AJ Life Sci. 2021, 4 (1): 161-167

Thermal stable and proteinase-K resistant insecticidal toxins produced by Photorhabdus luminescens

Ihsan Ullah * ,and Khalid M.S. Al-ghamdi

Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia


Photorhabdus is lives in a mutualistic association with nematodes from the family Heterorhabditis. Bacteria of the Photorhabdus can survive independently and cause toxicity in a larger variety of insects. In the present study, insecticidal activity of non-portentous heat-stable metabolites of Photorhabdus luminescens was evaluated against Galleria mellonella. For this purpose, the culture extract of P. luminescens was injected into the G. mellonella larvae, which killed almost 90% of larvae within 48 h. The extract showed 100% insecticidal activity after heat treatment of 70 C for 30 min and even 60% and 40% activity lasted at 80 C and 90 C respectively. The extract also showed a high degree of thermal stability and was 100% actives after 60 min at 70 C. In addition, insecticidal activity was preserved up to 100% after all proteinase-K treatments (0 ?g/mL to 50 ?g/mL). The results revealed that the extracts were non-portentous and showed high thermal resistance and stability.

Keywords: Photorhabdus, insecticidal activity, toxins, heat stable non-proteinaceous




July 26, 2021

Received Revised

August 25, 2021


August 26, 2021

Available Online

September 11, 2021

Corresponding author email:


How to Cite

Abasyn Journal of Life Sciences , ISSN (online): 2663-1040, Published by Abasyn University