1.Characterization of laccase from Trichoderma sp. UBDFT12 isolated from a Bornean tropical forest
Abdul Zul' ; Adly Mohaimin ; Pooja Shivanand ; Hussein Taha
Malaysian Journal of Microbiology 2024;20(no.2):140-147
Aims:
This study was aimed to characterize laccase from a selected fungal strain and examine the enzyme’s ability to remove lignin from paper pulp.
Methodology and results:
Twelve fungal strains were screened for laccase production, resulting in the selection of Trichoderma sp. UBDFT12. The highest laccase activity (103 U/L) was observed from the culture filtrate on the fourth day of incubation. The optimum temperature and pH for the enzyme were 40 °C and pH 4, respectively. However, the enzyme stability was found to be reduced with time after 1 h incubation. At 1 mM, it was found that AgNO3, CaCO3, CuSO4, KCl, MgSO4, MnSO4 and ZnSO4 increased the laccase activity to 107, 107, 111, 112, 106, 105 and 107%, respectively, whereas FeSO4 and NH4Cl reduced the activity to 84 and 99%, respectively. The addition of 1% H2O2, 1% NaCl, 1% sodium dodecyl sulphate (SDS), 1 mM ethylenediaminetetraacetic acid (EDTA), 10 mM EDTA, 1 mM
phenanthroline and 10 mM phenanthroline reduced the activity to 95, 73, 0, 79, 79, 73 and 37%, respectively. The culture filtrate was partially purified via ammonium sulphate precipitation and the recovered enzyme had a specific activity of 0.176 U/mg. Using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of the enzyme was approximately 65 kDa and its activity was confirmed by zymography. The culture filtrate was also found to be able to remove lignin from different types of paper pulp.
Conclusion, significance and impact of study
Laccase produced by Trichoderma sp. UBDFT12 was found to have the ability to remove lignin from paper pulp.
2.Analysing Public Health Impact of Misinformation During COVID-19 Pandemic using the Socio-Ecological Model: A Systematic Review
Khairul Hafidz Alkhair ; Muhammad Hafiz Yusof ; Mohd Faiz Itam ; Zul Aizat Mohamad Fisal ; Mohd Hamzi Mohd Yatim ; Rosliza Abdul Manaf
Malaysian Journal of Medicine and Health Sciences 2023;19(No.1):242-253
Introduction: Social media and Internet use during disasters have been proven to be useful tools in helping public
health agencies to respond to pandemics. However, this tool can also be the culprit in the spread of misinformation to
the public. This study aims to identify the public health impact of misinformation during the COVID-19 pandemic using the socio-ecological model. Methods: A systematic review guided by the Preferred Reporting Items for Systematic
Reviews and Meta-Analyses (PRISMA) guidelines was initially undertaken by searching relevant articles published
from January to November 2020 in several electronic databases including Medline, PubMed, and Springer link. All
publications produced in English regarding the impact of misinformation during the COVID-19 outbreak were included except review articles. Results: Eleven articles were identified from these databases. The public health impact
of misinformation from these articles was analysed and discussed according to the domains of the socio-ecological
model. It was found that various elements of misinformation on the COVID-19 pandemic caused a significant impact
on the individual, interpersonal, organisational, community, and policy levels across various nations. Conclusion:
This study concludes that addressing misinformation during a pandemic such as the COVID-19 phenomenon is an
important measure to improve public health response in mitigating the spread of pandemics.