BUKU ABSTRAK - Universiti Putra Malaysia

Agriculture
Efficient Recovery Method for Intracellular Polyhydroxyalkanoates by Nonsolvent
System
Prof. Dr. Mohd. Ali Hassan
Mitra Mohammadi, Nor Asma Abd Razak, Chong Mei Ling, Yoshihito Shirai, Wan Md Zin Wan Yunus, Suraini Abd. Aziz, Amirul
Al-Ashraf Abdullah, Hasfalina Che Man, Siti Nor Syairah Anis and Phang Lai Yee
Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 7514; phaglaiyee@biotech.upm.edu.my
Polyhydroxyalkanoates (PHAs) are polyesters of various hydroxyalkanoates, which are accumulated as
carbon and energy storage materials in various microorganisms usually under the condition of limiting nutritional
elements but in the presence of excess carbon source. PHAs have been drawing much attention as promising
substitutes for chemically synthesized polymers due to their similar mechanical properties to petroleum-derived
plastics and complete biodegradability. Currently, methods of PHA extraction and purification from bacterial
suspension use solvent or halogenated-based approaches which are costly and possess severe environmental
damage. This invention describes a cost-effective method for recovery and purification of PHA from freeze-dried
cell by using water.
Keywords: Freeze-drying, water extraction, bioplastic, recovery, purification
Improving Seed Viability and Vigour through Bio-priming
Prof. Dr. Sariah Meon
Most. Mahbuba Begum and Yasmeen Siddiqui
Institute of Tropical Agriculture, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8967; sariahm@putra.upm.edu.my
The soybean [Glycine max (L.) Merrill] is one of the most important legume crops, grown for its quality
protein and vegetable oil for human and animal consumption. Anthracnose disease caused by Colletotrichum
truncatum is the most destructive seed-borne disease, affecting seed viability and vigour resulting in reduced
seed germination and seedling establishment. Fungicides have been used to control seed-borne fungi of soybean.
However, increasing concern regarding possible risks associated with fungicides has given an impetus to search
for alternative strategies for mitigating losses in seed vigour. Bio-priming of seeds using biological control agents
(BCA) offers an alternative to fungicides. Bio-priming generates an environment for BCAs to proliferate on the
seed surface through increase moisture and nutrient uptake from seed exudates. The in vitro study indicated that
two fungal isolates Trichoderma harzianum (UPM40) and T. virens (UPM23), and a bacterium P. aeruginosa
(UPM13B8) demonstrated antagonistic activities against C. truncatum using both dual culture and culture filtrate
tests with percentage inhibition in mycelial growth of >80%. The efficacy of bio-priming for the control of
damping-off in soybean and seedling establishment using these isolates was evaluated under field conditions.
All bio-priming treatments significantly reduced pre- and post-emergence damping-off relative to controls. In
general, bio-priming with P. aeruginosa was the most effective treatment for controlling pre and post-emergence
damping-off, with percentage disease reductions of 50 % and 81%, respectively. Moreover, P. aeruginosa resulted
in enhancement of seed germination and healthy seedling stand. Bio-priming with T. harzianum reduced pre- and
post-emergence damping-off by 44 % and 60 %, respectively. However, P. aeruginosa was generally comparable
to T. harzianum and the fungicide Benlate®. Therefore, bio-priming can be used to increase agro-productivity for
sustainable agriculture.
Keywords: Bio-priming, biological control, agro-productivity, sustainable agriculture
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