The effect of simulated copper stress on genes associated with the metabolism of  polyphosphates and polyhydroxyalkanoates in Bacillus thuringiensis Y1

Low Yi Yik; Grace Joy Wei Lie Chin; Collin Glen Joseph; Kenneth Francis Rodrigues

Return

The effect of simulated copper stress on genes associated with the metabolism of polyphosphates and polyhydroxyalkanoates in Bacillus thuringiensis Y1

Author: Low Yi Yik ¹ ; Grace Joy Wei Lie Chin ² ; Collin Glen Joseph ³ ; Kenneth Francis Rodrigues ²
Author Information

1. Biomed Global, Menara Biomed, 13, Jalan Cempaka SD 12/5, Bandar Sri Damansara, 52200 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur.
2. Biotechnology Research Institute, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia.
3. Faculty of Science and Natural Resources, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia.
Publication Type:Journal Article
Keywords: Bacillus thuringiensis; copper stress; gene expression; polyhydroxyalkanoates; polyphosphates
From:Malaysian Journal of Microbiology 2023;19(no.6):594-601
CountryMalaysia
Language:English
Abstract: Aims:Bacillus thuringiensis Y1 is a copper-tolerant bacterium that can serve as a model for the elucidation of the mechanism of energy metabolism under simulated copper stress. This study aimed to elucidate the effects of simulated copper stress on the genes associated with the biosynthesis of polyhydroxyalkanoates (PAH) and the metabolism of polyphosphates (PP).
Methodology and results :The gene expression study involved the growth of the bacterium in nutrient broth supplemented with two concentrations of copper sulphate (0.4 mM and 0.8 mM), followed by RNA extraction and quantification of four and 11 genes associated with the metabolism of polyphosphate (PP) and polyhydroxyalkanoates (PAHs) respectively, using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Three genes associated with polyphosphate metabolism, which are polyphosphate kinase (ppk), exopolyphosphatase (ppx) and NAD kinase (ppnk), were all shown to be upregulated by both 0.4 mM and 0.8 mM copper, except for the 5’-nucleotidase (surE) gene that was downregulated under the second treatment. Among the 11 genes associated with the metabolism of polyhydroxyalkanoates, only the 3-ketoacyl-CoA-thiolase (phaA) gene was upregulated in both treatments and highly expressed in the second treatment; the majority were downregulated and repressed.
Conclusion, significance and impact of study :The study demonstrated that copper induces the metabolism of polyphosphates in B. thuringiensis Y1 that serve as an alternative source of energy under copper stress. This model can be extended to the study of other species of Bacillus under environmental stress.
Full text:20.2023my0063.pdf