TITLE:
Growth Characteristics of Phototrophic Bacterium Afifella marina in Wastewater
AUTHORS:
Sujjat Al Azad, Mohammad Tamrin Bin Mohamad Lal
KEYWORDS:
Afifella marina, Growth, Finfish Wastewater, Light Intensity
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.12 No.11,
November
22,
2024
ABSTRACT: Nutrients available in wastewater are supportive for the growth of phototrophic bacteria. Phototrophic bacterium, Afifella marina strain ME was grown in a characterized finfish hatchery wastewater. The effects of three light intensities (2000 lux, 2500 lux and 3000 lux) with 30% (v/v) inoculum on the growth, in terms of dry cell weight (g/L) and production of total carotenoids (mg/g dry cell weight) were observed in this study. Total nitrogen (mg/L) and phosphorus (mg/L) are the two major nutrients identified in wastewater. The highest bacterial cell weight of 0.37 g/L was obtained after 72 hours of culture at 2500 lux light intensity, whilst the highest total carotenoid production of 0.06 mg/g dry cell weight was determined in 24 hours of culture at same light intensity. Different light intensities affected the production of bacterial cell weight and total carotenoid production. However, statistical analysis indicated that there were no significant differences between bacterial dry cell weight and total carotenoid production due to the differing light intensities (p > 0.05). Poor growth (dry cell weight) and carotenoids production with low SGR, but efficient use of substrate. The 30% (v/v) inoculum level observed was not very supportive on the growth characteristics of bacterium. In addition, other opportunities for bacteria that remained in wastewater might suppressed the growth of Afifella marina strain ME, which need further investigation. Further, several other factors like, strain type, temperature of the culture substrate, nutrients and types of inoculum media, aerobic and anaerobic culture condition and agitation speed can alter and change the growth profile of bacterium, which need to be optimized. However, phototrophic bacterium Afifella marina strains ME is capable to grow in finfish in all these three light intensities but not at 30% (v/v) inoculum level.