Dr. Saeid Jafari completed his PhD studying the effects of papaya leaf and its extracts on methane production and fatty acid transformation in goats. His research found papaya leaf reduced methane emissions by 37% and improved the health profile of fatty acids. For his postdoctoral research, he is investigating antimicrobial resistance of Campylobacter in animals and humans in Southeast Asia, where data is scarce but resistance appears to be increasing. His published work aims to address this emerging public health crisis in the region.

1. My experiences and challenges as
PhD student in biological sciences
Presenter
Dr. Saeid Jafari
Seminar in Applied Animal
Sciences
(January 17, 2019)

2. Personal details:
Saeid Jafari
Born in Iran
Sep 7, 1984
Single

3. Academic background:
BSc & MSc
Islamic Azad University,
Iran (2002- 2010)
PhD
University of Putra,
Malaysia (2012- 2016)
Post-doctoral Fellow
Chulalongkorn University,
Thailand (2017-present)

4. High chance of
getting a good job.
Interest and ambition
Doing research is fun
Getting the title of “Dr”
Why studying PhD ?

5. PhD dissertation title
Effect of papaya leaf and its extract on rumen
methanogenesis and biohydrogenation
in goats: in vitro and in vivo

6. Head of Department of
Veterinary Preclinical
Sciences
Prof. Dr. Goh Yong Meng

7. Effect of papaya leaf and its extract on rumen
methanogenesis and biohydrogenation
in goats

8. Department of Veterinary Public Health
Rumen methanogenesis
Food materialFermentation
CO2 + 4 H2 CH4 + 2H2O
1
2
3 Methanogens

9. Methane as the second most
prevalent green-house gases

10. Global warming
Climate change

15. New york city under
water in less than
a century

16. Rumen biohydrogenation
(Rumen fatty acid transformation)
Unsaturated
fatty acid
Saturated
fatty acid
BH

17. High Saturated fatty acid increases
the risk of cardiovascular diseases

18. Cardiovascular diseases
as the top causes of
death (WHO, 2016)

19. Alternative strategies
Methanogenesis
Biohydrogenation

20. Plants containing
bioactive compounds:
Natural products
Environmentally friendly
Acceptable with regards
to food safety issues
Source: Bodas et al. (2012);
Anim Feed Sci Technol, 176,
78 – 93.

21. Papaya leaf
Natural product Nutrient productBroad spectrum
of bioactive comp.
Source: Ikram et al. 2015.
J Food Compos Anal, 41, 201–211.

22. Papaya leaf collection from
papaya farm in Johor Bahru

23. Papaya leaf extraction

24. Rotary evaporator
(Heidolph, Germany)
Freeze drier
(Labconco, USA)
Papaya leaf extraction (cont.)

25. In vitro gas production
Rumen contents from
four fistulated goats
Straining by four layers
of cheese cloth

26. Phosphate and Carbonate buffer Strained rumen fluid
In vitro gas production (cont.)
(2:1 ratio)

27. In vitro gas production (cont.)
Incubation for 48 h at 39◦ C
100 mL
syringe

28. Methane gas
determination
Gas chromatograph
Hewlett Packard
Avondale, PA, USA.

29. In vivo study:
n=4 Three treatment
groups:
Control (50% concentrate +
50% alfalfa hay)
MPL (25 % of AH in basal
diet replaced by papaya leaf)
HPL (50 % of AH in basal
diet replaced by papaya leaf)

30. Rumen sampling at 0, 2, 4, 6
and 8 h Post-morning feeding

31. Rumen Fatty acid analysis
Methanol, Chloroform, KOH, BF3,
Petroleum ether, Distilled water.
Gas chromatography (Agilent
Technologies, Palo Alto, CA, USA)
(Ebrahimi et al. 2015)

32. BH FA (T0) – FA (Tf)
FA (T0)
T0 : 0 h of measurement
Tf: post-fermentation measurement
FA: fatty acid
Rate of biohydrogenation
(%)
=

33. RESULTS

34. -37%
Figure 1. Effect of papaya leaf on
in vitro CH4 production

35. Figure 2. Effect of papaya leaf extracts
on in vitro CH4 production
-30%

36. a
b b
b
0.00
50.00
100.00
C 18:1n-9 C 18:2n-6 C 18:3n-3 C 18 PUFA
Biohydrogenation%
Fatty acids
CON
LPL
MPL
HPL
-50%
Figure 3. Effect of papaya leaf on
in vitro BH of fatty acids

37. a
c
b
ab
b
b
0
45
90
CON Hexane Chloroform Ethyl
acetate
Butanol Water
Biohydrogenation(%)
Treatments
Figure 4. Effect of papaya leaf extract on
in vitro BH of fatty acid
-30%

38. a
a a
b
a
a
c
b
b
30
60
90
0 2 4 6 8
Biohydrogenation(%)
Time of measurement (h)
CON
MPL
HPL
Figure 5. Effect of papaya leaf on
in vivo BH of fatty acid
-48%

39. CONCLUSION

40. Achieved the goal of
reducing CH4 emission

41. Improved the health benefits
of ruminant products for
human consumption

43. SUGGESTION

44. Let’s get back to nature and seek
for alternative natural solutions

45. Overcome the limitations of feed
sources in many parts of the tropics.

46. Take advantage of medicinal health
benefits in these natural products.

47. For more info:
http://psasir.upm.edu.my/view/type/thesis.html

48. STUDY
OUTCOME

49. 16 Published paper in peer-reviewed
journals
20 (peer-review journals)
https://scholar.google.co.th/

50. 6 (oral presentation)

59. Best oral presentation
award (MSAP, 2014)

60. Malaysian Society of
Animal Production (2015)

61. International Agriculture
Congress (2014)

68. LIFE OUTSIDE
PhD

74. POST-DOCTORAL
FELLOWSHIP

75. Department of Veterinary Public Health,
Faculty of Veterinary Sciences

77. (AMR)
with is
an emerging crisis worldwide.
Adopted from web
Antimicrobial resistance
Campylobacter infection

78. Increasing trend of AMR in
Campylobacter in southeast
Asia (SEA)
Premarathne et al. (2017). Crit Rev Food Sci Nutr ; 57 (18): 3971-3986.

79. The SEA region, a top tourist
destination in the world
Turner, R. (2014). The World Travel and Tourism Council.

80. “Antibiotic resistance”
“Antimicrobial resistance”
“Campylobacter”
“Human”
“Animal”
“Southeast Asia”.

81. Target animals
for sampling

82. Target groups for
human sampling

83. Figure 6. Antibiotic resistance in SEA
15
58
36
46
0
35
70
Cambodia Malaysia Philipines Thailand Vietnam
Antibioticresistance(%)
Country
65

84. Scarcity of data
in the SEA region.
A large variation of data
in the studies from SEA.
Increasing trends of
resistance to antibiotics.

86. Antimicrobial resistance in Campylobacter
spp. isolated from animals and humans in
Southeast Asia
Impact
factor:
2.02

95. Acknowledgement

96. Dr. Chackrit
Nuengjamnong
Special thanks to:

97. Please feel free to contact me
for questions or comments:
Email
Jafarisaeid1984@yahoo.com;
Saeid.j@chula.ac.th
H/P (Thailand)
+66624489397