IJERD – International Journal of Environmental and Rural Development (2011) 2–1

Research article
erdChanges in Surviving E.coli, Coliform Bacteria andGeneral Bacteria in Manure with Air Drying Treatment
YUTA ISHIKAWA
Graduate School of Agriculture, Tokyo University of Agriculture, Japan
Email: y.ishika@cronos.ocn.ne.jp

MACHITO MIHARA
Faculty of Regional Environment Science, Tokyo University of Agriculture, Japan
Received 16 December 2010

Accepted 20 January 2011

Abstract Approximately 87 million tons of dung is being produced annually from cattle
farms all over Japan. Considering the proper treatment of this waste product, applyingmanure to farmlands has been focused from a viewpoint of popularizing organicagriculture. However, pathogenic bacteria known as E.coli may be released from theimmature fermented manure that was applied in farmlands. So, the treatment for
decreasing E.coli should be considered. Although air drying is known as an effective
treatment for decreasing E.coli, it might affect beneficial bacteria as well as pathogenic
bacteria. So, this study dealt with the observation of the change in several microorganisms
such as E.coli, coliform bacteria and general bacteria under air drying treatment. In theexperiment, 3 types of cow manure such as fresh, 2 weeks fermented and 12 weeks
fermented were employed. Air drying treatment was carried out to observe the survival ofE.coli, coliform bacteria and general bacteria during 28 days. The experimental results
showed that the number of E.coli and coliform bacteria decreased with passing day of air
drying process. Also, the number of general bacteria decreased with time of air drying
process. However, it was considered that the decrease in general bacteria possibly affects
the decomposing process of manure. Therefore, it was concluded that air drying treatment
for fresh cow dung is not a proper way but is applicable to the manure fermented for 2weeks or 12 weeks.
Keywords cow dung, air drying, E.coli, coliform bacteria, general bacteria

INTRODUCTION
In Japan, about 87 million tons of dung has been produced annually from cattle farms. From aviewpoint of promoting organic agriculture, a proper treatment of this product has been recentlyfocused. However, in a bulk production of manure, the unintended inclusion of immaturefermented manure is possibly happened. Thus, there might be pathogenic bacteria known as E.coli
surviving and remaining in the produced manure (Chun-Ming et al., 2005). Once, these manures
were broadcasted into farmlands, the release of E.coli may occur through surface runoff resulting ina broad contamination of the surrounding environment, particularly in the watersheds (Mishra etal., 2007).
Accordingly, treatment for decreasing E.coli should be considered. Many kinds of treatment as
the supply of lime nitrogen and hot air were executed (Minato et al., 2001). Especially, air drying is
known as effective and simple treatment for decreasing E.coli (Saito and Mihara, 2010). However,air drying treatment might affect beneficial bacteria as well as pathogenic bacteria.
So, the objective of this study is to observe the differences of survival rate of several
microorganisms such as E.coli, coliform bacteria and general bacteria under air drying treatment.

© ISERD

88

IJERD – International Journal of Environmental and Rural Development (2011) 2–1

METHODOLOGY
The materials used in the experiment were collected from Fuji Farm of Tokyo University ofAgriculture. As shown in Figure 1, there were three types of materials collected; the fresh cow
dung, the 2 weeks and 12 weeks fermented manure having water content at 82%, 76% and 74%,respectively. In addition, organic matters constituted 88% in the fresh cow dung, 87% in the 2weeks fermented manure and 85% in the 12 weeks fermented manure. The colony-forming unit(cfu) of E.coli was 9×104 cfu/g for the fresh cow dung. However, E.coli was not observed in themanure fermented for 2 weeks or 12 weeks. The colonies of coliform bacteria were 36×106 cfu/g
for the fresh cow dung, 6×104 cfu/g for the 2 weeks fermented manure and 32×104 cfu/g for the 12weeks fermented manure. The colonies of general bacteria were 68×107 cfu/g for the fresh cow
dung, 43×106 cfu/g for the 2 weeks fermented manure and 3×106 cfu/g for the 12 weeks fermented
manure.

Cow dung
2 weeks fermented manure

12 weeks fermented manure

Fig.1 Cow dung and manure

Table 1 Properties of cow dung and manure
Periodfermented

E.coli(cfu/g)

Coliformbacteria(cfu/g)

Generalbacteria(cfu/g)

Watercontent(%)

Organicmatter(%)

Cow dung

0 days9×104

36×10668×10782

88

Manurefermented for 2weeks

2 weeks

06×10443×10676

87

Manurefermented for 12weeks

12 weeks

032×104

3×1067485

Air drying experiment was conducted for 28 days. At 4th, 7th, 11th, 18th and 28th day, samplingand mixing of manure was carried out (Fig. 2).
The colonies of E.coli, coliform bacteria and general bacteria were evaluated through thelaboratory experiments. The analysis of E.coli and coliform bacteria was carried out with XM-Gagar medium as shown in Fig. 3. The analysis of general bacteria was carried out with general agar
medium (Fig.4).

© ISERD

89

IJERD – International Journal of Environmental and Rural Development (2011) 2–1

Fig.2 Situation of air drying experimentE.coli

iColiform bacteria

Fig. 3 Colonies of E.coli and coliform bacteria

General bacteria

Fig. 4 Colonies of general bacteria

Fig.2 Air drying process in experiment

RESULTS AND DISCUSSION
Figs. 5-7 show the changes in the number of E.coli and water content in each sample. In cow dung,water content decreased with passing day, and further decreasing water content was not observed
after 7 days passed. In addition, it was observed that the number of E.coli also decreased with
passing day of air drying process. Based on the results of variance analysis, there was a significant
difference between the number of E.coli of 0 day and that after 4 days passed. However, E.coli
could not be sterilized perfectly. In 2 weeks or 12 weeks fermented manure, water content
decreased with passing day, and there was no change in water content after 7 days passed as well asthat of cow dung. In addition, E.coli was not detected from 2 weeks or 12 weeks fermented manure.
Figs. 8-10 show the changes in the number of coliform bacteria and water content in eachsample. In cow dung, there was a tendency for the number of coliform bacteria to decrease with
passing day of air drying process. And then, the number of coliform bacteria became stable ataround 15×103 cfu/g. In 2 weeks or 12 weeks fermented manure, the number of coliform bacteria
decreased with passing day of air drying process. Moreover, the number of coliform bacteria was
not observed after 7 days passed.
Based on the results of variance analysis, there was a significant difference between thenumber of coliform bacteria of 0 day and that after 4 days passed. In 12 weeks fermented manure,
the number of coliform bacteria also decreased with passing day of air drying process. Also, there
was a tendency for the number of coliform bacteria to be stable after 11 days passed. Based on theresults of variance analysis, a significant difference was observed between the number of coliform
bacteria of 0 day and that after 4 days passed. Therefore, it was considered that air drying treatment
is an effective way for decreasing pathogenic bacteria as E.coli or coliform bacteria.
Figs. 11-13 show the changes in the number of general bacteria and water content in eachsample. In cow dung, there was a tendency that the number of general bacteria decreased with
passing day of air drying process. Based on the result of variance analysis, there was a significant
difference between the number of general bacteria before 7 days passed and that after 11 days
passed. In 2 or 12 weeks fermented manure, the number of general bacteria decreased with passing
day of air drying process as well. In addition, a significant difference was observed between thenumber of general bacteria of 0 day and that after 4 days or 11 days passed for 2 or 12 weeks
fermented manure, respectively. Accordingly, it was considered that air drying process may
diminish the number of general bacteria, which includes beneficial bacteria for decomposing cow
dung.

© ISERD

90

B**

80

B**

B**

B** 60

1E+04
104

40

1E+02
102

20

100
1E+00

002457811 1418
11 14 17
Time (day)E.coli20282623

100
100

100

8080

806060604040

40

2020

2000

0245711 1418
11 14 17Time (day)8

Water content

E.coli

200282623

Water content (%)

E.coli (cfu/g)

**
B** B

1E+06
106

E.coli (cfu/g)

100

1E+08
108 A**

Water content (%)

IJERD – International Journal of Environmental and Rural Development (2011) 2–1

Water content

The data followed by different letters differs significantly at **99%

80

6060

60

4040

40

2020

202457811 141811 14 17Time (day)E.coli

20100
1E+00

60

2E+05
2×105

40

1E+051×10520B*

23B*
28
26

Coliform bacteria (cfu/g)

3E+05
3×105

Coliform bacteria20

1E+06 512×10B*B*B*

1E+06
10680
60

1E+04
104

40

1E+02
102

20

1E+00
10000245711 148Time11(day)14General bacteria

181720202328
260

Water content

80
60
40

4E+05
4×105

2320B**
0E+00 00245B**
7B** B** B**
11 14
188 11 14 17 20Time (day)

23B**
28260

Water content

28
26Fig. 10 Changes in coliform bacteria andwater content in 12 weeks fermented
manure

1E+09109 A**

100**
B** B

B** B**

106
1E+06

B**

B**

100
1E+008060
40103
1E+03

200245711 148 11 14Time (day)General bacteria

Water content

1817202328
260Water content

The data followed by different letters differs significantly at **99%

The data followed by different letters differs significantly at *95%

Fig. 11 Changes in general bacteria andwater content in cow dung

© ISERD11 141811 14 17Time (day)

8E+05
8×105

General bacteria(cfu/g)General bacteria(cfu/g)

1E+08108

8Coliform bacteria

100B*7The data followed by different letters differs significantly at **99%

Water content (%)

A*

5100

Water content

Fig. 9 Changes in coliform bacteria andwater content in 2 weeks fermentedmanure

A*

4A**

The data followed by different letters differs significantly at *95%

1E+101010 A*

40Fig. 8 Changes in coliform bacteria andwater content in cow dung

Water content (%)

Coliform bacteria (cfu/g)

0Coliform bacteria

80060

The data followed by different letters differs significantly at **99%

100B* B*
B*4711 1418258 11 14 17 20Time (day)

B**

20

Water content

4E+05
4×105 A*

B*

B**

B**

102
1E+02

Fig. 7 Changes in E.coli and water content
in 12 weeks fermented manure

0E+00 0B**

1E+04
104028262380

B** B**

Water content (%)

0100

A**

1E+06
106

Fig. 12 Changes in general bacteria andwater content in 2 weeks
fermented manure

91

Water content (%)

00

1E+08
108

Water content (%)

100

8080

Coliform bacteria (cfu/g)

100
100

Fig. 6 Changes in E.coli and water content
in 2 weeks fermented manure

Water content (%)

E.coli (cfu/g)

Fig. 5 Changes in E.coli and water content
in cow dung

100A*General bacteria(cfu/g)

1E+08
108 A*

B*

1E+06
106

B*

B*

B*

B*

1E+04
10460
40

1E+02102
100
1E+00

80

2002457811 1418
11 14 17Time (day)General bacteria

20232826

Water content (%)

IJERD – International Journal of Environmental and Rural Development (2011) 2–10Water content

The data followed by different letters differs significantly at *95%

Fig. 13 Changes in general bacteria and water content
in 12 weeks fermented manure

CONCLUSION
This study aimed to observe the difference in survival rate of E.coli, coliform bacteria and generalbacteria under air drying treatment through air drying experiment for cow dung, 2 weeks and 12weeks fermented manure.
Based on the experimental results, there was a tendency for the number of E.coli and coliform
bacteria to decrease with passing day of air drying process. In addition, there was a significant
difference between 0 day and after 4 days passed. It was considered that air drying treatment iseffective way for decrease of pathogenic bacteria as E.coli or coliform bacteria.
However, the number of general bacteria also decreased with passing day of air drying
process. It was considered that air drying process may diminish the number of general bacteria,
which includes beneficial bacteria for decomposing cow dung.
Therefore, it was concluded that air drying treatment for cow dung is not proper treatment, but
it is applicable to manure fermented for 2 weeks or 12 weeks from viewpoint of decreasing
pathogenic bacteria as E.coli and coliform bacteria and of decomposing manure sufficiently. For
manure fermented for 2 weeks or 12 weeks, it was proposed that air drying treatment for 10 days
may be enough to decrease the number of E.coli and coliform bacteria extremely and to sustain
certain population of general bacteria.
REFERENCES
Mishra, A., Benham, L. B. and Mostaghimi, S. (2007) Bacterial transport from agricultural lands fertilizedwith animal manure. Water Air Soil Pollut, 189-4, 127-134.
Gong, C., Koshida, J., Moriyama, N., Xiaodan Wang, Udou, T., Inoue, K., and Someya, T. (2005)
Occurrence and survival of coliform bacteria, Escherichia coli and salmonella in various manure andcompost. Journal of the Science of Soil and Manure, 76-6, 865-874.
Yagura, H., Tada, N., and Yasutomi, M. (2006) Nitrogen, phosphorus and coliform contamination of outflow
in cattle grazing land. Research Bulletin of the Kyoto Prefectural Livestock Technological ResearchCenter, 3, 71-73.
Minato, K., Tamura, T. and Maeta, Y. (2001) Effect of adding nitoroilime to composting of cattle manureand the impact on Esherichia coli. Bulletin of the Hokkaido Animal Research Center, 24, 11-16.
Minato, K., Tamura, T. and Maeta, Y. (2001) The effect of sterilized for Eschrichia coli in cattle manure bynitrolime adding. Bulletin of the Hokkaido Animal Research Center, 24, 21-24.
Saito, Y, and Mihara, M. (2010) Management of manure taking into account of E.coli loss from farmland.
IJERD-International Journal of Environmental and Rural Development, 1-1, 175-180.

© ISERD92