Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2018

Establishment of bacterial microbial biofilms from Antarctic soil bacteria. (#206)

Fabian Davamani Amalraj 1 , Chong Sze Ling Catherine 1 , Chong Han Lung Daniel 1 , Nur E’zzaty Nadhirah Mohamad 1 , Sanjeni Selvarajah 1 , Stephen Ambu 1 , Wan Loy Chu 1 2 , Pete Convey 3
  1. International Medical University, Bukit Jalil, KUALA LUMPUR, Malaysia
  2. 2National Antarctic Research Centre, University of Malaya, Kuala Lumpur, Malaysia
  3. British Antarctic Survey , Cambridge, CB3 0ET, United kingdom

The Antarctic soils are exposed to a wide range of environmental factors which can limit or promote the survival of psychrophilic/psychrotolerant microbes. Biofilms are the dominant life form which can withstand stressful conditions while biofilm-forming ability is an important survival strategy of microbial community. The physical extremes of temperature, ultraviolet (UV) radiation, salinity, low water and nutrient availability are amongst the growth-limiting factors of Antarctic bacteria. Temperature and nutrition were the growth-limiting parameters selected as the focus of the current study. The primary aim of this study was to assess the effects of temperature and nutrients on the growth of Antarctic bacterial biofilms. The soil samples from Signy Island were used to extract the microbes after vortexing and slow -speed centrifugation and plated on 24 different microbial media, including defined media and complex medium. The cultures were incubated at 4˚C, 10˚C and 15˚C for a period of 15-30 days and observed for the formation of biofilms. The biofilms formed were estimated by crystal violet method. Our experimental study highlighted that soil samples showed varied degree of growth. Simple descriptive statistics were used to describe the overall trend of biofilm growth together with the use of median absolute deviation to facilitate the identification of outliers in each data set. The data were non-normally distributed and positively skewed. Therefore, inferential statistics was used to evaluate the success in biofilm formation. Bootstrap method was used, where each data set was resampled and the mean confidence interval was determined.