Amir Hamzah Ahmad Ghazali, Associate Professor
 /  Amir Hamzah Ahmad Ghazali, Associate Professor

Amir Hamzah Ahmad Ghazali, Associate Professor

Associate Professor

Ph.D., B.Sc. (Hons.), Universiti Putra Malaysia

Ext. 3905/4008;


My research interest is mainly on understanding the biological nitrogen fixation process (BNF) and plant growth enhancement by diazotrophic microorganisms in association with legumes and non-leguminous plants. These two concepts are becoming increasingly important in efforts to develop more sustainable agricultural systems especially for oil palm and rice in Malaysia. Utilization of BNF is important to reduce dependence on synthetic N fertilizers and save on costs of crop production. The elimination or substantial reduction of fertilizer-N applications is considered a key factor in the development of environmentally-friendly agriculture for both crops. The overall research approach is thus concentrated towards development and progress of knowledge in the following areas: 1) Utilization of effective isolation techniques for diazotrophic bacteria from oil palm roots. The N2 fixation capacity of the isolates has been tested by Acetylene Reduction Assay (ARA). In addition, the isolates were also capable to produce phytohormones, which are important for plant growth and development. The findings clearly indicate the potential of the isolates as biofertilizers and bioenhancers for non-leguminous plant in Malaysia. 2) Understanding of the high potential of diazotrophs in tissue-cultured materials of oil palm. The microorganisms tested are capable of enhancing growth and development of plants and have shown similar responses as controls supplied with N fertilizer. 3) Understanding of the capability of diazotrophic microorganisms (both imported and locally-isolated rhizobacteria) to fix N2 in association with oil palm seedlings and aerobic rice. The N2 fixation capacity has been estimated by Acetylene Reduction Assay. 4) Understanding the colonization ability of diazotrophic microorganisms on the root surfaces and internal root tissues of the host plants. Some of the isolates are capable of colonizing the internal root tissues, thus benefiting the host and eliminating competition between the inocula and indigenous soil microorganisms. 5) Understanding the ability of the leguminous cover crop Mucuna bracteata to serve as a nitrogen source for oil palm, by establishing effective relationships between Mucuna and diazotrophic rhizobacteria. This goal entails several steps: isolating bacteria of potential use as bioinoculants, testing various strains of bacteria with Mucuna to determine the most effective strains, developing an appropriate carrier substrate by which the inoculants may be delivered to Mucuna, and field testing the inoculants.
  • Study on N2 fixation and phytohormone production of Azospirillum and locally-isolated rhizobacteria in association with non-leguminous plants.
  • Endophytic colonization of tissue-cultured oil palm plantlets and rice seedlings with locally isolated beneficial rhizobacteria.
  • Changes in diversity of soil microflora in response to applications of paraquat at oil palm plantations.
  • Isolation of local nitrogen-fixing bacterial symbiont for application with the covercrop Mucuna bracteata as a green manure.
  • Development of rhizobial inoculant for leguminous crop Mucuna bracteata using local kaolin and rice husk as carriers.
  • Malaysian Palm Oil Board
  • Japan Society for the Promotion of Science
  • Mardani Abdul Halim, Ahmad Yamin Rahman, Kee-Shin Sim, Hok-Chai Yam, Ainihayati Abdul Rahim, Amir Hamzah Ahmad Ghazali and Nazalan Najimudin (2016). Genome sequence of a Gram-Positive diazotroph, Paenibacillus durus type strain ATCC 35681. Genome Announcements, January/February. 2016. 4(1), 1-2.
  • Tan Tzy Yin, Ui Li Pin and Amir Hamzah Ahmad Ghazali (2015). Influence of external nitrogen on nitrogenase enzyme activity and auxin production in Herbaspirillum seropedicae (Z78). Tropical Life Sciences Research, 26(1), 101-110.
  • Pui Fun Chai, Xavier Rathinam, Maheswaran Solayappan, Amir Hamzah Ahmad Ghazali and Sreeramanan Subramaniam, (2014). Microscopic analysis of a native Bacillus thuringiensis strain from Malaysia that produces exosporium-enclosed parasporal inclusion. Microscopy (Tokyo), 63(5): 371-375.
  • Noor Ai’shah, O., Tharek, M., Keyeo, F., Chan Lai Keng, Zamzuri, I., Ahmad Ramli, M. Y. and Amir, H. G. (2013). Influence of Indole-3-Acetic acid (IAA) produced by diazotrophic bacteria on root development and growth of in vitro oil palm shoots (Elaeis guineensis Jacq.). Journal of Oil Palm Research. 25 (1), pp. 100-107.
  • N. Rathi, H.G. Amir, R.M.M. Abed, A. Kosugi, T. Arai, O. Sulaiman, R. Hashim and K. Sudesh (2013). Polyhydroxyalkanoate biosynthesis and simplified polymer recovery by a novel moderately halophilic bacterium isolated from hypersaline microbial mats. Journal of Applied Microbiology, 114, 384-395.
  • Salwani Shaffie, Amir Hamzah Ghazali and Nazalan Najimudin (2012). Estimation of Nitrogenase Enzyme Activities and Plant Growth of Legume and Non-legume Inoculated with Diazotrophic Bacteria. Malaysian Journal of Microbiology. 8 (2), pp. 123-125.
  • Salwani Shaffie, Amir Hamzah Ghazali and Nazalan Najimudin (2012). Evidence of non rhizobial diazotrophic symbionts in the leguminous cover crop. Journal of Tropical Agricultural Science. 35(3). 537-552.
  • Kaljeet, S., Keyeo, F. and Amir H.G. (2011). Influence of carrier materials and storage temperature on survivability of rhizobial inoculants. Asian Journal of Plant Sciences. 10(6), 331-337.
  • Azlin, C.O., Amir, H.G., Chan Lai Keng and Zamzuri, I. (2009). Microbial inoculation improves growth of oil palm plants (Elaeis guineensis Jacq.). Tropical Life Sciences Research. 20(2), 59-65.
  • Azlin, C.O., Amir, H.G., Chan Lai Keng and Zamzuri, I. (2007). Effect of plant growth promoting rhizobacteria on root formation and growth of tissue cultured oil palm (Elaeis guineensis Jacq.). Biotechnology. 6(4), 549-554.
  • Azlin, C.O., Amir, H.G. and Chan Lai Keng (2005). Isolation and characterization of diazotrophic rhizobacteria of oil palm roots. Malaysian Journal of Microbiology. 1(1), 31-35.
  • Amir, H.G., Shamsuddin, Z.H., Halimi, M.S., Ramlan, M.F.and Marziah, M. (2005). Enhancement in nutrient accumulation and growth of oil palm seedlings caused by PGPR under field nursery conditions. Communications in Soil Science and Plant Analysis. 36 (15 &16), 1-8.
  • Amir, H.G., Shamsuddin, Z.H., Halimi, M.S., Ramlan, M.F. and Marziah, M. (2003). N2 fixation and enhanced essential nutrient uptake in oil palm seedlings inoculated with associated plant growth promoting rhizobacteria (PGPR). Journal of Bioscience. 14(2), 93-98.
  • Amir, H.G., Shamsuddin, Z.H., Halimi, M.S., Ramlan, M.F. and Marziah, M. (2001). Effects of Azospirillum inoculation on N2 fixation and growth of oil palm plantlets at nursery stage. Journal of Oil Palm Research. 13(1), 42-49.
October 2022

Visitor counter

Visits since 2014

Your IP: