Detailed Analysis: Effect of pH on Mung Bean Growth - Biology Report

This report details an experiment investigating the effect of pH on the growth of mung beans (Vigna radiata). The study involved exposing mung beans to various pH solutions (2, 4, 6, 7, 8, 9, 10, and 11) and measuring changes in biomass over several weeks. The experiment was conducted in two batches, with initial and final biomass measurements recorded. The results revealed that pH 11 showed the maximum increase in biomass in both batches. A contingency experiment involving bacterial growth inhibition assay was also conducted to provide alternative data. Data analysis was performed using Microsoft Excel, and the results were compared with published data on optimal pH levels for mung bean germination. The report also includes discussions on health and safety measures, limitations of the experiment, and recommendations for future research. This experiment provides insights into the impact of pH on mung bean growth and germination, offering valuable data for biological studies.

1EFFECT OF pH ON MUNG BEANS
EFFECT OF pH ON MUNG BEANS
Name of the Student
Name of the University
Author’s Note

2EFFECT OF pH ON MUNG BEANS
Table of Contents
A. Introduction..............................................................................................................................3
B. Experimental protocols and discussions...................................................................................3
1. Mung beans experiment........................................................................................................3
a. Materials used for Mung beans experiment:.....................................................................3
b. Experiment........................................................................................................................4
c. Data....................................................................................................................................4
d. Data analysis......................................................................................................................7
e. Result.................................................................................................................................8
2. Contingency Experiment (Bacterial growth inhibition assay)............................................11
a. Materials used..................................................................................................................11
b. Method:...........................................................................................................................11
c. Analysis of the effectiveness of the contingency plan....................................................13
d. Justifying the experiment chosen....................................................................................13
3. Comparison of results with published data.........................................................................14
4. Health and Safety................................................................................................................14
5. Limitations...........................................................................................................................14
6. Recommendations for further study....................................................................................15
C. Evaluation of the skills developed in the project undertaken.................................................15
D. Areas for improvement...........................................................................................................16
E. Conclusion..............................................................................................................................16
F. References...............................................................................................................................17

3EFFECT OF pH ON MUNG BEANS
A. Introduction
Vigna radiate or the Mung bean belongs to the legume family and the beans or seeds
are angiosperms in nature. The production of mung beans is ubiquitous in Asia and is used in
multiple cuisines worldwide. The typical average germination time required for mung beans is
four days; however the actual germination rate depends on the temperature, pH, moisture and
presence of water.
pH of a medium refers to the alkalinity or the acidity of the solution based on the
logarithmic scale where 7 is neutral, lower values suggest higher acidity and higher values
indicate more alkaline.
To assess the effect of pH on the mung beans, a detailed experiment has been carried
out where seeds have been tested for change in biomass over a varied range of pH to avail
concrete data to successfully analyze the pH where maximum biomass has been attained by the
mung beans has been recorded.
B. Experimental protocols and discussions
1. Mung beans experiment
a. Materials used for Mung beans experiment:
The following materials has been used to experiment the effect of pH on mung beans
i. Petri dishes
ii. pH solutions of pH 2, pH 4, pH 6, pH 7, pH 8, pH 9, pH 10, pH 11.
iii. Beakers
iv. Weight boat
v. Weighing scale

4EFFECT OF pH ON MUNG BEANS
vi. Forceps
vii. Cotton
viii. Filter paper
ix. Tray to place all mung bean Petri dishes in one place
b. Experiment
 After planning an effective experimental framework, pH solutions of pH 2, pH 4, pH 6,
pH 7, pH 8, pH 9, pH 10, pH 11 were taken in different beakers and 10 mung beans
were put in each beaker.
 Then, eight Petri dishes were taken and two pieces of filter paper were place in the
bottom part of every Petri dish.
 A thin piece of cotton was then placed on top of the already placed filter papers in every
Petri dish.
 Next, the pre soaked mung beans are placed on top of the cotton.
 The premade pH solution is slowly added to the Petri dish so that the mung beans still
rest on the cotton. The Petri dish is filled till the time the mung beans are submerged.
 The above steps are carried out for all the pH solutions.
 pH solutions are refilled whenever the quantity reduces, so as the maintain the
submerged condition of the mung beans.
c. Data
Mung beans were weighed and categorized according to their respective pH solutions.
The experiment was performed in two batches as the first batch showed signs of contamination.
Table 1: Biomass data collected from the first batch of experiment, before growth

5EFFECT OF pH ON MUNG BEANS
Table 2:
Biomass data collected from the first batch of experiment, after 4 weeks of growth.
Table 3: Biomass data collected from the second batch of experiment, before growth.
pH (Batch one) Biomass (Initial: before growth) - grams
pH 2 0.93
pH 4 0.86
pH 7 0.84
pH 9 0.92
pH 11 0.90
pH (Batch one) Biomass (After 4 weeks of growth) – grams
pH2 1.08
pH4 N/A (Contaminated)
pH7 0.86
pH9 1.37
pH11 1.58

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Table 4:
Biomass data collected from the second batch of experiment, after 3 weeks of growth.
pH (Batch Two) Biomass (Initial: before growth) - grams
pH2 0.85
pH4 0.90
pH7 0.90
pH9 0.84
pH11 0.89
pH (Batch one) Biomass (After 3 weeks of growth) - grams
pH2 0.96
pH4 1.47
pH7 0.83
pH9 1.45
pH11 1.88

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d. Data analysis
The tabulated data is analyzed in Microsoft excel and graphically represented below
for proper comparative examination.
pH 2 pH 4 pH 7 pH 9 pH 11
0.93 0.8600000000000010.840000000000001 0.92 0.9
1.08
0
0.860000000000001
1.37
1.58
Growth pattern of Mung Beans in different pH solutions
Batch One
Initial growth Growth after 4 weeks
Figure 1: This figure shows the growth pattern of Mung Beans in different pH solutions in the
first batch. The data is tabulated in Table 1 and Table 2. pH 4 beans had shown signs of
contamination for which the data is missing.

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pH2 pH4 pH7 pH9 pH11
0.850000000000001 0.9 0.9 0.840000000000001 0.89
0.960000000000001
1.47
0.830000000000001
1.45
1.88
Growth pattern of Mung Beans in different pH solutions
Batch Two
Initial growth Column1
Figure 2: This figure shows the growth pattern of Mung Beans in different pH solutions in the
second batch. The data is tabulated in Table 3 and Table 4.
e. Result
pH 11 shows maximum increase in biomass, both in batch one and in batch two. The
increase in the biomass is tabulated below to note the gain in biomass after the weeks of
growth in the varied pH solutions.
Table 5: Biomass difference from 1st batch of experiment

9EFFECT OF pH ON MUNG BEANS
Table 6: Biomass difference from 2nd batch of experiment
Figure 3. The figure generated based on the tabulated data from table 5 shows the increase in
biomass over 4 weeks of experimentation.
pH (Batch one) Biomass (Initial: before
growth)
grams
Biomass (After 4
weeks of growth)
grams
Increase in
Biomass
(grams)
pH 2 0.93 1.08 0.15
pH 4 0.86 NA 0
pH 7 0.84 0.86 0.02
pH 9 0.92 1.37 0.45
pH 11 0.90 1.58 0.68
pH (Batch two) Biomass (Initial: before
growth)
grams
Biomass (After 3
weeks of growth)
grams
Increase in
Biomass
(grams)
pH 2 0.85 0.96 0.11
pH 4 0.90 1.47 0.57
pH 7 0.90 0.83 -0.07
pH 9 0.84 1.45 0.61
pH 11 0.89 1.88 0.99

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pH 2 pH 4 pH 7 pH 9 pH 11
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0.11
0.57
-0.07
0.61000000000000
1
0.99
Difference in Biomass (Grams)
Batch Two
Figure 4. The figure generated based on the tabulated data from table 6 shows the increase in
biomass over 4 weeks of experimentation, besides pH 7 where biomass has decreases by
0.07grams over the period of three weeks.
2. Contingency Experiment (Bacterial growth inhibition assay)
As the data generation from the mung beans pH experiment is time consuming,
another experiment was planned as a contingency experiment which would be beneficial if
the first experiment failed.
a. Materials used
The following materials have been used to carry out the experiment to investigate the growth
of bacteria:
i. Mouth wash
ii. Washing up liquid
iii. Conical flasks
iv. Nutrient Agar

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v. Bacterial strain Micrococcus luteus (Ml)
vi. Bacterial strain Bacillus subtilis (Bs)
vii. Tiny circular filter paper circles
viii. Bunsen burner
ix. Lawn spreader
x. Aluminum foil
xi. Black marker pen
xii. Sterile distilled H2O
b. Method:
i. The Petri dishes with premade nutrient agar were labeled with marker pens according
to the strain of bacteria that would be grown on it, namely MI for Micrococcus luteus
and BS for Bacillus subtilis and categorized into two groups, one with control and
other test which would be for the samples treated with either mouth wash or washing
liquid
ii. Mouth wash/ washing liquid solutions concentrations (%) of 25, 50, 75 and 100 were
made and poured into 100ml beakers.
iii. Tiny circular filter paper circles are taken and submerged into each beaker (The
number of paper circles will depend on the solution concentrations and the number of
Petri dishes used).
iv. Bunsen burner is turned on and set at the blue flame.
Concentration
Percentage (%)
Solution (ml) Water (ml)
100 2 0
75 1.5 0.5
50 1 1
25 0.5 1.5

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v. MI (Micrococcus luteus) and BS (Bacillus subtilis) are taken from the conical flask.
First, the aluminum foil is removed and the opening of the conical flask is burnt to
avoid contamination and a small amount is extracted by using a pipette. After
pipetting the required amount, the foil is replaced on the conical flask.
vi. Five to six drops of the bacterial culture is pipette on to the premade agar plates and
spread evenly with the aid of a lawn spreader, carefully, and with equal gentle
pressure. Once that is done, the Petri dish is covered with the top cover as soon as
possible.
vii. Next, a pair of forceps is taken from a beaker of ethanol, the end is heated to prevent
contaminants and tiny circular filter paper circles are taken from the beaker. Every
step is repeated with forceps sterilization so as to avoid the different concentrations of
the solutions from mixing.
c. Analysis of the effectiveness of the contingency plan
The initial plan was to carry out the mung bean practical, but mung beans were not in
possession, so the ‘bacteria growth’ practical was carried out at first. The bacteria growth
practical was also carried out in case the mung beans failed to grow. Even though they were
known to grow quickly, it was unclear if the same would occur in the laboratory. When
washing liquid ran out for the bacteria growth practical, mouth wash was used instead;
provided by technician. Although changes had to be made, it meant comparisons could be
made between washing liquid and mouth wash Petri dishes on bacteria growth and which one
had a greater impact on bacteria. This practical continued to be carried out even when mung
beans were acquired because it had already started, and it would be wise to collect the
necessary results and take pictures in case mung beans practical does not work properly.