, and O tolerance investigated in thioglycollate medium. At a ulterior day of the month extra trials that were done are temperature, on TSA agar home bases, pH, done in TSB tubings at pH 3, 5, 7 and 9, and osmotic force per unit area, done on TSA home bases of 0, 0.5, 2 and 5 % NaCl concentrations. ( adapted from Egger, 2009 )


The original settlement that was isolated from the original run home base was orange, convex with a smooth texture and an opaque/translucent visual aspect.

When the settlement was observed under the microscope at 1000x magnification, it had a rod form, and was arranged in bunchs. The dimension of the bacteria was 3-4 & A ; micro ; thousand x 0.5-1 & A ; micro ; m. After this was done the settlement underwent gm staining which resulted in a positive gm discoloration consequence, as the bacterium appeared violet under the microscope. The bacteria appeared to hydrolyse amylum because when I was added, a clear zone formed around the bacterium growing. The following trial examined was the SIM deep.

The SIM deep did non hold any black participate which indicated that there was no H sulphide production, but at that place was motion off from the original pang line which showed that the bacteria had motility. Following the SIM deep, all of the trials that were done to find the bacteria ‘s reaction with N in any signifier were examined and all came back negative as shown in Table 1. When inspecting the trial tubing contain thioglycollate medium, it was seen that the bacteria grew throughout the tubing, but with a higher concentration near the top of the medium. This shows that the bacteria is a facultative anaerobe.

When the bacterium on the TSA home base had hydrogen peroxide added to it, it began to froth, which indicated that it was positive for the catalase trial. The concluding three trials were done to find the optimal conditions under which this bacteria grew. The consequences for the optimum trials are summarized in Table 1.

The optimum pH trial revealed that it was able to turn under all pH conditions it was put into, even though its optimum pH was 7. For both the optimum temperature trial it did turn at 4 & A ; deg ; C and 22deg ; C, but non every bit good as it grew at 37deg ; C. The salt concentration trial revealed that it had similar growing at 0 and 0.5 % NaCl, with a little sum besides turning at 2 % .


One differentiation that focused the bacteria hunt was the colour of the settlements. The settlements of bacteria that were isolated on the sub-culture run home base were orange ( Table 1 ) in visual aspect. The coloring material of the settlement is the same as what is stated in the National Standard Method ( 2007 ) that was put out in concurrence by many microbiology groups of the United Kingdom for Cellulomonas sp.

Bergey ‘s Manual of Systematic Bacteriology ( Sneath et al. 1986 ) has the colors of the Cellulomonas genus as runing from lemon yellow to canary yellow. The coloring material for Cellulomonas sp.

appears to be rather variable as a survey done by Rahman et Al. ( 2009 ) has the Cellulomonas sp. as light brown and brown. The remainder of the settlement designation facets associated with Cellulomonas sp. are rather changeless throughout the different books and diaries.

The settlements can be round in form, opaque, convex and smooth ( Sneath et al 1986 ; Rahman et al 2006 ) .The unknown bacteriums had many features that were similar to many other bacteriums. However, there were a figure of features that made it easier to place. Having a gm positive bacteria greatly reduced the sum of bacteriums that it could be, as the bulk of bacteriums are gram negative.

The 2nd factor that helped contract down the hunt for the bacteria was that is a rod bacteria. When looking at the gm positive, rod bacteriums, it was easiest to contract the hunt down by the size of the bacterium. The unknown bacteria ranged in size from 0.5-1 & A ; micro ; thousand x 3-4 & A ; micro ; m. This was comparable to Cellulomonas sp.

as they range in size from 0.5-0.8 & A ; micro ; thousand x 2-4 & A ; micro ; m ( Sneath et al. 1986 ; Washington et al.

2006 ) . Besides the form of the rods, which varied ( Table 1 ) from straight to V shaped besides is changeless with what is stated for Cellulomonas sp. in Sneath et Al. ( 1986 ) , and Washington et Al. ( 2006 ) .

The staying bacteria designation trials shown in Table 1 had comparable consequences for Cellulomonas sp. in Sneath et Al. ( 1986 ) , Washington et Al. ( 2006 ) and Rahman et Al. ( 2009 ) . They all show motility, amylum hydrolysis, NO3 decrease and catalase as positive trial consequences. They besides all show negative consequences for the H2S trial, ammonification, indole production, and nitrification. Equally good as the antecedently mentioned trials Sneath et Al.

( 1986 ) , Washington et Al. ( 2006 ) and Rahman et Al. ( 2009 ) all have the bacteria Cellulomonas sp. as facultative anaerobes, mesophiles, and neutrophiles. The commonalty of all these trials with the unknown bacteria that was isolated led to the belief that the bacteria isolated was so Cellulomonas sp.

Further trials would necessitate to be conducted to find which species of Cellulomonas that it was.Though the unknown bacteria was positively identified, there are many other trials that could be done that would see that so it was Cellulomonas sp. Some of the other trials that could hold been done are trials for what beginning of sugars they utilize in production, as consequences for these trials are listed in both Sneath et Al. ( 1986 ) and Washington et Al. ( 2006 ) , what was found in their cell walls, hydrolysis of gelatin ( Sneath et al. 1986 ; Washington et al.

2006 ) and whether or non the bacteria needs vitamin H and vitamin B1 for growing ( Sneath et al. 1986 ) . These trials would assist concrete or deter the consequences of the trials shown in Table 1.

The trials that were performed for this experiment are limited because they are general trials, that can hold variable consequences based on techniques used in the lab, and non all trials are wholly conclusive. Some trials need to hold other trials done to solidify the consequences found, particularly in the nitrifying and denitrifying trials as the consequences were non ever decisive. One of the other bacteria that was isolated in this experiment, though it was non identified in this study, had a positive trial consequence for nitrifying, but so within a few proceedingss changed to a negative consequence. The consequences for this trial so came into inquiry for the consequences for the other bacteria.The unknown bacteria, Cellulomonas sp. , was found in the agricultural dirt. The possible grounds for it being found in agricultural dirt is that it is most likely one of the bacteriums that helps to interrupt down organic stuff in and on the dirt.

One of its major functions is the break down of cellulose, and the chief enzymes found in Cellulomonas sp. have been widely survey ( Sneath et al. 1986 ) . Cellulomonas sp. can besides be found in waste stuffs with high cellulose content ( Rahman et al. 2009 ; Sneath et Al. 1986 ) .

In one survey done by Riis et Al. ( 2003 ) it was found to assist interrupt down Diesel fuel that had been leached into the dirt. Cellulomonas sp. major function appears to be that of dirt waste decrease.The consequences of the trials summarized in Table 1 led to the designation of the unknown stray bacteria. The many trials corresponded to similar consequences posted in Sneath et Al. ( 1986 ) , Washington et Al. ( 2006 ) , and Rahman et Al.

( 2009 ) for the Cellulomonas genus. The designation of the bacteria that started with settlement and so bacteria features narrowed the hunt for the individuality of the unknown bacteria to Cellulomonas sp. The ability to place the bacteria is a considered a success for this experiment.


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